Cassia angustifolia extract is not hepatotoxic in an in vitro and in vivo study

Cassia angustifolia L. (senna) is traditionally used as a laxative. Its major components are sennosides that are responsible for the laxative effect. Senna is recommended for the short-term treatment of acute constipation. Nevertheless people use its preparations as self-medication, often for long periods, to treat chronic constipation thus exposing themselves to adverse reactions. Most reactions were associated with hepatotoxicity.

The present study was aimed to evaluate the toxicity of a C. angustifolia leafextract (standardized at 60% of sennosides) on rat liver cells and the long-term effects on liver functions, in Wistar rats.

Cytotoxicity was assessed in a buffalo normal rat liver cell line (BRL-3A) by the trypan blue assay and the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide reduction test. In vivo effects were observed after oral administration of the extract for 4 or 8 weeks at doses of 12 and 58 mg/kg/day. At the end of treatment, animals were sacrificed, the postmortem examination was performed and serum was used for biochemical analysis. Liver samples were used for histomorphological and immunohistochemical examination along with the determination of oxidative stress parameters.

In BRL-3A cells, the extract was cytotoxic at concentrations that appear largely higher than those attainable in humans. In Wistar rats, the extract did not induce any significant change in all of the parameters tested. In summary, the present study indicates a lack of hepatotoxicity of senna at doses higher than those generally used in humans.