Combretum micranthum G. Don (Combretaceae): Its physiological effects on hydro-electrolyte metabolism, renal tubular function and blood pressure

Background

Hydro-electrolyte balance is necessary to maintain body homeostasis and blood pressure values within narrow limits. This is accomplished, in part, by renal responses. We conducted this study to determine the effects of Combretum micranthum on hydro-electrolyte metabolism, renal function and arterial blood pressure.

Subjects and methods

We conducted a pilot study including 40 subjects: 10 control subjects, 10 subjects under Combretum micranthum G. Don (400 mg/day), 10 subjects under furosemide (120 mg/day), and 10 subjects under spironolactone (50 mg/day).

Anthropobiometric, cardiovascular parameters and the body composition were collected from each subject. Blood and 24-hour urine samples were collected for biological tests.

Results

At baseline, clinical and biological parameters were comparable for all groups. Consumers of combretum micranthum had a significant decrease in global body fat percentage (−1.63 %; p = 0.045). In the group of combretum micranthum consumers, the body water mass (BWM) is significantly evolved in the direction of an increase (4.37; p = 0.023) and similar to what was observed in the group of subjects treated with spironolactone (0.67; p = 0.042). Consumption of combretum micranthum showed a marked reduction in hypertension indices (systolic blood pressure, diastolic blood pressure and heart rate) identical to that induced by consumption of furosemide or spironolactone. The consumption of combretum micranthum resulted in a significant reduction in kaliemia (−1.07; p < 0.0001) and without any notable effect on natremia (p = 0.119) and chloremia (p = 0.708). In contrast, furosemide and spironolactone caused a significant decrease in natremia (respectivly, −0.80; p = 0.022 and −0.50; p = 0.009). In the combretum micrathum group, the kaliuresis and the chloruresis were significantly increased (respectively, 373.9; p = 0.005 and 441.3; p = 0.028), interestingly, we found a remarkable decrease in natriuresis (−193.3; p = 0.074). In the group of furosemide consumers, the kaliuresis and the chloruresis were significantly increased (respectively, 380.24; p = 0.013 and 425.5; p = 0.013), but with a tendency to increase natriuresis. In the group of subjects taking spironolactone, the urinary concentrations of the three electrolytes studied (natriuresis, kaliuresis and chloruresis) was increased significantly (respectively, 357.5; p = 0.037 and 222.5; p = 0.005 and 563.4; p = 0.007).

Conclusion

Combretum micranthum would have constituents involved in the maintenance of hydro-electrolyte homeostasis and in the regulation of blood pressure through the involvement of several mechanisms, especially at the renal level. These actions would be attributable to its polyphenolic components. A broader study is needed to better understand the physiological mechanisms underlying these effects.