Antimicrobial activity of extracts and a germacranolidetype sesquiterpene lactone from Tithonia diversifolia leaf extract

The in vitro antimicrobial activity of the hexane, ethyl acetate and methanol extracts of the leaf of Tithonia diversifolia, and one sesquiterpene lactone 1 isolated from the ethyl acetate extract wasstudied. Of the fourteen strains of bacteria used, the ethyl acetate extract was the most active, showing inhibitory activity against five Gram +ve and two Gram –ve organisms. This was followed by the hexane extract and then methanol. The ethyl acetate fractions (TDE 2 – TDE 5, TDE 7, TDE 8 and TDE 10) showed varying degrees of inhibitory activity. The sesquiterpene lactone 1 showed activity against all the tested microorganisms, except Staphylococcus aureus and Bacillus cereus (MICs = 15.6 – 62.5mg/ml for most stains). All the extracts, fractions and compound 1 showed activity against the fungusCandida albicans. The results of the present study indicate that the non-polar leaf extract of T.diversifolia could be useful in the treatment of some disease conditions and the sesquiterpene lactone 1 could be a good candidate as a phytotherapeutic agent against some bacterial infection

ANTAGONISTIC POTENTIALS OF TALINUM\ud TRIANGULARE EXTRACTS AGAINST IRON II –\ud INDUCED OXIDATIVE STRESS IN TISSUE\ud HOMOGENATES OF WISTAR ALBINO RAT -IN\ud VITRO

This studies show the inhibitory effects of an aqueous and ethanolic\ud extracts of Talinum triangulare (Tt) on tissue homogenates of matured\ud male albino rat (Rattus norvegicus) incubated with iron II (60 µM\ud FeSO4) to induced oxidative stress by thiobarbituric acid reactive\ud species (TBARS). The aqueous extract caused significant (p < 0.05)\ud increase in the inhibition against malondialdehyde (MDA) produced in\ud the brain (with IC50 value = 2.45 ± 0.04 µg/ml) and testes homogenates\ud (with IC50 = 0.75 ± 0.02 µg/ml) but significant (p > 0.05) decreased\ud was observed in the treated liver homogenate in dose-dependent\ud manner (0.33-3.33 µg/ml). However, the level of MDA produced was\ud significantly (p < 0.05) increased in the Talinum triangulare ethanolic\ud extract treated rat’s brain (with IC50 value = 1.63 ± 0.01 µg/ml) but\ud significant (p > 0.05) difference was observed in both the liver and the\ud testes homogenates when incubated with Iron II in the in vitro assay. Therefore, it could be\ud concluded that the plant is potentially active against iron II - induced oxidative stress in the\ud brain and testes as it has been implicated in the assay