Antibacterial potential of extracts from different Brazilian bamboo species

Since ancient times, bamboos have been used by different cultures in folk medicine for the treatment of many diseases, among them, bacterial infections. Brazil has a great diversity of herbaceous and woody bamboo species, many of them endemic. This study aimed to investigate the antibacterial potential of leaf extracts of seven Brazilian native bamboo species: Olyra glaberrima (OG), Parodiolyra micrantha (PM), Aulonemia aristulata (AA), Filgueirasia arenicola (FA), Filgueirasia cannavieira (FC), Merostachys neesii (MN), and Merostachys pluriflora (MP). Antibacterial activity of hexane (HE), hydroethanol (EE), and aqueous (AE) extracts from bamboo leaves were evaluated by the broth microdilution method against Pseudomonas aeruginosa and Escherichia coli (Gram-negative bacteria), and Bacillus subtilis (Gram-positive bacterium). Hexane extracts were the most active against all bacteria tested and showed a bacteriostatic effect. Hexane extracts of OG, FC, and MP inhibited the growth of B. subtilis ; IC 50 : 0.39, 0.86, and 0.87 mg mL −1 , respectively. Almost all HE was active against E. coli , exception for OG and FA extracts; furthermore, the HE of MP was the most active against E. coli , showing the lowest IC 50 (1.12 mg mL −1 ). Overall, the extracts were more promising against P. aeruginosa with HE of MP being the most active extract (IC 50 : 0.36 mg mL −1 ). In conclusion, Brazilian native bamboos, like the Asian ones, showed antibacterial activity. Moreover, the most promising studied species was M. pluriflora ; HE of MP inhibited the growth of the three bacteria tested.