Phytochemical Characterization and In vitro Evaluation of the Antioxidant, Anti-inflammatory, and Antidiabetic Activities of Pennisetum glaucum (Pearl Millet) Ethanolic Seed Extract
Abstract
Background: Pennisetum glaucum is a rich source of nutrients that is valued due to the presence of various phytochemicals with health promoting effects. Nevertheless, a complete study involving phytochemical characterization together with several in vitro biological activities remains scarce. Objective: In this study, we conducted a characterization of phytochemical constituents in the ethanolic seed extract of Pennisetum glaucum as well as its antioxidant, anti-inflammatory and antidiabetic enzyme inhibitory activities. Methods: Ethanolic seed extract was extracted via Soxhlet extraction method. Phytochemical analysis of the plant extract was carried out by Fourier Transform Infrared (FTIR) spectroscopy and Gas Chromatography Mass Spectrometry (GC-MS). Anti-inflammatory activity was studied in terms of bovine serum albumin denaturation assay, egg albumin denaturation and human red blood cells membrane stabilization assay. Antioxidant activity was studied using DPPH, hydrogen peroxide, FRAP, ABTS and nitric oxide scavenging assays. Antidiabetic activity was measured in terms of α-amylase and α-glucosidase inhibitions. One-way ANOVA was used for data analysis and differences were considered to be statistically significant at P < 0.05. Results: Along with several bioactive phytoconstituents discovered by GC-MS analysis, the FTIR study identified particular functional groups including hydroxyl, carbonyl, aromatic, and aliphatic that are connected to phenolic and flavonoid compounds. 16.2 μg/mL (BSA), 10.0 μg/mL (egg albumin), 7.5 μg/mL (membrane stabilization), 5.5 μg/mL (DPPH), 10.8 μg/mL (H2O₂), 5.8 μg/mL (ABTS), 6.2 μg/mL (nitric oxide), 11.7 μg/mL (α-amylase) inhibitory activity. Conclusion: The results indicated that the ethanolic extract of P. glaucum seeds possesses concentration-dependent antioxidant, anti-inflammatory, and antidiabetic enzyme inhibitory activity in vitro experiments. These results may serve as the basis for further quantitative phytochemical and in vivo studies.