Protective Effects of Thymus schimperi and Moringa stenopetala Leaf Extracts on Arterial Blood Pressure and Urine Protein Level in Pre-eclampsia Rat Models

Background: Pre-eclampsia (PE) is a common hypertensive disorder during pregnancy and one of the leading causes of perinatal mortality and morbidity. There is no curative modern drug to treat PE. Therefore, researches done on traditional medications have paramount importance in discovering therapeutic and /or protective agents from plant materials. In Ethiopia, there are claims that some indigenous medicinal plants such as Thymus and Moringa can have potential protective functions against PE. The aim of this study was to prove the claims.

Methods: Experiments were performed to investigate the effects of aqueous leaf extracts of Thymus schimperi (ALETS) and Moringa stenopetala (ALEMS) on PE rat models induced by nitro-L-arginine methyl ester (L-NAME); a nitric oxide synthase inhibitor. A non-invasive tail cuff blood pressure recorder (Model 179 Amplifier, IITC INC, Life Science Instruments, Woodland Hills, California) was used to determine the arterial blood pressure from rat tail. Urine analysis to determine protein levels was performed using a dipstick, semi-qualitative method as per manufacturer’s instructions (CYBO DFI Korea).

Results: ALETS treated PE rat models showed significantly reduced mean arterial blood pressure (MAP) in mmHg; 108±3 (P<0.05), 105±1 (P<0.01) and 99±2 (P<0.01); also the same pattern of results were seen in ALEMS treated PE groups with MAP of 106±1 (P<0.05), 103±1 (P<0.05) and 101±1 (P<0.05) at daily doses of 250 mg/kg, 500 mg/kg and 1000 mg/kg, respectively, compared to untreated case group that had 123±3.7 mmHg at gestation day (GD) 19 . Untreated PE rat models showed significant proteinuria (2000±20 mg/L) throughout the gestation period; while PE rat models treated with either ALETS or ALEMS had significantly reduced (p<0.05) proteinuria in dose dependent pattern (150±15 mg/L) at a dose of 1 gm/kg for each plant extract at GD 19.

Conclusion: Aqueous leaf extracts of either Thymus schimperi or Moringa stenopetala might reduce and control arterial pressure in PE rat models in a dose dependent manner. The extracts also could reduce level of proteinuria in the same pattern. Further investigation should, however, be carried out to confirm their uses in prevention and/or treatment of pregnancy-induced hypertension among human cases.