Evaluation of anti-nociceptive and anti-inflammatory activities of the methanol extract of Holigarna caustica (Dennst.) Oken leaves

Ethnopharmacological relevance: Holigarna caustica (Dennst.) is commonly used in traditional medicine to treat a variety of painful conditions such as eye irritation, inflammation, arthritis, skin diseases, cuts and wounds.Aim of the study: The present study was undertaken to investigate the anti-nociceptive and anti-inflammatory activities of the methanol extract of H. caustica leaves and to elucidate its possible mechanism(s) of action.Materials and methods: Fresh leaves of H. caustica were collected, dried, and extracted with methanol (MEHC). MEHC was subjected to activity testing, using chemical-induced (acetic acid and formalin test) and heat-induced (hot plate and tail immersion test) pain models. To determine the possible mechanism behind the anti-nociceptive activity of MEHC, the opioid antagonist naltrexone was used to evaluate the involvement of opioid receptors in the case of formalin, hot plate and tail immersion tests, while the involvement of the cGMP and ATP-sensitive K+ channel pathways were assessed using methylene blue and glibenclamide respectively, in the acetic acid-induced writhing test. In parallel, the carrageenan-induced paw oedema model was used to determine the anti-inflammatory potential of the extract. Exploratory and motor behaviours were evaluated by the open-field test. Various bioactive compounds potentially responsible for the anti-nociceptive and anti-inflammatory activities were ascertained using GC-MS analysis.Results: MEHC showed strong, significant and dose-dependent anti-nociceptive activity in all chemical-induced and heat-induced pain models at all experimental doses. The association of opioid receptors with the observed anti-nociceptive effects was confirmed by using naltrexone. The cGMP and ATP-sensitive K+ channel pathway was also shown to be involved in the anti-nociceptive activity of MEHC. In addition, MEHC exhibited a dose-dependent inhibition of inflammatory oedema induced by carrageenan. MEHC was not connected with changes in either the locomotor activity or motor responses of mice. In a GC-MS analysis, 40 compounds were identified, among which twelve are documented bioactive compounds with potent analgesic and anti-inflammatory properties.Conclusions: Our current study revealed that MEHC possesses strong central and peripheral anti-nociceptive as well as anti-inflammatory activity. It may also be concluded that both opioid receptors as well as the cGMP and ATP-sensitive K+ channel pathway are involved in the anti-nociceptive mechanism of MEHC. This study rationalizes the ethnomedicinal use of H. caustica leaves in various painful conditions.</p

Chemical composition and antimicrobial activity of Congea tomentosa, an ethnomedicinal plant from Bangladesh.

Congea tomentosa Roxb. (CT) is used as a medicinal plant by indigenous peoples of Bangladesh, but to date remains largely unexplored from a phytochemical or pharmacological perspective. In this study, the extracts of leaves, stems and flowers of CT were tested for antimicrobial activity using the agar well diffusion and micro-dilution methods. Compared with leaf and flower extracts, the crude stem extract was the most effective against the tested microorganisms. Therefore, the crude stem extract was further subjected to sequential fractionation, with the petroleum ether and ethyl acetate extracts proving the most active against tested microorganisms. Using GC–MS analysis, 10 compounds were identified within the petroleum ether extract, all of which are known to the literature, and some/all of which may have contributed to the observed antimicrobial properties. Additionally, two compounds (β-amyrin and stigmasterol) were isolated from the ethyl acetate fraction and identified using mass spectrometry and NMR spectroscopy. Compound 2 (stigmasterol) displayed promising antimicrobial activity against tested microorganisms. Despite the ethnobotanical importance of CT, this work represents the first scientific report supporting its traditional use, and demonstrates that both the stem extract of this ethnomedicinal plant and the isolated compound 2 (stigmasterol) may offer potential as antimicrobials

Evaluation of various solvent extracts of Tetrastigma leucostaphylum (Dennst.) alston leaves, a Bangladeshi traditional medicine used for the treatment of diarrhea.

Tetrastigma leucostaphylum (TL) is an important ethnic medicine of Bangladesh used to treat diarrhea and dysentery. Hence, current study has been designed to characterize the antidiarrheal (in vivo) and cytotoxic (in vitro) effects of T. leucostaphylum. A crude extract was prepared with methanol (MTL) and further partitioned into n-hexane (NTL), dichloromethane (DTL), and n-butanol (BTL) fractions. Antidiarrheal activity was investigated using castor oil induced diarrhea, enteropooling, and gastrointestinal transit models, while cytotoxicity was evaluated using the brine shrimp lethality bioassay. In antidiarrheal experiments, all doses (100, 200, and 400 mg/kg) of the DTL extract significantly reduced diarrheal stool frequency, volume and weight of intestinal contents, and gastrointestinal motility in mice. Similarly, in the cytotoxicity assay, all extracts exhibited activity, with the DTL extract the most potent (LC50 67.23 μg/mL). GC-MS analysis of the DTL extract identified 10 compounds, which showed good binding affinity toward M3 muscarinic acetylcholine, 5-HT3, Gut inhibitory phosphodiesterase, DNA polymerase III subunit alpha, and UDP-N-acetylglucosamine-1 carboxyvinyltransferase enzyme targets upon molecular docking analysis. Although ADME/T analyses predicted the drug-likeness and likely safety upon consumption of these bioactive compounds, significant toxicity concerns are evident due to the presence of the known phytotoxin, 2,4-di-tert-butylphenol. In summary, T. leucostaphylum showed promising activity, helping to rationalize the ethnomedicinal use and importance of this plant, its safety profile following both acute and chronic exposure warrants further investigation

Investigation of the biological activities and characterization of bioactive constituents of ophiorrhiza rugosa var. prostrata (D.Don) & Mondal leaves through in vivo, in vitro, and in silico approaches.

Ophiorrhiza rugosa var. prostrata is one of the most frequently used ethnomedicinal plants by the indigenous communities of Bangladesh. This study was designed to investigate the antidiarrheal, anti-inflammatory, anthelmintic and antibacterial activities of the ethanol extract of O. rugosa leaves (EEOR). The leaves were extracted with ethanol and subjected to in vivo antidiarrheal screening using the castor oil-induced diarrhea, enteropooling, and gastrointestinal transit models. Anti-inflammatory efficacy was evaluated using the histamine-induced paw edema test. In parallel, in vitro anthelmintic and antibacterial activities were evaluated using the aquatic worm and disc diffusion assays respectively. In all three diarrheal models, EEOR (100, 200 and 400 mg/kg) showed obvious inhibition of diarrheal stool frequency, reduction of the volume and weight of the intestinal contents, and significant inhibition of intestinal motility. Also, EEOR manifested dose-dependent anti-inflammatory activity. Anthelmintic action was deemed significant (P < 0.001) with respect to the onset of paralysis and helminth death. EEOR also resulted in strong zones of inhibition when tested against both Gram-positive and Gram-negative bacteria. GC-MS analysis identified 30 compounds within EEOR, and of these, 13 compounds documented as bioactive showed good binding affinities to M3 muscarinic acetylcholine, 5-HT3, tubulin and GlcN-6-P synthase protein targets in molecular docking experiments. Additionally, ADME/T and PASS analyses revealed their drug-likeness, likely safety upon consumption and possible pharmacological activities. In conclusion, our findings scientifically support the ethnomedicinal use and value of this plant, which may provide a potential source for future development of medicines