Effect of the triterpene 3ß, 6ß, 16ß-trihydroxylup-20(29)-ene isolated from the leaves of Combretum leprosum Mart. on cutaneous wounds in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Combretum leprosum Mart. is a native species of the Caatinga, an important biome in the Brazilian semi-arid region. This species is commonly used in Brazil as a healing agent, as well as for the treatment of skin diseases. AIM OF THE STUDY: This study investigated the healing potential of the ethanolic extract (EECL) and the bioactive triterpene 3ß, 6ß, 16ß-trihydroxylup-20 (29)-ene (CLF-1) isolated from the leaves of C. leprosum. MATERIALS AND METHODS: Skin wounds (1cm(2)) were created in the dorsal zone of mice with a scalpel blade number 15. The treatment consisted in a daily topical application of 100 µl of 150 mM NaCl, EECL and CLF-1 (at 10 µg/100 µl) for 12 days. The lesions were then macro and microscopically evaluated. RESULTS: On postoperative day (POD) 2, the lesions treated with EECL and CLF-1 showed a moderate presence of vessels of the granulation tissue progressing in the dermis. The same effect was not observed in the control group. The treatment with EECL and CLF-1 stimulated angiogenesis, resulting in a rapid deposition of extracellular matrix (ECM). Moreover, the animals treated with EECL and CLF-1 showed smaller lesions on POD 7, primarily due to the contraction in the reticular dermis induced by organization of myofibroblasts, which was not observed in the group treated with NaCl. In addition, the lesions treated with EECL and CLF-1 showed ECM restructuration and presence of epithelium coating, which was not observed in the group treated with NaCl, in which the lesions showed no epithelial lining, suggesting delayed healing. CONCLUSION: CLF-1 isolated from the leaves of C. leprosum may be considered to be an important molecule for the treatment of skin lesions. However, further investigations are necessary to establish its role in chronic lesions and to elucidate the mechanism of action involved in the cutaneous healing process. To the best of our knowledge, this is the first report describing the pro-healing activity of the ethanolic extract and the triterpene 3ß, 6ß, 16ß-trihydroxylup-20(29)-ene isolated from leaves of C. leprosum.

Antimicrobial effect of the triterpene 3ß,6ß,16ß-trihydroxylup-20(29)-ene on planktonic cells and biofilms from Gram positive and Gram negative bacteria.

This study evaluated the antimicrobial effect of 3ß,6ß,16ß-trihydroxylup-20(29)-ene (CLF1), a triterpene isolated from Combretum leprosum Mart., in inhibiting the planktonic growth and biofilms of Gram positive bacteria Streptococcus mutans and S. mitis. The antimicrobial activity was assessed by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The antibiofilm potential was determined by quantifying total biomass and enumerating biofilm-entrapped viable bacteria. In addition, the acute toxicity of CLF1 on Artemia sp. nauplii was also determined. The results showed that CLF1 was able in inhibiting the growth of S. mutans and S. mitis with MIC and MBC of 7.8 µg/mL and 15.6 µg/mL, respectively. CLF1 was highly effective on biofilms of both bacteria. Only 7.8 µg/mL CLF1 was enough to inhibit by 97% and 90% biomass production of S. mutans and S. mitis, respectively. On the other hand, such effects were not evident on Gram negative Pseudomonas aeruginosa and Klebsiella oxytoca. The toxicity tests showed that the LC50 of CLF1 was 98.19 µg/mL. Therefore, CLF1 isolated from C. leprosum may constitute an important natural agent for the development of new therapies for caries and other infectious diseases caused by S. mutans and S. mitis.