Toxicity study about a medicinal plant Casearia sylvestris: A contribution to the Brazilian Unified Health System (SUS)

Casearia sylvestris S.w (Salicaceae) is catalogued by the Brazilian Unified Health System as a plant of interest for the Brazilian population with the purpose of treating inflammatory disorders, such as pain and gastrointestinal disorders based on the folk use and some literature about efficacy; however, no toxicological studies concerned the safety of extract fluid of this plant have been reported.The present study was carried out to evaluate the acute and subchronic toxicity of the hydroethanolic extract fluid (FE) obtained from leaves of C. sylvestris in Wistar rats.In the acute toxicity test three female Wistar rats were treated with a single dose of FE (2000mg/kg) administered by oral gavage and observed for 14 days in order to identify signs of toxicity or death. In subchronic toxicity study animals received, by daily gavage three doses 60, 120 and 240mg/kg of the FE of the plant for 28 and 90 days. The animals were observed daily for clinical signs and mortality. Body weight and food consumption were measured weekly and at the end of treatment were analysed hematological, biochemical and histopathological parameters. Also was analysed the cellularity of bone marrow and spleen. Moreover, phytochemical analysis by HPLC–PDA–ESI⁺/MS and CG/MS/EI was carried out to qualify the constituents of the extract.The results of acute study indicated that the LD50 is higher than 2000mg/kg and at 28 and 90 day oral toxicity showed that there were no toxic effects detected in any of the parameters evaluated: body weight and relative organ weight, general behavioral changes, haematological and biochemical parameters and histopathological examination. The analysis by HPLC–PDA–ESI⁺/MS and CG/MS/EI identified the flavonoids rutin, quercetin and luteolin and also chlorogenic on the extract.Based on this study the hydroethanolic fluid extract of C. sylvestris could be safe even when used over a long period for therapeutic uses proposed by the Brazilian Unified Health System.