PHYTOCHEMICAL AND TOXICOLOGICAL STUDIES ON AQUEOUS EXTRACTS OF Nutmeg (Myristicafragrans Houtt)

Abstract

Nutmeg, the dried kernel of a broadly ovoid seed of Myristica fragrans, popularly taken as food and medicine was studied for its phytochemical and toxicological properties. Proximate analysis revealed high levels (percentage) of protein (10.61%), fat (45.42%), fibre (5.95%), Ash (1.81%), moisture (13.78%), and carbohydrate (16.52%), with the crude fat content being the highest (45.42 ± 1.15). The mineral contents ranged from Mg (403 ppm) to Pb (5.3 ppm). The antinutrients determined were found to be in little percentage that were not detrimental to health (tannin as total phenol 0.15% and phytate 0.38%). This implies that the minerals, especially Zn were bioavailable. From the phytochemical screemng, secondary metabolites found to be present in the seed were alkaloids, phlobatannins, anthraquinones, cardiac glycosides and flavonoids, while saponins and tannins were absent. In the toxicological study, five groups of albino rats were administered aqueous extract of the seed at a dose of 100 - 500 mg/kg, a sixth group (control) was administered 0.9% saline. This was carried out for 28 consecutive days, at the end of which the animals were sacrificed and the livers, hearts and sera collected for examination. The liver function tests revealed that in the liver, the bilirubin and ALT levels were not significantly affected as compared with the control (1.32 ± 0.17 - 1.45 ± 0.31 and 0.39 ± 0.03 - 0.40 ± 0.15 respectively). However, AST, ALP and total protein were significantly reduced in the treated groups while albumin was reduced only in the group treated with 400 mg/kg of nutmeg. In the serum, albumin level did not show a significant difference, bilirubin showed a slightly increased level down the group while the AST, ALT and ALP levels show an increase in activity down the group. Heamatological tests revealed a slight reduction in the PCV of the rats down the group, the Hb, RBC, MCV and platelet show no significant difference as compared with the control. Histopathological studies on the livers and hearts revealed a progressional increase of bile duct proliferation, liver congestion and periportal lymphocytic infiltration in the livers down the group while the heart revealed an increasing level of myocardial necrosis from the rats given doses of 300 mg/kg to 500 mg/kg. The study shows that nutmeg is nutritionally rich for energy production and normal growth promotion but care should be taken in dosage since high doses are toxic.