EFFECTS OF DETOXIFICATION ON SOME PHARMACOLOGICAL PROPERTIES OF JATROPHA CURCAS LINN. (EUPHORBIACEAE) SEED OIL IN LABORATORY ANIMALS

EFFECTS OF DETOXIFICATION ON SOME PHARMACOLOGICAL PROPERTIES OF JATROPHA CURCAS LINN. (EUPHORBIACEAE) SEED OIL IN LABORATORY ANIMALS

Abstract:

Jatropha curcas seed oil is a known energy source in biodiesel which but for its toxicity, also has potential of being used as food and in the pharmaceutical / cosmetic industries. This study was designed to detoxify solvent and mechanically extracted J. curcas oils and to ascertain the effects of detoxification on acute and sub-acute toxicities as well as on analgesic and laxative activities in laboratory animals. Following determination of the physicochemical properties of the extracted oils, detoxification of the oils was attempted by both the usual synthetic method of orthophosphoric acid degumming, sodium hydroxide deacidification, tonsil decolourisation and vacuum-heat deodorization; and by the use of natural materials in place of the synthetic agents such as distilled water for orthophosphoric acid, plantain peel ash extract for sodium hydroxide and bentonite for tonsil. Phytoconstituents, elemental and phorbol esters compositions of the oils were also determined. Acute toxicity studies for LD50 determination and sub-acute (14 days) studies for toxicity symptoms of the mechanically extracted oil in male rats were carried out. Weight changes, mortality, haematological liver / kidney assessment as well as histopathological analyses of liver, kidney and intestines were checked. Wherever appropriate olive oil was used as vehicular control. Statistical analyses were by ANOVA with appropriate post hoc tests. The extraction yields of the oils were 49.1% (petroleum ether solvent) and 14.9% (hand operated hydraulic screw press). The physicochemical properties of the extracted oils were similar. Alkaloids were the only phytoconstituent present in both the undetoxified and detoxified oils. Detoxification resulted in oil losses upward of 60%, but with reasonable amounts of formed soaps (fatty-acid precipitate). Elemental analyses showed higher toxic elements (lead, cadmium and copper) and nutritional elements (iron, calcium and zinc) in the undetoxified oils compared to detoxified. The level of phorbol ester rich fraction of solvent extracted oil detoxified with synthetic materials was significantly (p<0.05) reduced, but such reduction was not significant (p>0.05) for mechanically extracted oils detoxified either with synthetic or more natural materials. The oral LD50 of the detoxified oils of both extraction processes in both 3-day old cockerels and adult male mice were above 5,000 mg/kg. Sub-acute oral treatment with 125, 250 and 500 mg/kg of mechanically extracted oil resulted in dose-dependent toxic symptoms of ruffled fur, hyperpnoea, restlessness and decreased mobility mostly of the vii undetoxified (moderate to severe) as opposed to the detoxified oil (mostly mild). The rats that received the undetoxified oil suffered weight loss and dose-dependent mortality, but there was neither weight loss nor mortality in rats treated with the detoxified oil. Administration of the undetoxified oil caused significant (p<0.05) dose-dependent increased levels of WBC and platelets and also of serum Na+. Both the undetoxified and detoxified oils produced significantly (p<0.05) increased levels of kidney function (urea and creatinine) as well as liver function indices (serum albumin and enzymes, ALT, ALP, AST), but the increase in AST was more for the undetoxified oil. The undetoxified oil at 500 mg/kg, resulted in reduced liver and kidney to body weight ratios. Both the undetoxified and detoxifed oils at 250 and 500 mg/kg showed significant (P<0.05) central and peripheral analgesic activity, which was dose-dependent only for the undetoxified oil. The laxative activity in mice was not significant (p>0.05) for any of the oils. Histopathological examinations of the liver, kidney and intestines indicated a dose-dependent moderate to severe necrosis and degeneration of tissues from the undetoxified oil, while detoxified oil produced mild degeneration of tissues. But for the high oil losses in the process of detoxification, the detoxified oil, based on the various indices studied, ameliorated the toxic effects of J. curcas oil and revealed its potential for use medicinally.

EFFECTS OF DETOXIFICATION ON SOME PHARMACOLOGICAL PROPERTIES OF JATROPHA CURCAS LINN. (EUPHORBIACEAE) SEED OIL IN LABORATORY ANIMALS