Sida rhombifolia L., popularly known in Brazil as "SIDA" or "mata-pasto", is considered a weed; a plant of the American continent and widely distributed in North Africa, belongs to the Malvaceae family. In Brazil, S. rhombifolia L. is scattered throughout the national territory, infesting agricultural crops. Certain species of the genus Sida, including S. rhombifolia, are widely used in Indian, Chinese, African and American medicine. The present study was carried out with the objective of evaluating the nonclinical acute toxicity of crude ethanolic extract (CEE) obtained from S. rhombifolia L. In treated males, there was a statistically significant reduction in water and feed intake. Biochemical analyzes showed statistically significant changes in the parameters of aspartate aminotransferase, alanine aminotransferase and creatinine; hematological parameters showed altered erythrocytes, mean corpuscular volume, mean corpuscular hemoglobin and eosinophil parameters; observed only in treated male animals. The animals' organs showed no significant changes. The results suggest that the ethanolic extract obtained from S. rhombifolia L. presents low acute dose toxicity. However, chronic toxicological studies should be performed to demonstrate the safety of long-term use of the drug.

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.

Wissadula periplocifolia (L.) C. Presl. is a medicinal plant widely distributed in USA, but it has not yet been investigated extensively. Some pharmacochemical studies were performed at the Federal University of Paraiba, and the components of the crude ethanolic extract were identified; one of them was a tiliroside, which has already been shown to have excellent anti-inflammatory activity that can inhibit the arachidonic acid cascade and can inhibit the release of prostaglandins, prostacyclins, and leukotrienes from leukocytes and neutrophils. This study aimed to verify the possible long-term toxicity of this plant. Chronic toxicity tests were performed, including all recommended parameters; Wistar rats of both sexes were treated with 3 doses of the ethanolic extract of W. periplocifolia (L.) C. Presl leaves, and 2 satellite groups and a control group were set. The platelet and white blood cell counts for all treated males were higher than those in the controls. The anatomopathological tests did not reveal any alterations which were consistent with those obtained from the biochemical tests.