Graphical abstract

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.

Neurodegenerative diseases are ailments that disturb the brain, precisely the neurons. The utmost mutual indicators include failures in stability, inhalation, movement, reflexes, motor skills or heartbeat activity. These can be prevented using ordinary antioxidants, like vitamins E and C, flavonoids, and polyphenols compounds. Antioxidants show a substantial effect in human's health since they can ameliorate aging by fighting free radicals. Precisely Vitamin C can serve as a commanding antioxidant in reducing the consequence of oxidative injury triggered by pollutants, anxiety and poor diets amongst others. Thereby reducing the long-term risk of neurodegenerative diseases. Currently, neurodegenerative diseases have no cure, but they can be managed. This diseases management reduces the symptoms so as to sustain the value of life. Management with natural antioxidants such as polyphenols through diet or dietary supplements with lots of benefits have become an attractive alternative. The present knowledge on antioxidant in the treatment of neurodegenerative disorders and future bearings will be discussed and also assess the value for antioxidants as neuroprotective.

In this study, anti-hyperglycemic and anti-inflammatory activities of polyphenolic-rich extract of Syzygium cumini leaves in alloxan-induced diabetic rats were determined. Diabetes was induced by a single intraperitoneal injection of alloxan (150 mg/kg body weight) in female Wistar rats. The rats were orally administered with 400 mg/kg free phenol, 400 mg/kg bound phenol, and 5 mg/kg metformin, respectively. On the 14th day of oral administration, the animals were sacrificed, anti-hyperglycemic and anti-inflammatory were assessed. Fasting blood glucose and glycated hemoglobin levels; homeostasis model assessment–insulin resistance scores, lipid peroxidation concentration, glucose-6-phosphatase activity, and all concentrations of anti-inflammatory studied in alloxan-induced diabetic rats were significantly (P < .05) reduced with the administration of polyphenolic-rich extract of Syzygium cumini leaves. Also there was significant (P < .05) increase in glycogen and insulin concentrations, pancreatic β-cell scores, antioxidant enzymes and hexokinase activities, as well as glucose transporter levels in diabetic animals administered with polyphenolic-rich extract of S cumini leaves. The results indicate that S cumini leaves possess anti-hyperglycemic and anti-inflammatory activities.

View related articles View Crossmark data Citing articles: 6 View citing articles Ethyl acetate leaf fraction of Cnidoscolus aconitifolius (Mill.) I. M. Johnst: antioxidant potential, inhibitory activities of key enzymes on carbohydrate metabolism, cholinergic, monoaminergic, purinergic, and chemical fingerprinting

This study evaluated the inhibitory effect of ethyl acetate fraction of Solanum macrocarpon L. leaves on cholinergic, monoaminergic, purinergic enzyme activities and identification of bioactive compounds. 2,2‐azino‐bis‐3‐ethylbenthiazoline‐6‐sulphonic acid (ABTS), metal ion chelating radicals scavenging activity, total phenolic and flavonoid contents were determined using standard methods. The inhibitory effects of the ethyl acetate fraction of S. macrocarpon on the specified enzymes were determined spectroscopically. Ethyl acetate fraction of S. macrocarpon showed a high ABTS radical scavenging activity and metal ion chelating radical scavenging activity. The fraction showed high contents of phenol and flavonoid. The fraction also inhibited AChE, BChE, MOA, tyrosinase, arginase, ecto‐5′ ‐nucleotidase, PDE‐5, ACE and stimulated the activity of Na+/K+‐ATPase. Bioactive compounds present in ethyl acetate fraction of S. macrocarpon leaves include kaempferol‐3‐rutinoside, rutin among others. Ethyl acetate fraction of S. macrocarpon leaves inhibited cholinergic, monoaminergic, and purinergic enzymes and had a stimulatory effect on Na+/K+‐ATPase. Practical applications Solanum macrocarpon L. leaves are commonly consumed as vegetable. The enormous medicinal potential of the ethyl acetate fraction is invaluable as it’s a probable source of polyphenols characterized with strong antioxidant activity. In addition, the leaves are used as functional foods and may play a crucial role in the management/treatment of diabetes mellitus, neurodegenerative diseases, and erectile dysfunction.

Hence, possible mechanism through which the stem bark executes their anti-Alzheimer's disease activity might be by inhibiting cholinesterase activities in addition to suppressing oxidative-stress-induced neurodegeneration.

BackgroundThis study evaluates the antioxidant activity and enzyme inhibitory properties of the n-butanol fraction of Senna podocarpa leaves on α-amylase, α-glucosidase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, arginase, phosphodiesterase 5 (PDE-5), and angiotensin converting enzyme (ACE).MethodsThe total phenol and flavonoids, iron (Fe) chelation, and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging were used to determine the antioxidant activity, and the inhibitory activities of α-glucosidase, α-amylase, AChE, BChE, tyrosinase, arginase, PDE-5 and ACE were also assessed.ResultsThe n-butanol fraction of S. podocarpa shows high total phenol and total flavonoid contents. The n-butanol fraction of S. podocarpa leaves also chelates Fe2+ and ABTS radicals. The n-butanol fraction of S. podocarpa leaves also inhibited α-glucosidase, α-amylase, AChE, BChE, tyrosinase, arginase, PDE-5, and ACE at the concentration tested. Chromatographic analysis displayed the presence of β-elemene, phytol and caryophyllene oxide chrysophanol, 3-oxo-methyl ester, α-humulene, β-caryophyllene, rhein, emodin, and α-copaene.ConclusionsHence, the n-butanol fraction of S. podocarpa leaves demonstrates encouraging feat in controlling and/or managing cognitive dysfunction such as Alzheimer’s disease and also hypertension, diabetes, erectile dysfunction, endothelial dysfunction, and hyperpigmentation.