Antibacterial Potential of Bryophyllum pinnatum Leaf Extracts on Bacteria Obtained from Infected Infant Respiratory Tract

Background: Annual incidence of respiratory infection and death among infants aged between one (1) to two (2) years is increasing, especially in remote areas of the world. Herbal medicines have been the basis of treatment and cure for various diseases and physiological disorders. Plants contain various bioactive components that have been explored in ethnomedicine. Nigeria has abundance of such plants.

Aim: To evaluate the in vitro antibacterial activity and potency of Bryophyllum pinnatum leaf extracts on pathogens isolated from infants with respiratory tract infection.

Place of Study: The study was conducted at the Microbiology laboratory of the Cross River University of Technology in Cross River, Nigeria.

Methodology: The in vitro antibacterial potency of methanol and aqueous extracts of B. pinnatum leaf against Staphylococcus sp. and Streptococcus sp. isolated from sputum of five infants was tested. The susceptibility of the isolates to the extracts as well as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts were assayed on Mueller-Hinton Agar by the disc diffusion method, using concentrations of 100, 80, 60, 40 and 20 mg/ml. Selected antibiotics and the respective solvents used, served as positive and negative controls respectively.

Results: Staphylococcus sp. (52%), Streptococcus sp. (36.6%), Klebsiella sp. (9.4%) and pus cells (2%) were found in the samples. Both the methanol and aqueous extracts of B. pinnatum leaf showed strong antibacterial activity against Streptococcus sp (16.7; 17.3 mm) and Staphylococcus sp. (13.0; 16.3 mm). Antibacterial activity of both the methanol and aqueous extracts was more pronounced against Streptococcus sp. than against Staphylococcus sp. Methanol extract was more inhibitory to both isolates than the aqueous extract. The MIC of the aqueous extract was observed to be at 80 mg/ml and 100 mg/ml, while that of the methanol extract was 100 mg/ml and 80 mg/ml for Staphylococcus sp. and Streptococcus sp. respectively. The MBC of both the methanol and aqueous extracts was at 100 mg/ml concentration. Isolates were resistant to over 60% of the tested commercial antibiotics. Leaf extracts of B. pinnatum showed more antibacterial activity than some of the broad spectrum antibiotics.

Conclusion: B. pinnatum leaves could be useful in the treatment of infant respiratory infections and a potential source of antibacterial agents and raw material for the pharmaceutical industry if adequately explored.