Peptic ulcers are a common disorder of the entire gastrointestinal tract that occurs mainly in the stomach and the proximal duodenum. This disease is multifactorial and its treatment faces great difficulties due to the limited effectiveness and severe side effects of the currently available drugs. The use of natural products for the prevention and treatment of different pathologies is continuously expanding throughout the world. This is particularly true with regards to flavonoids, which represent a highly diverse class of secondary metabolites with potentially beneficial human health effects that is widely distributed in the plant kingdom and currently consumed in large amounts in the diet. They display several pharmacological properties in the gastroprotective area, acting as anti-secretory, cytoprotective and antioxidant agents. Besides their action as gastroprotectives, flavonoids also act in healing of gastric ulcers and additionally these polyphenolic compounds can be new alternatives for suppression or modulation of peptic ulcers associated with H. pylori. In this review, we have summarized the literature on ninety-five flavonoids with varying degrees of antiulcerogenic activity, confirming that flavonoids have a therapeutic potential for the more effective treatment of peptic ulcers.

Wissadula periplocifolia (L.) C. Presl is a plant of the Malvaceae family that is popularly known as white velvet leaf ("jangadeira" and "malva-malva" in Brazil). Species of this family are used in folk medicine as diuretic, anti-inflammatory and anti-rheumatic agents. This study evaluated the acute toxicity and anti-inflammatory effects of a crude ethanolic extract of W. periplocifolia. Acute toxicity testing revealed reduced food intake and decreased serum creatinine and alkaline phosphatase levels in males, as compared to the control group, suggesting a loss of muscle mass. Assessment of antiinflammatory activity using a rat paw carrageenan-induced edema model showed that 25 mg/kg of this ethanolic extract significantly reduced edema, although this was not observed at higher doses. These findings indicated that this W. periplocifolia extract was non-toxic and had some anti-inflammatory effects. However, a more comprehensive assessment is necessary to evaluate other possible indicators of toxicity, particularly during chronic administration.

R -(+) -limonene is a monoterpene found in several plant species. Studies have shown that plants that have this compound has anxiolytic activity. This study aimed to investigate the anxiolytic and toxicological activity in rats after inhalation of R -(+) -limonene for 30 min. For the anxiety tests using Elevated Plus Maze (EPM), concentrations of 1.0, 2.5 and 5.0% were determined. From the results, it was observed that the last concentration had achieved anxiolytic effect. Based on these results, it was found by biochemical and hematological tests, toxicity of 5% concentration in the period of 30 days with minor significant changes. In the hematological parameters, MCV, MCH and MCHC values were significant when compared to the control group, but were within the normal range when compared to values found in literature. In the biochemical parameters, changes occurred in AST and LDH levels. Elevated LDH levels can cause destruction of erythrocyte precursor cells in the bone marrow. In turn, AST may be associated to small changes in the liver. Therefore, the results demonstrated an anxiolytic activity with low toxicity at dose of 5% R -(+) -limonene via inhalation for 30 min.