Toxicilogical effects of aqueous extract of Hibiscus Sabdariffa on the liver and kidney.

Abstract

Background: Hibiscus Sabdariffa(HS) is widely consumed in Nigeria and many parts of the world as a refreshing drink. It is equally used in traditional medicine to treat various diseases such as cough, hypertension, stomach disorders, loss of appetite, upper respiratory congestion, nerve and heart disorders and menstrual difficulties. Some of these
ethnomedicinal claims have been confirmed by scientific researches. Some of these researches have shown that HS has protective effect on some body organs while others have demonstrated its toxic effect on some organs.

Aims and Objectives: The aim of the present study is to show the effect of graded doses of aqueous extract of HS on major excretory organs(Liver and Kidney) of albino Wistar rats. This may be helpful in determining the safety or otherwise of its consumption at different
concentrations.

Materials and methods: Sixty male albino Wistar rats weighing 150-250mg and aged 2-3 months were used for this study. Normal rat chow (Guinea feed) and distilled water were provided ad libitum. The rats were divided into five groups (A-E). Groups A-D were the test groups and were administered different doses of the HS extract: 20, 40, 80 and 160mg/kg respectively using oral feeder (Gavage). Group E served as control and was given only distilled water. The extract was administered daily for a period of 12 weeks. After 4 weeks, four rats were picked at random from each group and sacrificed. The histology of the liver and kidney was investigated. At 8th and 12th weeks, the experiments were repeated.

Results: There were no significant changes in the histology of the liver throughout the period of HS administration in all the groups. However, there were significant histological changes in the kidney which were more pronounced at higher doses (80 and 160mg/kg). There was shrinkage of glomerular tuft, increase in urinary pole, increase in size of tubular lumen and tubular damage. These effects were more marked as the duration of administration of the extract progressed with greatest effect observed at 12th week.

Conclusion: The results of the present study suggest that aqueous extract of HS has no harmful effect on the liver but when consumed in high doses could be harmful to the
kidney. Further research aimed at identifying the chemical composition and potential toxic agent(s) in HS is recommended.