Md. Ruhul Kuddus

In this study, the crude methanol extract of whole plant of Vernonia cinerea Less. has been investigated for anti-diarrheal, anxiolytic, antimicrobial and membrane stabilizing activities. Test for anti-diarrheal activity was carried out by castor oil-induced diarrhea in mice. The anxiolytic activity was examined in mice by using the hole-cross test and open field-tests (OFT). The preliminary antimicrobial activity was determined at 500 μg/disc by the disc diffusion method against a number of Gram positive and Gram negative bacteria and fungi. RBC membrane stabilization method was used for the evaluation of in-vitro anti-inflammatory activity. The crude methanol extract of V. cinerea showed significant and dose-dependent anti-diarrheal activity in castor oil-induced diarrhea in mice. The results showed that the crude extract significantly increased the number of hole crossing as compared to control in hole cross tests. In open field test, the extract showed significant increase in number of square crossed. The efficacy of the extract (200-400 mg/kg b.w.) was compared with standard anxiolytic drug diazepam (1 mg/kg). Furthermore, the plant extract, at 500 µg/disc exhibited moderate antimicrobial activity against Blastomyces dermatitidis (zone of inhibition = 17.7 mm) and Shigella dysenteriae (zone of inhibition = 14.0 mm). In red blood cell stability test,  the sample at 0.5 and 1 mg/ml  inhibited the heat-induced haemolysis of RBCs by 15.45% and 27.73%, respectively whereas standard acetyl salicylic acid (ASA) demonstrated 71.36% inhibition of haemolysis. The obtained results provide supports for the use of this plant in traditional medicine but further pharmacologic studies are required to isolate and identify the bioactive molecules.

The crude methanol extract of leaf of Tiliacora acuminata Miers as well as organic solvent (n-hexane, carbon tetrachloride and chloroform) fractions and methanolic fraction (aqueous) were subjected to screening for total phenolic content, antioxidant, cytotoxic, thrombolytic and antimicrobial activity. In total phenolic content analysis, the n-hexane soluble fraction of leaf was found to contain highest amount of phenolic content (TPC, 132.18 mg/gm of dry weight of extract, expressed as gallic acid equivalents). In the DPPH assay, the n-hexane soluble fraction of leaf displayed the highest free radical scavenging activity with IC50 value 64.54 μg/ml as compared to 27.5 μg/ml produced by butylated hydroxyl toluene.  A positive correlation was evident between total phenolic content and free radical scavenging activity of T. acuminata having correlation coefficient (R2) of 0.91. In cytotoxicity screening, the crude methanol extract of leaf demonstrated strong cytotoxic activity with LC50 value of 2.40 μg/ml as compared to 0.451 μg/ml produced by vincristine sulphate. During assay for thrombolytic activity, the crude methanol extract revealed 32.5% lysis of clot while standard streptokinase and water, used as positive and negative controls, demonstrated 70.4% and 3.62% lysis of clot, respectively. In antimicrobial assay by disc diffusion method, all the samples exhibited moderate to significant antimicrobial activity (zone of inhibition = 10.0-20.0 mm) against all the test organisms. Among all the samples, the carbon tetrachloride soluble fraction displayed strong antimicrobial activity against Escherichia coli (20.0 mm).