Herbal Formulation Comprised of Methanol Extracts of Tribulus terristris L. and Zingiber officinale Roscoe Has Antihypertensive Effects.

People prefer to use medicinal plants rather than chemical compounds because they are low cost and have fewer adverse events. Zingiber officinale Roscoe is a natural dietary rhizome with anti-oxidative, anti-inflammatory and anti-carcinogenic properties. Tribulus terrestris L. has been used for the treatment of impotence, to enhance sexual drive and performance and for its diuretic and uricosuric effects. The aim of this study was to evaluate the combined effect of 2 extracts, Tribulus terristris and Zingiber officinale (TZ) for antioxidant, enzyme modulation, liver function, kidney function, blood profile and anti-hypertensive effects, which may pave the way for possible therapeutic applications. Antioxidant potential was measured with the 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical method antioxidant assay (DPPH) and kojic acid was used as the standard drug for tyrosine inhibition assay. The effect of TZ on biochemical parameters of the liver (alanine transferase [ALT], alkaline phosphatase [ALP], aspartate aminotransferase [AST], total serum protein, total serum albumin, serum bilirubin), kidney (blood urea and creatinine) and hematology (hemoglobin, red blood cells [RBC], platelets, thin-layer chromatography, neutrophils, eosinophils, lymphocytes, monocytes, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration) of Wister rats were studied by administering 100, 250 and 500 mg/kg-1 body weight TZ dose orally for 28 days. Antihypertensive effects were measured by the invasive method. The results showed that the scavenging percentage of TZ was 78.5 to 80.4, with an IC50 value of 1166.7 µg/ ml and tyrosinase inhibition was 72% compared with 93% for kojic acid. Different doses (100, 250 and 500 mg/kg) did not show an increase in serum biomarkers of liver and renal parameters. A significant increase in hemoglobin, erythrocytes, hematocrit, white blood cells (WBC) and lymphocytes with no significant increase/decrease in platelet count was observed but blood pressure was significantly decreased. Therefore, we concluded that TZ is safe and can be used in the treatment of hypertension.