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 (IC₅₀ = 126.90 μg/ml), α‐glucosidase (IC₅₀ = 139.66 μg/ml), acetylcholinesterase (IC₅₀ = 347.22 μg/ml), and butrylcholinesterase (IC₅₀ = 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.

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.

Therapies directed towards controlling hyperglycemia, the hallmark of type-2 diabetes mellitus, go a long way in managing diabetes and its related complications. Reducing glucose level through the inhibition of the relevant carbohydrate hydrolyzing enzymes is one among many routes in the management of diabetes. This study investigates the in vitro enzyme inhibitory and antioxidant properties of solvent-partitioned fractions of Spondias mombin and Mangifera indica leaves; which are used extensively in the treatment of diabetic patients locally. The leaves of S. mombin and M. indica were extracted with methanol and fractionated to obtain n-hexane (HF), ethyl acetate (EAF), n-butanol (BF), and aqueous (AF) fractions successively. The α-amylase and α-glucosidase inhibitory activities of fractions of S. mombin and M. indica leaves were investigated while the antioxidant activity of each fraction was analyzed using iron chelating and ABTS (2,2’-azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid) radical scavenging assay. Our findings indicated that the ethyl acetate fraction of M. indica leaves contained a considerably higher (p < 0.05) amount of total phenolic, flavonoids, metal ion, and ABTS radical scavenging activity than the ethyl acetate fractions of S. mombin. Furthermore, the ethyl acetate fraction of M. indica had a considerably higher (p < 0.05) inhibitory effect on α-glucosidase (IC₅₀ = 25.11 ± 0.01 μg mL⁻¹), and α-amylase (IC₅₀ = 24.04 ± 0.12 μg mL⁻¹) activities than the S. mombin fraction. Hence, the inhibitory activities of S. mombin and M. indica leaves suggest that they are a potential source of orally active antidiabetic agents and could be employed to formulate new plant-based pharmaceutical and nutraceutical drugs to improve human health.

BackgroundOcimum gratissimum L. is a medicinal plant widely grown in tropical and subtropical regions with the leaf decoction usually taken in folk medicine to enhance erectile performance in men although the probable mechanism of actions remains undetermined. This study examined the inhibitory potentials of Ocimum gratissimum leaves on some key enzymes associated with erectile dysfunction in penile and testicular tissues of the rat.MethodsInhibitory effect of aqueous extract (1:10w/v) of O. gratissimum leaves on the activities of phosphodiesterase-5 (PDE-5), arginase, angiotensin I -converting enzyme (ACE), and acetylcholinesterase (AChE) in penile and testicular tissues were assessed. Also, the extract was investigated for ferric reducing antioxidant property(FRAP) and 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging abilities.ResultsThe extract showed higher PDE-5 (IC50=43.19g/mL), ACE (IC50=44.23g/mL), AChE (IC50=55.51g/mL) and arginase (IC50=46.12g/mL) inhibitory activity in the penile tissue than PDE-5 (IC50=44.67g/mL), ACE (IC50=53.99g/mL), AChE (IC50=60.03g/mL) and arginase (IC50=49.12g/mL) inhibitory activity in the testicular tissue homogenate. Furthermore, the extract scavenged free radicals and in a dose-dependent manner.ConclusionThe enzyme activities displayed might be associated with the bioactive compounds present in the extract which could possibly explain its use in the management of erectile dysfunction (ED).

Currently, there is no known cure for diabetes. Different pharmaceutical therapies have been approved for the management of type 2 diabetes mellitus (T2DM), some are in clinical trials and they have been classified according to their route or mechanism of action. Insulin types, sulfonylureas, biguanides, alpha-glucosidase inhibitors, thiazolidinediones, meglitinides, sodium–glucose cotransporter type 2 inhibitors, and incretin-dependent therapies (glucagon-like peptide-1 receptor agonists: GLP-1R, and dipeptidyl peptidase 4 inhibitors: DPP-4). Although some of the currently available drugs are effective in the management of T2DM, the side effects resulting from prolonged use of these drugs remain a serious challenge. GLP-1R agonists are currently the preferred medications to include when oral metformin alone is insufficient to manage T2DM. Medicinal plants now play prominent roles in the management of various diseases globally because they are readily available and affordable as well as having limited and transient side effects. Recently, studies have reported the ability of phytochemicals to activate glucagon-like peptide-1 receptor (GLP-1R), acting as an agonist just like the GLP-1R agonist with beneficial effects in the management of T2DM. Consequently, we propose that careful exploration of phytochemicals for the development of novel therapeutic candidates as GLP-1R agonists will be a welcome breakthrough in the management of T2DM and the co-morbidities associated with T2DM.