The antihypertensive and diuretic effect of crude root extract and saponins from Solanum sisymbriifolium Lam., in L-NAME-induced hypertension in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Solanum sisymbriifolium Lam., is used in Paraguayan folk medicine claiming antihypertensive and diuretic properties.

AIM OF THE STUDY

This study aimed to determine the influence of chronic oral administration of the crude root extract and saponins obtained from S. sisymbriifolium Lam., on the blood pressure of male and female rats with hypertension induced by L-NAME, and its consequences on diuresis, the body weight, blood glucose, and level of serum parameters of liver and kidney functionality.

MATERIALS AND METHODS

Wistar rats were randomly divided into seven male, and seven female groups (8 animals each), which received as 6-week pretreatment, 0.9% saline solution (two groups; 0.1mL/10 g of b.w.), L-arginine (100.0 mg/kg/day), enalapril (15.0 mg/kg/day), crude extract (CESs 100.0 mg/kg/day), and saponin purified fraction (1.0, and 10.0 mg/kg/day), and treated with L-NAME (20 mg/kg/day/i.p.) twice, 1, and 6 h after pre-treatment. The animals' body weight, glycemia, and blood pressure were recorded weekly, while serum, hepatic, renal, and histological parameters were analyzed at the end of 6-week of treatment.

RESULTS

A protective effect of CESs (100.0 mg/kg/day), and saponins (1.0, and 10.0 mg/kg/day) against hypertension induced by L-NAME was verified in the systolic, diastolic, and mean blood pressure values, which were significantly lower than the positive L-NAME-hypertensive control group (male and female) at the end of the 6-week treatment. Also, pretreatment with enalapril (15.0 mg/kg/day) induced an efficient protective activity, which validates the method used. Likewise, the volume of urine, creatinine, uric acid, urea, and electrolyte excretion was enhanced at the end of 6-week of treatment in concordance with the reduction in serum level of the same parameters, compatible with the improvement of the diuretic activity. The glycemia, body weight, heart rate, and functional hepato-renal parameters were not modified after a 6-week of treatment, in comparison to the control group, indicating relatively acceptable harmless properties of CESs and saponins. Interestingly, the HDL level in females was increased in contrast to male rats by chronic saponins treatment when compared with the negative control group.

CONCLUSIONS

It can be concluded that either the increment in blood pressure (systolic, diastolic, and median) or cardiorenal remodeling effects in male and female rats submitted to L-NAME-induced hypertensive condition, were prevented and well-preserved without a significant variation during a period of 6-week of pretreatment with CESs and saponins pretreatments. Likewise, an important diuretic effect was revealed after this period of treatment.

Antidepressant-like effect of Kyllinga brevifolia rhizomes in male mice and chemical characterization of the components of the active ethyl acetate fraction

ETHNO-PHARMACOLOGICAL RELEVANCE

Kyllinga brevifolia rhizomes (Cyperaceae) are used in Paraguayan traditional medicine as a refreshing beverage, and is claimed to own digestive, diuretic, sedative, tonic, antispasmodic and sudorific properties. We have previously reported that its hydro- ethanolic rhizome extract possess sedative, anxiolytic and anti-aggressive-like effects in mice. However, information on its potential for treatment of syndromes associated with mood disorders is scarce.

AIM OF THE STUDY

The purpose of this study is to characterize the putative antidepressant-like effects of the hydro-ethanolic extract (CEKb) and the ethyl acetate fraction (KbF-ethyl-ac) obtained from the rhizome of K. brevifolia (Rottb) on male mice exposed to forced swimming test. Also, chemical characterization of the components of the active ethyl acetate fraction was described.

MATERIALS AND METHODS

The antidepressant-like effects of CEKb and KbF-ethyl-ac were measured using the forced swimming test (FST) performance of male mice in single (acute), short-term and chronic modalities. Treatments in all modalities were made 1h before swimming test. The KbF-ethyl-ac was analyzed by LC-DAD-ESI-MS and LC-ESI-MS/MS in order to identify the active components.

RESULTS

A single doses (1.0, 10.0 and 100.0mg/kg, p.o; p<0.05) of CEKb, in male mice provoked a significant reduction of the immobility time. Such effect was also observed with oral short-term treatment (7 days) with doses of 10.0 and 100.0mg/kg/day (p<0.05) of CEKb. Moreover, in the treatments during 14 days with doses of 1.0 (p<0.05), 10.0 (p<0.05), and 100.0 (p<0.001) mg/kg, p.o, of CEKb, a statistically significant reduction of the immobility time were induced. Additionally, in a different set of experiments acute dose of 1.0 (p<0.05) and 10.0 (p<0.01) mg/kg, p.o, of KbF-ethyl-ac in male mice, a significant reduction of the immobility time were provoked. Likewise, short-term treatment (7 days) with 1.0, and 10.0mg/kg (p<0.05); and after 14 days of treatment with 0.01 (p<0.01) 0.1 (p<0.001), 1.0 (p<0.001), and 10.0 (p<0.05) mg/kg of KbF-ethyl-ac in male mice, a statistically significant reduction of the immobility time, were observed. Imipramine 32mg/kg/days, i.p, induced a statistically significant reduction of immobility time and was used as positive control to validate the method employed. Moreover, it was noted important differences in the onset of the antidepressant-like effect in the FST, depending on the modality of treatment with CEKb or KbF-ethyl-ac (acute, short-term or chronic). Both, efficacy and potency were higher when repeated administration of CEKb was used, and surprisingly the efficacy of 1.0mg/kg of KbF-ethyl-ac (14 days) was similar to imipramine. The main constituents of the KbF-ethyl-ac were identified as catechins and their dimers by LC-DAD-ESI-MS and LC-ESI-MS/MS, according to their UV and MS spectra, as compared with the literature data. These results indicate an important antidepressant-like profile of action for the CEKb and KbF-ethyl-ac; and meanwhile, this effect may partially reside on catechins and their dimers isolated from the KbF-ethyl-ac.

CONCLUSION

These findings indicate that K. brevifolia exerts antidepressant -like effects in mice and suggest its potential usefulness for the treatment of depression in humans and encourage us to pursue the isolation of the molecules associated to the effect observed in CEKb and KbF-ethyl-ac, and to determine the mechanism of antidepressant-like effect of Kyllinga brevifolia using adequate complementary test.