The issues of snakebite have been a foremost socio-medical challenge disturbing numerous societies worldwide, most especially the Asian and African continents as a whole. The cure is still reliant on the use of antisera as the key means of management, which has been greatly limited. Hospitals in rural societies are substandard; treatment of snakebite is often handled by traditional doctors, either due to the cost or unavailability of synthetic antivenins. The venom of diverse snake classes has a unique constituent; this constituent could be altered by other dynamics, such as geography, age, seasonal disparities, and sex. Usually, snake venom consists of minute molecules, such as proteins, enzymes, inorganic cations, and peptides. However, snake bite envenomation is extremely related to mortality after systemic circulation of the venom; certain examinations reveal that snake venom’s constituent possesses inherent medicinal significance. The modus operandi of synthetic antivenin, as well as the anti-venom obtained from certain plant materials, and the major constituents found in snake venom (phospholipases A2, disintegrins, snake venom serine proteinases, alpha-neurotoxins, activity of fibrinolytic enzyme, and three-finger toxins) are discussed in detail in this review. Some selected theories that proposed the mechanism of action of compounds obtained from herbal sources to combat snakebite, such as enhancing/modifying action, protein precipitation, chelating properties, and enzyme deactivation, have been discussed.

Synthetic antivenins, Snake bite envenomation, Anti-venom, Alpha-neurotoxins, Protein precipitation, Enzyme deactivation.

A toxic substance manufactured by wildlife, known as venom, is used as a defense and an attacking device. A huge number of poisonous snake classes have been recognized and examined by Matsui et al.[1] Lethal snakes typically have at least one set of fangs (pointed teeth) in their upper jaw that pierce the victim’s flesh, permitting the diffusion of venom manufactured in the snake’s venom reservoir gland, Chan et al.[2] Poisonous snakebite is measured as a municipal health challenge. Though epidemiological statistics recording the incidence of snakebites display a worldwide discrepancy owing to the heterogeneity of environmental and financial circumstances throughout the world. For example, it was perceived that farming events, particularly in humid and subtropical nations, were extremely connected with snakebite crises worldwide. The venom of snake is a distinctive multiple concoction of protein and enzymatic and non-enzymatic peptides also several other minute molecules whose absorption is via the systemic circulation could lead to adjustable and liberal multisystem expressions as well as native, necrotic, myotoxic, hematological, cytotoxic, inflammatory, neurotoxic, and cardio-toxic effects that could occasionally require thorough care, Chan et al.[2] and Vyas et al.[3] Postponed first aid or admission to suitable therapeutic amenities and antivenin remedy may result in a high degree of illness and death, Sanhajariya et al.[4] Amongst the 3150 snake classes, the amount of individual constituents in the venom varies. Reviewing this dissimilarity has an apparent significance, permitting the choice of the most suitable antivenin for the management of snakebite poisonousness, Chippaux et al.[5] Astonishingly, the venom of snakes has been extensively used for the management of some pathophysiological circumstances in primordial times. This aided medical workers to comprehend that the venom of a snake does not necessarily cause damage or the mortality of organisms, thus it also has healing capacity that may open the track for drug improvements with specifically harmless systems that transport the toxin straight to the location of action. In recent times, snake venom constituents have been utilized for their antitumor, antimicrobial, anti-agglutination, analgesic, and several other actions, as reported by Chan et al.[2]

The overriding class of venom constituents is secreted metalloproteinases (SVMP), phospholipases A2 (PLA2s), three-finger peptides (3FTX), and snake venom serine proteases (SVSP), while the subordinate class encompasses cysteine-rich discharging Lamino acid oxidases, proteins, natriuretic peptides, kunitz peptides, disintegrins, and C-type lectins, as studies by Tasoulis and Isbister et al.[6] and Slagboom et al.[7]

The therapeutic properties of snake venoms are categorized into 3 main groups: hemotoxic, neurotoxic, and cytotoxic (WHO, 2010). The main toxins tangled in these effects are the SVSPs, PLA2s, 3FTXs, and SVMPs, either alone or in mixture with others, which are accountable for the numerous pharmaceutical effects happening in the animal snakebite victims.  Some PLA2s and 3FTXs are capable of performing activities on pre-synaptic or post-synaptic intersections as blockers of ion channels and muscarinic or nicotinic receptors, leading to rapid and severe neurotoxicity, such as breathing tragedy and paralysis, as reported by Harris and Scott-Davey et al.[8] Casewell et al.[9] Lynch et al.[10] and Fry et al.[11]

This study helps detect toxic elements and upgrades diagnosis and treatment. It provides support for the synthesis of more efficient and alternative antivenins, minimizing risks and enhancing the chance of survival. Examining the nullifying properties of herbal and synthetic remedies guarantees safety and efficiency in treatments. Investigating both herbal and synthetic remedies may uncover complementary treatments, especially in resource-limited environments. This study aimed at improving public health, cost reduction and moderating the impact of snakebites worldwide.

Chemistry of snake venom: Haruna and Choudhury et al.[12] Studies have shown that venoms from snakes are extremely complex saliva comprising zootoxins utilized by snakes as a security instrument against a prospective predator and to restrain and enable digestion of their prey. The venom gland is responsible for producing venom, which is transported by an injection system of improved pointed (fangs) tooth that aids the venom to infiltrate into the target.

The venom consists of a complex combination of active materials, predominantly proteins and peptides, which interfere with the sequence of several biochemical patterns in humans or victims of the venom, Theakston and Reid et al.[13] The constituents include the following: phospholipase A2, L-amino acid oxidases, acetylcholinesterases, cytotoxins, mycotoxins, serine proteinases, metalloproteinases, hyaluronidases, phosphomono-esterases and phosphodiesterases, cardiotoxins, nucleosidases, hemorrhaging, neurotoxins, and coagulants. Soares et al.[14] Inorganic cations such as sodium, calcium, iron, magnesium, zinc, potassium, nickel, manganese, and cobalt are also contained in snake venom, Tohamy et al.[15] Anticholinesterase action is due to the presence of Zinc, while calcium is required to trigger enzymes such as phospholipase, Goje et al.[16] Toxins obtained from different snake venoms display different mechanisms of action. In addition, venoms isolated from different species differ significantly in their toxin constituent as explained by Haruna and Choudhury et al.[12] Selected discrete types of venom toxins whose activities differs include: Cardiotoxic toxins obtained the venom of Naja species, it precisely affect the heart by weakening muscle contraction thereby resulting to the heart beating haphazardly until complete seizure; Proteolytic toxins gotten from mambas and cobras venom which alter the molecular structure of the targeted body muscle therefore instigating disability and necrosis; Neurotoxic toxins could be obtained in the venom of sea snakes, cobras, mambas, coral snakes and kraits, it targets the brain and nervous system leading to a situation where the nerve stays activated, causing overwhelming muscle contractions which could result to mortality; Dendrotoxin toxins isolated from mambas and cobras venom, it is responsible for hindering neurotransmissions by obstructing the give-and-take (interchange) of negative and positive ions across the neuronal tissue resulting to inactivity of nerve impulse, thus paralyzing the prey. Hemotoxic venoms are associated with the venom obtained from Viperidae family members, causing destruction of red blood cells (erythrocytes) or hemolysis, which could eventually result in death. Variation in species, habitat, climate, age, and geographical location has a compounding effect on the toxicity of the snake venom. Also, the mechanism of action of diverse snakes makes it challenging to have a universal or general antivenin, Hossain et al.[17]

The venom leads to death by instigating tissue damage and extensive hemorrhage, which is bleeding from certain vital internal organs of the victim’s body related to a faulty clothing mechanism in the body system, as reported by Goje et al.[16] Over decades, a certain number of toxins from numerous snake venoms that upset the blood circulation process have been purified and characterized, Lu et al.[18]

Kini et al.[19] examined that some selected among the toxins upset platelet accretion; however, others affect blood clotting. Venom proteins that upset blood clotting can efficiently be categorized as anticoagulants or pro-coagulant proteins based on their capacity to reduce or prolong the blood coagulation or thickening process. Pro-coagulant proteins are, moreover, metalloproteinases or serine proteinases. They prompt blood clotting either by precisely triggering one of the blood clotting elements, zymogen, or by transforming soluble fibrinogen into an insoluble fibrin coagulate or clot directly.

Action of cobrotoxin rises from its capacity to bind intensely to postsynaptic neuron receptors. A release of a neurotransmitter is required which diffused through a small cavity or gap known as synapse so that the nerves cell can signal a neighbor. The postsynaptic neuron is at the other side of the synapse that contains protein which is precisely equipped to perceive the presence or existence of these neurotransmitters. However, if these receptors are obstructed, the nerve cells’ purpose is interrupted as a result of hindrance to the flow of signals. Cobrotoxin is capable of interrupting a particular category of receptor that is sensitive to acetylcholine. When this polypeptide fixes to the receptor, it becomes permanently attached, consequently, the nerve cell loses its capacity to hint (signal) the muscles it is meant to activate in other to carry out a functional response. For instance, if the nerve cell responsible for triggering the diaphragm muscle of a victim organism or animal is affected, the animal will eventually suffocate owing to its inability to breathe, Patel et al.[20]

Major constituent of snake venom and their individual effect on circulatory system
Phospholipase A₂ (PLA₂s): Phospholipases A₂ play a key part in the myotoxic and neurotoxic effects in cases of snake bites. The molecular weight of the protein is around 13-15 kDa and is categorized into sets I and II, which are obtained as main components in the venoms of Elapidae and Viperidae, respectively. Harris and Scott-Davey et al.[8] and Six and Dennis et al. [21]. Additionally, a third set of Phospholipases A2, designated IIE, has been mainly isolated from non-front-fanged snake venoms, even though their significance in the venom arsenal is yet to be identified (Perry et al.[22] and Fry et al.[11]). Research restructuring the evolutionary past of this multilocus genetic family has validated that each of these Phospholipases A2 categories, I, II, and IIE, has been individually conscripted into snake venom structures (Junqueira-DeAzevedo et al.[23] and Fry et al.[11]). Proposing they have advanced their venomous properties through convergent evolution as stated by Lomonte and Rangel et al.[24] Even though Phospholipases A2 from elapids and vipers exhibit similar enzymatic activities, both categories have undergone broad genetic replication over the evolutionary period of time, apparently enabling the development of new toxic tasks and leading to altered patterns of residue preservation.[25-27] Also, the venoms of viper snakes comprise the iso-forms of set II Phospholipases A2 that are active catalytically, such as Asp49, and less catalytically active, as Lys49, as studied by Lomonte and Rangel et al.[24]

The hydrolysis of tissue glycerophospholipids to discharge arachidonic acid lysophospholipids is catalyzed by Phospholipase A₂ enzymes, Leiguez et al.[27] The enzymes, extensively obtained in snake venoms, possess numerous effects such as inflammation, hypotension, myotoxicity, and neurotoxicity.[28-30] In the midst of these effects triggered by snake venom (Phospholipase A₂), the hypotensive characteristics are of concern for the treatment of hypertensive ailment, which is a significant reason for developing cardiovascular disease. For that reason, an in vivo investigation documenting the cardiovascular effects prompted by snake venoms revealed that 2 distinctive phenomena result after venom inoculation via injection: (a) a quick drop in blood pressure, which is known as cardiovascular collapse, and (b) prolonged hypotension. However, Phospholipase A₂ was proposed to be accountable for elongated hypotension through vasodilatation.[31] In accordance with such observations, two phospholipase A2s were extracted from the shore taipan (Oxuranus scutellatus) venom, which prompted a hypotension reaction devoid of cardiovascular collapse in vivo and undisturbed vascular muscle in vitro.[32] Also, Phospholipase A2 filtered from the Brazilian lance-headed (Bothrops moojeni) venom similarly prompts an in vivo hypotension activity.[33] The activity of crotoxin alongside Phospholipase A2 from rattlesnake venom in South American (Crotalus durissus terrificus) displays a vasoactive activity on human umbilical vein endothelial cells, signifying an anti-atherogenic activity which is worthy of further examination.[34]

Disintegrins: Disintegrins obtained from snake venom are utilized as a principal compound for the development of pills acting as contenders of platelet integrins and are thus medically distinct as anti-platelet antithrombotic or aggregation pills. Medically, these medicines minimize the possibility of acute ischemic events and avoid thrombotic problems. Disintegrins are non-enzymatic, comparatively small, ranging from 4 to 15 kDa, proteins rich in cysteine that are commonly found in the venom of snakes, and their functional grouping rests on their capacity to interact with a particular integrin, which is dependent on the presence of a specific integrin binding motif. These motifs are contained in the hairpin loop and vary in the sequence of amino acid. The major and most examined class of disintegrins is known as RGD disintegrins.[35,36] Numerous disintegrins were purified from the venoms of snakes, particularly from the venom of vipers, and labeled as antithrombotic remedies.[37] A disintegrin comprising the RGD (Arg-Gly-Asp) structure isolated from the viper venom of the usual bamboo (Trimeresurus gramineus), was exposed to prevent platelet accumulation in vivo and in vitro by obstructing fibrinogen attachment to aggregation agonist-stirred platelets, such as fibrinogen binding to adenosine phosphate-activated platelets.[38,39]

Snake venom serine proteinases: Snake venom serine proteinases (SVSPs) are categorized under the family of S1 serine proteinases and exhibit molecular weights within the range of 26 to 67 kDa and two distinctive structural domains. The venom toxins are developed from kallikrein-like serine proteases, also following their enlistment for use in the snake venom gland, have undergone gene replication events resulting in numerous isoforms.[40,41]

Snake Venom Serine Proteinases catalyze the splitting of polypeptide molecular chains on the C-terminal side of the hydrophobic or cationic amino acid residues as reported by Serrano et al.[41] and Page and Di Cera et al.[42] Snake venom serine proteinases have been identified in the venom of diverse kinds of snake families, even though they are classically and majorly plentiful in the venom of vipers and very minute in the venoms of colubrid and elapid snakes, as explained by Modahl et al.[43] and Tasoulis and Isbister et al.[6] The hemotoxic properties triggered by Snake venom serine proteinases include agitations of blood coagulation, either anti-coagulant or pro-coagulant, platelet aggregation, blood pressure, and fibrinolysis with possible fatal consequences for a victim of snakebite.[7,41,44,45] The pro-coagulant snake venom serine proteinases have been pronounced to trigger numerous coagulation factors, as well as pro-thrombin and factors V, VII, and X as reported by Serrano et al.[41] and Kini et al.[19] For instance, the initiation of pro-thrombin yields thrombin, which, as a result, yields fibrin cross-linked polymers. Thrombin also triggers the collection of platelets alongside the creation of fibrin clots, leading to coagulation.[45] Additionally, platelet-accumulating SVSPs will motivate the platelet-receptors to stimulate linkage to fibrinogen and clot development.[46] These platelet-aggregating and pro-coagulant properties will lead to the swift intake of significant factors in the clotting cascade and clot creation. However, anti-clothing snake venom serine proteinases properties include the initiation of Protein C, which afterward deactivates the clothing factors (Va and VIIIa) as explained by Kini et al.[19] In addition, fibrinolytic snake venom serine proteinases play a significant part in the removal of blood coagulates by acting as plasminogen activators and thrombin-like enzymes, which eradicate the fibrin in the coagulates and contribute significantly to the formation of the coagulopathy as reported by Serrano et al.[41] and Kang et al.[44] Alongside the depletion/activation and deactivation of these clotting factors, the coagulation of blood is avoided, resulting in non-coagulated blood and exterior and inner bleeding. Every minute, inflammatory reactions and hyperalgesia are encouraged by snake venom serine proteinases. Research proposes that phospholipases A2 (PLA2s) play an essential part in the inflammatory reactions and pain caused by the venom of snakes, whereas SVSPs play a significant part in inflammation and a slight part in pain. Snake venom serine proteinases in the venoms of Bothrops pirajai and Bothrops jararaca encourage inflammation via edema creation, leucocyte relocation, mainly neutrophils, and slight automatic hyperalgesia; nevertheless, the intermediaries involved in these special effects are yet to be known, as stated by Menaldo et al.[47] and Zychar et al.[48]

Alpha-neurotoxins: Hodgson and Wickramaratna et al.[29] reported that a very large group of toxins known as alpha-neurotoxins and more than 100 postsynaptic neurotoxins have been recognized and sequenced. The Nicotinic acetylcholine receptors of cholinergic neurons are attacked by α-neurotoxins. They take over the structural shape of the acetylcholine molecule, therefore fitting into the receptors, where they hinder the acetylcholine flow, resulting in a sensation of detachment or numbness and paralysis. The snakes that have α-neurotoxins include; king cobra, which is known as Ophiophagus Hannah, sea snakes (recognized as erabutoxin from the family of Hydrophilidae), cobras (also recognized as cobratoxin from Naja spp.), and many with stripes krait such as Bungarus multicinctus, which is said to contain α-bungarotoxin as examined by He et al.[49]

Activity of fibrinolytic enzyme: Venom of snakes has also been shown to contain fibrinolytic enzymes, which may perhaps aid as patterns for the expansion of substituted thrombolytic compounds of importance for scientific use, so as not to be deactivated by serine protease inhibitors present in the mammalian body fluid.[50] Fibrinolytic enzyme acts straight on fibrinogen, mainly attaching to α and β fibrinogen chains; however, γ-chain is excluded.[51] Diverse research exposed that fibrolysis can damage fibrin clots in vivo and in vitro. Fibrolase is active in breaking down fibrin and human blood clots in a specific dose by direct action on fibrin without triggering plasminogen. However, by means of an animal model of major thrombosis, fibrolase melts femoral arterial clots once a single intravenous bolus is administered. These statistics exposed the possibilities of this fibrinolytic enzyme to be used in treating occlusive thrombotic illness, but the challenges faced were that fibrolase is not an activator of plasminogen as explained by Ahmed et al.[52] Consequently, an alternative approach is to manufacture a chimeric derivative that retains the double capacity to destroy fibrin clots and to hinder platelet accretion and thrombus improvement from fibrolase. Other fibrinolytic enzymes were known and extracted from other species’ venom, such as lebetase obtained from Vipera lebetina, basiliscus fibrases obtained from the venom of a Mexican West-Coast rattlesnake, as studied by Swenson et al.[53] and Siigur et al.[54] and graminelysin I, which was obtained from Trimeresurus gramineus as reported by Siigur et al.[54] Apart from peptides isolated, recombinant proteins were also manufactured for medicinal purposes. For that reason, alfimeprase, a derivative of fibrolase in combination with thrombolytic activity, was advanced for the management of catheter occlusion disease and stroke.[55]

Three-finger toxins: Non-enzymatic proteins originate in snake venoms exclusively Elapidae which is known as Three-finger toxins. These toxins comprise 60 to 74 amino acid deposits, and 4 to 5 disulfide bridges. Their taxonomy originates from their structure, designed by 3β-stranded loops ranging from a minor, globular, hydrophobic core consisting of all four well-preserved disulfide bridges, similar to the 3 fingers of a human hand.[56] It has been recognized that these toxins have an expansive array of molecular targets, such as muscarinic acetylcholine receptors, nicotinic, and L-type calcium channels, leading to numerous biological activities.[57]

Among calciseptine, three-finger toxins, and FS2 toxins were sanitized from the black mamba venom, i.e, Dendroaspis polylepis, and described as L-type calcium channel blockers that result in a vaso-relaxant consequence on smooth muscles, also causing hypotensive behaviors as studied by Watanabe et al.[58] and De Weille et al.[59] Muscarinic toxin, also known as three-finger toxins from the venom of snakes, has been revealed to be an effective antagonist for the α-2B adrenoreceptor, which could be efficiently used for the treatment of blood pressure illnesses.[60] Low molecular weight three-finger toxins were isolated from the venom of the monocled cobra, i.e, Naja kaouthia, and stated as an anti-platelet agent. This three-finger toxin was proposed to constrain platelet accumulation by acting via Adenosine diphosphate (ADP) receptors situated on the platelet surface, and as a result, can be utilized for the treatment of blood coagulation ailments.[61]

Treatment and management snake envenomation: Antivenins obtained from animals are often reflected as the only specific remedy available for handling snakebite envenoming as explained by Ainsworth et al.[62] and Slagboom et al.[7] These comprise polyclonal immunoglobulin, for example, intact F(ab)2 or IgGs, or Fab fragments as stated. Roncolato et al.[63] and Maduwage and Isbister et al.[64] Got a highly resistant animal plasma/serum, particularly from sheep and horses. Once used hastily and suitably, they neutralized a life-threatening snakebite venom proficiently. Pathologies such as venom-induced hemorrhage, hypotensive shock, coagulopathy, and neurotoxic properties as reported by Ainsworth et al.[62], Slagboom et al.[7] and Maduwage and Isbister et al.[64] Antivenins can be categorized as monovalent or polyvalent, depending on the immunogenic components used during the manufacturing process.

Monovalent antivenins are formed by vaccinating animals with antivenin against a particular snake species, however polyvalent antivenins encompass antibodies fashioned from a concoction of venoms of numerous therapeutically significant snakes from a specific ecological region. Polyvalent antivenins are thus premeditated to address the inadequate para-specific cross reactivity of specific or monovalent antivenins by motivating the manufacturing of antibodies contrary to different venom toxins institute in numerous snake species, and to escape problems involving trial and error treatment or administration of antivenin due to the absence of existing snakebite analytical implements as stated by Abubakar et al.[65] and O’leary and Isbister.[66] Nevertheless, polyvalent remedies are associated with demerit; a higher dose is mandatory to function effectively, possibly resulting in an amplified risk of antagonistic reactions. As a result, it increases the cost to treat a snakebite victim, as reported by Roncolato et al.[63] Deshpande et al.[67]; and Hoogenboom et al.[68] Difference in venom components thus causes a pronounced challenge for the expansion of broadly active snake bite therapeutics. The multiplicity of toxins instituted in the venom of any one class signifies substantial complexity, which is further improved when trying to nullify the venom of numerous species, predominantly given disparities in the immunogenicity of the multi-purposeful toxins.

Antivenin efficiency is classically restricted to those classes whose venoms were used as immunogenic substances and, in some circumstances, closely associated snake classes that share adequate toxin overlap in order to generate antibodies to identify and neutralize the key toxic constituents, as examined by Ainsworth et al.[62]; Casewell et al.[9] Due to the disparity in venom constituents, it is ubiquitous at all phases of snake classification, such as ontogenetically, inter-specifically, and intra-specifically.[9,62,69,70] comprehension of venom content is pharmaceutically essential, snake class is treasured, and can notify predictions of the possible venom-specific neutralizing efficacy of an antivenin, and consequently the ecological applicability of a specific therapeutic. Therefore, venom toxicity analyses in mixture with venom proteomics, antivenin, and immunological studies have been combined to examine the Para specificity of antivenins as reported by Tan et al. [71]; Pla et al.[72] Calvete et al.[73] and Madrigal et al.[75] Such examinations have exposed astonishing cross-reactivity of antivenins against distinctive snake species, non-targeted, for example, (a) the possible efficacy of Asian antivenins established against land-dwelling elapid snakes in nullifying the venomousness of powerful sea snake venoms as reported by Tan et al.[71] (b) the apparent usefulness of African polyvalent antivenin in nullifying the venom of a genus of elapid serpents, excluding the vaccinating mixture, Whiteley et al.[75] and (c) the possibility for saw-scaled viper antivenin to be used as a substitute for the cure of snake bites by the boomslang (Dispholidus typus) in areas where the suitable species-specific antivenin is inaccessible or high-priced.[62]

The modern-day priority targets for snakebite medicinal cure are the multipurpose toxins such as SVMP, PLA2s, 3FTX, and SVSP, which are the key components that alter the organism’s systems in snakebite victims. It is expected that in the forthcoming days, these new medicines may offer greater specificities, cost-effectiveness, neutralizing capabilities, and security over conventional antivenins. Precisely, the choice, optimization, and analysis of new tools to battle snake envenoming is dependent upon the classification of the main pathogenic constituent, and regularly multi-purposeful toxins originate in the venom of a different array of therapeutically useful snake species.

Mode of action of herbal antivenin: It has been documented that herbal antivenins nullify the toxic venom components by the means of either adjuvant action, protein inactivation or precipitation, enzyme inhibition or deactivation, chelation activity, anti-oxidative activity, and a combination of all the listed activities. Enzyme deactivation/inhibition and protein precipitation are more suitable for antivenins.[76-81]

Protein coagulation/precipitation: Numerous phytochemical constituents, such as polyphenols, saponins, flavonoids, tannins, xanthenes, terpenoids, alkaloids, quinonoid, and steroids, possess protein binding activities and are very active against snake envenomation. They bind to lethal venom proteins therefore rendering them inactive. They may perhaps also block the target receptors competitively as studied by Gupta and Peshin et al. [82] Flavonoids compounds such as quercetin, amentoflavone and myricetin purified from the leaves of Byrsonima crassa and Davilla elliptica have anti-hemorrhagic properties against venom obtained from Bothrops jararaca, Nishijima et al.[83]

Sunitha et at.[84] studied the modus operandi of molecular polyphenols of plant crude extracts interrelate with α-cobratoxin (a neurotoxin isolated from venom of a particular Naja snakes) which causes paralysis to the victim organism by inhibiting the bond process of acetylcholine to a particular muscle-type nicotinic acetylcholine receptor. They assessed the collaboration between this venom toxin and some selected compounds of phenol (digallic acid, tannic acid, procyanidin dimer, and procyanidin trimer) contained in the crude extracts of some designated plants. However, molecular modeling exposed the establishment of hydrogen bonding among amino acid residues and hydroxyl groups of tannins near their bond-forming site to α-cobratoxin.

Chelation properties/activity: Plant extracts possess compounds that form a bond to divalent metallic ions, which are essential for specific enzymatic actions. The existence of suitable metal ion coordination is a necessity for the hydrolytic actions of metalloproteases and Phospholipases A2; any metabolite that can deteriorate the enzyme-metal ion relations will lead to the deactivation of the hydrolytic properties. Soares et al.[14]

Snake venom proteases predominantly disturb hemostasis, which is the process of retaining blood within a damaged vessel to stop bleeding, but the disturbance causes systemic hemorrhage (excess bleeding). The mode of action involved in the deactivation of these proteases by the crude plant extracts may perhaps be owing to the chelating activity of phenolic constituents contained in the plant crude extracts. It is described that compounds of phenol generate hydrogen bonds and powerfully bind to the residue of histidine contained in zinc ion (Zn²⁺) binding motifs of metalloproteases, subsequent drop in the hydrolytic activity of the enzyme.[85] The modus operandi by which plants extract can function against the constituent of snake venom (Phospholipases A₂) have been broadly examined. Amongst the phytochemicals such as flavones, catequines, anthocyanins and compressed tannins were interrelated in their capacities in the chelation of calcium ion (Ca²⁺) requisite for the catalytic action of Phospholipases A₂ in snake venom.[86]

It is recognized from documented literature that compounds of phenol can complex with metal ions simply when they possess appropriately oriented functional groups in their molecular structure.[87] The existence of 3-4 or 7-8 dihydroxy phenyl, which is also known as catechol groups, otherwise 5-hydroxyl or 3-hydroxyl, in addition to a C-4 keto-group in phenolic compound molecular structure, is significant for metallic ions bond formation as stated by Khokhar and Apenten et al.[88] The chelating action escalates when the galloyl moiety, which is 3’,4’,5’-hydroxyl trihydroxybenzene, exists in the molecular structure of phenol. When the biochemical structure of tannins is reflected, it can be alleged that compressed tannins, which are catechin polymers, form a bond with metal ions principally to catechol groups; however, hydrolysable tannins, such as the byproducts of gallic acid, form bonds to galloyl groups as studied by Karamac et al.[89]

Enhancing/modifying activity: Alam and Gomes et al.[76] described that a compound (2-hydroxy-4-methoxy benzoic acid) was purified from Indian medicinal plant (root extract) which is known as Sarsaparilla (Hemidesmus indicus) nullified the snake venom-driven pathophysiological alterations via modifying effects and anti-serum capability. The compound amplified the generation of antibody in hyper-immunized rabbits, as evidenced by the enlarged fold of snake venom nullification for both hemorrhagic and lethal activity. Though, it was discovered that, when the compound was inoculated via injection into a male albino rat, it revealed the enhancement of lymphocytes and macrophages as stated by Alam et al.[90] The snake venom antigen, once inoculated alongside the compound, results in an escalation of lymphocyte reaction, resulting in amplified production of antibodies.

In some cases, the compound functions as an enhancer, activating the retention of a little venom antigen constituent part and aiding in the creation of antibodies. Antiserum elevated together with the compound alongside the viper venom, efficiently nullified the disastrous activity prompted by the venom of Vipera russellii, Naja kaouthia, Ophiophagus Hannah, and Echis carinatus. But only viper venom alone instigates rabbit antiserum, which was observed to safeguard against the disastrous toxin effect of viper venom, but Ophiophagus, Echis, and Naja venoms were exempted. The compound (2-hydroxy-4-methoxy benzoic acid) in combination with viper-venom triggers rabbit antiserum deactivated; the Echis and viper venom-prompted hemorrhagic (i.e, bleeding of internal organs) action, but once only viper venom-prompted rabbit antiserum that is used; it only deactivated the viper venom, triggering hemorrhagic action. These opinions specify that the compound functions as an enhancer or modifier, therefore activating a higher amount of antibody, which efficiently defuses both the elapid and viperid venoms. The compound increased the potency of nullifying the venom action of snake venom antiserum sold or used in the hospital.

Advanced degree of deactivation of both viper and cobra venom was accomplished by the compound. It was recommended that the compound perform this effect by increasing antiserum retention and venom antigen performance for enhanced nullification process. Therefore, 2-hydroxy-4-methoxy benzoic acid has twin activity in these phenomena that is (i) presenting its enhancing effect and (ii) elevation of antiserum efficiency as reported by Alam and Gomes et al.[76]

Determination of toxicity of snake venom: The Toxicity of snake venom is measured by a toxicological analysis known as the median lethal dose (LD50), which defines the concentration or amount of a toxin required to kill half of the tested population members. The strength of wild snake venom differs significantly because of mixed influences such as physiological status, genetic variation, biophysical and environmental variables, ecological and molecular evolutionary influences. This is factual even for members of the same family species. Such a disparity is minimal in confined populations in laboratory settings; however, it cannot be eradicated. Though, research to define snake venom strength must be planned to curtail variability. Numerous methods have been devised for this end. One of the methods is to make use of bovine serum albumin (0.1%) as a diluent in order to obtain LD50 values. It leads to more precise and reliable LD50 determinations compared to the use of saline (0.1%) as a diluent. For instance, fraction V yields up to 95% purified dried crude venom (Albumin). Saline as a diluent regularly yields extensively variable LD50 results for virtually all poisonous snakes. It yields irregular disparity in precipitous purity ranging from 35 to 60%. Fraction V is operationally stable because it possesses seventeen disulfide bonds; it’s distinctive because it has the maximum solubility and lowest isoelectric point of key plasma proteins. This makes it the concluding portion to be precipitated or coagulated from its solution. Bovine serum albumin is found in fraction V. The agglutination of albumin is carried out by decreasing 4.8 (pH), close to the pH of proteins, and preserving the ethanol at 40% with 1% protein concentration. Hence, merely 1% of the original plasma is left over in the fifth fraction as reported by Rosen et al.[91] When the principal goal of processing plasma is isolating plasma constituents for transfusion or vaccination, then the plasma constituents must be extremely pure. During World War II, Edwin J. Cohn developed and first applied large-scale techniques of plasma separation or fractionation, which is recognized as the Cohn method or process. This procedure is also recognized as cold ethanol fractionation, because it requires progressively increasing the amount of ethanol in the solution at a temperature range of 5°C and 3°C. The Cohn Method exploits dissimilarities in plasma proteins characteristics, precisely, the low pH and high solubility of albumin. As the concentration of ethanol is amplified in phases starting from 0 to 40%, as a result, pH drops from a pH of approximately 7.0 (neutral) to almost 4.8, which is almost the pH of albumin as stated by Matejtschuk et al.[92] At every phase, proteins are coagulated or precipitated out of the solution and detached. The concluding coagulant is isolated and purified albumin. Numerous disparities to this method exist, as well as a modified method by Nitschmann and Kistler that made use of lesser steps, and substitute’s centrifugation and major freezing with purification, Matejtschuk ett al.[92] and Brodniewicz-Proba et al.[93]

Matejtschuk ett al.[92] reported that certain modern methods of albumin distillation add a supplementary purification procedure to the Cohn method and its disparities. Chromatographic albumin management began in the 1980s; on the other hand, it was not extensively accepted until later, owing to the insufficiency of large-scale chromatography apparatus. Procedure requiring chromatography usually starts with cryo-depleted plasma experiencing buffer swap through buffer interchange chromatography, to frame the plasma for ion exchange chromatography stages.

The following components were detected in snake venom.[94,95]

Table 1: Components of snake venom

Venom of snakes is among the greatest captivating animal venoms as regards their complication, development, and healing applicability. They are also proposed as one of the most perplexing and challenging targets owing to the diversity of their toxin constituents, introduced because of snakebite incidence. Acquiring a superior knowledge of the progress, structural activity on the victim system, and neurotic effects of these toxins is vital to improve healthier snakebite remedies and unique drugs. It has been discovered that organic products from both plant and animal sources are a key to pharmaceutical expansion.

A significant world population makes use of organic remedies for treatment and for the assistance of warning signs of snakebite. Plant fractions and purified compounds have exposed deactivating activity against snake envenomation and their isolated toxins. Moreover, this deactivation not only decreases local muscle or nerve destruction but also hinders the easy circulation of systemic toxins and hence elevates survival time.

Not reported

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Corresponding Author:
Magaji Amayindi
Department of Pure and Industrial Chemistry
Bayero University Kano, Nigeria
Email: magajiamayindi@gmail.com

Co-Authors:
Joel Yakubu
Department of Community Health
Taraba State College of Health Technology, Nigeria

Rubiyamisumma Dorcas Kaduna
Department of Science Education
Adamawa State University, Nigeria

All authors contributed to the conceptualization, investigation, and data curation by acquiring and critically reviewing the selected articles. They were collectively involved in the writing – original draft preparation, and writing – review & editing to refine the manuscript. Additionally, all authors participated in the supervision of the work, ensuring accuracy and completeness. The final manuscript was approved by all named authors for submission to the journal.

Not applicable

Not reported

None

https://doi.org/10.63096/medtigo3061213

Magaji A, Joel Y, Rubiyamisumma DK. Major Constituent and Mode of Action of Snake Venom and the Nullifying Activity of Both Synthetic and Herbal Remedies. medtigo J Pharmacol. 2025;2(1):e3061213. doi:10.63096/medtigo3061213 Crossref