No abstract

The antioxidant properties of the water and ethanol leaf extracts of kinkeliba (Combretum micranthum) were investigated, including scavenging of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (IC₅₀ values: 8.02 ± 0.34 for the ethanol extract [KE] and 9.1 ± 0.28 for the water extract [KW]), the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical (IC(50) values: 7.4 ± 0.14 for KE and 11.8 ± 0.01 for KW) and the hydroxyl radical (58.1% for KE and 61.1% for KW). The ferric thiocyanate method, reducing power, metal chelating activity, an assay of protein oxidation and the β-carotene-linoleic bleaching assay were also used. Butylated hydroxytoluene and ascorbic acid were used as the reference antioxidant compounds. At 20 mg mL⁻¹ concentration, KW and KE provided 36.8% and 75.1% inhibition of lipid peroxidation of linoleic acid emulsion, respectively. The IC₅₀ values of the ethanol extract in ABTS and DPPH tests were significantly lower than those from the water extract. Furthermore, crude polyphenols were extracted from kinkeliba leaf with 90% ethanol solution using a water bath treatment and then purified by a macroporous resin, AB-8. The polyphenols from kinkeliba leaf were subjected to analyses by RP-HPLC and ESI-MS. The dominant polyphenols in kinkeliba leaf were identified as gallic acid, rutin trihydrate, (+)-catechin and benzoic acid.

No abstract

No abstract

Summary Insoluble fibres were isolated from the two varieties of foxtail millet (white and yellow) grains and evaluated for their hypoglycaemic effects by in vitro studies. The hypoglycaemic effects of these fibres were compared with those of commercial soy insoluble fibre. The results revealed that minimum and maximum amounts of glucose were adsorbed on each sample at 10 and 200 μmol g−1 glucose concentrations respectively, indicating that the glucose adsorption capacity (GAC) of the fibre materials was proportional to glucose concentration for all samples. There was significant (P < 0.05) difference among all the fibre materials in relation to their GAC values. In the case of the effects of the fibres on glucose diffusion, the millets' insoluble fibres performed better than that of the commercial soy insoluble fibres. The glucose dialysis retardation indexes at the end of the maximum dialysis time were 1.1%, 27.4% and 22.6% for soy bean insoluble fibre, white foxtail millet insoluble fibre and yellow foxtail millet insoluble fibre in that order. The study showed that hypoglycaemic effects of yellow and white foxtail millet fibres were comparable to the commercial soy insoluble fibre.