Tracheal relaxation of five medicinal plants used in Mexico for the treatment of several diseases

Objective:To assess the relaxant effect of several organic extracts obtained from Agastache mexicana(A.mexicana),Cochlospermum vitifolium(C.vitifolium),Cordia morelosana(C.morelosana),Lepechinia caulescens(L.caulescens)and Talauma mexicana(71 mexicana)used in Mexican traditional medicine for the treatment of several diseases.Methods:Extracts were obtained by maceration at room temperature using hexane,dicliloromethane and methanol for each plant material.The organic extracts were evaluated ex vivo to determine their relaxant activity on the contractions induced by carbaehol(cholinergic receptor agonist,1μmol/L in isolated rat tracheal rings.Results:A total of 15 extracts were evaluated(three for each species).All test samples showed significant relaxant effect,in a concentration-dependent manner,on the contractions induced by 1μmol/L carbachol,with exception of extracts from C.morelosana.Active extracts were less potent than theophylline[phosphodiesterase inhibitor,EC_(50):(28.79±0.82)μg/mL]that was used as positive control.Concentration-response curves revealed that the extracts with more significant effects were dichloromethanic extracts of T.mexhxma[E_(max):(103.03±3.32)%and EC_(50):(159.39±3.72)μg/mL)and C.vitifolium[Emax:(106.58±2.42)%and EC_(50):(219.54±7.61)μg/mL].Finally,hexanic and dichloromethanic extracts from A.mexicana were fully effective but less potent than T.mexicana,and C.vitifolium.Conclusions:Less polar extracts obtained from A.mexicana,71 mexicana and C.vitifolium exhibited greater relaxant effect on tracheal rat rings,which allows us to suggest them as sources for the isolation of bioactive molecules with potential therapeutic value in the treatment of asthma.

Effect of Cyclooxygenase-2 Blockade on Renal Hypertrophy Development during Early Diabetes Mellitus

Diabetes mellitus is the leading cause of diabetic nephropathy;the early phase of diabetes is associated with kidney growth and hyperfiltration;several factors modulate these changes, among them, prostaglandins and angiotensin II. Previous studies have shown that cyclooxygenase-2 is implicated in experimental models of diabetes. The aim of this work was to study the effect of celecoxib treatment on renal hypertrophy development in early diabetes mellitus. In our rats with early streptozotocin-induced diabetes there was renal hypertrophy, and increased renal expression of cyclooxygenase-2, AT1 receptor, and transforming growth factor-β1. Treatment with the selective cyclooxygenase-2 inhibitor celecoxib reduced the urinary excretion of prostaglandins such as prostaglandin E2, 6-keto prostaglandin F1α, and thromboxane B2. Kidney hypertrophy was reversed by the treatment, and the renal expression of cyclooxygenase-2, AT1 receptor, and transforming growth factor-β1 decreased. The renoprotective effects of celecoxib were independent of the changes in plasma glucose levels. These results confirm that cyclooxygenase-2 inhibition in rats with streptozotocin-induced diabetes decrease renal hypertrophy;this effect in turn, may be mediated by reduction of the expression of AT1 receptors and transforming growth factor-b1 in the kidney.