Antibacterial properties of rain tree (Albizia saman) and Mexican sunflower (Tothonia diversifolia) used as fodder in ruminant nutrition

Abstract

Acetone and ethanol extracts of Albizia saman (ASL) and Tithonia diversifolia (TDL) leaves used as fodder for ruminant were evaluated for their antibacterial properties against selected pathogenic bacteria. Phytochemical screening was determined according to standard procedures, while antibacterial activity was by agar well diffusion and broth micro dilution methods. The levels of tannin (0.29 and 0.34 mg/100g); saponin (0.75 and 0.59 mg/100g); oxalates (0.17 and 0.14mg/100g); and phytate (0.11 and 0.12 mg/100g) in the fodder plants were below critical levels that may affect digestibility in ruminants. Acetone and ethanol extracts from ASL and TDL showed maximum zones of inhibition against Staphylococcus aureus (19.00 and 14.50mm; 23.00 and 21.50mm) and Pseudomonas aeruginosa (15.50 and 12.00mm; 18.50 and 17.00mm), respectively compared to Gentamycin (9.97mm). Minimum inhibitory concentration (MIC) values of acetone and ethanol extracts fromASL ranged from 0.10 to 0.28 mg/mL and 0.13 to 0.22 mg/mL, while TDL extracts ranged from 0.20 to 0.32 mg/mL and 0.20 to 0.31 mg/mL, respectively for all the tested organisms. Minimum bactericidal concentration (MBC) values of ethanol extracts from both plant ranged from 0.5-0.80 mg/mL and 0.7-0.90 mg/mL compared to MBC values (0.02-0.04 mg/mL) of the reference antibiotic (gentamycin) for all the tested bacteria species. In conclusion, antibacterial properties exhibited by the plant extract implied that the bioactive compounds are potential antibacterial agents against pathogenic bacteria of ruminant or foodborne pathogens in vitro.