Hibiscus sabdariffa L. polyphenolic-rich extract promotes muscle glucose uptake and inhibits intestinal glucose absorption with concomitant amelioration of Fe2+ -induced hepatic oxidative injury.

Abstract

In this current study, the antidiabetic effectiveness of Hibiscus sabdariffa and its protective function against Fe2+ -induced oxidative hepatic injury were elucidated using in vitro, in silico, and ex vivo studies. The oxidative damage was induced in hepatic tissue by incubation with 0.1 mMolar ferrous sulfate (FeSO4) and then treated with different concentrations of crude extracts (ethyl acetate, ethanol, and aqueous) of H. sabdariffa flowers for 30 min at 37°C. When compared to ethyl acetate and aqueous extracts, the ethanolic extract displayed the most potent scavenging activity in ferric-reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and nitric oxide (NO) assays, with IC50 values of 2.8μl/ml, 3.3μl/ml, and 9.2μl/ml, respectively. The extracts significantly suppressed α-glucosidase and α-amylase activities (p < .05), with the ethanolic extract demonstrating the highest activity. H. sabdariffa significantly (p < .05) raised reduced glutathione (GSH) levels while simultaneously decreasing malondihaldehyde (MDA) and NO levels and increasing superoxide dismutase (SOD) and catalase activity in Fe2+ induced oxidative hepatic injury. The extract of the plant inhibited intestinal glucose absorption and increased muscular glucose uptake. The extract revealed the presence of several phenolic compounds when submitted to gas chromatography-mass Spectroscopy (GC-MS) screening, which was docked with α-glucosidase and α- amylase. The molecular docking displayed the compound 4-(3,5-Di-tert-butyl-4-hydroxyphenyl)butyl acrylate strongly interacted with α-glucosidase and α-amylase and had the lowest free binding energy compared to other compounds and acarbose. These results suggest that H. sabdariffa has promising antioxidant and antidiabetic activity. PRACTICAL APPLICATIONS: In recent years, there has been increased concern about the side effects of synthetic anti-diabetic drugs, as well as their expensive cost, especially in impoverished nations. This has instigated a radical shift towards the use of traditional plants, which are rich in phytochemicals many years ago. Among these plants, H. sabdariffa has been used to treat diabetes in traditional medicine. In this present study, H. sabdariffa extracts demonstrated the ability to inhibit carbohydrate digesting enzymes, facilitate muscle glucose uptake and attenuate oxidative stress in oxidative hepatic injury. Hence, demonstrating H. sabdariffa's potential to protect against oxidative damage and the complications associated with diabetes. Consumption of Hibiscus tea or juice may be a potential source for developing an anti-diabetic drug.