Antibacterial Activity and Phytochemical Screening of Erythrina fusca Lour. Leaf Extract (Fabaceae)

Abstract

Erythrina fusca Lour. (family Fabaceae) is a flowering tree that is locally known as ‘chengkering’. The plant is traditionally used in treatment of some symptoms related to bacterial infections such as wound infections, inflammations, and skin itching. This work reports for the first time in vitro antibacterial screening of the E. fusca Lour. methanolic leaf extract against some common Gram-negative and Gram-positive bacteria such as Klebsiella pneumonia, Proteus vulgaris, Pseudomonas aeruginosa, Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus. The in vitro antibacterial assay was carried out using agar diffusion method with the extract concentration of 3 mg/well and vancomycin 30 µg/well as the positive control. It was found that the extract exhibits antibacterial effects in range of 10.5 – 14 mm of zone of inhibition (ZOI) against all tested bacteria except for K. pneumoniae. P. aeruginosa showing ZOI of 14 mm was the most sensitive bacterium while P. vulgaris (ZOI of 10.5 mm) was the least sensitive strain to the extract. Based on the preliminary phytochemical screening of using standard qualitative phytochemical tests, this species contains significant amount of alkaloids, flavonoids, terpenoids, and tannins, which might contribute to the antibacterial activity of the extract. Both antibacterial potential and presence of various phytochemicals in the extract could support the traditional uses of E. fusca , and the obtained results would serve as a basis for further exploration of antibacterial properties of the plant’s leaves.