Anti-Hyperglycemic and Antioxidant Potentials of Some Bioactive Compounds Identified From The Methanolic Kernel Extract of Anacadium ocidentale in vitro and in silico Investigations

Abstract

The phytochemical components of roasted kernel of cashew nut (Anacadium ocidentale), its antioxidant and anti-hyperglycemic potentials were investigated via in vitro and in silico.  The roasted kernel of cashew nut was extracted in 95 % methanol.  Using boron trifloride (10 % in 1-butanol), the extract was derivatized and the derivatized sample was analyzed using a Gas Chromatographic–Mass Spectrometry (GC-MS) method to establish its chemical constituents. Antioxidant potential was evaluated through 2, 2-diphenyl-1-picrylhydrazyl (DPPH^•) and 2,2′-azino-bis-(3-ethyl benzothiazoline-6-sulphonic acid)  (ABTS^•+)  radical scavenging assays. The anti-hyperglycemic potential of the crude methanol extract was investigated through α-glucosidase assay. The results of phytochemical screening revealed the presence of phytochemicals such as phenols, glycosides, alkaloids, steroids, carbohydrate, flavonoids and terpenoids. Total numbers of 20 phytochemicals belonging to different classes of natural products were identified by GC-MS analysis.  Carbonic acid, dodecyl vinyl ester (45.9 %) was found to be the major compound. Other compounds like N- serylserine, D- fructose, 3-0-methyl, β- Amyrone, β- Amyrin, Lupeol and 9- octadecenoic acid were also identified. The methanol extract of roasted cashew kernel showed highest DPPH scavenging activity (IC₅₀ 10 ± 0.001 µg/mL) which is statistically similar to positive controls, vitamin C and rutin (IC₅₀ = 4 ± 0.001 and 1 ± 0.0001 µg/mL) and also exhibited moderate ABTS scavenging activity (IC₅₀ = 14 ± 0.001 µg/mL) which is statistically significant as compared to positive controls, vitamin C (IC₅₀ = 13 ± 0.01 µg/mL) and rutin (IC₅₀ = 16 ± 0.001 µg/mL) respectively.  The result of enzyme inhibition assay showed that the extract possesses highest anti-hyperglycemic potential against α-glucosidase with IC₅₀ value (0.00024 ± 0.00002 µg/mL) compared to standard drug acarbose (IC₅₀ = 0.417 ±0.021 µg/mL). The in silico techniques comprising the molecular docking, bioactivity and toxicity studies provides insight into the inhibitory properties, structure-activity-relationship predictions and drug-likeliness activities of the identified compounds. The research reveals the bioactive components present in the roasted kernel of cashew nut that can be utilized for its antioxidant and anti-hyperglycemic properties.  Hence consumption of roasted cashew kernel could be beneficial for the treatment of diabetes mellitus and prevention of oxidative stress-related degenerative disorders