Phenolic Content, Antioxidant and 15-Lypoxygenase Inhibitory Effects of Daniellia oliveri (rolfe) Hutch. & Dalziel (Fabaceae)

Abstract
Aims: The aim of this study is to evaluate the content of phenolic compounds, antioxidant and 15-lipoxygenase inhibition effects of methanolic extract and its fractions of Daniellia. oliveri stem bark. Place and Duration of Study: The work was carried out in the Department of Traditional Pharmacopoeia and Pharmacy (MEPHATRA / PH) of the Institute for Research in Health Sciences (IRSS) and LABIOCA from Université Joseph KI-ZERBO in Ouagadougou between February 2018 and June 2019 Methodology: The phytochemical screening and phenolic content were determined by the methods described in the literature. Antioxidant activity was determined by DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,20-azinobis 3-ethylbenzoline-6-sulphonate), FRAP (ferric reducing antioxidant power), and lipid peroxidation (LPO). The anti-inflammatory activities were measured on the ability of the extract to inhibit the activity of enzymes such as 15-lipoxygenase Results: Phytochemical screening revealed the presence of flavonoids, tannins, saponins, anthocyanosides, triterpenes and sterols. The extract and its fractions showed a good content of phenolic compounds with values ranging from 773.97 ± 22.91 to 505.51 mg EAG / g for total polyphenols; from 24.38 ± 0.34 to 12.04 ± 0.08 mg EQ / g in total flavonoids, 311.65 ± 6.70 to 221 ± 0.52 mg EC / g in condensed tannins; 681.81 ± 3.97 to 421.29 ± 8.73 mg EUA / g in total triterpenes and from 280.29 ± 21.72 to 222.04 ± 20.99 mg EC / g for total sterols. The methanol fraction showed the best antioxidant activity as well as the best inhibitory effect on 15-lipoxygenase activity. Conclusion: These results showed that Daniellia. oliveri possessed an antioxidant power, an inhibitory effect of 15 lipoxygenase. Daniellia oliveri could be used in the management of inflammatory pathologies and oxidative stress.