A homoeriodictyol sodium mouthwash reduces bitterness sensitivity in patients with gynecological cancer receiving carboplatin-based chemotherapy

Bitter taste disorders are common chemotherapy-induced side effects that compromise nutrition and quality of life. Since no treatment exists for conditions such as bitter taste hypersensitivity and phantogeusia, we hypothesized that a homoeriodictyol sodium (Na-HED) mouthwash reduces chemotherapy-induced bitterness sensitivity caused by salivary platinum (Pt) species derived from intravenously administered carboplatin. In a clinical pilot study involving patients with gynecological cancer (n = 8) receiving carboplatin-based chemotherapy, dietary intake, salivary Pt concentrations, and changes in taste perception were investigated. Patients exhibited decreased energy and protein intake, and salivary Pt. Using an in vitro blood-saliva barrier model, the transfer of Pt-based agents, specifically carboplatin and cisplatin, was demonstrated. Standardized sensory testing in patients revealed increased bitter taste sensitivity compared with the chemo-naïve baseline. A rinse-and-spit solution containing Na-HED, an approved flavoring compound and antagonist of bitter taste receptors (TAS2Rs), reduced the perceived bitterness of caffeine in patients receiving carboplatin (n = 15). As various anticancer agents are predicted to bind to TAS2Rs, a prerequisite for bitter taste sensation, this bitter-masking strategy may have broader applicability. Our preliminary findings show that the Na-HED mouthwash reduces bitter taste sensitivity in patients, supporting its potential to alleviate chemotherapy-induced bitter taste hypersensitivity and phantogeusia.