Phytochemical screening and investigation of in-vitro antioxidant and antibacterial activity of leea aequata leaf extract

Abstract

Leea aequata (L. aequata) is a traditional medicinal plant in Bangladesh belonging from leeaceae family. The roots, stems and tubers of this plant are used as astringent. It is used as antiseptic, anesthetics, bronchitis, fever, itching and in tuberculosis. The objective of this study was to determine the phytochemical constituents and investigate in-vitro antioxidant and antibacterial activity of methanolic extract of L. aequata leaves. The phytochemical screening of methanolic extract of L. aequata leaves showed the presence of alkaloids, flavonoids, phenolic compounds, glycosides, tannins, carbohydrates and phytosterols. The antioxidant study was performed by using DPPH free radical scavenging activity, total phenolic content, total flavonoid content and total antioxidant capacity. The DPPH free radical scavenging activity study had exhibited that with increasing of concentration of the plant extract ranging from 50 to 1200 μg/mL, the free radical scavenging activity increased from 84.87% to 89.92%. The highest free radical scavenging activity (89.92%) found at 1200 μg/mL and the lowest free radical scavenging activity (84.87%) found at 50 μg/mL. The total phenolic content study revealed that with the increase in concentration from 200 to 1200 μg/mL, the total phenolic content of plant sample increases from 41.08 to 132.4 mg/g of gallic acid. Moreover, the total flavonoid content increased from 4.86 to 13.09 mg/g of quercetin at 200–1200 μg/mL and the total antioxidant capacity was found to be 44 to 60.96mg/g of ascorbic acid. In addition, the antibacterial activity of L. aequata leaf extract was determined by disc diffusion method against four bacterial strains such as, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Vibrio cholerae. Kanamycin and ampicillin were used as standard antibacterial drugs. The study revealed that this plant did not show any antibacterial effects on any of the four bacterial strains whilst kanamycin and amoxicillin had effects against the bacterial strains. This study has founded the possibility of using L. aequata leaf extract as an antioxidant and also encourages performing different preclinical and clinical studies for assuring the potential antioxidant effect in other methods along with different bioactivity studies.