The evaluation of effect of canarium schweinfurthii leaf and pulp extracts on blood glucose levels in oral glucose load - induced hyperglycemia, heamatological parameters and safety in wistar albino rats

Abstract

Background: Canarium schweinfurthii (C. schweinfurthii) is a common medicinal plant in Uganda used as food and as medicine in the management of Diabetes mellitus type 2 and anemia by local communities and traditional herbalists. However, its effectiveness in reducing blood sugar levels, anemia as well as safety has not been scientifically evaluated. Aim: To establish the effect of C. schweinfurthii aqueous leaf, pulp extracts on blood sugar levels, hematological indices and safety in Wistar albino rats. Methods An experimental laboratory based study was conducted. Eighteen (18) groups, each with 6 animals were dosed the extracts (Group 1distilled water, gp 2 Glibenclamide, gp 3-1000mg/ml,gp 4-500,gp -5 250,gp 6-100mg/ml) leaf extract,gp7-1000,gp8-500,gp 9-250 and gp10-100mg/ml of pulp extract. Single oral glucose load was used to induce hyperglycemia. Blood sugar levels were determined at a time 0, 30, 60, 180, and 240 minutes using automated blood glucose glucometer. Most active dose of 1000mg/ml body weight aqueous pulp was continued to be dosed daily for 28 days. Blood samples were collected at day 0, 7, 14, 21 and 28 from the tail vein. Automated hematological coulter counter machine was used to measure hematological parameters from which indices were calculated. Blood chemistry was analyzed using COBAS INTERGRA 400 Plus. Histological changes in the liver and kidney after 28 days of daily dosing of extracts to the Wistar albino rats were assessed. STATA VER 13 statistical package was used to analyze data, Means was compared using ANOVA. Results: Findings showed that the extracts of leaf, pulp of C. schweinfurthii had hyperglycemic effect as opposed to hyperglycemia activity. Since the curves were above that of glibenclamide and distilled water. However, minimal hypoglycemic activity was observed with aqueous pulp extract. For acute toxicity no animal died at limit maximum dose of 5000mg/kg within 24hrs in all 5 treated groups. No animal died by 5000mg/kg bwt within 24 hrs in all 5 treated groups. Findings on the RBC cell count, there was a slight increase in the RBC cells on day, 21 and 28.WBC cell count was reduced on day 14, and neutrophil count was reduced on day 14, and neutrophil count was significantly reduced by the extract on 7, 14 and 21 (p < 0.05). % Hematocrit significantly increased on day 21 (p < 0.05). Total bilirubin (µmol/L) was significantly reduced by the extract on day 14 (p < 0.05) while direct bilirubin was increased on day 14 and 21. Total protein (g/L) was significantly reduced on 7, 14 and 28 but increased on day 21(p < 0.05). For acute toxicity, there was no death at maximum limit dose of 5000mg/kg bwt. For sub-acute toxicity the findings showed that the hepatocytes and kidney architecture remained normal for both the controls, and the rats that received the intervention following daily dosing for 28 days. Conclusions: The extracts showed a hyperglycemic effect short term as opposed to hypoglycemia effects long term since the reduction values were lower than that of distilled water and Glibenclamide controls. There was also mild increase in RBC count and % hematocrit. The extracts were safe for the study animals (acute toxicity) and hematology (sub-acute) thus confirming its use by the local communities as food and medicine. There were no pathological changes or abnormalities in kidney and liver of Wistar albino rats for sub-acute toxicity study.