Oxidative Stress Modulation by Cameroonian Spice Extracts in HepG2 Cells: Involvement of Nrf2 and Improvement of Glucose Uptake
Achille Parfait Atchan Nwakiban,
Stefania Cicolari,
Stefano Piazza,
Fabrizio Gelmini,
Enrico Sangiovanni,
Giulia Martinelli,
Lorenzo Bossi,
Eugénie Carpentier-Maguire,
Armelle Deutou Tchamgoue,
Gabriel A. Agbor,
Jules-Roger Kuiaté,
Giangiacomo Beretta,
Mario Dell’Agli,
Paolo Magni
Affiliations
Achille Parfait Atchan Nwakiban
Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 96 Dschang, Cameroon
Stefania Cicolari
Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133 Milano, Italy
Stefano Piazza
Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133 Milano, Italy
Fabrizio Gelmini
Department of Environmental Science and Policy, Università degli Studi di Milano, via G. Celoria 2, 20133 Milano, Italy
Enrico Sangiovanni
Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133 Milano, Italy
Giulia Martinelli
Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133 Milano, Italy
Lorenzo Bossi
Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133 Milano, Italy
Eugénie Carpentier-Maguire
Department of Science and Technology, University of Lille, Rue de Lille, 59160 Lille, France
Armelle Deutou Tchamgoue
Centre for Research on Medicinal Plants and Traditional Medicine, Institute of Medical Research and Medicinal Plants Studies (IMPM), Yaoundé 4124, Cameroon
Gabriel A. Agbor
Centre for Research on Medicinal Plants and Traditional Medicine, Institute of Medical Research and Medicinal Plants Studies (IMPM), Yaoundé 4124, Cameroon
Jules-Roger Kuiaté
Department of Biochemistry, Faculty of Science, University of Dschang, P.O. Box 96 Dschang, Cameroon
Giangiacomo Beretta
Department of Environmental Science and Policy, Università degli Studi di Milano, via G. Celoria 2, 20133 Milano, Italy
Mario Dell’Agli
Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133 Milano, Italy
Paolo Magni
Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Via G. Balzaretti 9, 20133 Milano, Italy
Oxidative stress plays a relevant role in the progression of chronic conditions, including cardiometabolic diseases. Several Cameroonian plants, including spices, are traditionally used as herbal medicines for the treatment of diseases where oxidative stress contributes to insulin resistance, like type 2 diabetes mellitus. This study evaluated the antioxidant capacity and the effects on oxidative-stress-induced impairment of glucose uptake of 11 Cameroonian spice extracts. H2O2-induced reactive oxygen species (ROS) production by human HepG2 cells was significantly reduced by 8/11 extracts. The most effective extracts, Xylopia parviflora, Echinops giganteus, and Dichrostachys glomerata, showed a concentration-dependent ROS-scavenging activity, which involved Nrf2 translocation into the nucleus. Xylopia parviflora, Tetrapleura tetraptera, Dichrostachys glomerata, Aframomum melegueta, and Aframomum citratum extracts showed the highest antioxidant capacity, according to oxygen radical absorbance capacity (ORAC) (2.52–88 μM Trolox Eq/g of extract), ferric-reducing antioxidant power (FRAP) (40.23–233.84 mg gallic acid Eq/g of extract), and total phenol (8.96–32.96% mg gallic acid Eq/g of extract) assays. In HepG2 cells, glucose uptake was stimulated by 4/11 extracts, similarly to insulin and metformin. H2O2-induced oxidative stress reduced glucose uptake, which was rescued by pretreatment with Xylopia aethiopica, Xylopia parviflora, Scorodophloeus zenkeri, Monodora myristica, and Dichrostachys glomerata extracts. The ROS-scavenging ability of the spice extracts may reside in some secondary metabolites observed by phytochemical profiling (reverse-phase high-performance liquid chromatography coupled to a diode array detector (HPLC-UV-DAD)). Further studies are needed to better clarify their biological activities and potential use to control oxidative stress and promote insulin sensitivity.
