ANTIOXIDANT POTENTIAL OF FRACTIONS FROM THE STEM METHANOL EXTRACT OF UVARIA COMPEREI (ANNONACEAE)Abstract
Oxidative stress is incriminated in many human diseases such as cancer, diabetes, ischemia, rheumatoid arthritis, neurodegenerative diseases, etc. The extracts from plants could be used to discovering the new antioxidant product. In the aim to evaluate the antioxidant activity of fractions of Uvaria comperei stem extract, the fractions of the stem extract obtained by vacuum chromatography from Uvaria comperei were screened for their in vitro antioxidant properties. Total phenolic content, total flavonoid content, and phytochemical screening were also determined. The antioxidant activity was evaluated using DPPH and ORAC assays, whereas total phenolic and total flavonoid contents were determined using folin-ciocalteu method and aluminum chloride assay, respectively. The phytochemical constituents were assessed using standard methods. In the DPPH scavenging activity assay, the EC50 values of 6.03 µg/Ml to > 2000 µg/mL were obtained from the fractions. The fraction F16 showed the strongest scavenging activity with EC50 of 6.03 µg/mL near to the EC50 value of catechin (3.57 µg/mL). All the fractions presented the antioxidant activity with ORAC assay; however, the fraction F16 showed the greatest value of 6157 ± 316.4 µmoltrol/mL l. The results revealed that the total phenolic content (TPC) and total flavonoid content (TFC) varied among the different fractions obtained in various solvent systems. The fraction F16 had the highest quantity of phenolic compounds, whereas the less polar fractions possessed more flavonoids. The major groups of compounds identified using phytochemical screening were glycosides, alkaloids, and phenols. The results suggested that some fractions U. comperei could be used as natural antioxidants.
M. Simo *, M. Donati, G. Siwe, S. Majoumouo, Z. Chen, R. Toghueo, R. Keumoe, P. Jazet, M. Sameza and F. Fekam
Department of Biochemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon.
10 February 2020
24 March 2020
26 March 2020
31 March 2020