The Protective Effect of Polyphenol - Rich Extract of Syzygium cumini Leaves on Cholinesterase and Brain Antioxidant Status in Alloxan - Induced Diabetic Rats

Syzygium cumini leaves are used locally especially in Nigeria for the treatment \ management of diabetes mellitus and Alzheimer’s disease. This study was designed to investigate the effects of polyphenols extracted from Syzygium cumini l eaves on the occurrence of oxidative stress in the brain of rats with diabetes, which can trigger Alzheimer’s disease by determining both in vitro and in vivo c holinesterase, the antioxidant defense system, and the extent of oxidative damage. The effect of polyphenols extracted from Syzygium cumini leaves was investigated on in vitro c holinesterase. Thereafter, the extract (400 mg/kg body weight) of both free and bound polyphenols was administered orally to alloxan - induced rats, and the effect were monitore d on in vivo c holinesterase, superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, lipid peroxidation and hydroperoxides. The extract demonstrated inhibitory effects against in vitro c holinesterase. A significant reduction in the c ho linesterase activities increased the activities of superoxide dismutase, catalase, glutathione peroxidase, and reduced glutathione. A reduction in lipid peroxidation and hydroperoxide concentrations was observed in the brain of diabetic rats treated with p olyphenols extracted from Syzygium cumini leaves. This study suggests that the polyphenols of Syzygium cumini leaves have anti - Alzheimer and antioxidant boosters, as well as antiperoxidative activities. Therefore, the plant is recommended for both diabetic and Alzheimer’s disease patients worldwid

In vitro antioxidant activities and inhibitory effects of phenolic extract of Senecio biafrae (Oliv and Hiern) against key enzymes linked with type II diabetes mellitus and Alzheimer's disease

The phenolic extract of Senecio biafrae leaves was investigated to determine the in vitro antioxidant, phenolic profiles, and inhibition of key enzymes relevant to type II diabetes mellitus (α‐amylase and α‐glucosidase) and Alzheimer's disease (acetylcholinesterase and butrylcholinesterase). The phenolic extract demonstrated significant scavenging abilities against all in vitro antioxidant parameters assessed. Reversed‐phase HPLC of the extract revealed the presence of gallic acid, chlorogenic, caffeic acid, rutin, quercetin, and kaempferol. The extract also inhibited activities of α‐amylase (IC 50 = 126.90 μg/ml), α‐glucosidase (IC 50 = 139.66 μg/ml), acetylcholinesterase (IC 50 = 347.22 μg/ml), and butrylcholinesterase (IC 50 = 378.79 μg/ml), which may be attributed to the antioxidant potential of the extract and its phenolic composition. Therefore, this study suggests that the leaves of S. biafrae may be useful in the management of diabetes mellitus and Alzheimer's disease