**2.4 Cu(II) and Ni(II) complexes**

Cu(II), Ni(II) complexes and its N-Ethyl-2-(phenyl(pyridin-2-yl)methylene) hydrazine carbothioamide cytotoxic activity was evaluated against human lung cancer cell lines (A549) and normal cell lines (L929). The results indicates that the copper complexes shows better activity than nickel complexes and both complexes were less harmful to normal cells [58]. 2,4′-Dibromoacetophenone thiosemicarbazone and its Cu(II), Ni(II), Pd(II) complexes, Antioxidant and antitumor activities *Cytotoxic Activity of Schiff Bases and Their Complexes DOI: http://dx.doi.org/10.5772/intechopen.108570*

#### **Figure 3.** *Cytotoxic activity of Cu(II) complexes of thiosemicarbazones.*

were studied. Nickel complex shows good antitumor activity against HepG2 hepatoblastoma cell lines [59]. Cu(II) and Ni(II) complexes and its Cinnamaldehyde and cuminaldehyde thiosemicarbazones were tested in vitro anti-leukemic activity on U937 human cell line. Metal complexes shows better activity than ligands [60]. 3,4-Difluoroacetophenone thiosemicarbazone; 2-bromo-4′-chloroacetophenone TSC and its Cu(II), Ni(II) complexes were tested for antitumor activity against HepG2 human hepatoblastoma cells. The results indicates that the copper complexes of the both ligands had better activity than others against cancer cell line [61]. (Z)-2- (Amino(pyridin-2-yl) methylene)-N-methylhydrazine carbothioamide and its Cu(II), Zn(II) complexes Cytotoxic activity was studied against HeLa, HepG-2 and SGC-7901 cell lines. The results shows that copper complex had better activity among the others [62].

Bis(citronella thiosemicarbazone); Pyridoxal TSC and its Ni(II), Cu(II) Metal complexes were tested for antiretro-viral activity against HIV-1 and HTLV-1/−2. The results indicates that copper complex has potent anti HIV activity (**Figure 4**) [63].
