European Journal of Medicinal Plants

A comparison of in vitro antioxidant, antimicrobial, insecticidal and cytotoxic activities of two medicinal plants, Allamanda cathartica and Mimusops elengi have been studied by spectrophotometric and disk diffusion methods in this research. It was observed that different leaf extract of A. cathartica exhibited less antioxidant activity in comparison to that of the extract of M. elengi. The highest antioxidant activity (4.588±0.001 mg/mL) was found in the dia-ion resin adsorbed fraction of M. elengi and the least activity (1.82±0.002 mg/mL) was found in the methanolic fraction of A. cathartica. From the results of antimicrobial activity test, it was observed that the petroleum ether fraction of A. cathartica showed the maximum inhibition with the diameter of 16–20 mm while the ethyl acetate fraction of M. elengi showed the least inhibition with the diameter of 10–16 mm. The insecticidal activity against the pathogenic bacteria Tribolium castaneum of A. cathartica was very pronounced with the LD₅₀ values of 225.205 mg/cm² where as M. elengi showed the least and/or no insecticidal activity. All the extracts such as methanol, petroleum ether, chloroform, ethyl acetate and dia-ion-resin adsorbed fraction of both A. cathartica and M. elengi displayed higher level of toxicity towards brine shrimps lethality bioassay. Based on the results obtained, the A. cathartica and M. elengi leaf extracts could serve as the potential source of natural antioxidant, antimicrobial and anticancer agents. Also they could be used for the treatments of different oxidative disorders, infection diseases caused by the resistant microorganisms and cancer cells, respectively.