The present investigation aimed at evaluating the effect of powder fractionation based on particle size on the chemical composition in macronutrients, polyphenol contents, and antioxidant properties of powders of Boscia senegalensis seeds, Dichrostachys glomerata fruits, and Hibiscus sabdariffa calyces. Significant differences ( p < 0.05) among granulometric classes of each plant were observed for the chemical composition in macronutrients. A decrease in particle size of plant powders was associated with an increase in ash, protein, and fat contents, while carbohydrate content was lowered. The following Granulometric classes, [0–180 µm] for Boscia senegalensis , [180–212 µm] for Dichrostachys glomerata, and [212–315 µm] for Hibiscus sabdariffa, respectively, were found to maximize total phenolic content and antioxidant activity. These results confirm that the grinding and controlled differential screening technology is an approach may serve as a useful guide to obtain optimum polyphenol extraction and enhance antioxidant activity of plant products .

Abstract. Tubers of Tacca leontopetaloides (L.) Kuntze (Dioscoreales: Dioscoreaceae) play an important role in food substitution during the periods of food shortage in occidental and central Africa. It is also used in traditional medicine for the treatment of the diarrhea, dysentery, stomach evil, viral hepatitis and the infection of guinea worn. This study attempted to evaluate the antihyperlipidemic and hypolipidemic properties of aqueous extracts of the tubers of T. leontopetaloides in rats. For this experimentation, two tests were done: antihyperlipidemic and hypolipidemic tests. Hyperlipidemia was induced in rats with High Fat Diet containing 300 g of egg yolk, 2 g of cholesterol, 250 g of coconut oil and 50 g of soya oil. The group of rats on which the antihyperlipidemic test was done was fed with High Fat Diet and supplemented with T. leontopetaloides aqueous extract at 27.34 mg/kg, and 54.68 mg/kg; after 21 days of experimentation, the different groups of rats were sacrificed. The lipid profile and some biochemical parameters were evaluated. Organs like kidneys, liver and stomach were taken for histopathological evaluation. For the hypolipidemic test, after three weeks of induction of hyperlipidemia, the diet was changed to normal diet and aqueous extract of tubers was given to rats during 21 days at doses of 3.41 mg/kg and 13.67 mg/kg. The animals were sacrificed after 21 days of experimentation. The lipid profile, some biochemical parameters and histopathology of organs were evaluated. The antihyperlipidemic and hypolipidemic tests of aqueous extract of the tubers of T. leontopetaloides induced reduction in total cholesterol, triglyceride, LDL-cholesterol and an increase in HDL-cholesterol significantly (p < 0.05); decreasing activities of ALAT and ASAT enzymes, levels of creatinin remained no changed. Histopathological study revealed that extracts did not repair the destructions of liver cells and glomerules of kidneys caused by High Fat Diet. Aqueous extract of tubers of T. leontopetaloides exhibits antihyperlipidemic and hypolipidemic activities; hence it could be important in the management of cardiovascular diseases.