Comparative studies on nutrient content and antidiabetic effects of sugar palm (Borassus flabellifer) fruit pulp & endosperm on rats

Abstract

• Sugar palm fruit pulp, immature & germinated endosperm are rich with carbohydrate, fiber, zinc and phytochemicals. • Sugar palm fruit is safe for medicinal uses and significantly reduced fasting blood glucose (FBG) levels. • Germinated endosperm showed maximum antidiabetic effects followed by immature endosperm and pulp, respectively. • Both germinated & immature endosperm may restore damaged pancreatic β-cell function. Nutrient contents of sugar palm (Borassus flabellifer) fruit pulp (SPFP) cultivated in Bangladesh are yet to be well-reviewed. Moreover, the nutrient contents of other popularly consumed edible portions of sugar palm fruit, i.e., immature endosperm (IE), and germinated endosperm (GE) are not studied yet. The current study showed that SPFP, IE, and GE were rich in carbohydrate, fiber, sodium, potassium, and zinc. IE contained the highest amount of fiber, while SPFP contained the highest amount of copper. Twenty-five phytochemicals having known antidiabetic effects were investigated for their presence in pulp, immature & germinated endosperm. GE contained the highest number of phytochemicals (23) followed by IE (19) and SPFP (14). Diabetic patients usually avoid edible portions of sugar palm, fearing that these may further deteriorate existing hyperglycemia. In the present study, this suspicion was investigated in alloxan-induced diabetic rats through supplementary feeding of SPFP, IE, & GE in addition to the regular diet for the nine consecutive weeks. Study results clearly showed that SPFP, IE, & GE significantly reduced fasting blood glucose (FBG) levels of experimental rats. GE showed maximum antidiabetic effects followed by IE and SPFP, respectively. GE, and IE returned the FBG levels within normal range by the end of the sixth week but not by the SPFP. Endosperms supplemented diabetic rats maintained the normal FBG levels even after withdrew the supplementary diets. These results suggested that supplemental feeding of the GE and IE to the experimental diabetic rats may restore alloxan damaged pancreatic β-cell function, and the reasons might be the presence of fiber, zinc and phytochemicals content of the endosperm.