Distribution of Metabolites and Antioxidant Activity in the Berry and Shoot of Solanum pseudocapsicum Grown in Nigeria

Abstract

Aim: To evaluate the distribution of metabolites and in vitro antioxidant activity in the berry and shoot of Solanum pseudocapsicum (S. pseudocapsicum). Study Design: Berry and shoot samples of S. pseudocapsicum were randomly collected from different plants of the species in the same natural habitat, and were subsequently processed and used for the spectrophometric quantification of their metabolites and in vitro antioxidant activity. Methodology: The samples were oven-dried to a constant weight, and were later milled separately into a fine particle size powder. The milled samples were extracted with methanol, and the extracts were analyzed for their metabolites content and In vitro antioxidant activity using appropriate methods. Results: The berry had significantly (P < 0.05) higher total protein, total lipid and amylose levels than the shoot. Conversely, the shoot had significantly (P < 0.05) higher starch, total soluble sugar, amylopectin, and vitamin C contents than the berry. Secondary metabolites (total phenol, tannin, total flavonoid, total saponin and total alkaloid) were consistently more predominant in the berry than in the shoot, except total carotenoid. Methanol extracts of both the berry and the shoot displayed antioxidant activity in vitro, with the berry having significantly (P < 0.05) higher ABTS radical scavenging ability and ferric reducing antioxidant power (FRAP) than the shoot. Both extracts also scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical in a dose-dependent manner; with the IC50 of the shoot (1.88 mg/mL) being lower than that of the berry (2.33 mg/mL). Conclusion: The distribution of metabolites and antioxidant activity in the berry and the shoot of S. pseudocapsicum provide support for their medicinal uses. However, the preponderance of secondary metabolites and antioxidant activity in the berry than in the shoot might confer it with more potential to ameliorate oxidative stress in disease conditions, than the shoot.