Antiamylase, Anticholinesterases, Antiglycation, and Glycation Reversing Potential of Bark and Leaf of Ceylon Cinnamon (Cinnamomum zeylanicum Blume) In Vitro

Ethanol (95%) and dichloromethane : methanol (DCM : M, 1 : 1 v/v) bark extracts (BEs) and leaf extracts (LEs) of authenticated Ceylon cinnamon (CC) were studied for antiamylase, antiglucosidase, anticholinesterases, and antiglycation and glycation reversing potential in bovine serum albumin- (BSA-) glucose and BSA-methylglyoxal models in vitro. Further, total proanthocyanidins (TP) were quantified. Results showed significant differences (p < 0.05) between bark and leaf extracts for the studied biological activities (except antiglucosidase) and TP. BEs showed significantly high (p < 0.05) activities for antiamylase (IC50: 214 ± 2-215 ± 10 μg/mL), antibutyrylcholinesterase (IC50: 26.62 ± 1.66-36.09 ± 0.83 μg/mL), and glycation reversing in BSA-glucose model (EC50: 94.33 ± 1.81-107.16 ± 3.95 μg/mL) compared to LEs. In contrast, glycation reversing in BSA-methylglyoxal (EC50: ethanol: 122.15 ± 6.01 μg/mL) and antiglycation in both BSA-glucose (IC50: ethanol: 15.22 ± 0.47 μg/mL) and BSA-methylglyoxal models (IC50: DCM : M: 278.29 ± 8.55 μg/mL) were significantly high (p < 0.05) in leaf. Compared to the reference drugs used some of the biological activities were significantly (p < 0.05) high (BEs: BChE inhibition and ethanol leaf: BSA-glucose mediated antiglycation), some were comparable (BEs: BSA-glucose mediated antiglycation), and some were moderate (BEs and LEs: antiamylase, AChE inhibition, and BSA-MGO mediated antiglycation; DCM : M leaf: BSA-glucose mediated antiglycation). TP were significantly high (p < 0.05) in BEs compared to LEs (BEs and LEs: 1097.90 ± 73.01-1381.53 ± 45.93 and 309.52 ± 2.81-434.24 ± 14.12 mg cyanidin equivalents/g extract, resp.). In conclusion, both bark and leaf of CC possess antidiabetic properties and thus may be useful in managing diabetes and its complications.