In vitro antimicrobial activity study and in vivo antiemetic, antinociceptive activity evaluation of leaves extract of Erioglossum rubiginosum using experimental animal model

The present study explored the phytochemical screening, in vitro antimicrobial activity, in vivo antiemetic and antinociceptive potentialities of methanol extract of Erioglossum rubiginosum leaves for the first time. Crude extract of E. rubiginosum and different fractions were assayed for in vitro antimicrobial activity using disc diffusion method. The antiemetic activity was evaluated using chick emesis model; while acetic acid induced writhing test in mice was conducted to determine the antinociceptive activity. Different extracts possess carbohydrate, flavonoids, saponin, tannin, alkaloids, phenol and cardiac-glycoside in varying concentrations. Among different extractives, only the chloroform soluble fraction showed promising antimicrobial activity (zone of inhibition 6.5 to 10 mm) in comparison to positive control-ciprofloxacin, against wide range of tested microorganisms. In antiemetic assay, all the extracts showed significant (P<0.05) activities; among them both chloroform and carbon tetrachloride extracts showed better activity (inhibition 91 and 90 % respectively) compared to the standard drug metoclopramide (inhibition 74 %). In antinociceptive assay, remarkable writhing inhibitory activity was found for the chloroform extract (53.05 %), while the standard drug diclofenac sodium inhibited 42.01 % writhing of the test animals (P<0.05). Therefore, further studies and compound isolation are suggested to confirm the mechanism of the key compounds as the plant extracts of E. rubiginosum revealed potential biological and pharmacological activities.