Antibacterial properties of some medicinal plant extracts against pathogenic bacteria forming biofilms: Bioactive compounds identification from potential extract and cytotoxicity activity

Abstract

Medicinal plant extracts are excellent resources of bioactive compounds with perfect antibacterial and ‎antioxidant activity. Phytochemicals are an exciting source of natural pharmaceuticals that are applied ‎instead of synthetic ones and control the growth of multidrug‏ ‏resistant bacteria. About 41.66% of Gram-‎positive bacteria were detected as biofilm-forming bacteria, while 36.66% were classified as biofilm-forming ‎bacteria belonging to the Enterobacteriaceae family. Marigold aquatic extract scored the highest inhibition ‎zone with 7.4 to 13.7%, followed by Moringa with 7.4 to 12.6% against all G+ve bacteria. While the tested ‎Enterobacteriaceae G-ve shows higher resistance to the effect of aquatic extracts. The inhibition zone of ‎ethanolic extracts reached 8.4 to 26.3% for Sage, followed by Cinnamon and marigold, which scored 9.5 to ‎‎22% and 7.4 to 21%, respectively. The extracts yield percentages ranged from 11.24 to 12.8%. The clear ‎zone diameter recoded by ethanolic Sage extract against G+ve and G-ve in descending order was Salmonella ‎Typhimurium ATCC25566> Listeria monocytogenes ATCC7646> Bacillus cereus ATCC11778> ‎Staphylococcus aureus ATCC5638. The bacterial activity of all ethanolic plant extracts achieved the ‎greatest clear zone against tested bacteria, whereas chloroform and methanol recorded the weakest ‎solvents. According to examination using gas chromatography and mass spectrometry, ethanolic Sage ‎extract contains 27 different phytochemical components, with 13-Docosenamide, (Z)- having the highest ‎area with a percentage 14.4%. At doses up to 100 µg/ml, the ethanolic Sage extract showed no cytotoxicity ‎effect to the typical Vero cell line, whereas the IC50 value reached 190.67±4.23µg/ml.‎