Antihypertensive effect of Dialium guineense Wild. and Trema orientalis L. in L-NAME-induced hypertensive rats

Dialium guineense (Caesalpiniaceae) and Trema orientalis (Celtidaceae) are traditionally used to treat and manage many diseases such as hypertension, headache and diabetes. Despite their recognized efficacy in traditional medicine, their antihypertensive properties are not yet effective. Therefore, the current study aimed to investigate the antihypertensive effect of ethanolic extracts of Dialium guineense and Trema orientalis on L-NAME-induced hypertensive rats. The systolic, diastolic and mean arterial pressure were recorded using CODATM non-invasive blood pressure system. The phenolic compounds were also quantified using High Pressure Liquid Chromatography. Ethanolic extracts of both plants induced significant decrease of mean arterial pressure. At 500 mg/kg bw, both plants decreased mean arterial pressure from 126.4 ± 0.48 to 90.6 ± 3.12 mmHg and from 154.8 ± 7.84 to 103 ± 5.6 mmHg respectively for Dialium guineense and Trema orientalis. Losartan and Captopril, used as standard drugs at 100 mg/kg body weight, also significantly decrease blood pressure. Trema orientalis was the most active with a blood pressure reduction percentage of 33.46 ± 3.06 % comparable to Losartan (31.37 ± 3.13 %) and Captopril (31.76 ± 2.63 %). The probable bioctives compound identified were chlorogenic, gallic, caffeic, ellargic, tannic acids, and luteolin, isorhamnetin and chrysin.