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

A Narrative Review on the Phytochemistry, Pharmacology and Therapeutic Potentials of Clinacanthus nutans (Burm. f.) Lindau Leaves as an Alternative Source of Future Medicine

The application of natural products and supplements has expanded tremendously over the past few decades. Clinacanthus nutans (C. nutans), which is affiliated to the Acanthaceae family, has recently caught the interest of researchers from the countries of subtropical Asia due to its medicinal uses in alternative treatment for skin infection conditions due to insect bites, microorganism infections and cancer, as well as for health well-being. A number of bioactive compounds from this plant's extract, namely phenolic compounds, sulphur containing compounds, sulphur containing glycosides compounds, terpens-tripenoids, terpens-phytosterols and chlorophyll-related compounds possess high antioxidant activities. This literature search yielded about one hundred articles which were then further documented, including the valuable data and findings obtained from all accessible electronic searches and library databases. The promising pharmacological activities from C. nutans leaves extract, including antioxidant, anti-cancer, anti-viral, anti-bacterial, anti-fungal, anti-venom, analgesic and anti-nociceptive properties were meticulously dissected. Moreover, the authors also discuss a few of the pharmacological aspect of C. nutans leaves extracts against anti-hyperlipidemia, vasorelaxation and renoprotective activities, which are seldom available from the previously discussed review papers. From the aspect of toxicological studies, controversial findings have been reported in both in-vitro and in-vivo experiments. Thus, further investigations on their phytochemical compounds and their mode of action showing pharmacological activities are required to fully grasp both traditional usage and their suitability for future drugs development. Data related to therapeutic activity and the constituents of C. nutans leaves were searched by using the search engines Google scholar, PubMed, Scopus and Science Direct, and accepting literature reported between 2010 to present. On the whole, this review paper compiles all the available contemporary data from this subtropical herb on its phytochemistry and pharmacological activities with a view towards garnering further interest in exploring its use in cardiovascular and renal diseases.

A sensitive and specific indirect competitive enzyme‑linked immunosorbent assay for the detection of icariin

In the present study, a novel monoclonal antibody (MAb) specific for icariin (ICA) was prepared and characterized. A hybridoma‑secreting MAb against icariin was produced by fusing splenocytes immunized with an ICA‑bovine serum albumin conjugate with a hypoxanthine‑aminopterin‑thymidine‑sensitive mouse myeloma SP2/0 cell line. The antibody showed high specificity for ICA with almost no cross‑reactivity against the majority of structurally‑related chemicals. Subsequently, an indirect competitive enzyme‑linked immunosorbent assay (ELISA) for ICA was established and characterized. In this assay, an effective measuring range of 10‑1,000 ng/ml of ICA (R2=0.9828) was detected. Intra‑ and inter‑assay repeatability and precision were achieved with a relative standard deviation (RSD) of <10%. A mean recovery of 95‑115% was obtained, with an RSD of <10%. In addition, the levels of ICA in traditional Chinese herbal prescriptions were determined, and correlation between the ELISA and high‑performance liquid chromatography analyses of total ICA was obtained. These results demonstrated that a reliable ELISA method had been successfully developed to determine ICA in traditional Chinese herbs and may contribute to further clinical investigations.

Clinacanthus nutans Extracts Modulate Epigenetic Link to Cytosolic Phospholipase A2 Expression in SH-SY5Y Cells and Primary Cortical Neurons

Clinacanthus nutans Lindau (C. nutans), commonly known as Sabah Snake Grass in southeast Asia, is widely used in folk medicine due to its analgesic, antiviral, and anti-inflammatory properties. Our recent study provided evidence for the regulation of cytosolic phospholipase A2 (cPLA2) mRNA expression by epigenetic factors (Tan et al. in Mol Neurobiol. doi: 10.1007/s12035-015-9314-z , 2015). This enzyme catalyzes the release of arachidonic acid from glycerophospholipids, and formation of pro-inflammatory eicosanoids or toxic lipid peroxidation products such as 4-hydroxynonenal. In this study, we examined the effects of C. nutans ethanol leaf extracts on epigenetic regulation of cPLA2 mRNA expression in SH-SY5Y human neuroblastoma cells and mouse primary cortical neurons. C. nutans modulated induction of cPLA2 expression in SH-SY5Y cells by histone deacetylase (HDAC) inhibitors, MS-275, MC-1568, and TSA. C. nutans extracts also inhibited histone acetylase (HAT) activity. Levels of cPLA2 mRNA expression were increased in primary cortical neurons subjected to 0.5-h oxygen-glucose deprivation injury (OGD). This increase was significantly inhibited by C. nutans treatment. Treatment of primary neurons with the HDAC inhibitor MS-275 augmented OGD-induced cPLA2 mRNA expression, and this increase was modulated by C. nutans extracts. OGD-stimulated increase in cPLA2 mRNA expression was also reduced by a Tip60 HAT inhibitor, NU9056. In view of a key role of cPLA2 in the production of pro-inflammatory eicosanoids and free radical damage, and the fact that epigenetic effects on genes are often long-lasting, results suggest a role for C. nutans and phytochemicals to inhibit the production of arachidonic acid-derived pro-inflammatory eicosanoids and chronic inflammation, through epigenetic regulation of cPLA2 expression.

Comparative proteomic analysis of two wasps venom, Vespa tropica and Vespa affinis

Vespid venom is composed of many bioactive compounds. The venom of the banded tiger wasp (Vespa affinis, or VA) and the great banded wasp (Vespa tropica, or VT)-which are locally found in the northeastern part of Thailand and are well known for their life-threatening venom potency-were comparatively studied in terms of potency, composition and biological activity. Clinical studies that included word-of-mouth information shared by traditional healers in local areas noted that the venom of VT is more potent than that of VA. Our previous study showed that the venom of VA is lower in potency (PD50 = 12.5 μg/g body weight) than that of VT (PD50 = 3 μg/g body weight). Analysis with the PAGE technique showed that these two venoms showed similar patterns of active proteins. Most protein spots were basic proteins at an isoelectric point (pI) ranging from 5 to 10, with molecular weights between 27 and 50 kDa. These spots were identified as hyaluronidase, phospholipase, antigen 5, dipeptidyl peptidase and albumin-like protein. The proportion of hyaluronidase was 2.5 times higher in VT than in VA. VT also showed higher hyaluronidase, phospholipase and dipeptidyl peptidase activities, suggesting that these components made VT venom more potent than VA venom.

Clinacanthus nutans Protects Cortical Neurons Against Hypoxia-Induced Toxicity by Downregulating HDAC1/6

Many population-based epidemiological studies have unveiled an inverse correlation between intake of herbal plants and incidence of stroke. C. nutans is a traditional herbal medicine widely used for snake bite, viral infection and cancer in Asian countries. However, its role in protecting stroke damage remains to be studied. Despite of growing evidence to support epigenetic regulation in the pathogenesis and recovery of stroke, a clear understanding of the underlying molecular mechanisms is still lacking. In the present study, primary cortical neurons were subjected to in vitro oxygen-glucose deprivation (OGD)-reoxygenation and hypoxic neuronal death was used to investigate the interaction between C. nutans and histone deacetylases (HDACs). Using pharmacological agents (HDAC inhibitor/activator), loss-of-function (HDAC siRNA) and gain-of-function (HDAC plasmid) approaches, we demonstrated an early induction of HDAC1/2/3/8 and HDAC6 in neurons after OGD insult. C. nutans extract selectively inhibited HDAC1 and HDAC6 expression and attenuated neuronal death. Results of reporter analysis further revealed that C. nutans suppressed HDAC1 and HDAC6 transcription. Besides ameliorating neuronal death, C. nutans also protected astrocytes and endothelial cells from hypoxic-induced cell death. In summary, results support ability for C. nutans to suppress post-hypoxic HDACs activation and mitigate against OGD-induced neuronal death. This study further opens a new avenue for the use of herbal medicines to regulate epigenetic control of brain injury.

Protective activity of medicinal plants and their isolated compounds against the toxic effects from the venom of Naja (cobra) species

ETHNOPHARMACOLOGICAL RELEVANCE

Various medicinal plants have protective properties against the toxicities of the venom of cobra snake (Naja species). They may be used as local first aid for the treatment of snakebite victims, and can significantly inhibit lethality, cardio-, neuro-, nephro- and myotoxicity, hemorrhage, and respiratory paralysis induced by the cobra snake venom. The plants or their extracts may also complement the benefits of conventional anti-serum treatment.

AIM OF THE REVIEW

This review provides information on the protective, anti-venom, properties of medicinal plants against snakebites from cobras. In addition, it identifies knowledge gaps and suggests further research opportunities.

METHODS

The literature was searched using databases including Google Scholar, PubMed, ScienceDirect, Scopus and Web of Science. The searches were limited to peer-reviewed journals written in English with the exception of some books and a few articles in foreign languages.

RESULTS

The plants possess neutralization properties against different cobra venom enzymes, such as hyaluronidase, acetylcholinesterase, phospholipase A2 and plasma proteases. Different active constituents that show promising activity against the effects of cobra venom include lupeol acetate, β-sitosterol, stigmasterol, rediocides A and G, quercertin, aristolochic acid, and curcumin, as well as the broad chemical groups of tannins, glycoproteins, and flavones. The medicinal plants can increase snakebite victim survival time, decrease the severity of toxic signs, enhance diaphragm muscle contraction, block antibody attachment to venom, and inhibit protein destruction. In particular, the cardiovascular system is protected, with inhibition of blood pressure decline and depressed atrial contractility and rate, and prevention of damage to heart and vessels. The designs of experimental studies that show benefits, or otherwise, of use of medicinal plants have some limitations: deficiency in identification and isolation of active constituents responsible for therapeutic activity; lack of comparison with reference drugs; and little investigation of the mechanism of anti-venom activity.

CONCLUSION

Despite some current deficiencies in experimental or clinical analysis, medicinal plants with anti-venom characteristics are effective and so are candidates for future therapeutic agents. We suggest that emphasis on identification and testing of active ingredients in research in the future will assist better understanding of their anti-venom activity.

The Effectiveness of Ethanolic Extract ofAmaranthus tricolorL.: A Natural Hepatoprotective Agent

The ethanolic extract of Amaranthus tricolor L. (ATE) leaves was tested for its efficacy against CCl4-induced liver toxicity in rats. The hepatoprotective activity of ATE was evaluated via measuring various liver toxicity parameters, the lipid profile, and a histopathological evaluation. A sleeping time determination study and an acute toxicity test were performed in mice. The results clearly showed that oral administration of ATE for three weeks significantly reduced the elevated levels of serum GOT, GPT, GGT, ALP, bilirubin, cholesterol, LDL, VLDL, TG, and MDA induced by CCl4. Moreover, ATE treatment was also found to significantly increase the activities of NP-SH and TP in liver tissue. These biochemical findings have been supported by the evaluation of the liver histopathology in rats. The prolongation of narcolepsy induced by pentobarbital was shortened significantly by the extract. The acute toxicity test showed that no morbidity or mortality was caused by the extract. The observed hepatoprotective effect appears to be due to the antioxidant properties of A. tricolor, which may pave the way to finding a new drug to be used for fighting liver diseases.

Gastric antisecretory and cytoprotective effects of leaf extracts of Amaranthus tricolor Linn. in rats

OBJECTIVE

The present study was aimed to evaluate the antiulcer activity of leaf extracts of Amaranthus tricolor Linn. (Amaranthaceae) in rats.

METHODS

The effects of A. tricolor leaves on gastric secretion and the effect of gastric cytoprotection were evaluated using five different models of gastric ulcers: acetic acid-induced, pylorus ligation-induced, ethanol-induced, indomethacin-induced and ischemia-reperfusion-induced gastric ulcers. The different extracts, namely, ethanolic extract (EAT), petroleum ether extract (PEAT), chloroform extract (CAT) and ethyl acetate extract (EAAT) of A. tricolor leaves were administered at a dose of 200 mg/kg per oral (p.o.).

RESULTS

The acute oral toxicity study revealed that all the extracts were safe up to 2 000 mg/kg, p.o; hence one-tenth of this dose was selected for evaluation of antiulcer activity. The EAT and EAAT (200 mg/kg, p.o.) showed gastric ulcer-healing effect in acetic acid-induced chronic gastric ulcers. The EAT and EAAT inhibited gastric secretion in pylorus-ligated rats and showed gastric cytoprotective effect in ethanol-induced and indomethacin-induced gastric ulcers, while PEAT and CAT showed no significant antiulcer effect.

CONCLUSION

The leaf extracts of A. tricolor are found to possess very good antiulcer property in the experimental animal models of gastric ulcers which is consistent with the literature report in folk medicine.

Curcuma zedoaria Rosc. (white turmeric): a review of its chemical, pharmacological and ethnomedicinal properties

Objectives

Curcuma zedoaria Rosc is a perennial herb found in tropical countries, such as India, Japan and Thailand. Various parts of this plant are used in Ayurveda and other folk medicines for the treatment of different ailments such as diarrhoea, cancer, flatulence and dyspepsia. This study is an attempt to compile an up-to-date and comprehensive review of C. zedoaria that covers its traditional and folk medicinal uses, phytochemistry and pharmacology.

Key findings

Research carried out using different in-vitro and in-vivo techniques of biological evaluation supports most of the claims.

Summary

This review presents the botany, chemistry, traditional uses and pharmacological data of the plant.

Screening of plants acting against Heterometrus laoticus scorpion venom activity on fibroblast cell lysis

The aqueous extracts of 64 plant species, listed as animal- or insect-bite antidotes in old Thai drug recipes were screened for their activity against fibroblast cell lysis after Heterometrus laoticus scorpion venom treatment. The venom was preincubated with plant extract for 30 min and furthered treated to confluent fibroblast cells for 30 min. More than 40% efficiency (test/control) was obtained from cell treatment with venom preincubated with extracts of Andrographis paniculata Nees (Acanthaceae), Barringtonia acutangula (L.) Gaertn. (Lecythidaceae), Calamus sp. (Palmae), Clinacanthus nutans Lindau (Acanthaceae), Euphorbia neriifolia L. (Euphorbiaceae), Ipomoea aquatica Forssk (Convolvulaceae), Mesua ferrea L. (Guttiferae), Passiflora laurifolia L. (Passifloraceae), Plectranthus amboinicus (Lour.) Spreng. (Labiatae), Ricinus communis L. (Euphorbiaceae), Rumex sp. (Polygonaceae) and Sapindus rarak DC. (Sapindaceae), indicating that they had a tendency to be scorpion venom antidotes. However, only Andrographis paniculata and Barringtonia acutangula extracts provided around 50% viable cells from extract treatments without venom preincubation. These two plant extracts are expected to be scorpion venom antidotes with low cytotoxicity.