Antimicrobial and anti-inflammatory activity of folklore: Mallotus peltatus leaf extract

Since ages Mallotus peltatus (Geist) Muell. Arg. var acuminatus (Euphorbiaceae) leaf and stem bark is used in folk medicine to cure intestinal ailments and skin infections. In several intestinal ailments, localized inflammation is of common occurrence and hence we have evaluated the antimicrobial as well as anti-inflammatory activity of M. peltatus leaf extract. The crude methanol extract of M. peltatus leaves was found to be active against Staphylococcus aureus, Staphylococcus saprophyticus, Streptococcus faecalis, Bacillus subtilis, Escherichia coli and Proteus mirabilis and the dermatophytic fungi Microsporum gypseum. The minimum inhibitory concentration (MIC) ranges from 128 to 2000 microg ml(-1) for bacteria and 128 mg ml(-1) for fungi, while the minimum bactericidal concentration (MBC) was 2-4-fold higher than MIC. The methanol-water fraction of the extract showed similar activity against Staphylococcus, Streptococcus, Bacillus and Proteus isolates. The anti-inflammatory activity of the extract against carrageenan (acute model) and dextran-induced (subacute model) rat paw oedema and cotton pellet-induced granuloma (chronic model) in rats were studied using indomethacin (10 mg kg(-1)), a nonsteroid anti-inflammatory drug, as standard. The methanol extract at 200 and 400 mg kg(-1), and the n-butanol fractions A and B at 25 mg kg(-1), exhibited significant anti-inflammatory activity in Albino rats, compared with indomethacin. Phytochemical study revealed the presence of tannins, saponins, terpenoids, steroids and reducing sugars in the crude extract while the n-butanol fractions showed the presence of ursolic acid, beta-sitosterol and some fatty acids as major compounds. Further study with fractions showed that the antibacterial and anti-inflammatory activity is due to either fraction A (ursolic acid) alone or the combination of fractions A and B (beta-sitosterol and fatty acids) of the extract.