AIM OF THE STUDY: To test extracts of P. glaucus in a number of bioassays and determine the legitimacy of its traditional use.
MATERIALS AND METHODS: The stems, leaves, roots and fruits of P. glaucus were collected and extracted sequentially with hexane, chloroform and ethanol, respectively. The anti-inflammatory activity was assessed by testing the ability of the extracts to inhibit heat induced protein denaturation, stabilise human red blood cells under hypotonic stress and by testing the inhibitory activity of the extracts against cyclooxygenases 1 and 2. Cytotoxicity was tested using the human lung epithelial cell line MRC-5 and nasopharangeal carcinoma cell line HK1 in the MTT assay.
RESULTS: Many of the samples showed an ability to prevent heat induced protein denaturation, as well as prevent lysis of red blood cells. Most of the extracts demonstrated inhibitory activity towards both of the COX enzymes. The ethanol extracts tended to demonstrate greater toxicity than other extracts, with some of the other extracts significantly enhancing growth and metabolism of the cells.
CONCLUSION: The benefit of P. glaucus for the treatment of diseases related to inflammation and cancer was supported by the in vitro assays adopted in this study.
METHODS: An in silico approach was used in this study to determine through molecular docking the binding affinities and site of binding of these phytochemicals to the 3C-like protease of COVID-19 which is considered as the main protease of the virus.
RESULTS: A number of anti-malarial phytochemicals like apigenin-7-O-glucoside, decurvisine, luteolin-7-O-glucoside, sargabolide J, and shizukaols A, B, F, and G showed predicted high binding energies with G values of -8.0 kcal/mol or higher. Shizukaols F and B demonstrated the best binding energies of -9.5 and -9.8, respectively. The acridone alkaloid 5-hydroxynoracronycine also gave a predicted high binding energy of -7.9 kcal/mol.
CONCLUSION: This is for the first time that decursivine and several shizukaols were reported as potential anti-viral agents. These compounds merit further studies to determine whether they can be effective drug candidates against COVID-19.
OBJECTIVE: The present study examines the antibacterial properties of 18 medicinal plants used by the Khyang tribe in day-to-day practice against human pathogenic bacteria.
MATERIALS AND METHODS: Leaves, bark, fruits, seeds, roots and rhizomes from collected plants were successively extracted with hexane, ethyl acetate and ethanol. The corresponding 54 extracts were tested against six human pathogenic bacteria by broth microdilution assay. The antibacterial mode of actions of phytoconstituents and their synergistic effect with vancomycin and cefotaxime towards MRSA was determined by time-killing assay and synergistic interaction assay, respectively.
RESULTS AND DISCUSSION: Hexane extract of bark of Cinnamomum cassia (L.) J. Presl. (Lauraceae) inhibited the growth of MRSA, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii with MIC values below 100 µg/mL. From this plant, cinnamaldehyde evoked at 4 × MIC in 1 h an irreversible decrease of MRSA count Log10 (CFU/mL) from 6 to 0, and was synergistic with vancomycin for MRSA with fractional inhibitory concentration index of 0.3.
CONCLUSIONS: Our study provides evidence that the medicinal plants in Bangladesh have high potential to improve the current treatment strategies for bacterial infection.