In vitro antioxidant, lipoxygenase and xanthine oxidase inhibitory activities of fractions from Cienfuegosia digitata Cav., Sida alba L. and Sida acuta Burn f. (Malvaceae)

In this study polyphenol content, antioxidant activity, lipoxygenase (LOX) and Xanthine Oxidase (XO) inhibitory effects of n-hexane, dichloromethane, ethyl acetate and n-butanol fractions of aqueous acetone extracts from S. alba L., S. acuta Burn f and Cienfuegosia digitata Cav. were investigated. The total phenolics, flavonoids, flavonols and total tannins were determined by spectrophotometric methods using Folin-ciocalteu, AlCl3 reagents and tannic acid, respectively. The antioxidant potential was evaluated using three methods: inhibition of free radical 2,2-diphenyl-1-picrylhydramzyl (DPPH), ABTS radical cation decolorization assay and Iron (III) to iron (II) reduction activity (FRAP). For enzymatic activity, lipoxygenase and xanthine oxidase inhibitory activities were used. This study shows a relationship between polyphenol contents, antioxidant and enzymatic activities. Present results showed that ethyl acetate and dichloromethane fractions elicit the highest polyphenol content, antioxidant and enzymatic activities.

In vitro antioxidant, xanthine oxidase and acetylcholinesterase inhibitory activities of Balanites aegyptiaca (L.) Del. (Balanitaceae)

The present study aimed to test the validity of Balanites aegyptiaca remedies used for the treatment of rheumatisms and mental disorders by examining the antioxidant, xanthine oxidase and acetylcholinesterase inhibitory activities of galls and leaves extracts and fractions. The total phenolics and flavonoids were measured using Folin-Ciocalteu and AlCl3 reagents, respectively. Two methods i.e., FRAP and ABTS were used to estimate the total antioxidant capacity of the plant materials. The FRAP and ABTS antioxidant activities showed that among all extracts and fractions tested, the best antioxidant activities were found with the galls dichloromethane and the leaves ethyl acetate fractions. The antioxidant activities did correlated significantly with the total phenolic and flavonoid contents. The study also showed that B. aegyptiaca galls and leaves fractions exhibited a moderate xanthine oxidase inhibitory activity comparatively to the acetylcholinesterase which was weakly inhibited by the tested extracts and fractions.

Polyphenol contents and antioxidant activities of five Indigofera species (Fabaceae) from Burkina Faso

Aqueous acetone extracts prepared from five Indigofera species of Burkina Faso, namely Indigofera colutea (Burm.) Murril., I. macrocalyx Guilld et Perr., I. nigritana Hook f., I. pulchra willd. and I. tinctoria L., were investigated for their phytochemical composition and their antioxidant activities. Standard methods and TLC were used to screen the phytochemical composition. The total phenolic and flavonoid content of extracts were assessed by Folin-Ciocalteu and AlCl3 methods, respectively. These extracts were also evaluated for their antioxidant potentials using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonate) (ABTS) assays. Flavonoids, saponins, quinones, sterols/triterpenes and tannins were present in all these species except for I. pulchra where quinones were not found. Gallic acid, caffeic acid, rutin and myricetin in I. colutea; gallic acid, quercitrin, myricetin in I. tinctoria; galangin and myricetin in I. macrocalyx were identified by thin layer chromatography. Among these, I. colutea, I. tinctoria, I. nigritana and I. macrocalyx, which had the highest phenolic content, were also found to possess the best antioxidant activities. The results indicated a good correlation between antioxidant activities and total phenolic content (p<0.05 for FRAP/DPPH and DPPH/ABTS and p<0.01 for FRAP/ABTS). These plants represent promising sources of natural antioxidants and these findings give scientific bases to their ethnopharmacological uses.

The effect of age on the mating competitiveness of male Glossina fuscipes fuscipes and G. palpalis palpalis

The effect of age on male Glossina fuscipes fuscipes, Newstead, and Glossina palpalis palpalis, Austin (Diptera: Glossinidae) competiveness were investigated with a view to estimate optimal age for sterile male release. Sterile insect technique involves the mass production, sterilization and sequential release of males of the target species to out compete the wild male population. Mating between released sterile males and wild females produce inviable progeny and the population is reduced over several generations to unsustainable levels. It is vital that the released male are of high quality and are sexually competitive. Age is one parameter affecting the sexual competiveness of the male tsetse fly. The optimal release age was estimated by assessing sexual competitiveness of flies of different age categories, 1, 5, 8 and 13-days after adult eclosion. A walk-in field-cage was used in order to approximate as closely as possible the actual field scenario during sterile insect release programes. It was shown that 8 and 13-day old males mated significantly more frequently, i.e. were more competitive, in the presence of equal numbers of 1 and 5-day old males. The age of male tsetse flies significantly affected competitiveness in both species studied. The ability of G. f. fuscipes to inseminate was not age dependent, and insemination occurred in all females that mated regardless of male age. In G. p. palpalis, however, 1-day old males were least able to inseminate. Mating duration was not significantly affected by age in both species. Eight to thirteen day old males of the test species are here recommended as the optimal sterile male release age.