الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
Abstract
The present study was aimed at creating a combination between lower dose of sulfamethoxazole (S) as abroad-spectrum synthetic antibiotic and quercetin (Q), a natural polyphenol to decrease the antibiotic side effects and increase its antioxidant activity. Staphylococcus aureus infected animal model was studied both in vitro and in vivo in comparison to doxycycline (Dox) as standard antibiotic. The in vitro test results indicated that Q exhibited activity alone and in combination with S against tested bacterial strains, while S in low concentration was inactive. The in vivo results revealed that the S+Q combination in mice showed significant improvements in the liver and kidney functions as compared to those in the infected group or S- and Dox-treated groups. Moreover, malondialdehyde level was significantly decreased, while superoxide dismutase and catalase activities were significantly increased in the sera of (S+Q)-treated group in comparison to other treated groups. The spleen recovery in the (S+Q)-treated group was observed with the disappearance of S. aureus colonies as compared to the infected mice. In conclusion, the in vivo treatment of S. aureus infection with S+Q combination decreased the sulfamethoxazole side effects while increasing its antibacterial activity, which supported the therapeutic use of this combination in humans.
Quercetin is a nutritive polyphenol that showed antioxidant and anticancer effects both in vitro and in vivo. Sulfamethoxazole is also had in vitro and in vivo anticancer activity. The combination therapy between natural polyphenols and anticancer drugs was used to decrease the drug adverse effect and increase the effectiveness and antioxidant activity of the combined one. Our in vitro data revealed the potent anticancer activity of the (S+Q), through induction of apoptotic pathway and cell-cycle arrest. The EAC inoculated mice treated with (S+Q100) or (S+Q200) have elevated SOD, GSH, CAT and TAC levels with decreased MDA compared to untreated EAC group which revealed the antioxidant and protective action of (S+Q) combination against EAC cells invasion. Also, the down-regulation of NFkB with the up-regulation of caspase3 genes in the in EAC inoculated mice treated with both (S+Q100) and (S+Q200) have proved the induction of apoptotic pathway and decreased EAC cells proliferation and metastasis. Thus, the (S+Q) combination could be promising anticancer agent via induction of apoptosis and selective toxicity to the cancer cells with protecting the vital organs. The in vivo study demonstrated different aspects on protecting the vital organs as well as selective toxicity to the cancer cells which weren’t appeared in the in vitro studies.