Acute toxicity and antimicrobial activity of leaf tincture Baccharis trimera (Less).

Background: The present study aimed to evaluate the possible acute oral toxicity of Baccharis trimera leaf dye as well as its antimicrobial activity. Method: Organization for Economic co-operation and development (OECD) 423 was used to assess acute oral toxicity and as per protocol a dose of 2000 mg/kg of tincture was administered to Wistar rats, male and female, and observed for 14 days. Biochemical and hematological analyzes were performed with sample collected of rat. The dye was evaluated for antimicrobial activity by agar diffusion and microdilution methods, which allow to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) and antibiofilm potential. Results: The results showed that there was no loss of animals and no significant changes in hematological and biochemical parameters after oral administration of 2000 mg/kg of tincture and was considered safe by the OECD, classified as category 5. The dyeing also showed an important antimicrobial activity against gram positive and gram negative bacteria also significantly decreased the microbial biofilm. Conclusion: The tincture of B. trimera leaf when given orally once can be considered safe and has a relevant antimicrobial potential that should be elucidated in subsequent research.