This study was carried out to examine the efficacy of roasted Sphenostylis stenocarpa and Glycine max flours on persistent physically induced stress in wistar albino rats. Thirty two (32) male wistar rats weighing between 130-192g were distributed into eight (8) groups of four (4) rats each to acclimatize to feed and environment. Six hundred (600g) of S. stenocarpa and G. max used in this study were purchase from local markets in Enugu State. Group 1 to 6 were induced physical stress persistently for 2 hours in week 1, and 3 hours in week 2 daily. Group 1 to 3 and groups 4 to 6 were treated with roasted 500mg/kg bw, 1000mg/kg bw and 2000mg/kg of S. stenocarpa and G. max flours respectively. Group 7 (stress control) and group 8 (normal control) were not treated but were fed with feed and water ad libitum. Chemical analysis was done to determine the proximate, phytochemical, minerals, vitamins and antinutrient compositions of the samples. Blood samples were collected from the animals on the 7th and 14th day through ocular puncture. They were used to determine enzymatic and non enzymatic antioxidants parameters. Data obtained from the study were subjected to statistical analysis and the results were presented as mean and standard deviation. Differences between mean were determined by ANOVA and pos hoc multiple comparisons. Results showed that Sphenostylis stenocarpa and Glycine max had protein (22.29% and 36.79%), fibre (12.70% and 3.50%), and carbohydrate (60.5% and 22.62%) respectively. Phytochemical and antinutrient compositions of the legumes contained bioactive chemical substances with strong presence of alkaloids (29.76mg.100g-27.98mg/100g), flavonoids (32.68mg/100g-22.03mg/100g), glycosides (0.88mg/100g-0.87mg/100g), tannins (0.53mg/100g-296.63mg/100g) and phytates (0.53mg/100g-38.30mg/100g) respectively. Pro-vitamins A (87.75mg/100g-207.67mg/100g), vitamin C (272.87mg/100g-38.30mg/100g) and vitamin E (81.60mg/100g-276.01mg/100g) ranges were detected in both samples. The mineral contents indicated the presence of Mg (83.43mg/100g-82.87mg/100g), Fe (16.53mg/100g-7.64/mg/100g) Ca (72.03mg/100g-263.20/mg/100g) in both samples while Se (12.60), Zn (0.80) and Cu (42.30) were found to be present in S. stenocarpa. A significant (p < 0.05) decrease of 0.55mg/dl-0.82mg/dl was observed in the serum malondaidehyde (MDA) concentration of rats in the treated groups when compared to the control groups (1.21mg/dl-1.35mg/dl) while serum catalase (1.74mg/dl – 4.21mg/dl) and superoxide dismutase (1.07 IU/L – 1.133 IU/L) of the treatment groups differed significantly (p > 0.05) compared to control groups (1.06 IU/L -1.08 IU/L). The peroxidase (GPx) activity in all the treated groups had a significant (p < 0.05) change. There was increase of 0.47mg/dl – 0.52mg/dl and decrease of 0.36mg/dl – 0.43mg/dl of Vitamin C activity in the groups treated with S. stenocarpa and in the group treated with G. max, respectively. A significant (p < 0.05) decrease was observed in vitamin E (0.06mg/dl – 0.08mg/dl) activity in all the treated groups compared to control groups (0.08mg/dl – 0.09mg/dl). There was an increase of 0.54mg/dl – 1.77mg/dl in vitamin A activity in all the treated groups when compared to stress group (0.27mg/dl). The glutathione (GSH) activity in all the experimental groups differed. Apart from stress control group that had decrease percentage change (0.04%) in body weight, all the other groups of the experimental rats had increase percentage change (1.11- 6.90%) in body weights. The antioxidant contents of S. stenocarpa and G. max were able to reduce behavioral changes in rats that were physically stressed after treatment. The results of antioxidant enzymes showed that these legumes could be used to scavenge free radicals in the system which often leads to risks of various diseases associated with persistent physical stress.
Key words: Bioactive potentials, Sphenostylis stenocarpa, Glycine max, Antioxidants, Induced stress.
1.1: Background to the Study
African yam bean (Sphenostylis stenocarpa) and soy bean (Glycine max) belong to the legume family. Leguminous plants play important role in human nutrition. They provide a significant amount of food in developing countries (Okaka, Akobundu & Okaka, 2002). Leguminous seeds are important source of protein energy and other nutrients in the diet of large population groups and the world. They form an excellent source of thiamine and contributing appreciable quantities of the other water soluble vitamin. African yam bean is mainly cultivated in West, East, Central Africa, and in Malawi and Zimbabwe (Utter, 2007). In Nigeria it is locally known as “odudu” in Abia State, “ekpakpani” in Urhobo, Delta state; “illoloegwa” in Edo state (Nwosu, Onwuamanam, Onuegbu, Ogueke & Ojukwu, 2012) and ijiriji and Azamu in Nsukka and Ezeagu local government areas of Enugu state respectively.
Soy bean protein has increased attention in recent years among consumers, and researchers (Asif & Acharya, 2013). Botanically, soy bean belongs to the order Rosaceae, family Leguminosae, the genus Glycine and the cultivar Glycine max. African yam bean is one of the leguminous crops that contribute about 18% of the world protein requirements (Olawumi et al., 2013). The deficiency of protein in the diet cause a disease known as “kwashiorkor” a condition characterized by depigmentation of the hair in children and oedema. In order to bridge the protein supply gap that exists today, scientists have focused their attention on the lesser known protein crops among which is the African yam bean (Okaka & Okaka, 2001).