Antioxidant fractions of Khaya grandifoliola C.DC. and Entada africana Guill. et Perr. induce nuclear translocation of Nrf2 in HC-04 cells.
The in vitro antioxidant properties, cytoprotective activity, and ability to induce nuclear translocation of nuclear factor E2-related factor-2 (Nrf-2) of five solvent fractions of the methylene chloride/methanol (1:1 v/v) extract of Khaya grandifoliola (Meliaceae) and Entada africana (Fabaceae) were evaluated. Five antioxidant endpoints were used in the antioxidant activity investigation. The total phenolic content of the fractions was assessed as to the Folin-Ciocalteu method and the profile of interesting fractions analyzed by high-performance liquid chromatography (HPLC). The cytoprotective activity of fractions was determined by H2O2-induced oxidative stress in HC-04 cells by measuring lactate dehydrogenase (LDH) leakage into culture medium. HC-04 cells were used to investigate the ability to induce nuclear translocation of Nrf2. For both plants, the methylene chloride/methanol (90/10; v/v) fraction (F10), methylene chloride/methanol (75/25; v/v) (F25), and the methanolic fraction (F100) were found to have the highest total polyphenol content and exhibited high antioxidant activity strongly correlated with total polyphenol content. The cytoprotective activity of fraction F25 from both plants was comparable to that of quercetin (3.40 ± 0.05 μg/mL), inhibiting LDH leakage with a low half inhibition concentration (IC50) of 4.05 ± 0.03 and 3.8 ± 0.02 μg/mL for K. grandifoliola and E. africana, respectively. Lastly, fraction F25 of K. grandifoliola significantly (P < 0.05) induced nuclear Nrf2 translocation by sixfold, whereas that from E. africana and quercetin was only twofold. The results indicate for the first time that fraction F25 of the studied plants is more antioxidant and cytoprotective and induces nuclear translocation of Nrf2 in a human hepatocyte cell line.
Laboratory of Pharmacology and Toxicology, Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaounde, Cameroon.|Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut, 06269, USA.
Frédéric Nico
FN
Njayou
Laboratory of Pharmacology and Toxicology, Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaounde, Cameroon.
Atsama Marie
AM
Amougou
Laboratory of Pharmacology and Toxicology, Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaounde, Cameroon.
Romeo
R
Fouemene Tsayem
Laboratory of Pharmacology and Toxicology, Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaounde, Cameroon.
Jacqueline
J
Njikam Manjia
Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut, 06269, USA.
Swetha
S
Rudraiah
Department of Food Science, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Bolling
B
Bradley
Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut, 06269, USA.
José Enrique
JE
Manautou
Laboratory of Pharmacology and Toxicology, Department of Biochemistry, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Yaounde, Cameroon. pmoundipa@hotmail.com.
Paul
P
Fewou Moundipa
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D007887:Fabaceae / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D029582:Meliaceae / Q000737:chemistry*; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D059808:Polyphenols / Q000378:metabolism; D051381:Rats
D000975:Antioxidants; D051267:NF-E2-Related Factor 2; D010936:Plant Extracts; D059808:Polyphenols; D006861:Hydrogen Peroxide
Antioxidant; E. africana; Fraction F25; K. grandifoliola; Nrf2