Antitrichomonal and antioxidant activities of Dorstenia barteri and Dorstenia convexa

N.O.A Omisore,B.T Ngadjui,J Watchueng,B.M Abegaz,J.A Ojewole,C.O Adewunmi,E.O Iwalewa,T.K Adenowo

doi:10.1590/s0100-879x2005000700012

Abstract

Dorstenia barteri and D. convexa extracts and some isolated components of the former were investigated for effectiveness against Trichomonas gallinarum and compared with quercetin and quercitrin. The antioxidant activity of the extracts/compounds was also determined. The minimum lethal concentrations (MLCs) for the extract of D. barteri leaves and twigs at 24 h were found to be 15.625 and 15.625 microg/ml, respectively. However, the MLCs of the leaf and twig extract of D. convexa were 125 and 437.5 microg/ml, respectively. The prenylated and geranylated chalcones were as active as the prenylated flavones, 6-prenylapigenin and the diprenylated derivative 6,8-diprenyleridictyol. The order of the antitrichomonal activity of the compounds at 24 h was: quercetin (0.121 microg/ml) > quercitrin (0.244 microg/ml) > or = bartericin B (0.244 microg/ml) > bartericin A (0.73 microg/ml) > stigmasterol (0.98 microg/ml) > 6,8-diprenyleridictyol = isobavachalcone = dorsmanin F (31.25 microg/ml). D. barteri extracts, quercitrin, and bartericin A, and the prenylated flavonoids had potent antioxidant properties. The twig extract of D. barteri was more potent than the leaf extract. Moderate (EC50 >50 microg/ml) and high (EC50 <50 microg/ml) antioxidant activities were detected in the leaf and twig extracts of D. barteri and the prenylated flavonoids. Prenylated flavonoids and the isolated compounds with antioxidant properties described here may account for the anti-inflammatory action of these extracts. The antitrichomonal and antioxidant activities shown by the extracts and compounds in this study are consistent with the ethnomedicinal and local use of the Dorstenia species studied.

Highlights

There are about 170 species of the genus Dorstenia (Moraceae) worldwide [1]
The prevalence of trichomoniasis is significantly higher in communities with high HIV prevalence (29.3% in Kisumu and 34.3% in Ndola) than in Cotonou (3.2%) and Yaoundé (17.6%) [4]
Quercetin [18], quercitrin [19], amenthoflavone [20], and gedunine were obtained from Carapa grandifolia [21]

Summary

Introduction

There are about 170 species of the genus Dorstenia (Moraceae) worldwide [1]. Decoctions of the leaves of some of these species are used for cough, headache and stomach pain [2]. Other uses include gout and various skin diseases [3]. Trichomoniasis affects men and animals causing untold economic loses in poultry and livestock and sometimes high morbidity in man. Trichomonas gallinarum affects birds including poultry, causing high morbidity and mortality especially in young birds. Patients have adverse reactions to high doses of metronidazole or are allergic to this agent [13]. The present study was carried out to examine and identify an agent from the array of compounds and extracts of Dorstenia species that possess antitrichomonal and antioxidant activities, to complement the use of this plant in the treatment and/or management of human disorders including arthritis, rheumatism, gout, stomach disorders, cough, headache, and skin diseases [1,2,3]

Methods

Results

Conclusion