Antidiarrhea activity and preliminary phytochemical screening of Indigofera arrecta, Cyathula uncinulata, Persea americana and Cupressus lusitanica
The treatment of diarrhea diseases occupies an outstanding place in the Rwandese traditional medicine and several plants or combinations of plants are used. For this purpose, Indigofera arrecta, Cyathula uncinulata, Persea americana Mill and Cupressus lusitanica are currently used by the traditional healers.
Aqueous and ethanolic leaves extracts were screened in vitro for antibacterial activities against clinical isolates of selected diarrhea causing bacteria: Salmonella typhi, Shigella flexneri and Escherichia coli. The Cupressus lusitanica, aqueous and ethanolic extracts, were the most effective with a minimum inhibitory concentration (MIC) between 0.7 and 4mg/ml for all tested bacteria. The aqueous and ethanolic extracts of Persea americana and Cyathula uncinulata leaves showed very weak activity against all bacteria with a minimum inhibitory concentration between 2–13mg/ml. The ethanolic extract of Indigofera arrecta was effective at the concentration between 1–4.5mg/ml but its aqueous extract did not show any activity. The least sensible bacteria was Escherchia coli. The preliminary phytochemical screening revealed the presence of tannins, anthocyans and leucoanthocyans in all the 4 plants. Quinones and anthraquinones were found only in Cupressus lusitanica and Persea americana while Flavonoids and Saponosides were found only in Indigofera arrecta and Cyathula uncinulata.
References: Williams, L.R., Home, VN. (1998) International Journal of Aromatherapy 8:30–40.