Isolation, purification and partial characterization of viper venom inhibiting factor from the root extract of the Indian medicinal plant sarsaparilla (Hemidesmus indicus R. Br.)

A comprehensive review on recent advances in the use of ethnomedicinal plants and their metabolites in snake bite treatment

Snakebites are a severe medical and social issue, particularly in tropical and subtropical countries with minimal medical facilities, where the most dangerous snakes are found. Worldwide, most rural areas use medicinal plants alone or in combination as antidotes for snakebite treatment. Local knowledge of medicinal plants for snakebite treatment plays a more critical role in primary healthcare services in rural areas. As a result of this review, it is revealed that 39% of herbs, 38% of shrubs, 18% of trees, 2% of climbers, 2% of bulbs, and 1% of ferns have snake antivenom potential, which is indicative of the presence of numerous phytochemicals such as alkaloids, coumarins, curcuminoids, flavonoids, steroids, triterpenoids, and cinnamic acid in particular plants. According to the availability of information, the data focus on the plants, their families, and their parts from various literature sources. In the future, the valuable plants reported here and their phytoconstituents may be potential sources for developing effective natural drugs for snake bite treatments. Therefore, this review is a comprehensive study of the snake antivenom potential of various medicinal plants and their bioactive compounds.

Proteomic diversity of Russell's viper venom: exploring PLA2 isoforms, pharmacological effects, and inhibitory approaches

Snakebite envenomation is a serious health concern in tropical regions, resulting in high mortality. The World Health Organization (WHO) has declared it a neglected tropical disease and is working on strategies to reduce mortality. Russell's viper (Daboia russelii) is one of the most abundant venomous snakes found across Southeast Asia. Proteomic analysis of Russell's viper venom has demonstrated variation, with phospholipase A2 (PLA2) being the most abundant toxin across geographic boundaries. PLA2, a major constituent of the low-molecular-weight fraction of snake venom, hydrolyses phospholipids at the sn-2 position, releasing arachidonic acid and lysophospholipids. They are reported to cause various pharmacological effects, including hemolysis, anticoagulation, neurotoxicity, myotoxicity, and oedema. Though administration of antivenoms (ASV) is the primary treatment for envenomation, it has many drawbacks. Besides causing hypersensitivity reactions and life-threatening anaphylaxis, treatment with ASV is further complicated due to its inability to neutralize low-molecular-weight toxins. Thus, there is a greater need to produce next-generation antivenoms that can target specific toxins in the venom. In this review, we explored the classification of Russell's viper and the variation in its proteomic profile across Southeast Asia to date. In addition, we have also summarized the mechanism of action of PLA2 and discussed various isoforms of PLA2 found across different regions with their respective pharmacological effects. Finally, the drawbacks of commercially available antivenoms and the molecules investigated for inhibiting the low-molecular-weight toxin, PLA2 are discussed.

The Need for Next-Generation Antivenom for Snakebite Envenomation in India

The limitations posed by currently available antivenoms have emphasized the need for alternative treatments to counteract snakebite envenomation. Even though exact epidemiological data are lacking, reports have indicated that most global snakebite deaths are reported in India. Among the many problems associated with snakebite envenomation, issues related to the availability of safer and more efficient antivenoms are of primary concern. Since India has the highest number of global snakebite deaths, efforts should be made to reduce the burden associated with snakebite envenoming. Alternative methods, including aptamers, camel antivenoms, phage display techniques for generating high-affinity antibodies and antibody fragments, small-molecule inhibitors, and natural products, are currently being investigated for their effectiveness. These alternative methods have shown promise in vitro, but their in vivo effectiveness should also be evaluated. In this review, the issues associated with Indian polyvalent antivenoms in neutralizing venom components from geographically distant species are discussed in detail. In a nutshell, this review gives an overview of the current drawbacks of using animal-derived antivenoms and several alternative strategies that are currently being widely explored.

Pharmacological re-assessment of traditional medicinal plants-derived inhibitors as antidotes against snakebite envenoming: A critical review

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional healers have used medicinal plants to treat snakebite envenomation worldwide; however, mostly without scientific validation. There have been many studies on the therapeutic potential of the natural products against snake envenomation.

AIM OF THE STUDY

This review has highlighted snake venom inhibitory activity of bioactive compounds and peptides from plants that have found a traditional use in treating snakebite envenomation. We have systematically reviewed the scenario of different phases of natural snake venom inhibitors characterization covering a period from 1994 until the present and critically analysed the lacuna of the studies if any, and further scope for their translation from bench to bedside.

MATERIALS AND METHODS

The medicinal plant-derived compounds used against snakebite therapy were reviewed from the available literature in public databases (Scopus, MEDLINE) from 1994 till 2020. The search words used were 'natural inhibitors against snakebite,' 'natural products as therapeutics against snakebite,' 'natural products as antidote against snake envenomation,' ' snake venom toxin natural inhibitors,' 'snake venom herbal inhibitors'. However, the scope of this review does not include computational (in silico) predictions without any wet laboratory validation and snake venom inhibitory activity of the crude plant extracts. In addition, we have also predicted the ADMET properties of the identified snake venom inhibitors to highlight their valuable pharmacokinetics for future clinical studies.

RESULTS

The therapeutic application of plant-derived natural inhibitors to treat snakebite envenomation as an auxiliary to antivenom therapy has been gaining significant momentum. Pharmacological reassessment of the natural compounds derived from traditional medicinal plants has demonstrated inhibition of the principal toxic enzymes of snake venoms at various extents to curb the lethal and/or deleterious effects of venomous snakebite. Nevertheless, such molecules are yet to be commercialized for clinical application in the treatment of snakebite. There are many obstacles in the marketability of the plant-derived natural products as snake envenomation antidote and strategies must be explored for the translation of these compounds from drug candidates to their clinical application.

CONCLUSION

In order to minimize the adverse implications of snake envenomation, strategies must be developed for the smooth transition of these plant-derived small molecule inhibitors from bench to bedside. In this article we have presented an inclusive review and have critically analysed natural products for their therapeutic potential against snake envenomation, and have proposed a road map for use of natural products as antidote against snakebite.

Plant-Derived Toxin Inhibitors as Potential Candidates to Complement Antivenom Treatment in Snakebite Envenomations

Snakebite envenomations (SBEs) are a neglected medical condition of global importance that mainly affect the tropical and subtropical regions. Clinical manifestations include pain, edema, hemorrhage, tissue necrosis, and neurotoxic signs, and may evolve to functional loss of the affected limb, acute renal and/or respiratory failure, and even death. The standard treatment for snake envenomations is antivenom, which is produced from the hyperimmunization of animals with snake toxins. The inhibition of the effects of SBEs using natural or synthetic compounds has been suggested as a complementary treatment particularly before admission to hospital for antivenom treatment, since these alternative molecules are also able to inhibit toxins. Biodiversity-derived molecules, namely those extracted from medicinal plants, are promising sources of toxin inhibitors that can minimize the deleterious consequences of SBEs. In this review, we systematically synthesize the literature on plant metabolites that can be used as toxin-inhibiting agents, as well as present the potential mechanisms of action of molecules derived from natural sources. These findings aim to further our understanding of the potential of natural products and provide new lead compounds as auxiliary therapies for SBEs.

Herbal Compounds as an Antidote against Snake Bite

Snakebites have been declared a neglected health problem that must be considered a national disease of the WHO[world health organisation]. Asian countries like India have high snakebite death rates due to short antidotes and poorly equipped doctors. In today's scenario, local resources like herbs need to be used to prepare cheap antidotes and often available to victims. Snake bites should be viewed as an emergency problem and require additional national guidelines, doctor training, expertise, and human concentration for effective and timely treatment-measures to be taken to ensure the availability and mass production of antidotes. Currently available, antidotes have problems with storage, manufacture, and aspects of the results. Attention should be paid to the natural compound Gedunin with antitoxic effects. To determine Gedunin's therapeutic efficacy well-designed clinical research is required. This article emphasizes and proves the therapeutic effectiveness of the herbal plant active ingredient Gedunin against snakebites.

Indian Sarsaparilla (Hemidesmus indicus): Recent progress in research on ethnobotany, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Hemidesmus indicus (L.) R. Br. ex Schult. (Apocynaceae) is widely used in traditional medicine in the different parts of the Indian subcontinent due to the various biological activities attributed to its different parts, especially the roots. It has traditionally been used for treating snakebites, scorpion stings, diabetes, urinary diseases, dyspnea, menorrhagia, oligospermia, anorexia, fever, abdominal colic and pain, dysentery, diarrhea, cough, rheumatism, headache, inflammation, pyrosis, skin diseases, leprosy, sexually transmitted diseases and cancer. In Ayurveda, the plant is used in the treatment of bone-loss, low body weight, fever, stress, topical wound and psoriasis. Besides, Ayurvedic literature also depicts its use as anti-atherogenic, anti-spasmodic, memory enhancing, immunopotentiating and anti-inflammatory agents.

AIM OF THE STUDY

In this review, we aim to present a comprehensive update on the ethnopharmacology, phytochemistry, specific pharmacology, and toxicology of H. indicus and its bioactive metabolites. Possible directions for future research are also outlined in brief.

MATERIALS AND METHODS

Popular and widely used international databases such as PubMed, Scopus, Science Direct, Google Scholar and JSTOR were searched and traditional literature were consulted using the various search strings to retrieve a number of citations related to the ethnopharmacology, biological activity, toxicology, quality control and phytochemistry of H. indicus. All studies on the ethnobotany, phtochemistry, pharmacology, and toxicology of the plant up to 2019 were included in this review.

RESULTS

H. indicus has played an important role in traditional Indian medicine (including Ayurveda) and also in European medicine. The main pharmacological properties of H. indicus include hepatoprotective, anti-cancer, anti-diabetic, antioxidant, neuroprotective, anti-ophidian, cardioprotective, nephroprotective, anti-ulcerogenic, anti-inflammatory, and antimicrobial properties. Phytochemical evaluations of the root have revealed the presence of aromatic aldehydes and their derivatives, phenolics, triterpenoids and many other compounds, some of which were attributed to its bioactivity. This review also compiles a list of Ayurvedic formulations and commercial preparations where H. indicus has been used as an active ingredient. We have included the critical assessment of all the papers cited in this manuscript based on experimental observation and other important points which reflect the loop-holes of research strategy and ambiguity in the papers reviewed in this manuscript.

CONCLUSIONS

The study presents an exhaustive and updated review on the traditional, pharmacological and phytochemical aspects of H. indicus with notes on its quality control and toxicological information. Although the crude extracts of H. indicus exhibit an array of pharmacological activities, it is high time to identify more active phyto-constituents by bioactivity-guided isolation besides elucidating their structure-activity relationship. More designed investigations are needed to comprehend the multi-target network pharmacology, to clarify the molecular mode of action and to ascertain the efficacious doses of H. indicus. Moreover, H. indicus is not fully assessed on the basis of its safety and efficacy on human. We hope this review will compile and improve the existing knowledge on the potential utilization of H. indicus in complementary and alternative medicine.

An Appraisal of Antidotes' Effectiveness: Evidence of the Use of Phyto-Antidotes and Biotechnological Advancements

Poisoning is the greatest source of avoidable death in the world and can result from industrial exhausts, incessant bush burning, drug overdose, accidental toxication or snake envenomation. Since the advent of Albert Calmette’s cobra venom antidote, efforts have been geared towards antidotes development for various poisons to date. While there are resources and facilities to tackle poisoning in urban areas, rural areas and developing countries are challenged with poisoning management due to either the absence of or inadequate facilities and this has paved the way for phyto-antidotes, some of which have been scientifically validated. This review presents the scope of antidotes’ effectiveness in different experimental models and biotechnological advancements in antidote research for future applications. While pockets of evidence of the effectiveness of antidotes exist in vitro and in vivo with ample biotechnological developments, the utilization of analytic assays on existing and newly developed antidotes that have surpassed the proof of concept stage, as well as the inclusion of antidote’s short and long-term risk assessment report, will help in providing the required scientific evidence(s) prior to regulatory authorities’ approval.

Exploring the potent inhibitors and binding modes of phospholipase A2 through in silico investigation

Snake venom of Naja naja comprises of several types of enzymes, and among them, water-soluble proteolytic enzyme, phospholipase A2 (PLA₂), is noteworthy for its numerous adverse effects, such as cytotoxicity, cardiotoxicity, hemolytic, anti-coagulant, and hypotensive effects, including being highly potent as a neurotoxin. Limited anti-venom therapy (with their lower efficacy) has attracted considerable pharmacological interest to develop potent inhibitors of PLA₂. Thus, 34 experimentally proven and diverse synthetic inhibitors of PLA₂ were screened primarily on the basis of Glide extra precision docking and MM-GBSA rescoring function. Then, ten potential hits were subjected to induced fit docking, in which top three potential inhibitors were considered, and those were found to interact with Ca²⁺, disulfide binding site, and phosphatidylcholine activation sites, thereby, possibly disrupting the catalytic activity of Ca²⁺ as well as the inflammatory functions of PLA₂. These compounds showed positive remarks on various physiochemical properties and pharmacologically relevant descriptors. Gap energy and thermodynamic properties were investigated by employing density functional theory for all compounds to understand their chemical reactivity and thermodynamic stability. Molecular dynamics simulation was performed for 100 ns in order to evaluate the stability and binding modes of docked complexes, and the energy of binding was calculated through MM-PBSA analysis. On the whole, the proposed compounds could be used for targeted inhibition. Communicated by Ramaswamy H. Sarma.

Perspective on the Therapeutics of Anti-Snake Venom

Snakebite envenomation is a life-threatening disease that was recently re-included as a neglected tropical disease (NTD), affecting millions of people in tropical and subtropical areas of the world. Improvement in the therapeutic approaches to envenomation is required to palliate the morbidity and mortality effects of this NTD. The specific therapeutic treatment for this NTD uses snake antivenom immunoglobulins. Unfortunately, access to these vital drugs is limited, principally due to their cost. Different ethnic groups in the affected regions have achieved notable success in treatment for centuries using natural sources, especially plants, to mitigate the effects of snake envenomation. The ethnopharmacological approach is essential to identify the potential metabolites or derivatives needed to treat this important NTD. Here, the authors describe specific therapeutic snakebite envenomation treatments and conduct a review on different strategies to identify the potential agents that can mitigate the effects of the venoms. The study also covers an increased number of literature reports on the ability of natural sources, particularly plants, to treat snakebites, along with their mechanisms, drawbacks and future perspectives.

Anti-Ophidian Properties of Herbal Medicinal Plants: Could it be a Remedy for Snake Bite Envenomation?

Snake bite envenoming causes high rates of morbidity and mortality and is one of the serious health-related concerns all over the globe. Around 3200 species of snakes have been discovered till date. Amid these species, about 1300 species of snakes are venomous. On account of its severity, World Health Organization (WHO) recently included snakebite envenoming in the list of neglected tropical diseases. Immunotherapy has partially solved the issues related to snakebite envenomation. However, it is associated with numerous adverse effects, due to which alternative treatment strategies are required for the treatment of snakebite. Traditionally, a large repository of herbal medicinal plants is known to possess activity against snake venom. An exploration of the therapeutic benefits of these medicinal plants used for the treatment of snakebites reveals the presence of various potential phytochemicals. The aim of the present review is to provide an outline regarding poisonous snakes all over the world, various compositions of snake venom, adverse effects related to anti-snake venom and numerous medicinal plants used for the anti-ophidian activity.

Ethnopharmacological survey of medicinal plants used by traditional healers and indigenous people in chittagong hill tracts, bangladesh, for the treatment of snakebite

Snakebites are common in tropical countries like Bangladesh where most snakebite victims dwell in rural areas. Among the management options after snakebite in Bangladesh, snake charmers (Ozha in Bengali language) are the first contact following a snakebite for more than 80% of the victims and they are treated mostly with the help of some medicinal plants. Our aim of the study is to compile plants used for the treatment of snakebite occurrence in Bangladesh. The field survey was carried out in a period of almost 3 years. Fieldwork was undertaken in Chittagong Hill Tracts, Bangladesh, including Chittagong, Rangamati, Bandarban, and Khagrachari. Open-ended and semistructured questionnaire was used to interview a total of 110 people including traditional healers and local people. A total of 116 plant species of 48 families were listed. Leaves were the most cited plant part used against snake venom. Most of the reported species were herb in nature and paste mostly used externally is the mode of preparation. The survey represents the preliminary information of certain medicinal plants having neutralizing effects against snake venoms, though further phytochemical investigation, validation, and clinical trials should be conducted before using these plants as an alternative to popular antivenom.

Inhibitory effect of plant Manilkara subsericea against biological activities of Lachesis muta snake venom

Snake venom is composed of a mixture of substances that caused in victims a variety of pathophysiological effects. Besides antivenom, literature has described plants able to inhibit injuries and lethal activities induced by snake venoms. This work describes the inhibitory potential of ethanol, hexane, ethyl acetate, or dichloromethane extracts and fractions from stem and leaves of Manilkara subsericea against in vivo (hemorrhagic and edema) and in vitro (clotting, hemolysis, and proteolysis) activities caused by Lachesis muta venom. All the tested activities were totally or at least partially reduced by M. subsericea. However, when L. muta venom was injected into mice 15 min first or after the materials, hemorrhage and edema were not inhibited. Thus, M. subsericea could be used as antivenom in snakebites of L. muta. And, this work also highlights Brazilian flora as a rich source of molecules with antivenom properties.

Antivenom activity of triterpenoid (C34H68O2) from Leucas aspera Linn. against Naja naja naja venom induced toxicity: antioxidant and histological study in mice

The isolated and identified triterpenoid, 1-hydroxytetratriacontane-4-one (C34H68O2), obtained from the methanolic leaf extract of Leucas aspera Linn. was explored for the first time for antisnake venom activity. The plant (L. aspera Linn.) extract significantly antagonized the spectacled cobra (Naja naja naja) venom induced lethal activity in a mouse model. It was compared with commercial antiserum obtained from King Institute of Preventive Medicine (Chennai, Tamil Nadu, India). N. naja naja venom induced a significant decrease in antioxidant superoxide dismutase, glutathione (GSH) peroxidase, catalase, reduced GSH and glutathione-S-transferase activities and increased lipid peroxidase (LPO) activity in different organs such as heart, liver, kidney and lungs. The histological changes following the antivenom treatment were also evaluated in all these organs. There were significant alterations in the histology. Triterpenoid from methanol extract of L. aspera Linn. at a dose level of 75 mg per mouse significantly attenuated (neutralized) the venom-induced antioxidant status and also the LPO activity in different organs.

Do herbal medicines have potential for managing snake bite envenomation?

Snake envenomation is a global public health problem, with highest incidence in Southeast Asia. Inadequate health services, difficult transportation and consequent delay in antisnake venom administration are the main reasons for high mortality. Adverse drug reactions and inadequate storage conditions limit the use of antisnake venom. The medicinal plants, available locally and used widely by traditional healers, therefore need attention. A wide array of plants and their active principles have been evaluated for pharmacological properties. However, numerous unexplored plants claimed to be antidotes in folklore medicine need to be studied. The present article reviews the current status of various medicinal plants for the management of snake bite.

The bioactive and therapeutic potential of Hemidesmus indicus R. Br. (Indian Sarsaparilla) root

The root of Hemidesmus indicus R. Br., commonly known as Indian Sarsaparilla, is used traditionally to treat a wide variety of illnesses including rheumatism, leprosy, impotence, urinary tract and skin infections. The anticancer, antioxidant, anti-inflammatory, antipyretic, analgesic, antimicrobial, antidiabetic, hepatoprotective, cardioprotective, renoprotective, neuroprotective and immunomodulatory properties of H. indicus have been investigated in numerous in vivo and in vitro studies. Among these, the antioxidant and antimicrobial activity was well documented. This review details the phytochemistry and therapeutic applications of H. indicus root.

Therapeutic application of natural inhibitors against snake venom phospholipase A(2)

Natural inhibitors occupy an important place in the potential to neutralize the toxic effects caused by snake venom proteins and enzymes. It has been well recognized for several years that animal sera, some of the plant and marine extracts are the most potent in neutralizing snake venom phospholipase A(2) (svPLA(2)). The implication of this review to update the latest research work which has been accomplished with svPLA(2) inhibitors from various natural sources like animal, marine organisms presents a compilation of research in this field over the past decade and revisiting the previous research report including those found in plants. In addition to that the bioactive compounds/inhibitor molecules from diverse sources like aristolochic alkaloid, flavonoids and neoflavonoids from plants, hydrocarbones -2, 4 dimethyl hexane, 2 methylnonane, and 2, 6 dimethyl heptane obtained from traditional medicinal plants Tragia involucrata (Euphorbiaceae) member of natural products involved for the inhibitory potential of phospholipase A(2) (PLA(2)) enzymes in vitro and also decrease both oedema induced by snake venom as well as human synovial fluid PLA(2). Besides marine natural products that inhibit PLA(2) are manoalide and its derivatives such as scalaradial and related compounds, pseudopterosins and vidalols, tetracylne from synthetic chemicals etc. There is an overview of the role of PLA(2) in inflammation that provides a rationale for seeking inhibitors of PLA(2) as anti-inflammatory agents. However, more studies should be considered to evaluate antivenom efficiency of sera and other agents against a variety of snake venoms found in various parts of the world. The implications of these new groups of svPLA(2) toxin inhibitors in the context of our current understanding of snake biology as well as in the development of new novel antivenoms therapeutics agents in the efficient treatment of snake envenomations are discussed.

Traditional use of plants against snakebite in Indian subcontinent: a review of the recent literature

Snakebite has been a major cause of mortality across the tropical countries including Indian subcontinent. The present review deals with the enormous amount of ethnobotanical work performed in the last few years involving use of different plants against snakebite in Indian subcontinent (India, Bangladesh, Pakistan and Nepal). From a variety of literature sources the data has been compiled mentioning the plants, parts used, dosage, mode of administration, name of the ethnic communities, geographical locations etc. depending on the availability of information.

Effect of 2-Hydroxy-4-Methoxy Benzoic Acid from the Roots of Hemidesmus indicus on Streptozotocin-induced Diabetic Rats

The aim of the present study was to investigate the effect of 2-hydroxy-4-methoxy benzoic acid isolated from the roots of Hemidesmus indicus on plasma glucose, plasma, erythrocyte and erythrocyte membrane lipid peroxidation and membrane-bound Ca(2+) ATPase activity in streptozotocin-induced diabetic rats. In our study, diabetic rats had increased levels of blood glucose and lipid peroxidation in plasma, erythrocytes and erythrocyte membrane and decreased level of plasma insulin and decreased activity of low affinity Ca(2+) ATPase in erythrocytes. Restoration of plasma insulin and glucose in diabetic rats indicates the effect of HMBA on insulin, glucose and lipid peroxidation. HMBA also restored diabetes-induced alterations in the activity of membrane-bound Ca(2+) ATPase. Based on the results of this study it can be concluded that HMBA mediated normalization of membrane-bound ATPase in erythrocytes is due to improved glycemic control and antioxidant activity.

Antioxidant effect of 2-hydroxy-4-methoxy benzoic acid on ethanol-induced hepatotoxicity in rats

Alcoholic liver disease (ALD) is one of the most common diseases in society. A large number of studies are in progress to identify natural substances that are effective in reducing the severity of ALD. 2-Hydroxy-4-methoxy benzoic acid (HMBA), the active principle of Hemidesmus indicus, an indigenous Ayurvedic medicinal plant in India, is expected to significantly inhibit the development of liver injury in ethanol administration. It is expected to reduce the severity of liver damage in terms of body weight, hepatic marker enzymes, oxidative stress, antioxidant status and histological changes in ethanol-induced hepatotoxic rats. Hepatotoxicity was induced by administering 20% ethanol (5 g kg−1 daily) for 60 days to male Wistar rats, which resulted in significantly decreased body weight and an increase in liver-body weight ratio. The liver marker enzymes aspartate transaminase, alanine transaminase, alkaline phosphatase, γ-glutamyl transpeptidase and lactate dehydrogenase were elevated. In addition, the levels of plasma, erythrocyte and hepatic thiobarbituric acid reactive substances, hydroperoxides and conjugated dienes were also elevated in ethanol-fed rats as compared with those of the experimental control rats. Decreased activity of superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, vitamin C and α-tocopherol was also observed on alcohol administration as compared with experimental control rats. HMBA was co-administered at a dose of 200 μgkg−1 daily for the last 30 days of the experiment to rats with alcohol-induced liver injury, which significantly increased body weight, significantly decreased the liver-body weight ratio, transaminases, alkaline phosphatase, γ-glutamyl transpeptidase and lactate dehydrogenase, significantly decreased the levels of lipid peroxidative markers, significantly elevated the activity of enzymic and non-enzymic antioxidants in plasma, erythrocytes and liver and also increased levels of plasma and liver vitamin C and α-tocopherol at the end of the experimental period as compared with untreated ethanol-administered rats. The histological changes were also in correlation with the biochemical findings. The results suggest that HMBA administration may afford protection against ethanol-induced liver injury in rats.

Effect of 2-hydroxy 4-methoxy benzoic acid on an experimental model of hyperlipidaemia, induced by chronic ethanol treatment

The aim of the present study was to determine the effect of 2-hydroxy 4-methoxy benzoic acid (HMBA), the active principle of Hemidesmus indicus, an indigenous Ayurvedic medicinal plant in India. We investigated the effect of HMBA on hyperlipidaemia induced by ethanol, exploring food intake, body weight, and hepatic and plasma lipids and lipoproteins. Male Wistar rats weighing 130–180 g were given ethanol (5 g kg−1 p.o.) daily for 30 days. Subsequently, ethanol-fed rats were given HMBA intragastrically at a dose of 200 μg kg−1 per day for 30 days. At the end of the total experimental period of 60 days, plasma concentrations of total cholesterol (CHO), triglycerides (TG), lipoproteins (LP), phospholipids (PL), free fatty acids (FFA) and lipoprotein lipase (LPL), and hepatic CHO, TG and PL were measured. Treatment of ethanol-fed rats with HMBA significantly decreased plasma CHO, TG, LP, PL and FFA and hepatic CHO, TG and PL, and increased plasma LPL concentrations compared with values in untreated ethanol-fed rats (all P < 0.05). Food intake and average body weight at the end of the experimental period were significantly increased by HMBA administration. In conclusion, administration of HMBA decreased lipids and lipoprotein concentrations significantly in an animal model of ethanol-induced hyperlipidaemia.

Phenylalanine ammonia-lyase-mediated biosynthesis of 2-hydroxy-4-methoxybenzaldehyde in roots of Hemidesmus indicus

The fragrant rootstocks of Hemidesmus indicus are known to accumulate 2-hydroxy-4-methoxybenzaldehyde (MBALD), yet, the enzymatic route to this hydroxybenzoate is not known. Therefore, root organs of H. indicus hold promises to unravel the biosynthesis related to this phenolic fragrance. Chitosan treatment at 200mg/L concentration to the excised roots effectively increased phenolic accumulation in both the cortex and cork tissues reaching a peak after 24h treatment and decreasing thereafter. The activity of phenylalanine ammonia-lyase (PAL) enzyme in excised roots also increased upon chitosan elicitation, and the maximum specific activity was recorded after 12h of elicitation. Suppression of PAL in vivo by using a specific irreversible inhibitor aminooxyacetic acid (AOAA) resulted in the decrease in MBALD content, indicating its formation via phenylpropanoid pathway.

Ethnobotanical survey of folk plants for the treatment of snakebites in Southern part of Tamilnadu, India

Ethnobotanical surveys were conducted in four different indigenous groups in Southern parts of Tamilnadu, India, using a questionnaire. The herbal practitioners in the study area were interviewed, and information on medicinal plants was collected from the traditional healers called "Vaidyars". This survey covers 72 medicinal plants belonging to 53 families that are used for the treatment of snakebite in a traditional way. Traditional approach was evaluated scientifically with some selected plant extracts (7.2 mg/kg bw) and partially purified fractions (2.4 mg/kg bw) were orally administered to mice experimentally envenomed with rattlesnake venom s.c. injection (2.5-15 microg/kg bw). Tested fractions (Aristolochia indica, Hemidesmus indicus, Gloriosa superba, Strychnos nux-vomica, Eclipta prostrata, and Andrographis paniculata) showed potent neutralizing effect against the venom. Compared to the extracts, administration of purified fractions was more effective in increasing the body weight. Control mice injected with the venom alone showed weight loss and severe toxicity at 15 microg/kg bw. The purified fractions (2.4 mg/kg bw) produced significant protection against venom induced changes in serum SOD and LPx levels. The isolated fractions effectively inhibited the toxic effect of snake venoms in vitro than in vivo. The above observations confirmed the protective activity of plants-Aristolochia indica, Hemidesmus indicus, Gloriosa superba, Strychnos nux-vomica, Eclipta prostrata, and Andrographis paniculata against the lethal action of snake venom and need further investigation.

Hemidesmus indicus protects against ethanol-induced liver toxicity

Alcoholic liver disease (ALD) is one of the most common diseases in modern society. A large number of studies are in progress aiming to identify natural substances that would be effective in reducing the severity of ALD. Although there are currently a number of drugs on the market, their long-term use can have numerous side effects. Hemidesmus indicus is an indigenous Ayurvedic medicinal plant used in soft drinks in India. In this study, we examined the effects of its ethanolic root extract on experimental liver damage in order to evaluate its hepatoprotective effects against hepatotoxicity induced in rats by ethanol at a dosage of 5 g/kg body weight for 60 days. The H. indicus root extract was given at a dose of 500 mg/kg body weight for the last 30 days of the experiment. The animals were monitored for food intake and weight gain. The liver was analysed for the degree of lipid peroxidation using thiobarbituric acid reactive substances (TBARS) and antioxidant status using the activities of glutathione-dependent enzymes. The degree of liver damage was analysed using serum marker enzyme activities, the total protein, albumin, globulin, ceruloplasmin and liver glycogen contents, and the A/G ratio. The Fourier transform infrared spectra (FT-IR) of the liver tissues were recorded in the region of 4000-400 cm(-1). The ethanol-fed rats showed significantly elevated liver marker enzyme activities, lipid peroxidation levels and reduced antioxidant levels as compared to the control rats. Oral administration of H. indicus for the latter 30 days resulted in an increased food intake and weight gain, decreased TBARS levels, near normal levels of glutathione-dependent enzymes, increased total protein, albumin, globulin and liver glycogen contents, an increased A/G ratio, and decreased liver marker enzyme activities and ceruloplasmin levels. The relative intensity of the liver FT-IR bands for the experimental groups were found to be altered significantly (p < 0.05) compared to the control samples. For the group that had H. indicus co-administered with ethanol, the intensity of the bands was near normal. Moreover, the results of the FT-IR study correlated with our biochemical results.

Inhibitory effect of Hemidesmus indicus and its active principle 2-hydroxy 4-methoxy benzoic acid on ethanol-induced liver injury

The study evaluates the inhibitory activity of ethanolic root extract of Hemidesmus indicus (H. indicus) and its active principle 2-hydroxy 4-methoxy benzoic acid (HMBA) on liver fibrotic markers and characteristics such as collagen content, matrix metalloproteinases (MMPs) 2 and 9 in ethanol-fed rats. Experimental groups were control, H. indicus (500 mg/kg body weight every day during the last 30 days), HMBA (200 microg/kg body weight every day during the last 30 days), alcohol (5 g/kg body weight by intragastric intubation everyday, i.e. throughout the experimental period of 60 days), alcohol plus H. indicus and alcohol plus HMBA. Ethanol administration significantly increased the levels of liver collagen and hydroxy proline content, cross-linked fluorescence, shrinkage temperature and lipid peroxidation and significantly decreased the solubility of liver collagen and the ascorbic acid content when compared with control rats. On treatment with H. indicus and HMBA the ethanol-fed rats showed significantly reduced levels of liver collagen and hydroxyproline content, cross-linked fluorescence, shrinkage temperature and lipid peroxidation and enhanced solubility of liver collagen and ascorbic acid levels when compared with untreated ethanol-fed rats. MMPs were extracted from the liver of control, H. indicus-treated, HMBA-treated, ethanol-administered, ethanol with H. indicus-coadministered and ethanol with HMBA-coadministered rats. The inhibition was analyzed by gelatin zymography and the percentage of expression was determined by a gel documentation system. The activities of MMPs 2 and 9 were significantly increased in ethanol-supplemented rats. Cotreatment of H. indicus/HMBA with ethanol showed significantly decreased activities of these enzymes when compared with those of the untreated rats. H. indicus/HMBA alone treatment showed no such significant alterations. Thus, our present study reveals the strong inhibitory activity of H. indicus and HMBA on the quantitative and qualitative properties of hepatic collagen and also MMPs involved in the extracellular matrix degradation during ethanol intoxication.

Daboia russellii and Naja kaouthia venom neutralization by lupeol acetate isolated from the root extract of Indian sarsaparilla Hemidesmus indicus R.Br

The present study reports the isolation and purification of lupeol acetate from the methanolic root extract of Indian medicinal plant Hemidesmus indicus (L.) R.Br. (family: Asclepiadaceae) which could neutralize venom induced action of Daboia russellii and Naja kaouthia on experimental animals. Lupeol acetate could significantly neutralize lethality, haemorrhage, defibrinogenation, edema, PLA(2) activity induced by Daboia russellii venom. It also neutralized Naja kaouthia venom induced lethality, cardiotoxicity, neurotoxicity and respiratory changes in experimental animals. Lupeol acetate potentiated the protection by snake venom antiserum action against Daboia russellii venom induced lethality in male albino mice. Venom induced changes in lipid peroxidation and super oxide dismutase activity was antagonized by lupeol acetate. Snake venom neutralization by lupeol acetate and its possible mechanism of action has been discussed.

Antinociceptive activity of alcoholic extract of Hemidesmus indicus R.Br. in mice

The ethanolic extract of roots of Hemidesmus indicus R.Br. (family: Asclepiadaceae) was investigated for possible antinociceptive effect in mice. Three models were used to study the effects of extracts on nociception, which was induced, by acetic acid (Writhing test), formalin (Paw licking test) and hot plate test in mice. Hemidesmus indicus R.Br. extract was administered in the dose range of 25, 50 and 100mg/kg orally 1h prior to pain induction. The preliminary phytochemical screening of the extract showed the presence of triterpenes, flavonoids, pregnane glycosides and steroids. Oral administration of Hemidesmus indicus extract revealed dose-dependent antinociceptive effect in all the models for antinociception and it blocked both the neurogenic and inflammatory pain and the nociceptive activity was comparable with the reference drug. The results indicate that alcoholic extract of Hemidesmus indicus R.Br. possesses a significant antinociceptive activity. The activity can be related with the significant phytochemicals such as triterpenes, flavonoids, and sterols reported in the root extract.

Use of Pavo cristatus feather extract for the better management of snakebites: neutralization of inflammatory reactions

In Indian traditional medicine, peacock feather in the form of ash (Bhasma) or water extract are used against snakebite and to treat various problems associated with lungs. This study was aimed to evaluate the water extract of peacock feather (PCF) against the local tissue damage caused due to snakebite. PCF water extract showed inhibition towards phospholipase A2 enzyme activity from snake venom (Naja naja and Vipera russelii), inflammatory fluids (synovial, pleural, ascites) and normal serum in a dose-dependent manner. Hyaluronidase and proteases are other major enzymes in snake venoms responsible for local tissue damage. PCF water extract inhibited hyaluronidase and proteolytic enzyme activities from Vipera russelii, Naja naja and Trimeresurus malabaricus venom. The active principle is a hydrophilic molecule easily extractable in water or polar solvents. PCF water extract gave positive results for the presence of protein and secondary metabolites like carotenoids and steroids. Analysis of metal ions revealed that iron is the major ion (> 20-fold). Other metal ions detected in smaller amount are copper, chromium, zinc and nickel. The least amount of ion detected is gold. Co-injection of PCF water extract with snake venom and inflammatory PLA2 enzymes neutralize the edema inducing activity of all the PLA2 enzymes studied. Since it inhibits hyaluronidase and proteases enzyme activity from snake venom PCF water extract is a powerful neutralizing agent, which has therapeutic application against venom toxicity.

Screening of plants containing Naja naja siamensis cobra venom inhibitory activity using modified ELISA technique

Enzyme-linked immunosorbent assay (ELISA) has been modified for screening plants with antagonistic activity to Naja naja siamensis cobra venom. Aqueous extracts from plants were investigated for their inhibitory effects on the binding of anti-cobra venom antibody to antigen, cobra venom, fixed onto 96-well microtiter plates. Ingredients in extracts were allowed to react with immobilized venom before the subsequent addition of antivenom antibody. Venom components affected by exposure to the extracts, unable to interact with their specific antibody, were predicted to be unable to bind to their native destinations or natural receptors. Curcuma cf. zedoaria, an old Thai medicinal plant, showed clear inhibitory activity in the ELISA test. Neurotoxin and protein degradative enzymes, major components in venom, were identified as targets of this extract in Western immunoblotting analysis. Ingredients in the extract showed high affinity to the toxin in competition assay by immunoprecipitation. The extract attenuated toxin activity by extending contraction time of diaphragm muscle after envenomation and had a potency to protect cellular proteins from venom degradative enzymes. Curcuma parviflora, with less activity in ELISA, exhibited acceptable results in two experiments but negative results in two experiments, whereas Curcuma longa, having low activity in the ELISA test, never showed any favorable results. Screening of 36 samples could classify plants into an inhibition range of 0 to 86%. This modified ELISA is recommended as a preliminary screening method for inhibitors with a large number of samples.

Effect of Annona senegalensis rootbark extracts on Naja nigricotlis nigricotlis venom in rats

Annona senegalensis Pers (family: Annonaceae) is used traditionally in Nigeria to treat victims of snakebite. The potency of the methanol extract of the root bark of the plant was tested against cobra (Naja nigricotlis nigricotlis Wetch) venom in rats. The extract was also tested on brine shrimp (Artemia saline Leach). The activity of the extract against the venom induced mortality, occurrence of toxic signs, activity on liver enzymes as well as its ability to reverse experimentally induced increase in body temperature were evaluated. Results indicated that the extract caused reduction in the induced hyperthermia and directly detoxified the snake venom used by 16-33%. It, however, failed to restore the biochemical functions (sGOT and sGPT) of the liver. The extract exhibited an LC(50) of 232.7 microg/ml in the brine shrimp test.

Radiation protection of DNA and membranein vitro by extract ofHemidesmus indicus

Radioprotective effect of H. indicus root extract on lipid peroxidation in rat liver microsomes and plasmid DNA was examined. Hemidesmus indicus (HI) root extract was found to protect microsomal membranes as evident from reduction in lipid peroxidation values. The extract could also protect DNA from radiation induced strand breaks.

Neutralization of the edema-forming, defibrinating and coagulant effects of Bothrops asper venom by extracts of plants used by healers in Colombia

We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae), Ficus nymphaeifolia (Moraceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plant of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); rhizomes of Renealmia alpinia (Zingiberaceae), Heliconia curtispatha (Heliconiaceae) and Dracontium croatii (Araceae), and the ripe fruit of Citrus limon (Rutaceae). After preincubation of varying amounts of each extract with either 1.0 microg venom for the edema-forming effect or 2.0 microg venom for the defibrinating effect, the mixture was injected subcutaneously (sc) into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g). All extracts (6.2-200 microg/mouse) partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76% inhibition), with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 microg/mouse) also showed 100% neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40% for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection), the neutralization of edema increased for six extracts, reaching levels up to 64% for C. limon.

Renoprotective effect of Hemidesmus indicus, a herbal drug used in gentamicin-induced renal toxicity

BACKGROUND AND AIMS

Owing to the global trend towards improved 'quality of life', there is considerable evidence of an increase in demand for medicinal plants. The WHO guidelines define basic criteria for the standardization of herbal medicines. The present work is an effort in this direction to prove the safety and efficacy of Hemidesmus indicus Linn. in the management of nephrotoxicity induced by aminoglycosides such as gentamicin.

METHODS AND RESULTS

Simple, quality control methods using high performance thin layer chromatographic (HPTLC) phytochemical fingerprint, proximate analysis, and the stability of the H. indicus root powder were developed. From the toxicity study using albino Swiss mice, it was observed that the drug (H. indicus) was relatively safe up to 7 g/kg bodyweight dose. Efficacy was evaluated against gentamicin-induced nephrotoxicity in albino Wister rats. The study examined animals from the following groups: no treatment, gentamicin treated, gentamicin treated recovery, and gentamicin and plant treated. Animals from all groups were killed on day 13 of the study; those from gentamicin treated group were killed on the seventh day. Assessment of the drug efficacy drug was conducted by using haematological and histological examination.

CONCLUSION

The treatment with H. indicus helped in the management of renal impairment, which was induced by gentamicin in rats. This is evident from the results obtained for various kidney function tests for gentamicin, along with the results from the plant treated group, and is in comparison with the results found for the gentamicin recovery group. A histological examination of kidneys also supports the findings from haematological evaluations. The plant shows promise as an adjunct therapy along side aminoglycosides as it reduces nephrotoxicity caused by aminoglycosides.

Evaluation of antioxidant properties of root bark of Hemidesmus indicus R. Br. (Anantmul)

Hemidesmus indicus R. Br. (Asclepiadaceae) is a well known drug in Ayurveda system of medicine. In the present study, antioxidant activity of methanolic extract of H. indicus root bark was evaluated in several in vitro and ex vivo models. Further, preliminary phytochemical analysis and TLC fingerprint profile of the extract was established to characterize the extract which showed antioxidant properties. The in vitro and ex vivo antioxidant potential of root bark of H. indicus was evaluated in different systems viz. radical scavenging activity by DPPH reduction, superoxide radical scavenging activity in riboflavin/light/NBT system, nitric oxide (NO) radical scavenging activity in sodium nitroprusside/Greiss reagent system and inhibition of lipid peroxidation induced by iron-ADP-ascorbate in liver homogenate and phenylhydrazine induced haemolysis in erythrocyte membrane stabilization study. The extract was found to have different levels of antioxidant properties in the models tested. In scavenging DPPH and superoxide radicals, its activity was intense (EC50 = 18.87 and 19.9 microg/ml respectively) while in scavenging NO radical, it was moderate. It also inhibited lipid peroxidation of liver homogenate (EC50 = 43.8 microg/ml) and the haemolysis induced by phenylhydrazine (EC50 = 9.74 microg/ml) confirming the membrane stabilization activity. The free radical scavenging property may be one of the mechanisms by which this drug is effective in several free radical mediated disease conditions.

Plant natural products active against snake bite--the molecular approach

The article surveys the substances identified in plants reputed to neutralize the effects of snake venoms. Protective activity of many of them against the lethal action of the venom of the jararaca (Bothrops jararaca) snake was confirmed by biological assays. It was shown that all belong to chemical classes capable of interacting with macromolecular targets--receptors and enzymes. In a few cases it has been shown that exogenous natural micromolecules can mimic the biological activity of endogenous macromolecules. From the evidence presented, it can be inferred that micromolecules which neutralize the action of snake venoms mechanistically replace endogenous antitoxic serum proteins with venom neutralizing capacity such as produced by some animals.

Snakebites and ethnobotany in the northwest region of Colombia. Part III: neutralization of the haemorrhagic effect of Bothrops atrox venom

Thirty-one of 75 extracts of plants used by traditional healers for snakebites, had moderate or high neutralizing ability against the haemorrhagic effect of Bothrops atrox venom from Antioquia and Chocó, north-western Colombia. After preincubation of several doses of every extract (7.8-4000 microg/mouse) with six minimum haemorrhagic doses (10 microg) of venom, 12 of them demonstrated 100% neutralizing capacity when the mixture was i.d. injected into mice (18-20 g). These were the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plants of Pleopeltis percussa (Polypodiaceae), Trichomanes elegans (Hymenophyllaceae) and Senna dariensis (Caesalpiniaceae); rhizomes of Heliconia curtispatha (Heliconiaceae); leaves and branches of Bixa orellana (Bixaceae), Philodendron tripartitum (Araceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the ripe fruits of Citrus limon (Rutaceae); leaves, branches and stem of Ficus nymphaeifolia (Moraceae). Extracts of another 19 species showed moderate neutralization (21-72%) at doses up to 4 mg/mouse, e.g. the whole plants of Aristolochia grandiflora (Aristolochiaceae), Columnea kalbreyeriana (Gesneriaceae), Sida acuta (Malvaceae), Selaginella articulata (Selaginellaceae) and Pseudoelephantopus spicatus (Asteraceae); rhizomes of Renealmia alpinia (Zingiberaceae); the stem of Strychnos xinguensis (Loganiaceae); leaves, branches and stems of Hyptis capitata (Lamiaceae), Ipomoea cairica (Convolvulaceae), Neurolaena lobata (Asteraceae), Ocimum micranthum (Lamiaceae), Piper pulchrum (Piperaceae), Siparuna thecaphora (Monimiaceae), Castilla elastica (Moraceae) and Allamanda cathartica (Apocynaceae); the macerated ripe fruits of Capsicum frutescens (Solanaceae); the unripe fruits of Crescentia cujete (Bignoniaceae); leaves and branches of Piper arboreum (Piperaceae) and Passiflora quadrangularis (Passifloraceae). When the extracts were independently administered by oral, i.p. or i.v. route either before or after an i.d. venom injection (10 microg), neutralization of haemorrhage dropped below 25% for all the extracts. Additionally, B. rosademonte and P. percussa extracts were able to inhibit the proteolytic activity of B. atrox venom on casein.

Snakebites and ethnobotany in the northwest region of Colombia: Part II: neutralization of lethal and enzymatic effects of Bothrops atrox venom

Twelve of 74 ethanolic extracts of plants used by traditional healers for snakebites in the northwest region of Colombia, were active against lethal effect of Bothrops atrox venom when they were i.p. injected into mice (18-20 g). After preincubation of sublethal doses of every extract (0.5-4.0 mg/mouse) with 1.5 i.p. lethal dose 50% (LD50) (99.3 microg) of venom, seven of them demonstrated 100% neutralizing capacity within 48 h. These were the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); rhizomes of Renealmia alpinia (Zingiberaceae) and Heliconia curtispatha (Heliconiaceae); the whole plants of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); and the ripe fruits of Citrus limon (Rutaceae). The other five extracts showing partial neutralization (45-80%; 10-30% survival rate in the control group receiving the venom alone; P<0.05) were: leaves, branches and stem of Costus lasius (Costaceae); the whole plant of Sida acuta (Malvaceae); rhizomes of Dracontium croatii (Araceae); leaves and branches of Bixa orellana (Bixaceae) and Struthanthus orbicularis (Loranthaceae). When the extracts were independently administered per oral or i.p. route 60 min before an i.m. venom injection (204 microg=1.5 i.m. LD50), C. limon, T. elegans, B. orellana and T. rosea extracts had partial and significant neutralizing capacity against B. atrox venom lethal effect. C. limon extract was also partially effective when it was administered either i.v. 15 min before or i.p. 5 min after an i.m. venom injection. Three of the 12 extracts with anti-lethal effect (C. limon, D. croatii and S. acuta) were devoid of antiphospholipase A2 activity, when they were tested against one minimum indirect hemolytic dose of B. atrox venom (2 microg) in agarose-erythrocyte-egg yolk gels.

Molecular mechanism of lung hemorrhage induction by VRV-PL-VIIIa from Russell's viper (Vipera russelli) venom

The basic phospholipase A(2) (VRV-PL-VIIIa) from Vipera russelli venom induces multiple toxic effects including neurotoxicity, myotoxicity, edema and hemorrhage. This phospholipase A(2) has been extensively characterized for its pharmacological properties except for hemorrhagic activity. In the present investigation, the lung hemorrhagic activity was assayed using lung dye diffusion method. The investigations to understand the mechanism of lung hemorrhage induction by VRV-PL-VIIIa was followed by chemical modification studies and also by interaction with an antihemorrhagic factor p-anisic acid (4-methoxy benzoic acid). In presence of 1:2 mol:mol PLA(2): anisic acid, the lung hemorrhagic and edema inducing activities were completely neutralized in experimental animals; however, catalytic and anticoagulant activities were not neutralized. Carbamylation of VRV-PL-VIIIa resulted in the loss of lung hemorrhage and edema inducing activities. In contrast, carbamylation of VRV-PL-VIIIa in the presence of anisic acid could not neutralize the lung hemorrhage and edema inducing activities. The anticoagulant and enzyme activities were only partially neutralized when carbamylated both in the presence and absence of anisic acid.

Protective effect of Hemidesmus indicus against rifampicin and isoniazid-induced hepatotoxicity in rats

Oral treatment with the ethanol extract of Hemidesmus indicus roots (100 mg/kg, for 15 days) significantly prevented rifampicin and isoniazid-induced hepatotoxicity in rats.

Adjuvant effects and antiserum action potentiation by a (herbal) compound 2-hydroxy-4-methoxy benzoic acid isolated from the root extract of the Indian medicinal plant 'sarsaparilla' (Hemidesmus indicus R. Br.)

The adjuvant effect and antiserum potentiation of a compound 2-hydroxy-4-methoxy benzoic acid were explored in the present investigation. This compound, isolated and purified from the Indian medicinal plant Hemidesmus indicus R. Br, possessed antisnake venom activity. Rabbits immunized with Vipera russellii venom in the presence and absence of the compound along with Freund's complete adjuvant, produced a precipitating band in immunogel diffusion and immunogel electrophoresis. The venom neutralizing capacity of this antiserum showed positive adjuvant effects as evident by the higher neutralization capacity (lethal and hemorrhage) when compared with the antiserum raised with venom alone. The pure compound potentiated the lethal action neutralization of venom by commercial equine polyvalent snake venom antiserum in experimental models. These observations raised the possibility of the use of chemical antagonists (from herbs) against snake bite, which may provide a better protection in presence of antiserum, especially in the rural parts of India.

Viper venom-induced inflammation and inhibition of free radical formation by pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from anantamul (Hemidesmus indicus R. BR) root extract

The present investigation explored the possible venom neutralizing effect of a pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from the methanolic root extract of Hemidesmus indicus R.Rr. 2-OH-4-MeO benzoic acid possessed potent anti-inflammatory, antipyretic and antioxidant properties. The compound effectively neutralized inflammation induced by Vipera russelli venom in male albino mice and reduced cotton pellet-induced granuloma in rats. The compound produced a significant fall in body temperature in yeast-induced pyrexia in rats but did not change the normothermic body temperature. The compound effectively neutralized viper venom-induced changes in serum phosphatase and transaminase activity in male albino rats. It also neutralized free radical formation as estimated by TBAPS and superoxide dismutase activities. The antisnake venom activity of the pure compound is partly mediated through the above physiological process.