PHYTOCHEMICAL AND BIOLOGICAL STUDIES ON THE SEEDS OF JATROPHA CURCAS LINN. (EUPHORBIACEAE)

PHYTOCHEMICAL AND BIOLOGICAL STUDIES ON THE SEEDS OF JATROPHA CURCAS LINN. (EUPHORBIACEAE), A RESEARCH PROJECT TOPIC ON MICROBIOLOGY

ABSTRACT

Jatropha curcas Linn. (Euphorbiaceae) is a shrub that grows up to 5m in height. It thrives well in tropical countries. It grows in the wild as an uncultivated, non-food plant. It is traditionally used as a living fence to protect gardens from animals.

An ethnobotanical survey of the seed of J. curcas was carried out in parts of Zaria and Zonkwa in Kaduna State of Nigeria. The seeds are used in traditional medicine for analgesic, antimicrobial, purgative, laxative and aphrodisiac purposes. Sometimes, the seeds serve as food when cooked. Some of the common toxic effects of direct consumption of the seeds include purging, body weakness, convulsion and abdominal pains.

Pharmacognostic study of the seed was carried out including macroscopy, microscopy and the determination of some physical standards. A study on the phytochemical constituents and biological activities of J. curcas seeds was carried out. The thin layer chromatographic analysis using random solvent systems showed rich composition of chemical constituents like flavanoids, steroids and triterpenes using various solvent systems.

The seed extract was tested for analgesic activity using the acetic acid induced writhing response in mice. Chemomicroscopic and fluorescence analyses of the seed were carried out.

Using agar well diffusion method, the methanolic extract of J. curcas seeds and four fractions of the extract; petroleum ether fraction, ethyl acetate fraction, n-butanol fraction and aqueous fraction, were used for antimicrobial test. Two fold serial dilution of the extract and fractions were made to obtain 200mg/ml, 100mg/ml, 50mg/ml, 25mg/ml, 12.5mg/ml,     6.25mg/ml,     3.13mg/ml     and   1.57mg/ml.     The     test     organisms     were; Staphylococcus aureus, Escherichia coli, Salmonella typhi, Streptococcus pyogenes and Candida albicans. The seed oil was found to have an acid value of 5.61 and a saponification value of 297.33. Preliminary phytochemical studies revealed the presence of flavonoids, carbohydrates, saponins, tannins and steroids. Acute toxicity test revealed that the methanolic extract has an LD₅₀ of 471.17 mg/kg in albino mice, making it very toxic.

The seed methanolic extract significantly (P < 0.05) reduced writhes induced by acetic acid. The results of the analgesic test were comparable to the standard drug (paracetamol 100mg/kg). Although not all organisms were susceptible throughout, it was discovered that the methanolic extract, aqueous fraction, ethyl acetate fraction, n-butanol fraction and petroleum ether fraction generally exhibited activity against the test organisms at 50-200µg/ml concentrations.

PHYTOCHEMICAL AND BIOLOGICAL STUDIES ON THE SEEDS OF JATROPHA CURCAS LINN. (EUPHORBIACEAE), A RESEARCH PROJECT TOPIC ON MICROBIOLOGY