| S/N | Reference | Parts utilized | Solvent for extraction | Dose | Bioactive compound | Experimental model/human | Treatment effect |
| 1 | Djeujo et al. [36] | Roots and leaves | Distilled water, ethanol, and Soxhlet | 10–100 μM | Luteolin and vernodalol | In vitro | α-Glucosidase activity, antioxidation, advanced glycation end products (AGEs) | 2 | Patathananone et al. [37] | Leaves | Methanol, ethanol and acetone, isopropanol, ethyl acetate and hexane | 10–100 μl | Flavonoids, phenols, coumarins, saponins, tannins, terpenoids, steroids, and cardiac glycosides | In vitro | Antioxidant activity, antityrosinase activity, and antiamylase activity | 3 | Medjiofack Djeujo et al. [38] | Roots and leaves | Distilled water, ethanol, Soxhlet | 5-500 μg/ml | Catechin, caffeic acid, chlorogenic acid, luteolin, vernodalol | In vitro | α-Glucosidase activity, AGE formation, and oxygen radical absorbance capacity | 4 | Erukainure and Islam [39] | Leaves | Ethanol, distilled water, ethyl acetate | 500 mg/kg | Not reported | Sprague Dawley rats | Antioxidative and antidiabetic | 5 | Okoduwa et al. [40] | Fresh leaves | Methanol | 10 mg/kg b.w | 11β,13-Dihydrovernolide | Albino Wistar rats | Hypoglycemic effect | 6 | Erukainure et al. [41] | Leaves | Distilled water | 30, 60, 120, and 240 μg/ml | L-Serine, L-cysteine, L-proline, Cumidine, nicotinic acid, isoquinoline, 3-methyl-salicylic acid, and γ-octalactone | Sprague Dawley rats | Glucose uptake and neuroprotection | 7 | Erukainure et al. [42] | Leaves | Distilled water | 15, 30, 60, 120, and 240 μg/ml | Acidic lipid, mucilage and pectin, lipids, polyphenols, and alkaloids | Sprague Dawley rats | α-Glucosidase activity, DPPH, FRAP, DNA fragmentation, glucose uptake, and absorption | 8 | Wu et al. [43] | Leaves | Ethanol | 50, 100, and 150 mg/kg | Not reported | Kunming mice | Hypoglycemic effect, improved insulin resistance, suppression of gluconeogenesis | 9 | Aba and Udechukwu [44] | Leaves | Distilled water | 200 mg/kg | Saponins, flavonoids, tannins, glycosides, alkaloids, terpenes | Albino Wistar rats | Hypoglycemic effect | 10 | Okon and Umoren [45] | Leaves | Distilled water | 52 mg/kg | Flavonoids, terpenes, polyphenols, alkaloids, saponin, steroids, and cardiac glycosides | Albino Wistar rats | Hypoglycemic effect | 11 | Okoduwa et al. [46] | Leaves | Methanol | 250 mg/kg b.w | Alkaloids, carbohydrates, glycosides, flavonoids, polyphenols, saponins. Steroids, tannins, and tritapene | Albino Wistar rats | Hypoglycemic, antilipidemic, pancreatic β-cell regeneration, restoration of biomarkers of liver and kidney function | 12 | Asante et al. [13] | Young and old leaves | Ethanol | 10, 30, and 300 mg/kg b.w | Flavonoids, saponins, alkaloids, saponins, tannins, glycosides, terpenoids, anthraquinones, and reducing sugars | Sprague Dawley rats | Hypoglycemic, antilipidemic, and tissue regeneration | 13 | Okoduwa et al. [47] | Leaves | Methanol | 250 mg/kg b.w. | Carbohydrates, glycosides, cardiac glycosides, saponins, steroids, triterpenes, tannins, flavonoids, alkaloid | Albino Wistar rats | Hypoglycemic effect | 14 | Atangwho et al. [48] | Leaves | Petroleum ether and chloroform | 200 and 400 mg/kg | Not reported | Sprague Dawley rats | Suppression of gluconeogenesis | 15 | Atangwho et al. [49] | Leaves | Water, methanol, chloroform, petroleum | 400 mg/kg | Fatty acids, vitamin E | Sprague Dawley rats | Hypoglycemic effect | 16 | Akinola et al. [50] | Leaves | Ethanol | 400 mg/kg | Polyphenols | Albino Wistar rats | Antihyperglycemic effect | 17 | Atangwho et al. [51] | Leaves | Ethanol | 400 mg/kg b.w. | Alkaloids, glycosides, tannins, saponins, flavonoids, reducing sugars, polyphenols, steroids, hydroxymethyl anthraquinones | Albino Wistar rats | Antihyperglycemic, pancreatic β-cell regeneration | 18 | Akah et al. [52] | Leaves | Methanol | 80, 160, and 320 mg/kg | Flavonoids, saponins, carbohydrates, combined and free reducing sugars, tannins, sterols, and balsams | Albino Wistar rats | Hypoglycemic, hypolipidemic | 19 | Nwanjo [53] | Leaves | Distilled water | 200 mg/kg | Alkaloids, carbohydrates, tannins, saponins, flavonoids, and glycosides | Albino Wistar rats | Hypolipidemic and antioxidant | 20 | Gyang et al. [54] | Leaves | Chloroform | 750 mg/kg | Not reported | Albino Wistar rats | Hypoglycemic effect |
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