###### Abstract  
The aim of this study was to evaluate the _in vitro_ antimicrobial activity of medicinal methanolic plant extracts against multidrug-resistant bacteria to determine the cytotoxicity of these extracts on eukaryotic cells, and to confirm their efficacy against Methicillin-Resistant _Staphylococcus aureus_ (MRSA) in experimental animals. The effects of the methanol extract of sixty folk plants were investigated on; MRSA, Extended Spectrum Beta-Lactamase _E. coli_ and MDR _Pseudomonas aeruginosa_ by disc diffusion and MIC assay. Cytotoxicity was determined using MTT and hemolysis of human erythrocytes. Three plant extracts with the highest antimicrobial activities were tested using a challenge experiment on mice. Systemic infection was performed by intraperitoneal inoculation of (5 \(\times\) 10\({}^{6}\) CFU/mL) of MRSA isolate. Then mice received 300 mg/kg body weight of the plant extracts daily for seven days. The efficacy of plant extracts was evaluated by general health, mortality rate, gross lesion, and histopathology study of inoculated mice. Only ten plants showed activities against different MDR bacteria with inhibitory zones ranging from (8 to 22 mm) in diameter. Of the ten medicinal plant extracts, _Camellia sinensis_ and _Aloysia citroda_ showed the highest activities against MRSA and MSSA isolates, with MIC value ranging from 0.5 to 1.5 mg/ml, followed by _Hibiscus subariffu, Thymus vulgaris_, and _Glycyrhizia glabru_. Furthermore, the extract of the effective plants showed low toxicity against Vero and fibroblasts cell lines, along with inhibitory activities to erythrocytes membrane disruption. The _in vivo_ study demonstrated that _Camellia sinensis_ showed significant activity against MRSA infections in mice. The results validate that these plants are effective and safe antibacterial agents against multidrug-resistance bacteria, and have the potential to be utilized as an alternative to antibiotics for the treatment of bacterial infections. medicial plants; antibacterial efficacy; MRSA; ESBLEC; MDR _P. aeruginosa_ +
Footnote †: journal: Applied  
**Citation**: [PERSON]; Anthacterial Efficacy of Some Medicinal Plants on Eukaryotic Cells. **Citation**: [PERSON]; Anthacterial Efficacy of Some Medicinal Plants on Eukaryotic Cells. **Citation**: [PERSON]; Anthacterial Efficacy of Some Medicinal Plants on plants that are characterized as antimicrobial agents are significant and differ in structures and activity against bacterial pathogens [8; 9]. Plant-derived products are an attractive source of antimicrobial agents considering they are natural and affordable, nontoxic to host and active at low concentrations [10; 11; 12]. Numerous recent studies have reported plant components that have antimicrobial properties and are effective against a wide spectrum of Gram positive and Gram negative bacteria, fungi, and viruses [13]. Methanol plant extracts were used to evaluate their antimicrobial effects. A comparative study performed by [14], showed that methanol extraction yield high content of phenolic, flavonoid, alkaloid and terpenids. They also revealed high antioxidant capacity and promising anti-inflammatory activity when compared with other extracts such as ethanol, chloroform, dichloromethane, acetone, gallic acid and ascorbic acid. The Arab world is blessed with diverse climate conditions which enable the growth of a wide variety of plants [15]. Many folk herbal plants used in traditional remedies are still unexplored, and many of them need studies to ensure that they can be used as drugs for different infectious diseases caused by multidrug-resistant bacteria. According to the world health organization, medicinal plants would be the best source for getting a diversity of drugs [16]. Traditional plants may contain compounds that have adverse effects on humans [17]. Contrarily, plants associated microorganisms referred to as phytomicrobione have the potential to secrete metabolites important industrially, in medicine and for environmental preservation [18].