Anti-inflammatory and diuretic effects of the diterpene ent-dihydrotucumanoic acid.

Gymnosperma glutinosum (Spreng) Less (Asteraceae) is a shrub used in traditional medicine for the treatment of inflammatory and renal diseases. The ent-dihydrotucumanoic acid (DTA) is a diterpene obtained from G. glutinosum. This study evaluated the antioxidant, genotoxic, and diuretic properties of DTA, as well as its in vitro and in vivo anti-inflammatory actions. The antioxidant actions of DTA were assessed with the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assays, the genotoxic action was assessed with the comet assay, and the diuretic effects of DTA were assessed using metabolic cages. The anti-inflammatory actions were evaluated using primary murine peritoneal macrophages stimulated with LPS and the λ-carrageenan-induced hind paw edema test. DTA lacked antioxidant (IC50 > 25,000 µg/mL) activity in the ABTS, FRAP, and DPPH assays. DTA at 500-1,000 µg/mL showed moderate genotoxicity. In LPS-stimulated macrophages, DTA showed IC50 values of 74.85 µg/mL (TNF-α) and 58.12 µg/mL (NO), whereas the maximum inhibition of IL-6 (24%) and IL-1ß (36%) was recorded at 200 µg/mL. DTA induced in vivo anti-inflammatory effects with ED50 = 124.3 mg/kg. The in vitro anti-inflammatory activity of DTA seems to be associated with the decrease in the release of TNF-α and NO. DTA promoted the excretion of urine (ED50 = 86.9 mg/kg), Na+ (ED50 = 66.7 mg/kg), and K+ (ED50 = 8.6 mg/kg). The coadministration of DTA with L-NAME decreased the urinary excretion shown by DTA alone. Therefore, the diuretic activity is probably associated with the participation of nitric oxide synthase. In conclusion, DTA exerted anti-inflammatory and diuretic effects, but lacked antioxidant effects.

Antidiabetic effects of Justicia spicigera Schltdl (Acanthaceae).

ETHNOPHARMACOLOGICAL IMPORTANCE: Justicia spicigera is a plant species used for the Teenak (Huesteca Potosina) and Mayan (Yucatan peninsula) indigenous for the empirical treatment of diabetes, infections and as stimulant. AIM OF THE STUDY: To evaluate the cytotoxicity, antioxidant and antidiabetic properties of J. spicigera. MATERIALS AND METHODS: The effects of ethanolic extracts of J. spicigera (JSE) on the glucose uptake in insulin-sensitive and insulin-resistant murine 3T3-F442A and human subcutaneous adipocytes was evaluated. The antioxidant activities of the extract of JSE was determined by ABTS and DPPH methods. Additionally, it was evaluated the antidiabetic properties of JSE on T2DM model. RESULTS: JSE stimulated 2-NBDG uptake by insulin-sensitive and insulin-resistant human and murine adipocytes in a concentration-dependent manner with higher potency than rosiglitazone 1mM. JSE showed antioxidant effects in vitro and induced glucose lowering effects in normoglycemic and STZ-induced diabetic rats. CONCLUSION: The antidiabetic effects of administration of J. spicigera are related to the stimulation of glucose uptake in both insulin-sensitive and insulin-resistant murine and human adipocytes and this evidence justify its empirical use in Traditional Medicine. In addition, J. spicigera exerts glucose lowering effects in normoglycemic and STZ-induced diabetic rats.