Liposomalization of Oxaliplatin Exacerbates the Non-Liposomal Formulation-Induced Decrease of Sweet Taste Sensitivity in Rats

Here, we investigated whether or not the characteristics of the oxaliplatin-induced sweet taste sensitivity were altered by PEGylated liposomalization of oxaliplatin (liposomal oxaliplatin), which enhances its anticancer efficacy. Liposomal oxaliplatin and oxaliplatin were intravenously and intraperitoneally, respectively, administered to male Sprague-Dawley rats at the total dose of 8 mg/kg. A brief-access test for evaluation of sweet taste sensitivity on day 7 revealed that both liposomal oxaliplatin and oxaliplatin decreased the sensitivity of rats, the degree with the former being greater than in the case of the latter. Liposomalization of oxaliplatin increased the accumulation of platinum in lingual non-epithelial tissues, through which taste nerves passed. The lingual platinum accumulation induced by not only liposomal oxaliplatin but also oxaliplatin was decreased on cooling of the tongue during the administration. In the current study, we revealed that liposomalization of oxaliplatin exacerbated the oxaliplatin-induced decrease of sweet taste sensitivity by increasing the accumulation of platinum/oxaliplatin in lingual non-epithelial tissues. These findings may suggest that reduction of liposomal oxaliplatin distribution to the tongue on cooling during the administration prevents exacerbation of the decrease of sweet taste sensitivity, maintaining the quality of life and chemotherapeutic outcome in patients.