HEXANE EXTRACT OF Dacryodes edulis FRUITS POSSESSES ANTI-DIABETIC AND HYPOLIPIDAEMIC POTENTIALS IN ALLOXAN DIABETES OF RATS

Abstract

Background: The fruit extract of Dacryodes edulis (D. edulis), the African pear or plum, a tree indigenous to the humid tropics has been used for managing wounds, skin diseases, sickle cell anaemia, dysentery and fever in some African nations. In South Eastern Nigeria, 'herbal doctors' include its marshed fruit in decoctions administered to diabetic patients. However no scientific substantiation of their claim and use exist in literature. Hence, the need to evaluate the antidiabetic and hypolipidaemic activity of hexane extracts of D. edulis fruit in alloxanised animal model.

Materials and methods: Sub-toxic doses between 400 and 1600mg/kg were orally administered sub-chronically to alloxan-induced diabetic rats for 15 days and compared to glibenclamide (2.5mg/kg). The glycaemia levels, body weights, lipid profile, blood urea, creatinine and liver enzyme levels were measured. Basic histology of the pancreatic tissue was also performed to examine the effects on the pancreas as possible mechanistic lead.

Results: Oral acute dosing of D. edulis hexane extract decreased blood glucose levels, while sub-chronic treatment of the extract down-regulated significantly hyperglycaemia, total cholesterol, triglycerides, LDL-C, ALT and ALP levels. However, the HDL-C levels increased significantly. Histopathological examination of the pancreatic tissues after sub-chronic treatment showed that glibenclamide and the highest dose of the extract 1600mg/kg restored the afore-damaged pancreatic β-cell architecture.

Conclusion: Our findings portend that D. edulis hexane fruit extract possesses hypoglycaemic and hypolipidaemic activities as well as restoration of the pancreatic architecture without any obvious untoward hepatic damages, suggesting that its use in the management of the diabetes may be valid. List of Non-standard abbreviations:D. edulis = dacryode edulis, DEnH = Dacryodes edulis n-hexane fruit extract, B.wt. = Body weight, Per os = Oral administration, NC = normal control, DC =Diabetic control, SC = Standard control, LDL-C = low density lipoprotein cholesterol, HDL-C = High density lipoprotein cholesterol, TG = Triglyceride, TC = Total cholesterol.

Keywords: Dacryodes edulis; anti-diabetic; diabetes; hypolipidaemic.

Figure 1

Mean hourly blood glucose levels (mg/dL) of fasted experimental rats acutely dosed with D. edulis. Data represents Mean ± SEM, n= 4.

Figure 2

Mean blood glucose levels (mg/dL) of alloxan-diabetic experimental rats that were sub-chronically dosed for 15-days with D. edulis administration of hexane fruit extract. Data is presented as Mean ± SEM, n = 4, followed by Tukey’s post hoc test #P<0.01; ###P<0.0001

Figure 3

Effects of 15-day oral administration of hexane extract of Dacryodes edulis fruit on the body weight (g) of diabetic rats. Data is shown as Mean ± SEM, n = 4, followed by Tukey’s post hoc test, *P<0.05, **P<0.001.

Figure 4

Assessment of the effect of sub-chronic oral administration of DEnH extract on cholesterol and triglyceride levels in alloxan-diabetic rats. Data is presented as Mean ± SEM, n = 4; followed by Tukey’s post hoc analysis with value set at P<0.05.

Figure 5

Fold changes in creatinine levels following sub-chronic oral administration of n-hexane extract of Dacryodes edulis fruit to alloxan diabetic rats. Data is presented as Mean ± SEM, n = 4; followed by Tukey’s post hoc analysis. ^#P<0.05, ^##P<0.001 when values are compared to non-diabetic animals (NC).

Figure 6

Effects of DEnH fruit extract on Blood Urea levels of diabetic rats expressed in terms of fold changes. Results were presented as Mean ± SEM, n = 4; means separated by Tukey’s post hoc analysis. ^#P<0.05; ^##P<0.001; ^###P0.0001 when values are compared to non-diabetic animals (NC).

Plates A, B, C, D, E & F shows histo-morphology of pancreatic section of rats used in the study. Untreated control animals (A) presenting a pancreatic morphology with clearly defined islets (I) and acinar cells (AC), alloxan diabetic animals (B) with small atrophied islets (SI), hypertrophy (CT) of acinar cells and mononuclear cellular infiltration (CI). Glibenclamide-treated standard control animals(C) shows islets small apparently salvaged islets with lesions (SIL). DEnH400mg/kg treated (D) shows cells with HT and SIL. DEnH800mg/kg dosed animals (E) show SIL and CI without CT while animals orally administered with DEnH1600mg/kg (F) presents normal pancreatic morphology (H&E X400).