Safflower seed extract synergizes the therapeutic effect of cisplatin and reduces cisplatin-induced nephrotoxicity in human colorectal carcinoma RKO cells and RKO-transplanted mice

Safflower seed is effective against oxidative stress, mediating the activation of the apoptotic signaling pathway in the renal tissues of cisplatin-treated mice. The anticancer activity of safflower in various cancer cell lines has also been reported. The present study was conducted to evaluate the potential synergistic anticancer effects of the co-treatment of safflower seed extracts and cisplatin in RKO cells and in BALB/c mice bearing RKO cell-derived human colorectal tumors. In the cellular system, RKO cells were treated with safflower seed extract in the presence or absence of cisplatin for 48 h and the cytotoxicity was evaluated by using microscopy. In the in vivo system, mice were injected with RKO cells and subsequently orally administered 100 or 200 mg/kg body weight safflower seed extract plus cisplatin-treated or untreated mice for 3 days to examine the inhibitory effect on the tumor. Treatment with safflower seed extract or cisplain to RKO cells resulted in a greater cell death than in with untreated cells. In the RKO cells co-treated with both safflower seed extract and cisplatin, greater cell damage was observed. In addition, mice co-administered safflower seed extract and cisplatin had lower concentrations of serum creatinine, which were indicative of less damage to the kidney, and had a lower solid tumor mass and higher expression of the caspase-3 protein. The results showed that safflower seed extract was highly toxic to RKO cells and inhibited tumor growth in cisplatin-treated mice through renoprotective effects.