This study investigated the phytoconstituents in Neem (seed and flower), Jatropha curcas (stem and root bark) and grape (stem bark and leaves) in some selected solvents. Phytochemical screening revealed the presence of bioactive compound saponin in all the parts of the three plants in water extract only. Saponin was absent in other solvents used (ethanol, ethyl acetate, propan-2-ol, methanol, nbutanol and acetone). Ethanol, ethyl acetate and methanol were the most promising solvents to extract flavonoids in both the seed and flower of Neem plant. Acetone and ethanol were the most promising solvents to extract flavonoids in the stem bark of J. curcas. In the root bark of J. curcas, acetone and ethyl acetate were the most promising solvents to extract flavonoids. In grape (Citrus paradisi) leaves, ethanol, water and acetone were the most promising solvents to extract flavonoids. In the stem bark of grape, water, ethyl acetate and acetone proved promising as extraction solvents for flavonoids. All the parts of the plants studied were positive for alkaloid in ethanol and acetone extracts. The seed extract of Neem (Azadirachta indica) was strongly positive in ethanol only. Terpenoids were detected in ethyl acetate and n-butanol in all the parts of the three plants. Aged flower extract of Neem plant with pale pink colour could be exploited as a novel source of colourant. Volatile oil was not restricted to J. curcas stem and root barks, it was also present in C. paradisi stem and root barks. The nutritional significance, economic and toxicological implications of phytoconstituents analysed in the plants were discussed.

Calotropis procera is an evergreen perennial shrub, which is found mainly in the arid regions and produces copious latex when cut. It has been reported to possess medicinal properties but equally pose deleterious effect in animals. In a bid to exploit its pharmacological properties, it was necessary to ascertain its level of safety. A toxicological evaluation of the aqueous extract of fresh leaves of the plant was therefore conducted in the more sensitive female rabbits of the same weight range. Low levels of phytochemicals (alkaloids, saponins, tannins, cardiac glycosides and flavonoids) were found, while elemental analyses showed traces of iron, lead, sodium, and potassium in concentrations of 0.23, 0.03, 0.82 and 9.5 mg/g, respectively. Acute toxicity study was conducted with oral administration of 200, 400, 800 and 1600 mg/kg of the extract once to groups I, II, III and IV, respectively with a 24 h observation period. Clinical signs such as mouth chewing, photophobia, bradycardia, coughing, vomiting and convulsion amongst others were noticed. Four rabbits died within 24 h and LD 50 was estimated (940 mg/kg). 80, 40 and 20 mg/kg of the extract were administered daily to groups I, II, and III, respectively, during sub-acute toxicity study for 14 days. Grossly, catarrhal enteritis and mesenteric congestion of the small intestines, congestion of the lungs, hepatization and paleness of the liver, congestion and pallor of the kidney cortex, and congestion of the meninges were noticed. Histopathological examination of the tissues revealed mild pulmonary oedema and peribronchial lymphocytic infiltration of the lungs, hepatization of the liver, disruption of cardiac architecture, generalised cell necrosis and erosion of the villi of the small intestine. All the rabbits that survived gained weight, which is indicative of some nutrient value in the extract. It was concluded that the extract had dose-dependent deleterious effects on the tissues as higher dose groups were more affected. Hence, it is evident that sub-chronic toxicity studies would reveal greater lesions to better ascertain extent of damage.

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