Gastroprotective and cicatrizing activity of the Ziziphus joazeiro Mart. leaf hydroalcoholic extract.

Ziziphus joazeiro Mart., popularly known as 'juazeiro', is a species used in popular medicine for the treatment of bronchitis, gastric ulcers, skin wounds, and in the manufacture of cosmetic and food products. The objective of this study is to evaluate the gastroprotective and cicatrizing activity of the Z. joazeiro Mart. leaf hydroalcoholic extract (EHFZJ). The acute pre-clinical toxicity was determined by the single administration of the EHFZJ (2000 mg/kg/p.o.) and by assessing clinical signs of toxicity, according to established criteria by Malone, or mortality. Gastroprotective activity was identified through classical models of acute gastric lesions induced by indomethacin, absolute and acidified ethanol (100, 200 and 400 mg/kg/per os) and the physical barrier mechanism (400 mg/kg/per os or intraperitoneally). The cicatrizing activity of the EHFZJ was investigated by measuring the speed of wound closure and the percentage of contraction. The acute pre-clinical toxicity of EHFZJ showed no signs of toxicity and mortality. The EHFZJ demonstrated a gastroprotective effect at the 400 mg/kg dose in the classical models of acute gastric injury induced by indomethacin, absolute and acidified ethanol. The EHFZJ administration (orally) demonstrated significant inhibition, suggesting a possible physical barrier mechanism exists. The EHFZJ showed no significant differences in terms of percentage of contraction or the speed of wound closure during the observation times (0, 3, 7, 11 and 14 days). The results obtained in this study provide evidence of a potential gastroprotective activity for the Ziziphus joazeiro Mart. Leaf hydroalcoholic extract.

Chemical Analysis and Study of Phenolics, Antioxidant Activity, and Antibacterial Effect of the Wood and Bark of Maclura tinctoria (L.) D. Don ex Steud.

Maclura tinctoria (L.) D. Don ex Steud. has one of the highest qualities among the coefficients for Brazilian woods (up to 9.6) and resistance rates equivalent to Indian teak (Tectona grandis). In this study, the macromolecular constituents and total phenols compounds as well as the antioxidant and antibacterial activities of this wood were evaluated. Total phenols and proanthocyanidin levels were higher in wood when compared with bark levels. The antioxidant activity of wood extracts (IC(50) = 18.7 µg/mL) was more effective than that of bark extracts (IC(50) = 20.9 µg/mL). Wood and bark extracts revealed a high potential for inhibition of aerobic and anaerobic bacteria. The bark extracts were the most active (MIC from 20 to 60 µg/mL). Both antioxidant activity and high potential for bacteria inhibition turn these extracts promising for drug formulations, especially as antibacterial agent.

Effects of the nonsteroidal anti-inflammatory drug nimesulide on energy metabolism in livers from adjuvant-induced arthritic rats.

The effects of nimesulide on energy metabolism and the hepatic metabolic alterations produced by adjuvant-induced arthritis were investigated in the perfused rat liver an in isolated liver mitochondria. Nimesulide, at therapeutic levels (20-50 microM), produced: (1) stimulation of oxygen consumption in the perfused rat liver and in isolated mitochondria, (2) inhibition of gluconeogenesis; (3) reduction of ADP/O ratio and the respiratory control ratio and stimulation of glycogenolysis in the livers from healthy rats, but not in livers from arthritic rats. These results indicate that nimesulide acts as a mitochondrial uncoupler. The main alterations produced by adjuvant-induced arthritis were: higher rates of oxygen consumption in both perfused livers and isolated mitochondria, with no decrease in the efficiency of mitochondrial energy transduction; (2) decreased gluconeogenesis and lack of glycogenolytic response to uncouplers, but not to alpha 1-agonists. These data allow to conclude that nimesulide-induced impairment of energy metabolism should worsen the hepatic disturbances that are already associated with the adjuvant disease.