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.

Antihypertensive effect of nuatigenin-3-O-ß-chacotriose from Solanum sisymbriifolium Lam. (Solanaceae) (ñuatî pytâ) in experimentally hypertensive (ARH+DOCA) rats under chronic administration.

The aim of the study is to assess the hypotensive properties of the hydro-ethanolic crude root extract (CRE), the n-butanol fraction (F(BtOH)) and nuatigenin-3-O-ß-chacotriose, from Solanum sisymbriifolium Lam., in adrenal regeneration hypertension+deoxycorticosterone acetate (ARH+DOCA) rats, following a chronic administration. The roots of S. sisymbriifolium Lam. (Solanaceae) were extracted by reflux with ethanol-water 7:3 and the active extract was fractionated by bioassay-guided liquid-liquid separation. Nuatigenin-3-O-ß-chacotriose (B(3-1)) was identified as the main hypotensive compound from the crude drug by spectroscopic methods. Immature Wistar rats of both sexes were submitted to both surgery and deoxycorticosterone acetate treatment to obtain adrenal regeneration hypertensive rats (ARH+DOCA). Different groups of experimentally induced hypertensive rats were randomly allotted and received during 16 weeks a daily oral administration of 1% saline solution (0.1 mL/100g body weigh), 100.0 mg/kg of CRE, 10.0, 30.0 and 50.0 mg/kg of F(BtOH), and 1.0 mg/kg of B(3-1), respectively. In addition, two groups of ARH+DOCA rats were randomly assigned to receive either B(3-1) (1.0 mg/kg/day) or 1% of saline solution (0.1 mL/100g body weight/day) for 7 weeks and then a cross over procedure was performed in order to complete the 16th-week treatment. After 16 weeks of oral administration of crude root extract (CRE), butanolic fraction (F(BtOH)) and nuatigenin-3-O-ß-chacotriose (B(3-1)) a significant reduction of blood pressure value was induced in hypertensive animals (ARH+DOCA) in comparison to the control group receiving 1% saline solution, at the end of experiment. Administration of B(3-1) (1.0 mg/kg/day p.o.) to ARH+DOCA rats provoked a significant reduction of blood pressure, observed gradually from 5th week (p<0.05) to the end of the 16th week period of treatment (p<0.01). Moreover, in a cross over design it was observed that the reduction of blood pressure to normotensive condition is associated to B(3-1). The latest demonstrated that the blood pressure-lowering effect, in clearly hypertensive animals, is reversible and depend upon administration of nuatigenin-3-O-ß-chacotriose (B(3-1)). Our results demonstrated that daily oral administration of CRE, F(BtOH) and nuatigenin-3-O-ß-chacotriose from S. sisymbriifolium for a 16-week period exhibits an antihypertensive effect in experimentally hypertensive (ARH+DOCA) rats.