Evaluation of the toxicity of crude aqueous Pleurotus tuber-regium (Fr.) Singer extract in mice.

OBJECTIVES: The study aimed to determine the phytochemical profile and safety of the aqueous extract of Pleurotus tuber regium using laboratory animal model. METHODS: The pulverized sample was macerated with water and allowed to stand for 24 h, then filtered. Preliminary qualitative phytochemical screening was carried out on the crude extract and LD50 determination was done using standard procedures. Haematological and serum biochemical parameters to assess the kidney and liver functions were carried out using standard methods. RESULTS: The phytochemical screening revealed the presence of alkaloids, cardiac glycosides, saponins, phenolic compounds, tannins, steroids, carbohydrates, flavonoids and terpenoids. However, anthraquinones were observed to be absent in the extracts. The LD50 of the extract was found to be greater than 5,000 mg/kg when administered orally with no physical signs of toxicity and death over the 14-day period. There was no significant (p>0.05) increase in the level of serum alanine aminotransferase, aspartate transaminase, alkaline phosphatase, blood urea nitrogen and creatinine (p<0.05) when compared to the control group. There was a significant (p<0.05) increase in the total white blood cells of the mice administered with P. tuber-regium. CONCLUSIONS: This study showed that P. tuber-regium (Fr.) Singer does not possess toxic principles, hence, the wide safety margin observed in the mice.

Effects of crude methanol extract of Adansonia digitata fruit pulp on Naja nigricollis venom-induce toxicity in Wistar rats.

OBJECTIVES: This study evaluated the effects of Crude Methanol Extract of Adansonia digitata Fruit Pulp on Naja nigricollis Venom-Induce Toxicity in Wistar rats. METHODS: A. digitata was extracted using 70% methanol and median lethal dose (LD50) of both the extract and venom were determined using the up-and-down method. Sixty Wistar rats were randomly assigned into 10 groups of 6 rats each and were administered with normal saline, venom only, venom + antivenom, 125 mg/kg, 250 mg/kg and 500 mg/kg crude methanol extract (CME) pre-envenomation, 125 mg/kg, 250 mg/kg and 500 mg/kg CME post-envenomation, and venom + antivenom + 250 mg/kg CME, respectively. Blood samples were collected 8-h post-envenomation in EDTA and plain sample bottles. Erythrocyte osmotic fragility (EOF) test was carried out on the EDTA blood samples while serum was harvested and used for Malondialdehyde (MDA) and Superoxide Dismutase (SOD) assays. RESULTS: LD50 of the CME and venom was >5,000 mg/kg and 0.889 mg/kg, respectively. N. nigricollis-induced oxidative stress was evident in group B through increased % haemolysis, MDA and lowered SOD activities. The groups treated with antivenom only, 250 mg/kg CME post-envenomation and antivenom +250 mg/kg CME significantly (p<0.05) reduced EOF, MDA values and increased SOD. The CME revealed better ameliorative effect than protective via inhibition of EOF, MDA values and increased SOD activity. CONCLUSIONS: The CME when administered singly showed more ameliorative properties and the combination of CME with antivenom for protection was not as effective as when compared to single administration.

Fishmeal replacement with Spirulina Platensis and Chlorella vulgaris in African catfish (Clarias gariepinus) diet: Effect on antioxidant enzyme activities and haematological parameters.

This study explored fishmeal replacement with two freshwater microalgae: Spirulina Platensis and Chlorella vulgaris in African catfish (Clarias gariepinus) diet. The effect of inclusion of the two microalgae on biomarkers of oxidative stress, haematological parameters, enzyme activities and growth performance were investigated. The juvenile fish were given 3 distinct treatments with isonitrogenous (35.01-36.57%) and isoenergetic (417.24-422.27 Kcal 100 g-1) diets containing 50% S. platensis (50SP), 75% S. platensis (75SP), 50% C. vulgaris (50CL), 75% C. vulgaris (75CL) and 100% fishmeal (100% FM) was used as the control diet. The result shows that all the diets substituted with both S. platensis, and C. vulgaris boosted the growth performance based on specific growth rate (SGR) and body weight gain (BDWG) when compared with the control diet. The feed conversion ratio (FCR) and protein efficiency ratio (PER) was significantly influenced by all the supplementations. The haematological analysis of the fish shows a significant increase in the value of red and white blood cells upon supplementation with 50SP and 50CL but decrease slightly when increased to 75SP and 75CL. Furthermore, the value of haematocrit and haemoglobin also increased upon supplementation with 50SP and 50CL but decrease slightly when increased to 75SP and 75CL. The white blood cell (WBC), red blood cell (RBC) increased, while total cholesterol (TCL), and Plasma glucose levels decreased significantly upon supplementation of algae. This is a clear indication that S. platensis and C. vulgaris are a promising replacement for fishmeal, which is a source protein in the C. gariepinus diet.