Modern Scientific Press

ABSTRACT: Cysteine proteases (E.C. 3.4.22) are used extensively in the food industry. However, it would be of benefit to find additional sources of cysteine proteases with potentially better useful properties. Therefore, the present work was carried out to purify and characterize the enzyme from one of the Nigerian common onion cultivars (Red Creole). The enzyme had overall purification fold and purification yield values of 15.94 and 9.25%, respectively. The enzyme had a single band of 22 kDa by SDS-PAGE, which suggests relative purity. Characteristically, the optimum pH and temperature are 4 and 45 ^oC, respectively. It was stable at pH range 4-6 and temperature range 20 - 50 ^oC. Eighty-nine percent of the enzyme activity remained after 1 h time-dependent inactivation at 45 ^oC. The Michaelis-Menten constant (KM) and the maximum velocity (Vmax) using casein as substrate were found to be 6.74 mg/mL and 0.86 U/mL, respectively. The enzyme also showed more affinity towards casein (KM = 6.74 mg/mL) than other examined substrates. Some of the examined metal cations, which include Li⁺, Mg²⁺ and Mn²⁺ activated the enzyme, while Ca²⁺, Cu²⁺, Hg²⁺ and Zn²⁺ inhibited the enzyme activity. Mercuric ion (Hg²⁺), known to be an inhibitor of cysteine proteases exhibited the highest inhibition (34.79%). The proteolytic activity of the enzyme was inhibited by thiol-specific inhibitor, ethyl iodoacetate (5 mM), in a mixed inhibition pattern. The characteristics of this enzyme provide basis for its use in various food industries.

ABSTRACT: This study is aimed at investigating and comparing the in vitro antioxidant effects of ethanolic extracts of Psidium guajava stem bark and Telfairia occidentalis leaf using 2, 2-diphenyl 1-picrylhydrazyl (DPPH) free radical scavenging assay. Ascorbic acid and ??????-tocopherol were used as standards in this study. The results obtained showed that Telfairia occidentalis leaf contained a significantly high amount of vitamin C, total flavonoids and phenolics than Psidium guajava stem bark, which were 0.17 ?????? 0.05%, 0.05 ?????? 0.01%; 0.84 ?????? 0.32 g/100 g, 0.43 ?????? 0.05 g/100 g; 8.21 ?????? 0.20 g/100 g, 1.15 ?????? 0.12 g/100 g, respectively. Telfairia occidentalis leaf inhibited more free radicals than Psidium guajava stem bark, with maximum inhibition at 0.5 mg/mL, which were 81% and 75%, respectively. This study showed that Telfairia occidentalis leaf had higher antioxidant activity compared to Psidium guajava stem bark, which were both lower than those of ascorbic acid and ??????-tocopherol which were used as standard antioxidants. 

ABSTRACT: Azadirachta indica (AI) is used in traditional medicine for household remedy against various human diseases. The purpose of the study was to evaluate the potency of the aqueous leaves extract of AI in preventing liver damage in rats administered subcutaneously with 75mg/kg CCl₄. The activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TB) and the levels of serum malondialdehyde (MDA) were determined in rats administered with 75mg/kg CCl4 and rats treated with 100mg/kg and 200mg/kg of AI after CCl₄ administration. The activities of these serum parameters analyzed in CCl₄ control group were found to be significantly (P< 0.05) higher when compared with those of normal control rats. This increase was significantly (P< 0.05) decrease in all the treated groups, with those received 200mg/kg of the extracts been more active. The decrease on level of MDA was not statistically significant from that of CCl₄control group in all the treated groups. The result was further confirmed by the histological analysis of the liver. There was improvement in the CCl₄-induced hepatic histological changes. These results were comparable with that of standard drug, silymarin. The amount of alkaloid, flavonoids, saponins, phenolics and saponins in AI leaves were found to be 0.62%, 0.69%, 0.11% and 1.59% respectively. Hence, this established the potency of the aqueous leaves extract of AI in curing the liver damage in rats administered with CCl₄.

ABSTRACT: The present investigation was aimed to extract oil from edible insect Macrotermis bellicosus and carry out studies on its physicochemical properties. The result obtained shows that the oil extracted from the Macrotermis bellicosus is a clear, odourless liquid, with a light yellow colour. The physicochemical properties of the oil revealed 122.30 mg KOH/g for saponification value, 0.52 mg/100 g for iodine value, 7.59 meq/kg for peroxide value, 4.07 mg KOH/g for acid value, 117.73 mg KOH/g for ester value and that it contained 31.43% for crude lipids. These findings show that the termite Microtermis bellicosus contains high percentage of quality crude oil, which could be stable in storage, less susceptible to oxidation and rancidity. This suggests that the oil could be exploited for domestic, pharmaceutical and industrial purposes. Also the oil extracted contains unsaturated fatty acids which could be nutritionally essential and therefore justify their consumption in various communities in Nigeria and Africa.

ABSTRACT: In the present endeavour, a total of 27 mold isolates were obtained from 10 soil samples by serial dilution agar plate technique and all these fungal isolates were screened for production of alkaline protease on casein agar plates. The most promising isolate was identified on the basis of cultural and microscopically characteristics as Aspergillus niger. Various cultural parameters such as substrate concentrations, enzyme concentrations, pH and temperature were observed for the optimization of production of alkaline protease. Optimum enzyme activity was observed at 1% substrate concentration, 10% enzyme concentration, at temperature 50 ??????C and at pH 8.5. In presence of casein, alkaline protease of Aspergillus niger retained 66-86% activity in the presence of commercially available detergents such as Tide, Surf excel, Wheel, Rin and Nirma, indicating its suitability for application in detergent industry. The lab-scale study on protease production by Aspergillus niger might give the basic information of further development for large scale production.