Bioassay of cathartics. I. Emodin type

Laxative activities of Cassia sieberiana and Senna obtusifolia

BACKGROUND

The root and stem bark of Cassia sieberiana DC. (Caesalpiniaceae) and the root of Senna obtusifolia (Linn) Irwin and Barneby (Caesalpiniaceae), used for constipation in Nigeria, were assayed for laxative properties in male albino rats using the official senna leaf (Senna alexandrina Mill. family Caesalpiniaceae) as the reference standard. This is with a view to finding alternative laxative drug to official senna which is presently being imported into Nigeria from the United Kingdom.

MATERIALS AND METHODS

The mean percentage of wet faeces in rats, an indication of laxative activity, were obtained using established methods. The laxative activity was established at 500 mg/kg after the infusion of the drug was orally administered on male albino rats following established methods while a set of data was analyzed at 95 % confidence level.

RESULTS

At 500 mg/kg, Senna obtusifolia root gave about 45 % wet faeces while Cassia sieberiana root gave about 40 % wet faeces while at the highest dose of 700 mg/kg, they produced 60 % and 38 % wet faeces, respectively. At these two doses, the official Senna gave 50.6 % and 66 % wet faeces, respectively. Thus, S. obtusifolia and C. sieberiana roots exhibited 89 % and 80 % of the potency of S. alexandrina (the official drug), respectively. The analysis of variance revealed a significant statistical difference in the levels of wet faeces produced by rats dosed with C. sieberiana root.

CONCLUSION

The results have shown that the roots of the two species could be developed as mild laxative drugs for children and pregnant women for whom the official senna will be contraindicated.

The Characterisation of Crystalline and Amorphous Aloin

Tests are described showing the differences between amorphous aloin and that of the B.P. 1953. One of these tests might, with advantage, be incorporated in official publications to differentiate crystalline aloin from the relatively impure and less active amorphous aloin.

Chemical and biological analyses of Nigerian Cassia species for laxative activity

The leaves of 10 Cassia species (Leguminosae), cultivated in Nigeria, were assayed spectrophotometrically for combined anthraquinone content and also pharmacologically for their laxative properties in male albino rats using official senna leaves (Cassia acutifolia Del.) as the reference standard. Leaves of C. podocarpa Guill, and Perr. and of senna had identical laxative potency. The results of both the chemical and the biological experiments suggested that C. alata L. and C. podocarpa are the most likely candidates for drug development in Nigeria. The use of a laxative index is proposed for the comparative study of Cassia (or any plant species) and its possible application to the quality control of these drugs is discussed.