**7. Cytotoxic activities**

Salts (**4a-j**) and Ag(I) complexes (**5a-j**) were screened for their in vitro anticancer activities on human cancer cell lines MCF7 and MDA-MB-231 using the MTT test. The results are given in **Table 5**.



*The concentration was 30 μg. NA: not active; IC50: half maximal inhibitory concentration; MCF7 and MDA-MB-231: human cancer cell lines; NT: not tested. Values are mean value ± standard deviation of three different replicates.*

#### **Table 5.**

*Anticancer activity of synthesized of benzimidazoles salts [27–31] 4a-4j and Ag(I) complexes 5a-5j.*

The cytotoxicity of **5i** and **5f** was higher in MCF7 with half-maximal inhibitory concentration (IC50) values of 0.63 and 0.69 μg mL−1, respectively, as compared to their activity on MDA-MB-231 cells. Complexes **5j** and **4a** were also determined to be toxic towards MCF7 and MDA-MB-231 with values of (IC50) 2.1 and 2.8 μg mL − 1 respectively. While, the compound 4d was inactive against MCF7.
