ANTIBACTERIAL AND ANTI-BIOFILM ACTIVITY OF FLAVONOIDS AND TRITERPENES ISOLATED FROM THE EXTRACTS OF FICUS SANSIBARICA WARB. SUBSP. SANSIBARICA (MORACEAE) EXTRACTS

Background: Ficus species are used in African traditional medicine in the treatment of a wide variety of ailments and diseases such as convulsive disorder, wound healing, gonorrhea, tuberculosis, diabetes, diarrhoeal infections, dysentery, malaria and HIV. The aim of this study was to isolate the phytochemical constituents in the plant and test them for their antibacterial activity. Materials and methods: The fruits, leaves and stem bark were extracted with organic solvents and the compounds in the extracts separated and purified by column chromatography before being identified by NMR spectroscopy and by comparison of the NMR data against values reported in the literature. The antibacterial activity of the pure compounds and extracts were tested using the disk diffusion method. Results: Three triterpenes and three flavonoids: lupeol acetate (1); cycloart-23-ene-3,25-diol (2); β-sitosterol (3); 5,7,4'-trihydroxyflavan-3-ol (4); epicatechin (5); and isovitexin (6) were isolated in this study. Antimicrobial activity was observed at 8 mg mL-1 for Staphylococcus aureus ATCC 29213 with four of the six isolated compounds, with no activity being observed at 1 – 4 mg mL-1 against Escherichia coli ATCC 25922, E. coli ATCC 35218 and S. aureus ATCC 43300. Epicatechin (5) was found to decrease adhesion of E. coli ATCC 25922 and S. aureus ATCC 29213. Decreased adhesion of S. aureus ATCC 29213 was also observed with 5,7,4'-trihydroxyflavan-3-ol (4) and isovitexin (6). Conclusions: The results of this study provide baseline information on F. sansibarica’s potential validity in the treatment of infections associated with Gram-positive microorganisms

Comparative Evaluation of Antioxidant Activity and Phytochemical Profile of Four Capsicum Fruits Species

Capsicum fruits are commonly consumed vegetables included in foods worldwide as spices. Capsicum species are known to improve digestion and appetite, cure colds, coughs, fever, colic, dysentery, worms, and piles among others. This research is therefore aimed at evaluating the phytochemicalas well as the antioxidant activities of four different varieties of Capsicum commonly consumed in Africa. The fruits were extracted using 3 different solvents; n-hexane, ethyl acetate, and methanol. The phytochemical evaluation was carried out using standard methods. Antioxidant activities were evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The highest yield of extract was obtained with methanol from Capsicum annuum var. grossum (25.48%); The phytochemical screening of crude extracts revealed the presence of alkaloids, saponins, flavonoids, phenols, terpenoids, tannins, coumarins, and cardiac glycosides. The total phenolic contents of crude extracts of Capsicum species ranged from 25.10±0.3 to 62.01±0.1 mg GAE g-1 (Gallic acid equivalent) of dry weight and the flavonoid contents ranged from 206.08±0.03 to 474.23±0.04 mg QE g-1 (Quercetin equivalent) of dry weight. The capacity to neutralize DPPH radicals was found to be at the highest in methanolic extracts of Capsicum species which neutralized 50% of free radicals at the concentrations of 5.79 μg mL-1, 8.08 μg mL-1, 5.76 μg mL-1, and 8.81 μg mL-1for Capsicum annuum var. accuminatum, Capsicum frutescens var. baccatum, Capsicum annuumvar. grossum and Capsicum annuum var. abbreviatum respectively. The study has concluded that Capsicum species contain phytoconstituents with high antioxidant activities and great potential to combat oxidative stress and other related diseases