Antifungal and antibacterial activities of endemic Pittocaulon spp. from Mexico

Abstract

Extracts from Pittocaulon spp. (Asteraceae) have been used in folk medicine to treat many ailments, particularly as anti-inflammatory and antimicrobial. Neither the bioactive components responsible nor the mechanisms involved have been evaluated. Here we report the antibacterial activities of their methanol and CH2Cl2 extracts and the effects on some fungal strains treated with CH2Cl2 extracts from root, stems, and flowers of P praecox (Cav.) H. Rob. & Brett., P hintonii H. Rob. & Brett., P. filare (McVaugh) H. Rob. & Brett, P. velatum (Greemn) H. Rob. & Brett., and P. bomby-cophole (Bullock) H. Rob. & Brett. Thirteen extracts were obtained with McOH and CH2Cl2 solvents from aerial parts and roots of five Pittocaulon spp. for the first time in this species, and their antimicrobial activities were determined. The antimicrobial activities of these extracts were evaluated against the bacteria Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, and Vibrio cholerae (one El Tor strain, and a clinic case CDC-V12). Additionally, the CH2Cl2 extract was evaluated against Aspergillus niger, Fusarium moniliforme, Fusarium sporotrichum, Rizoctonia solanii, and Trichophyton mentagrophytes. The most sensitive bacteria against these extracts were B. subtilis, S. epidermidis, and V cholerae, a key bacterium in contaminated water. However, CH2Cl2 extracts from P praecox, P bombycophole, and P hintonii exhibited a significant antifungal activity against the fungal strains F sporotrichum, R. solanii, and T mentagrophytes: at 1000 mu g per disk, these extracts completely inhibited the mycelial growth of these fungi.