02632nas a2200241 4500008004100000245016400041210006900205260001500274300001200289490000700301520184400308653001602152653000902168653002802177653001802205653001202223100003102235700002102266700001602287700002302303700002402326856004002350 2020 eng d00aCondensed Tannins Content and their Influence on the Antioxidant Activity of Bark Hydroethanol Extract of Piliostigma reticulatum (Dc) Hochst and its Fractions0 aCondensed Tannins Content and their Influence on the Antioxidant cMarch 2020 a361-3680 v123 a

Background: Consumption of natural products from plants is implicated in the reduction of the occurrence of diseases related to oxidative stress. Piliostigma reticulatum is a plant well known to traditional practitioners in Senegal where leaves and bark are often used against many diseases, such as ulcers, boils, syphilitic cancer, toothache, gingivitis and diarrhea. Aim: This study compared hydroethanol extract from the plant bark and its fractions by assessing their total phenol contents, antioxidant activity and the influence of condensed tannins on their activity. Method: barks were extracted by a moderate decoction with ethanol-water followed by a silica column fractionation with successively ethyl acetate, methanol and water. For this study, assays were carried out before and after precipitation of tannins by BSA and PVPP tests. Total phenol and condensed tannins of hydroethanolic extract and its fractions were performed by Folin Ciocalteu and hydrolysis methods. Antioxidant activity was evaluated by DPPH and CUPRAC tests. Results: Tannins precipitation leads a light decrease of total phenol and condensed tannins contents of samples. Total phenol content of hydroethanolic extract was 51.2 mg GAE/g vs 3.2 after BSA test and 1.7 after PVPP test whereas condensed tannins content obtained 72.2% vs 4.2% and 2.3% after precipitation. Antiradical activity was lost following the elimination of tannins with IC50: 5.33 ± 0.04 mg/l vs 78.86 ± 0.92 after BSA and > 500 after PVPP. Conclusion: This results showed the condensed tannins would be in charge of antiradical and reducing activities of plant barks and PVPP precipitated much better the tannins from those extracts than BSA.

10aAntioxidant10aBark10aPiliostigma reticulatum10aPrecipitation10aTannins1 aDIENG, Serigne, Ibra Mback1 aMathieu, Céline1 aSARR, Abdou1 aDiatta-Badji, Kady1 aFALL, Alioune, Dior uhttps://www.phcogj.com/article/1107