Abstract
The present study evaluates the in vitro antioxidant activity of the leaves and stem-barks extracts and fractions of Ochna schweinfurthiana. To this effect, the different extracts were obtained by maceration in four solvents namely ethyl acetate, methanol, acetone and water- ethanol mixture (20-80). The methanol extract which exhibited the best antioxidant activity was partitioned in hexane and ethyl acetate. The ethyl acetate fraction was fractionated by column chromatography with the aid of methyl dichloride/methanol (a€–CHa€—_2 a€–Cla€—_2/ MeOH) solvent system at different polarities. The antioxidant activity of the extracts and fractions was assessed by the 2,2-diphenyl-1-picrilhidrazil (DPPH), ferric reducing antioxidant power assay (FRAP) and the total polyphenol content was evaluated using the Folin-Ciocalteu reagent. The results were analyzed using SPSS 20 presented as mean ± standard deviation. The results phytochemical screening confirmed the abundance of flavonoids and catechic tannins in the methanol and water-ethanol extracts whose content vary between 37.83 ± 1.6 mg ascorbic acid equivalent (EAA)/g dry weight (dw) and 96.4 ±2.33 mg EAA/g dw. The leaves methanol extract possess the best antiradical power (AP) of 0.00114 ± 0.00001 g/mg and the best ferric reducing antioxidant power (542.33±16.51 mg EAA/g dw). The F3 fraction obtained usinga€– CHa€—_2 a€–Cla€—_2/MeOH 5/1 elution system possess the best AP of 0.00125 ± 0.00001 g/mg identical to that of ascorbic acid (AP = 0.00125 ± 0.00002 g/mg) and the strongest ferric reducing antioxidant power (508.66 ± 18 mg EAA/g dw). A positive correlation between the two antioxidant tests and the polyphenols content was obtained. Thus, Ochna schweinfurthiana could be used by the population to prevent some diseases caused by oxidative stress, due to its high antioxidant effect. Key words: Ochna schweinfurthiana, extracts, fractions, antioxidant activity.
Highlights
The aims of this study were to search for new natural antioxidant molecules by evaluating the antioxidant properties of the extracts and fractions of O. schweinfurthiana
The results indicated the abundance of flavonoids, saponins and catechic tannins in the methanolic extracts; the presence of alkaloids and triterpenes in other extracts
The methanol extract of the leaves shows the greatest scavenging activity, followed by the hydroethanol extract of the leaves; the fraction F3 shows a high scavenging activity followed by the F4 fraction
Summary
Oxidative stress is defined as the disequilibrium between the biochemical processes of free radical (FR) production and those of antioxidant defenses in favour of free radical production (Sayre et al, 2008) These free radicals could react with a series of biological substrates such as DNA, proteins, lipids and carbohydrates. In the North of Nigeria, O. schweinfurthiana is used to treat measles, typhoid fever and skin fungal infections Literature review on this plant revealed that the antimicrobial effect of the methanol and acetone extracts of the leaves of this plant on some selected pathogens has been carried out (Abdullahi et al, 2010). The aims of this study were to search for new natural antioxidant molecules by evaluating the antioxidant properties of the extracts and fractions of O. schweinfurthiana
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
