Solidago chilensis Meyen hydroalcoholic extract reduces JNK/IκB pathway activation and ameliorates insulin resistance in diet-induced obesity mice.

Hydroalcoholic extract of Solidago chilensis (Sc) is employed in popular medicine to treat inflammatory disease. The low-grade proinflammatory state and the activation of serine/threonine kinases in adipose tissue, like c-jun kinase (JNK) and IKK, and transcription factors, have an important role in obesity-associated insulin resistance. The aim of this study was to further investigate the effects of the Sc extract on glucose homeostasis in diet-induced obesity mice. Male Swiss mice were randomized to three groups: a control group (C) fed with standard laboratory chow; a group with an experimental high-fat diet (HFD); and a group fed with a high-fat (45% kcal from fat) diet + extract of Sc (via intraperitoneal, 3 mg/kg) (ScHFD). The dietary treatment lasted for eight weeks. Subsequently, the expression and phosphorylation of proteins of interest in the liver, hypothalamus and skeletal muscle were evaluated by Western blot analysis. Body weight, epididymal fat pad mass and liver triglycerides were higher in HFD than in control mice, but these parameters were reduced by intraperitoneal administration of the extracts (3 mg/kg) to the HFD group. AKT phosphorylation stimulated by insulin in the liver, hypothalamus and skeletal muscle was higher in ScHFD as compared with HFD mice. Additionally, liver expression of phosphoenolpyruvate carboxykinase (PEPCK) and fatty acid synthase were lower in ScHFD as compared with HFD mice. Nuclear factor κB, p-IκB and p-JNK levels were higher in HFD when compared with control mice, but they were lowered by treatment with extract (ScHFD). In addition, in db/db mice, Sc extract also improved liver AKT phosphorylation stimulated by insulin and reduced PEPCK expression. The data presented herein show that Sc improves AKT activation. This effect may be promoted by reduction of the proinflammatory pathway in the liver and hypothalamus. Therefore, systemic action of the Sc components may contribute to improve obesity-associated pathophysiology.

Antispasmodic effects of essential oil of Pterodon polygalaeflorus and its main constituent ß-caryophyllene on rat isolated ileum.

This study investigates the effects of essential oil of Pterodon polygalaeflorus (EOPP) and ß-caryophyllene (ß-CAR). EOPP and ß-CAR relaxed the basal tone of ileum smooth muscle in a concentration-dependent manner (IC(50) s = 394.35 ± 62.12 and 68.65 ± 9.51 µg/mL respectively), an effect that was unaltered by hexamethonium, L-nitroarginine methyl ester or indomethacin. Both EOPP and ß-CAR evoked a concentration-dependent relaxation of ileum pre-contracted with KCl with an IC(50) value of 107.78 ± 10.47 and 17.35 ± 0.75 µg/mL, respectively. EOPP and ß-CAR inhibited the contractions induced by acetylcholine (ACh) and by KCl. In ileal preparations, the CaCl(2) -induced contractions were reduced by EOPP (300 µg/mL) and ß-CAR (100 µg/mL). Furthermore, CaCl(2) -induced contractions were also reduced by EOPP (300 µg/mL) and ß-CAR (100 µg/mL) in ileal preparations pretreated with ACh under Ca(2+) -free condition and in the presence of verapamil. EOPP (100 and 300 µg/mL) and ß-CAR (30 and 100 µg/mL) reduced the ACh-induced contractions of isolated rat ileum under Ca(2+) -free conditions. In the presence of high KCl and Ca(2+) -free conditions, EOPP (300 µg/mL) and ß-CAR (100 µg/mL) reduced the contractions induced by barium. A similar effect was also observed with verapamil. It is concluded that (i) ß-CAR is an important constituent involved in the myorelaxant and antispasmodic effects induced by EOPP; (ii) the inhibitory effect on intestinal contractility is myogenic and seems mainly mediated through an intracellular mechanism. However, the ability of EOPP and ß-CAR to decrease Ca(2+) influx through cytoplasmic membrane could not be discounted.