Antibacterial effect on mature biofilms of oral streptococci and antioxidant activity of 3 β,6β,16β-trihydroxylup-20(29)-ene from Combretum leprosum

This study aimed to evaluate the antioxidant effect and antibacterial activity of the triterpene 3 β,6β,16β-trihydroxylup-20(29)-ene (CLF1) isolated fromCombretum leprosum leaves on mature biofilms fromStreptococcus mutans andS. parasanguinis, both involved in dental caries. In order to determine the bacterial death time curve promoted by CLF1, minimum inhibitory concentration and minimum bactericidal concentration were also assessed. The susceptibility of mature biofilms from both species to CLF1 was investigated through total biomass quantification and enumeration of biofilm-entrapped colony forming units. Moreover, the effect of CLF1 onS. mutans biofilm architecture was investigated by scanning electron microscopy. Additionally, the antioxidant properties of CLF1 were assessed by scavenging of 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) free radical, ferrous ion chelating assay, ferric-reducing antioxidant power, and β-carotene bleaching assay. The minimum inhibitory concentration and minimum bactericidal concentration of CLF1 for both species were 3.9 and 15.6 μg/mL, respectively, and no bacterial growth was detected at 24 h treatment. Moreover, CLF1 reduced the biomass and viability of biofilms from both species. Electron micrographs ofS. mutans biofilms confirmed such results and showed damages on bacterial surface. Regarding antioxidant activity, CLF1 showed efficient antioxidant ability in scavenging DPPH radical and inhibiting β-carotene oxidation. In summary, CL...
Source: Medicinal Chemistry Research - Category: Chemistry Source Type: research