The crude methanol extract of Bearded Argostemma (Argostemma involucratum Hemsl., Rubiaceae) showed a good and broad spectrum of antibacterial activity against both Gram-negative and Gram-positive bacteria. The activity was increased on fractionation (hexane, dichloromethane and water), particularly in the aqueous fraction which was more active than the methanol extract and streptomycin (no activity was shown against tested moulds). Both the hexane and dichloromethane fractions were inactive. The objective of this experiment was to investigate the antibacterial activity of hexane, dichloromethane, and aqueous fractions of Argostemma involucratum Hemsl. The aqueous fraction of Bearded Argostemma may be a possible new option for the treatment of bacterial infections.
The hexane, dichloromethane, ethyl acetate and methanol fractions of leaves of Acalypha siamensis Oliv. ex Gage were evaluated for antibacterial and antifungal activity. The antibacterial activity was more pronounced in the ethyl acetate and methanol extracts. No activity was shown against tested moulds.