Pulp Extracts of Picralima nitida: a Larvicidal Agent in Malaria Vector Control

The methanolic and aqueous pulp extracts of Picralima nitida as an eco-friendly alternative in malaria vector control were investigated. The sample yielded a 3.93% extract with methanol and 0.89% with aqueous. The phytochemicals constitutes of crude methanolic and aqueous extracts of P. nitida pulp include the alkaloids, cardiac glycosides, saponins, tannins, flavonoids, terpenes and steroids. Laboratory reared larvae of Anopheles gambiae 4th instar were exposed to varying concentrations of the P. nitida pulp extracts ranging from 0.5 to 5.0mg/ml, according to WHO Bioassay Methods for susceptibility. Probit analysis using statistical package for social sciences version 16.0, at (P<0.05) gave time dependent LC50 and LC95 values of 4.979 mg/ml and 18.541mg/ml, 4.299 mg/ml and 16.008 mg/ml and 2.792 mg/ml and 10.397 mg/ml for aqueous pulp extracts at 24, 48 and 72 hours while methanolic extract values were 12.285 and 96.993 mg/ml, 9.700 and 76.584 mg/ml and 6.490 and 51.236 mg/ml at 24h, 48h and 72 h respectively. The Relative Potency estimate revealed that methanolic extract has 1.525, 1.554 and 1.880 times the potency of aqueous extract at 24 h, 48 h and 72 h respectively. Keywords: Picralima nitida, Eco-friendly, Insecticides, Resistance, Larvicidal

Effect of Vernonia amygdalina Ethanolic Root Extract on the Hepato- and Nephro-Protective Properties of Albino Rats (Rattus novergicus)

The hepato- and nephro-protective potentials of Vernonia amygdalina ethanolic root extract was evaluated for 14 days using standard bioassay in 45 normal male albino rats. The rats were divided into four treatment groups I – IV and a control group V. Groups I – IV were given 100mg.kg-1, 200mg.kg-1, 400mg.kg-1 and 600mg.kg-1 body weight, respectively while the control (group V) was given equal volume of feed and water. The extracts were administered orally to the animals for 14 days. Blood samples were collected using the ocular puncture method before and weekly after administration to evaluate the extracts’ effects on aspartate transaminase (AST), acid phosphatase (ACP), alanine transaminase (ALT), alkaline phosphatase (ALP), bilirubin, creatinine and blood urea nitrogen (BUN) levels. The mean serum levels of the liver marker enzymes AST, ACP, ALT, ALP, total bilirubin and direct bilirubin ranged from 10.00±0.53 to 11.44±0.44, 31.29±0.64 to 33.14±0.56, 27.22±0.94 to 29.67±0.37 and 37.83±0.59 to 40.57±1.02, 3.42±0.08 to 3.61±0.07 and 2.06±0.11 to 2.51±0.05 respectively. The mean levels of the nephrotic enzymes, creatinine and BUN also ranged from 39.87±1.79 to 43.04±1.57 and 6.62±0.21 to 15.98±0.17 accordingly. Although no significant difference (p>0.05) was observed in the serum levels of the liver marker enzymes and creatinine when compared with the control, a dose and duration dependent significant increase (p<0.05) occurred in the BUN level. This tends to suggest that the ethanolic root extract of Vernonia amygdalina on a short term basis has some hepato-protective property while its nephro-protective ability is still doubtful. Keywords: Vernonia amygdalina, Ethanolic root extract, Liver maker enzymes, Nephrotic enzymes, Albino rat

Eco-physiological adaptation of the land snail Achatina achatina (Gastropoda: Pulmonata) in tropical agro-ecosystem

The survival of land snails in an adverse environmental condition depends on the integral physiological, morphological and behavioural adaptations. These adaptations are essential in understanding the species-specific habitat requirements and in predicting their environmental responses. In this study, the monthly and the periodic patterns of eco-physiological adaptation of land snail, Achatina achatina in Nsukka tropical agro-ecosystem were assessed from December 2012 to July 2013. Standard methods were employed in sampling the land snail and determination of the water content, biochemical fuel reserves and enzyme concentrations of the samples. The present results showed that lipids were high at the beginning of aestivation and depleted as the aestivation progressed. Glycogen was significantly low throughout the aestivation months (December–March) and increased in the active months (April–July). Protein content recorded a definite pattern all through the months studied. Catabolism of lactate and a decrease in activity of LDH during aestivation and substantial increase upon activation were observed. Data showed that transaminase and aspartate enzymes depleted during the aestivation months indicating that the snails may have developed potential cell injury due to oxidative stress and thermal heat. A disassociation between the physiological responses and climatic data was recorded. The physiological adaptation of A. achatina ensures regular adjustment under extreme conditions and compensates for its metabolic regulation in the tropics. It is concluded that survival of A. achatina is not environmentally predicted; rather it depends on the species-specific inherent process in predicting responses for survival