Antidiabetic activities of chloroform fraction of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes

Abstract

Ethnopharmacological relevance: Anthocleista vogelii Planch is a medicinal plant traditionally used in West Africa for the management and treatment of diabetes mellitus.

Aim of the study: To determine the antidiabetic activities of chloroform fraction (CF) of Anthocleista vogelii Planch root bark in rats with diet- and alloxan-induced obesity-diabetes.

Materials and methods: Inhibitory activities of CF against α-amylase and α-glucosidase activities were determined in vitro. Three weeks old rats were fed with high-fat diet for 9 weeks to induce obesity prior to further induction of diabetes using alloxan (150 mg/kg body weight, i.p.). Blood glucose levels and body weight were measured every 7 days throughout the experiment. Glucose tolerance was assessed in normal and CF-treated rats on day 21. Terminal blood samples were collected from sacrificed animals for the measurement of serum insulin levels. Pancreases were excised from treated and untreated animals for histopathological examination.

Results: LCMS/MS chromatographic profile of CF via positive and negative modes revealed 13 and 23 compounds respectively. Further analysis revealed quebrachitol (QCT), loganin, sweroside, oleoside 11-methyl ester and ferulic acid, which have been previously reported for their antidiabetic activities, as constituents of CF. CF inhibited activities of α-amylase (IC₅₀ = 51.60 ± 0.92 µg/ml) and α-glucosidase (IC₅₀ = 5.86 ± 0.97 µg/ml) in a dose-dependent manner. Treatment of animals with obesity-diabetes with 100 and 200 mg/kg CF significantly improved glucose tolerance (P < 0.001) and enhanced serum insulin levels (P < 0.05) compared to diabetic control rats.

Conclusions: Antidiabetic activities of CF might be mediated via inhibition of α-amylase and α-glucosidase activities, elevation of serum insulin concentration, and enhancement of insulin and leptin sensitivity in obesity-diabetes rats. This study further substantiates the traditional use of A. vogelii in the management and treatment of diabetes in Africa and encourages further studies to investigate its mechanism of action.

Keywords: (+)-Maackiain 3-O-glucoside (PubChem CID: 44257441); 3-Hydroxy-3-methyl-glutaric acid (PubChem CID: 1662); 3-bromo-2E-acrylic acid (not found); 5,7-Dihydroxy-3',4'-dimethoxy-6,8-dimethylflavone (not found); 5,7-Dihydroxy-3-methoxy-4'-prenyloxyflavone (not found); 5-Acetylamino-6-formylamino-3-methyluracil (PubChem CID: 108214); Alloxan; Anthocleista vogelii; Antidiabetic; Apigenin 7-methyl ether 5-glucoside (not found); C16 Sphinganine (PubChem CID: 70679052); D-Glucoside (PubChem CID: 64947); Di-alpha-furfuryl ether (PubChem CID: 263034); Emmotin A (PubChem CID: 42608142); Ferulic acid (PubChem CID: 445858); Galactopinitol B (PubChem CID: 101926786); LCMS/MS; Loganin (PubChem CID: 87691); Methylorsellinic Acid, Ethyl Ester (PubChem CID: 3084545); N-hexanoyl-L-Homoserine lactone (PubChem CID: 10058590); Oleamide (PubChem CID: 5283387); Oleoside 11-methyl ester (PubChem CID: 10692563); Phellodensin D (PubChem CID: 5316782); Phlorisobutyrophenone (PubChem CID: 5326317); Phytosphingosine (PubChem CID: 122121); Quebrachitol (PubChem CID: 151108); Samidin (PubChem CID: 442150); Sweroside (PubChem CID: 161036); Theobromine (PubChem CID: 5429); Undecanedioic acid (PubChem CID: 15816); alpha-Bromocrotonic acid (PubChem CID: 5312952); gamma-Thujaplicin (PubChem CID: 12649); α-amylase; α-glucosidase.