María I Aguilar1, Wendy V Benítez2, Arturo Colín2, Robert Bye3, Ramiro Ríos-Gómez4, Fernando Calzada5. 1. Facultad de Química, Universidad Nacional Autónoma de México, Mexico. Electronic address: ilaurents@hotmail.com. 2. Facultad de Química, Universidad Nacional Autónoma de México, Mexico. 3. Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico. 4. Unidad de Investigación en Sistemática Vegetal y Suelo, FES Zaragoza. Universidad Nacional Autónoma de México, México D.F. 04510, Mexico. 5. Unidad de Investigación Médica en Farmacología UMAE, Hospital de Especialidades-CORCE, 2° piso, Centro Médico Nacional Siglo XXI, IMSS, Av. Cuauhtémoc 330, Col. Doctores, México, D.F. 06725, Mexico.
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE: Doradilla is a plant that has a long history in the Mexican traditional system of medicine for gall and renal stones, diuresis, stomach and liver inflammation among other diseases. Major components isolated from these plants include biflavonoids as amentoflavone (1), robustaflavone (2) and (S)-2,3-dihydrorobustaflavone (3) and the carbohydrate trehalose (4). The aim of this study was to evaluate the diuretic effect of the decoction of Selaginella nothohybrida Valdespino and Selaginella lepidophylla (Hook & Grev) Spring (Selaginellaceae), and compounds 1-4. We also explored the probable mode of action comparing the effects when using nonspecific and specific COX׳s inhibitors. MATERIALS AND METHODS: Three biflavonoids (1-3) were isolated from the ethyl acetate extraction of the aqueous decoction and the carbohydrate trehalose (4) from the aqueous phase. The structures of all compounds were elucidated by spectroscopic methods and comparisons were made against published data. The diuretic activity was assessed in mice by oral administration of the decoctions in doses of 1000 and 2000mg/kg and biflavonoids 1-3 and trehalose (4) in a dose range of 10mg/kg using furosemide as a standard drug. Inhibitors of COX׳s such as acetyl salicylic acid, sodium naproxen, indomethacin and Celebrex were also assayed to analyze the involvement of renal prostaglandins in diuresis. Water excretion rate, pH, density, conductivity, and contents of Na(+) and K(+) were measured in the urine of mice. RESULTS: Decoction of Selaginella lepidophylla showed lower effect in the urine output at doses of 1000 and 2000mg/kg, while decoction of Selaginella nothohybrida produced an increase at 2000mg/kg (P<0.05). Urinary electrolytes excretion was also affected by this last extract and pure compounds: decoction diminished urinary excretion of sodium and potassium ions, so as compounds 1 and 4; compounds 2 and 3 observed just a natriuretic effect. Pretreated mice with COX׳s inhibitors and then with test compounds 1, 2, 4 and decoction showed inhibition of diuresis in all cases exception for treatment with trehalose (4); natriuretic effect was observed in all cases except for biflavonoid robustaflavone (2) which behaved as the reference compound furosemide. Selaginella nothohybrida decoction behaved similarly to COX-2 inhibitor Celebrex (8), inhibiting diuresis. CONCLUSIONS: Selaginella nothohybrida presents a moderate diuretic effect, which appears to be in partly mediated by the presence of biflavonoids and trehalose. Renal prostaglandins may be involved in the mechanism of diuresis. The present results provide a quantitative basis explaining the traditional folk medicine use of Selaginella nothohybrida as a diuretic agent by Mexican population.
ETHNOPHARMACOLOGICAL RELEVANCE: Doradilla is a plant that has a long history in the Mexican traditional system of medicine for gall and renal stones, diuresis, stomach and liver inflammation among other diseases. Major components isolated from these plants include biflavonoids as amentoflavone (1), robustaflavone (2) and (S)-2,3-dihydrorobustaflavone (3) and the carbohydrate trehalose (4). The aim of this study was to evaluate the diuretic effect of the decoction of Selaginella nothohybrida Valdespino and Selaginella lepidophylla (Hook & Grev) Spring (Selaginellaceae), and compounds 1-4. We also explored the probable mode of action comparing the effects when using nonspecific and specific COX׳s inhibitors. MATERIALS AND METHODS: Three biflavonoids (1-3) were isolated from the ethyl acetate extraction of the aqueous decoction and the carbohydrate trehalose (4) from the aqueous phase. The structures of all compounds were elucidated by spectroscopic methods and comparisons were made against published data. The diuretic activity was assessed in mice by oral administration of the decoctions in doses of 1000 and 2000mg/kg and biflavonoids 1-3 and trehalose (4) in a dose range of 10mg/kg using furosemide as a standard drug. Inhibitors of COX׳s such as acetyl salicylic acid, sodium naproxen, indomethacin and Celebrex were also assayed to analyze the involvement of renal prostaglandins in diuresis. Water excretion rate, pH, density, conductivity, and contents of Na(+) and K(+) were measured in the urine of mice. RESULTS: Decoction of Selaginella lepidophylla showed lower effect in the urine output at doses of 1000 and 2000mg/kg, while decoction of Selaginella nothohybrida produced an increase at 2000mg/kg (P<0.05). Urinary electrolytes excretion was also affected by this last extract and pure compounds: decoction diminished urinary excretion of sodium and potassium ions, so as compounds 1 and 4; compounds 2 and 3 observed just a natriuretic effect. Pretreated mice with COX׳s inhibitors and then with test compounds 1, 2, 4 and decoction showed inhibition of diuresis in all cases exception for treatment with trehalose (4); natriuretic effect was observed in all cases except for biflavonoidrobustaflavone (2) which behaved as the reference compound furosemide. Selaginella nothohybrida decoction behaved similarly to COX-2 inhibitor Celebrex (8), inhibiting diuresis. CONCLUSIONS:Selaginella nothohybrida presents a moderate diuretic effect, which appears to be in partly mediated by the presence of biflavonoids and trehalose. Renal prostaglandins may be involved in the mechanism of diuresis. The present results provide a quantitative basis explaining the traditional folk medicine use of Selaginella nothohybrida as a diuretic agent by Mexican population.