Open Access Original Research Article

Green Synthesis, Antioxidant and Antimicrobial Activity of Silver Nanoparticles Using Gnetum africanum Extracts

I. M. Uneze, J. O. Otonko, A. K. Adigun, S. J. Adebayo

Asian Journal of Biochemistry, Genetics and Molecular Biology, Page 1-7
DOI: 10.9734/ajbgmb/2021/v9i230210

The synthesis and application of nanoparticles is an important area of research that is gaining attention recently. In this recent project, we report the synthesis of silver nanoparticles, AgNP using aqueous solution of silver nitrate and Gnetum africanum leaf extract (reducing agent). The synthesis of AgNP was achieved by mixing aqueous solution of silver nitrate (70ml, 15.75mM) with a solution of Gnetum africanum leaf extract 100 ml) in a reaction flask and allowed to stand for 24 hours in a dark cupboard. A color change from light brown to yellowish brown was observed which indicated that synthesis of silver nanoparticles took place. The presence of AgNP was ascertained using UV-vis spectra analysis and absorption at 442 nm showed the presence of AgNP. The antioxidant assay of both the synthesized AgNP and the leaf extract was determined using DPPH. Antimicrobial activity was conducted using three different organisms which were Staphylococcus aureus, Escherichia coli and Pseudomonas respectively. The antioxidant results using DPPH scavenging ability of AgNp showed that at concentrations of 2mg/ml,1mg/ml and 0.1mg/ml, the percentage inhibition  of  DPPH  by AgNp was 61.69, 53.06 and 38.31 respectively and that of Gnetum africanum leaf extract was 81.32, 78.49, and 58.29 respectively at the same concentrations using Ascorbic acid as a standard. The antimicrobial activity of both the synthesized AgNps and Gnetum Africanum Leaf extract using one gram positive bacteria (Staphylococcus aureus) and two gram negative bacteria (Escherichia coli and Pseudomonas) revealed that the synthesized AgNps showed lesser activity than Gnetumafricanum leaf extract for both the gram positive bacteria (Staphylococcus aureus) and gram negative bacteria (Pseudomonas) and (Escherichia coli). From the above findings, it can be observed that Gnetum Africanum Leaf extract reduced Ag+ to Ag0 and also both the synthesized AgNps and the Gnetum Africanum Leaf extract showed reasonable antioxidant activity against DPPH and antimicrobial activity against the tested microorganisms. This implied that both samples have medicinal values.

Open Access Original Research Article

Chemical Composition and Nutraceutical Potential of Velvet Tamarind (Dialium guineense wild) Fruit Pulp

Augustine I. Airaodion, Emmanuel B. Ayita, Simeon O. Oluba, Sunday A. Emaleku, Ojo J. Osunmuyiwa, Anthony U. Megwas

Asian Journal of Biochemistry, Genetics and Molecular Biology, Page 8-19
DOI: 10.9734/ajbgmb/2021/v9i230211

Background: Fruits are known as excellent source of mineral and vitamins and may be used to increase rural population food quality. Consuming fruits and vegetables may usually aid in the prevention of chronic and degenerative diseases.

Aim: This study was designed to evaluate the chemical composition of velvet tamarind (D. guineense wild) fruit and its nutraceutical potential.

Methodology: The fruit of velvet tamarind was purchased from “Oja-Oba” market in Ibadan, Nigeria. The fruits were sun-dried, the coat and seed were removed by mechanical means. The pulp was ground using a pestle and mortar, and were transferred into an electric blender (Moulinex) for further grinding. After grinding, the powder was sieved into a finer particle and was used to determine the proximate, phytochemical, vitamin and mineral compositions of velvet tamarind fruit.

Results: Velvet tamarind fruit contains high concentration of carbohydrate (79.78%) but very low concentration of fat (0.43%). The phytochemical composition of the fruit has flavonoid (33.78 mg) and phytate (0.07mg) as the highest and lowest phytochemicals respectively. Velvet tamarind pulp was observed to be rich in vitamins with vitamin C (28.82 mg/100g) and vitamin B1 (0.84) having the highest and lowest concentrations respectively. Velvet tamarind pulp contained 5.85 mg/100g of potassium and 0.38 mg/100g of phosphorus as the highest and lowest minerals respectively.

Conclusion: The composition of velvet tamarind fruit obtained in this study revealed that it is a good source of nutrient, phytochemicals, vitamins and minerals. It should be incorporated as food supplement to reduce malnutrition. It is a fruit with promising nutraceutical potential, thus it is a useful tool for further drug development from the natural plant products.

Open Access Original Research Article

Kinetics of Crude Peroxidase from the Rind of Watermelon Fruit

O. M. Iniaghe, O. Ibukun, R. E. Giwa

Asian Journal of Biochemistry, Genetics and Molecular Biology, Page 20-27
DOI: 10.9734/ajbgmb/2021/v9i230212

Aims: To study the kinetics of crude peroxidase from the rind of watermelon fruit in various assay conditions.

Study Design: In vitro enzyme assay.

Place and Duration of Study: Department of Biochemistry, Faculty of Life Sciences, Ambrose Alli University, Ekpoma, Edo State, Nigeria between October 2015 and January 2016.

Methodology: The activity of the crude peroxidase extracted from the rind of watermelon was determined by measuring the rate of oxidation of KI at 25oC in a 3.0 ml reaction mixture which contained 2.3 ml of 25 mM - 400 mM sodium acetate buffer (pH 3.5-6.0), 0.2 ml of 2 mM KI, 0.1ml of the crude peroxidase, and 0.2 ml of varying concentrations of chlorpromazine (0.01 mM - 0.1 mM). In all cases, 0.2 ml of 0.01 mM – 1 mM H2O2 was added last to initiate the reaction. Only one parameter was varied per assay. Assays were done in five replicates. The initial velocity of the crude peroxidase for KI oxidation was determined using the absorbance at 353 nm.

Results: The concentration of H2O2 that generated an optimal activity for the crude peroxidase extracted was 0.2 mM, while a pH of 5.5 was optimal for the crude enzyme. The activity of the crude enzyme increased proportionately within a buffer concentration range of 25 mM and 400 mM. Chlorpromazine (0.01 mM - 0.1 mM) proportionately increased the enzyme activity, while promethazine within a range of 0.01 mM and 0.06 mM proportionally increased the enzyme activity. Further increase in promethazine concentration beyond 0.6 mM resulted in a decreased activity of the enzyme.

Conclusion: This study suggests that the Rind of watermelon is an alternative source of peroxidase. The activity of this peroxidase can be enhanced by high buffer concentrations in the presence of some redox mediators like promethazine and chlorpromazine at a pH of 5.5.

Open Access Original Research Article

Isolation and Biochemical Characterization of Cellulase Produced by Bacterial Isolates from Sugarcane Waste Soil

A. U. Hassan, R. Jafaru, I. B. Mato, E. Kereakede, A. H. Galadanci, A. H. Madu, I. A. Oyong, K. Onuh Onuh, U. O. Ozojiofor

Asian Journal of Biochemistry, Genetics and Molecular Biology, Page 28-35
DOI: 10.9734/ajbgmb/2021/v9i230213

Cellulase is one of the most economically important enzyme, which aids in catalyzing cellulolysis, the decomposition of cellulose and other related polysaccharides. So the demand/importance of this enzyme in both domestic and commercial sectors cannot be over emphasized. In this research cellulase-producing bacteria were isolated from soil around sugarcane waste dumping area, which was identified to be P. fulorescens after numerous biochemical and microbiological analysis. The bacteria were then grown and used to ferment certain biomass, with the aim of using the organisms to produce the cellulase enzyme. The total protein/cellulase enzyme activity of the medium was ascertained. Optimization/characterization for maximum cellulase activity was done by varying the temperature, pH, enzyme concentration and substrate concentration, in which the optimum condition for cellulase production was ascertain to be at a temperature and pH of 40˚C and pH 7 respectively. SDS-PAGE electrophoresis was carried out to determine and reconfirm the presence and molecular weight of the isolated enzyme. The estimated extrapolated molecular weight of the enzyme was found to be 13.5KDa.

Open Access Original Research Article

Effect of Hexane Extracts of Chromolaena odorata (Linn.) on Hematotoxicity Induced by Cyanide in Male Albino Wistar Rats

Fiyinfoluwa Demilade Ojeniyi, Adeola Folashade Ehigie, Aluko Oluwatosin Lydia, Gbadebo Emmanuel Adeleke, Leonard Ona Ehigie

Asian Journal of Biochemistry, Genetics and Molecular Biology, Page 36-43
DOI: 10.9734/ajbgmb/2021/v9i230214

Aim: To investigate the effect of Hexane extract of Chromolaena odorata (HECO) on cyanide induced hematotoxicity in male Albino Wistar rats.

Methodology: Thirty-five (35) male albino rats weighing between 100g and 150g were distributed randomly into 7 groups of 5 rats each. Group 1 which comprised of normal rats received distilled water and served as the normal control, while groups 2-7 comprised of rats exposed to Potassium cyanide (KCN) (3 mg/kg). Group 2 received no treatment and served as the negative control. Groups 3, 4 and 5 received 100, 150 and 200 mg/kg of HECO respectively. Group 6 received 200 mg/kg HECO and 200 mg/kg sodium thiosulphate while group 7 was treated with a sodium thiosulphate (200 mg/kg), an established antidote, and served as the positive control. All administrations were done via the oral route and lasted for 14 days. Complete blood count was conducted after the experimental period. Data were analyzed using one-way analysis of variance, followed by Tukeys multiple comparisons test and P < .05 was considered significant.

Results: Results obtained indicate Red cell indices and white blood cell and differential were all significantly raised (P < .05) in treated rats relative to the negative control rats. Platelet value and Mean corpuscular volume were raised and lowered respectively during induction by the treatments, however, no statistical significance (P < .05) was observed. The results therefore suggest that C. odorata could be valuable in the management of the hematological changes induced by cyanide.

Conclusion: HECO reversed the adverse hematological changes in rats induced by cyanide at 100, 150 and 200 doses, with the 200 mg dose being more effective.