in vitro antibacterial activity of crinum purpurascens herb. leaf extract against the salmonella species causing typhoid fever and its toxicological evaluation

background: crinum purpurascens is a herbaceous plant belonging to the amaryllidaceae family. we aimed to evaluate the antisalmonellal properties of the leaf extracts and fractions of c. purpurascens , and the toxicity of the most active extract.   methods: three extracts and three fractions were prepared from the leaves of crinum purp urascens herb. (amaryllidaceae) and tested for their antisalmonellal activities and toxicity profile. the antibacterial activity was determined using agar diffusion, agar dilution, and broth dilution techniques. phytochemical screening of the various extracts and fractions was performed. the toxicity profile of the ch 2 cl 2 /meoh (1:1) extract was studied.   results: all the extracts and fractions, except hexane fraction, showed antimicrobial activity against salmonella typhi , salmonella paratyphi a and salmonella paratyphi b. the ch 2 cl 2 /meoh (1:1) extract showed the highest activity. the minimum inhibitory concentration values were 2.50 mg/ml against s. typhi , and 1.88 mg/ml against s. paratyphi a and s. paratyphi b. the minimum bactericidal concentration values were 7.50 mg/ml against s. typhi and 3.75 mg/ml against s. paratyphi a and s. paratyphi b. mice administered high doses of extract exhibited reduced reaction to noise, locomotion, reactivity and reaction to pinch, and losses in body weight. additionally, the rats that received high doses of the extract showed increase in liver, spleen and kidney to body weight ratios, and decrease in total protein concentrations of the liver and lung, and in hematocrit value.   conclusion: c. purpu rascens leaf extract contains antisalmonellal principle(s) and at high doses, may have a depressant or sedative effect on the central nervous system and analgesic activity. also, it may be anorexiant, hepatotoxic, and nephrotoxic.