F. E. Olumese

Diabetes mellitus represents a major global health challenge, with over 800 million adults affected worldwide and limited therapeutic options, particularly in resource-constrained settings. This study investigated the in vitro antidiabetic properties of crude ethanol extract and solvent fractions of roots of Tetracera alnifolia, a medicinal plant traditionally used for managing diabetes in West Africa particularly Nigeria. The aim was to evaluate the alpha-amylase and alpha-glucosidase inhibitory activities of the plant extracts and fractions, and to determine their potential as natural antidiabetic agents. The roots of T. alnifolia were cut, dried, pulverized and extracted using ethanol. The crude extract was subsequently fractionated using solvents of increasing polarity (n-hexane, chloroform, dichloromethane, n-butanol, and water). Enzyme inhibition assays were performed using standard methods, with acarbose as the control. The IC₅₀ values were calculated to determine inhibitory potency. Results showed that the crude extract exhibited remarkable alpha-glucosidase inhibitory activity (IC₅₀ = 0.10 mg/mL), approximately 9-fold more than the IC₅₀ of acarbose (IC₅₀ = 0.93 mg/mL). For alpha-amylase inhibition, the crude extract (IC₅₀ = 0.68 mg/mL) was less than that of acarbose (IC₅₀ = 0.46 mg/mL). All solvent fractions similarly outperformed acarbose in alpha-glucosidase inhibition, with the n-hexane fraction showing the strongest activity (IC₅₀ = 0.19 mg/mL). The superior performance of the crude extract over individual fractions provided compelling evidence for synergistic interactions among multiple phytochemical constituents. The differential selectivity potent alpha-glucosidase inhibition with moderate alpha-amylase inhibition represents an ideal therapeutic profile that may offer a better postprandial glucose control. The study concludes that T. alnifolia possesses antidiabetic potential in vitro and this may be responsible for its hypoglycemic property in treatment of diabetes in traditional medicine. Therefore, further investigation through in vivo studies, phytochemical characterization, and determination of bioactive agent for potential development as a natural antidiabetic therapeutic.

The study focused on the Gas Chromatography Mass Spectrometry of phenolic compounds and antioxidant related constituent in the aqueous extract of Sphenocentrum jollyanum stem, a medicinal plant commonly used in traditional healthcare across Nigeria. The stem samples were sourced from Iwo Market in Osun State. The analysis was carried out using Gas Chromatography–Mass Spectrometry (GC–MS) at LEEDEX Laboratory in Lagos to identify the major bioactive constituents responsible for antioxidant activity. A total of 33 compounds were detected in the aqueous extract. Among these, four major compounds were identified due to their relevance to phenolic and antioxidant properties. Peaks 2 and 4 were confirmed as phenolic compounds—Phenol, 2,6-dimethoxy- and Phenol, 3,4,5-trimethoxy—indicating the presence of significant phenolic content in the extract. Peaks 32 and 33 were identified as Squalene and di-α- Tocopherol, respectively. Although non-phenolic, both compounds are well-documented antioxidants that contribute to the overall antioxidant capacity of the extract. The presence of both phenolic and non-phenolic antioxidant compounds suggests that the aqueous extract of Sphenocentrum jollyanum possesses strong antioxidant potential. These findings support the medicinal value of the plant and align with its traditional use for managing oxidative stressrelated conditions. The results highlight the importance of further research to explore additional therapeutic properties, optimize extraction methods, and understand the stability of its bioactive constituents.

Diabetes mellitus is characterized by chronic hyperglycemia–induced oxidative stress and electrolyte disturbances that exacerbate tissue injury and long-term complications. Traditional use of Tetracera alnifolia in Nigerian ethnomedicine suggests it may possess antidiabetic and antioxidant properties worthy of scientific evaluation. Adult Wistar rats were rendered diabetic via a single intraperitoneal injection of streptozotocin (65 mg/kg) and, after confirmation of hyperglycemia, randomly assigned to six groups (n=6): three groups received daily oral doses of T. alnifolia ethanol extract (200, 500, or 800 mg/kg) for 35 days; one group received glibenclamide (5 mg/kg); one remained untreated diabetic control; and one served as healthy control. Fasting blood glucose was measured on days 1, 7, 14, 21, 28, and 35. At study end, livers and pancreases were harvested for assessment of glutathione peroxidase (GPx) and glutathione reductase (GR) activities, respectively, and serum was analyzed for potassium levels. T. alnifolia extract induced a dose–dependent decline in fasting blood glucose, with the 800 mg/kg dose achieving values comparable to glibenclamide by day 35. Hepatic GPx activity, suppressed by diabetes (2.86 ± 0.38 U/g), was restored to 34.26 ± 0.62 U/g at 800 mg/kg (Table 4.1), exceeding the glibenclamide response (20.65 ± 0.01 U/g). Pancreatic GR activity rose from 2.42 ± 0.22 U/g in diabetic controls to 8.41 ± 0.26 U/g and 10.28 ± 1.28 U/g in the 800 mg/kg and glibenclamide groups, respectively (Table 4.2). Serum potassium, diminished by diabetes, was normalized across all extract doses. The ethanol extract of T. alnifolia exerts potent hypoglycemic, antioxidant, and electrolyte‐ stabilizing effects in STZ‐induced diabetic rats, validating its traditional antidiabetic use. These findings support further molecular and histopathological studies to clarify its mechanisms and therapeutic potential