LC-MS Analysis, Total Polyphenol Content and Antioxidant Activity of Ethanolic Fractions of Skin (Epicarp) and Seed Pulp (Mesocarp) of Green and Red Wild Africa Berries.

Abstract Background These green and red wild African berries (Lannea microcarpa) are not cultivated like other known crops but grow in the wild, mostly in the northern part of Nigeria. Although its culinary uses are quite popular during the early part of the rainy season, its chemistry remains vague, hence the present study. Aim The study aims at assessing the antioxidant activity of these berries and further identifying the phytocompounds to determine their biofunctional abilities. Methods and Materials The fresh fruits of green and red wild berries were collected and identified. The antioxidant activity of the berry types was assessed employing three assays (2-diphenyl-1-picrylhydrazil (DPPH) free radical scavenging assay, 2, 2 - azino-bis-(3-ethyl) benzothiazoline-6-sulfonic acid (ABTS) radical cation scavenging activity, hydrogen peroxide (H2O2) reducing power) of the skin and pulp of green and red wild African berries (FUS = Green Berries Skin, FRS = Red Berries Skin, FSP = Red Berries Seed Pulp, UFSP = Green Berries Seed Pulp). The total polyphenol content (TPC), total flavonoid content (TFC), and total anthocyanins (TAC) were also investigated. These ethanolic fractions of the extracts were evaluated employing Liquid Chromatography-Mass Spectrometry (LC-MS). Results Total anthocyanin content is interestingly higher in FRS and FSP (deep red berries) than in FUS and UFSP (green berries). In the DPPH assay, the antioxidant activity of the various parts of the two berry types followed the following trend: UFSP ˃ FUS ˃ FRS ˃ FSP and a similar trend was noticed in the ABTS assay. Interestingly, the H2O2 assay followed the following trend: FUS ˃ UFSP ˃ FRS ˃ FSP. About 21 compounds belonging to different phenolic families, namely anthocyanidins, flavones, flavonols, flavan-3-ols, flavanones, hydroxycinnamic acids, hydroxybenzoic acids, and hydroxycoumarins, were identified. Cyanidin-3-O-glucoside is reportedly present in all the parts investigated. Conclusion This study provided insight into the phytochemical profiles and pharmacological importance of L. microcarpa beyond its basic nutritional values. This fruit can be useful as a functional food.