Non Antimicrobial Effects of Antibacterial Agents

Aside from their antibacterial activity, antimicrobial agents have also some beneficial effects due to their chemical structures. These effects include anti-inflammatory, immunomodulatory, anti-cancer, anti-angiogenic, neuroprotective, cardioprotective, augmented gastrointestinal motility, and binding toxins. This paper does not comprise non-antimicrobial effects of all antibiotics due to the fact that the issue is very extended. We reviewed use of penicillins in mushroom poisoning and their promising inhibitor effect on proliferation of cervical carcinoma and leukemia cells. We summarized neuroprotective effect of ceftriaxone and its inhibitory potential on proliferation of lung cancer cells. Tetracyclines are agents that have been focused on and investigated for a long time, and demeclocycline that belongs to this group is used for inappropriate antidiuretic hormone secretion. Moreover, low-dose doxycycline that is also a tetracycline, has been approved for the treatment of periodontitis, and inhibition of matrix metalloproteinase enzyme is the responsible mechanism for its anti-inflammatory action. Matrix metalloproteinase inhibition also provides a decrease in tumor angiogenesis and metastasis. Minocycline, another tetracycline, reduces the synthesis of beta-amyloid which plays a key role in Alzheimer’s disease and other neurodegenerative diseases, and it also inhibits glial inducible nitric oxide (NO) synthase and NOmediated neurotoxicity. Erythromycin that is a macrolide antibiotic is used as a gastrointestinal motility augmenter; azithromycin gives an early improvement in patients with cystic fibrosis due to its anti-inflammatory effect. It has been shown that clarithromycin decreases the metastatic activity of melanoma and lung cancer in mice. In a study of Staphylococcus aureus opsonization kinetics, it has been demonstrated that clindamycin has a toxin binding and phagocytosis induction activity. In addition, linezolid, a protein synthesis inhibitor, has an anti-inflammatory and anticancer activity. Tetra-fluoroquinolones inhibit cell production in breast and lung cancer cell culture in a dose-dependent manner. Fluoroquinolones show an immunomodulatory action throughout enhancing the synthesis of colony-stimulating factor and inhibiting synthesis of interleukin-1 and tumor necrosis factor-alpha. Moreover, this review includes beneficial effects of ciprofloxacin on hepatic regeneration in mice model. Although non-antimicrobial effects of some antibiotics may show promise for some diseases in the future, the results of human clinical studies should be waited for. Furthermore, the fact that prolonged antibiotic use may cause development of resistance against those antimicrobials may cause future problems