Evaluation of α-amylase Inhibition and Cytotoxic Activities of the Arachis hypogaea and Cinnamomum tamala

Abstract

Background: Diabetes mellitus is the most occurring non-communicable disease resulting in a high blood glucose level. There has been an immense interest in the development of alternative medicines for diabetes treatment, specifically screening functional foods for phytochemicals with the capability of delaying or preventing glucose absorption through digestive enzymes (e.g. α-amylase) inhibition. So, the development of α-amylase inhibitors derived from natural food products is an alternative way to prevent diabetes mellitus. Objective: In this study, organic solvent extracts of the Arachis hypogaea (Peanut) and Cinnamomum tamala (Indian bay leaf/Tejpata) were used to investigate their potential α-amylase inhibition and cytotoxic activities through α-amylase inhibition assay and brine shrimp lethality bioassay respectively. Methods: The α-amylase inhibition assay was performed using the 3,5-dinitrosalicylic acid method for different concentrations of plant extracts. The optical density (OD) of the solutions were measured to determine the inhibition activity at 540 nm using a spectrophotometer. The cytotoxicity of the plant extracts was measured using brine shrimp (Artemia salina) lethality bioassay. Results: Among the different organic solvent extracts, peanut seed ethanol extract showed the highest α-amylase inhibition activity (67.68±8.67%) at 1.25 μg/mL concentration with an IC50 value of 0.61 μg/mL which is very close to standard α-amylase inhibitor Acarbose (72.34±4.23%) with an IC50 value of 0.32 μg/mL while acetone extract of Indian bay leaf exhibited the lowest inhibition activity (47.75±1.63%) with an IC50 value of 1.42 μg/mL at the same concentration. Besides, the maximum cytotoxic activity was found in acetone extract of peanut shell with an LC50 value of 57.87 μg/mL, whereas ethanol extract of peanut seed showed the lowest cytotoxicity with an LC50 value of 413.90 μg/mL. Conclusion: The result of the present work clearly indicates the potentiality of peanut seed ethanol extract to be used in the management of hyperglycemia as it significantly inhibits α-amylase activity while showing less cytotoxic activities.