## 6 Pharmacological Properties of _Apium_ Plants
### Antimicrobial Activities of Apium Plants
subtilis_, and _P. aeruginosa_. It was observed that crude ethanolic fraction of _A. gravelens_ exhibited good activity as fraction was effective against _S. typhi_ and _B. subtilis_ having a MIC value of 0.96 ug/mL and 0.82 ug/mL, respectively, whereas, the same fraction was least effective against _E. coli_, recording MIC values of 17.7 ug/mL. Hexane and methylated spirit showed at par activity while methylated spirit was a slightly less effective inhibitor against _P. aeruginosa_ (MIC: 11 ug/mL) [154]. _A. gravelens_ was also evaluated against antifungal activity using different strains of fungi. The data showed that the ethanolic fraction of _A. gravelens_ was more effective against _A. flavus_ having a MIC value of 5 ug/mL followed by hexane fractions (MIC: 12 ug/mL). Similarly, the methylated spirit fraction also proved to be effective against relevant fungal strains followed by the methanolic fractions. It was also noted that the crude ethanolic fraction of _A. gravelens_ revealed good activity as compared with other fractions [154]. [PERSON] and [PERSON] revealed that moderate antimicrobial activity was shown by _A. gravelens_ against multidrug-resistant _Salmonella typhi_[155]. Similar results were reported by [PERSON] et al. and [PERSON] et al. [150,152]. [PERSON] et al. also indicated that the ethanolic fraction of _A. gravelens_ was more effective against _A. flavus_, followed by hexane fractions. Similarly, the methylated spirit fraction also showed activity against relevant fungal strains followed by methanolic fractions [154]. [PERSON] and [PERSON] reported that the methanolic extract of _A. gravelens_ seeds had an inhibitory effect on the growth of _C. albicans_ and _C. parapsilasis_ at 100 ug/mL [107]. Similarly, [PERSON] et al. concluded that the methanolic extract of _A. gravelens_ had the best antifungal activity against various yeasts such as _C. albicans_, _C. kreussei_, and _C. parapsilosis_ with MIC values that varied from 0.08 to 0.31 mg/mL [150,152]. [PERSON] et al. reported similar results for the antifungal activity of methanolic extract of _A. gravelens_ against _Candidia_ servovars with MIC values ranging between 0.08 and 0.31 mg/mL and with minimum fungicidal concentration values ranging between 0.08 and 0.63 mg/mL [109]. According to the obtained results, which confirmed earlier studies by different authors, the antimicrobial activity of each extract can be varied within each other and that methanol is the best solvent for the extraction of the antimicrobial substances from _Apium_ plants as compared with the other solvents [152,156]. Moreover, the development of fractionations of extracts should be carried out for further investigation of their possible use as food preservatives to adopt their promising potential in the food industry [152]. _A. gravelens_ extract antimicrobial activity has been associated with numerous free hydroxyls, limonene, \(\beta\)-seline, and other compounds that are able to combine with the carbohydrates and proteins in the bacterial cell wall and or the lipophilic character of these compounds, leading to either enzyme inhibition or accumulation in membranes and resulting energy depletion which is associated with their antibacterial properties [130]. In short, _Apium_ plants show antifungal and antibacterial activities [109; 151; 153; 154]. In many studies investigating the antimicrobial effect of essential oil or extracts of _Apium_ plants, authors generally reported the minimum inhibitory concentration (MIC) of tested samples by using different methods. These methods varied from the agar dilution method to the disc diffusion method [130]. The MIC is defined as the lowest concentration of extract needed to prevent growth of any microorganism [153]. The results of these studies revealed some activity against specific pathogens which varied from none to moderate.