Effects of Catechol containing fraction and other fractions of Nauclea latifolia aqueous root-bark extract on blood glucose, lipid profile and serum liver enzymes in streptozotocin – induced diabetic Wistar albino rats

Abstract

Background. Diabetes mellitus has been a menace to healthy human condition from antiquity. There has been continuous search for plant medicinal substances for drug development with an aim to managing this ailment with minimal drug side effects. In this research work, effects of fractions of aqueous root-bark extract of Nauclea latifolia on blood glucose, lipid profile and serum liver enzymes in diabetic rats were investigated. Thirty –five Wistar albino rats weighing 164.1 – 171.6 grammes were used for this study involving aqueous root-bark extract fractions A, B, C and D. The rats were divided into 7 groups of 5 rats each. Group 1 was normal non diabetic control, group 2 was diabetic control and groups 3, 4, 5 and 6 were rats treated with 250 mg/kg body weight of varying root-bark fractions while group 7 was diabetic rats treated with 5mg/kg. body weight of glibenclamide, the standard anti-diabetic drug. Fasting blood glucose levels were determined using digital glucometer (Acuu-chek, Mannheim, Germany). Lipid profile was determined using standard procedures. Serum liver enzymes were determined using assay kits. Fraction A was analyzed using gas chromatography- mass spectroscopy and nuclear magnetic resonance spectroscopy. Results. Fraction A demonstrated the most effective anti-diabetic property compared to fractions B, C and D. It caused significant reduction in blood glucose levels. It also brought about significant decrease in the levels of triacylglycerol, very low density lipoprotein cholesterol and low density lipoprotein cholesterol. Aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase levels were also significantly reduced by it. Fraction A was found to contain catechol as the most abundant active principle. Conclusion. Previous works on catechol show that catechol moiety either exists as a free molecule or a substituent of flavonoids and that it confers on them their anti-diabetic property. Since the catechol containing fraction A caused significant reduction in glucose levels, lipid profile and serum liver enzymes, it therefore has the potential for the management of diabetes mellitus and ameliorating its complications in clinical medicine.