Effect of gibberellic acid on the levels of tumor necrosis factor-α, interleukin-4 and interleukin-10 in rats

The effects of plant growth factors used indiscretely for increasing the amount of agricultural products, on human health are unknown. Gibberillic acid (GA3), a member of gibberillin family, which is used very commonly at agriculture exists at growing fruit seeds and plays an important role at fruit growth. There are studies demonstrating the effects of GA3 at tumor growth. But the physiopathology of the relationship isn't completely recognized. It's possible that GA3 induces or eases tumor growth by changing cytokine balance and consequently the inflammation response and this study aims to test this possibility. It's known that chronic inflammation spesifically eases cancer growth and metastasis. TNF-α, IL-4, IL-10 are important cytokines at cancer growth and prevention. The main aim of our study was to inspect whether changes at cytokine balance takes place at tumor-growing effect of GA3. Fifty Wistar rats were divided into five groups to inspect both acute and chronic effects of GA3. At chronic treatment experiments, first group was given 2 mg/kg of GA3, second group was given 20 mg/kg of GA3 and solvent was given to third group three days a week for 30 days with intraperitoneal injections. At acute treatment group, high dose GA3 treatment (20 mg/kg) or solvent was given once as IP and tissues were taken out three hours after injection. Levels of TNF-α, IL-4 and IL-10 were examined at isolated sera. At our study, it was shown that without feeding change GA3 increased weight gain significantly when it's administrated alone, especially at high dose. It was also found that 4-week exposure to GA3 increased both TNF-α and IL-4 levels and it didn't cause a change at the level of IL-10. As a result, GA3 both changes cytokine balance and causes metabolical changes. These changes may attribute to growth or progression of inflammatory diseases and malignancies.