Oral intake of royal jelly improves anti-cancer effects and suppresses adverse events of molecular targeted therapy by regulating TNF-α and TGF-β in renal cell carcinoma: A preliminary study based on a randomized double-blind clinical trial

Molecular targeted therapies are commonly used in patients with metastatic renal cell carcinoma (RCC). However, the efficacy and safety of these therapeutic interventions require enhancement to improve prognosis in these patients. Royal jelly (RJ) has anti-cancer effects and adverse events across a variety of types of malignancy. The present study investigated the detailed mechanism underlying the effects of oral administration of RJ in patients with advanced RCC that were treated with molecular targeted agents in a randomized clinical trial. The study cohort comprised 16 patients treated with RJ and 17 patients treated with a placebo. Serum levels of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β were measured using enzyme-linked immunosorbent assays. The results of the present study demonstrated a larger decrease in tumor size upon supplementing patients with RJ following molecular targeted therapy compared with that in patients administered with the placebo. Patients exhibited reduced anorexia and fatigue in the RJ group compared with the placebo group. The relative dose intensity for patients in the RJ group was higher than that in patients in the placebo group. Post- and pre-treatment ratios of the serum levels of TNF-α and TGF-β in patients in the RJ group were lower than those in patients in the placebo group, and these ratios correlated with decreasing tumor size and frequency of anorexia or fatigue in patients. In conclusion, the results of the present study indicated that oral intake of RJ improved the efficacy and safety of molecular targeted therapy in patients with RCC and changed the levels of TNF-α and TGF-β in the serum of patients, which is speculated to serve an important role in RJ-induced biological activities.