Evaluation of Chemotherapy-induced Dysgeusia in Patients With Gastrointestinal Cancer: A Pilot Study.

BACKGROUND/AIM: Dysgeusia, one of the adverse effects of cancer chemotherapy, and anorexia due to taste disorder can significantly impair the quality of life of patients. However, an evaluation method for dysgeusia has not yet been established. The present prospective study aimed to utilize a combination of subjective and objective assessment methods to evaluate dysgeusia in patients with gastrointestinal cancer initiating chemotherapy, to determine chemotherapeutic drugs and regimens causing dysgeusia, and to assess whether dysgeusia was associated with zinc deficiency. PATIENTS AND METHODS: A total of 21 patients with newly diagnosed gastrointestinal cancer were registered between August 2020 to March 2021. The following regimens were also included in the evaluation if the patients did not develop dysgeusia. A total 30 regimens were administered to the patients during the study period. A salt-impregnated test paper (Salsave®) was used as a subjective assessment, and the chemotherapy-induced taste alteration scale was used as an objective assessment. RESULTS: Based on physician interviews, dysgeusia was diagnosed in 8 of 21 patients (38%) treated with 8 of 30 regimens (27%). All regimens that resulted in dysgeusia contained platinum-based drugs. The patients who developed dysgeusia had higher controlling nutritional status scores at the start of chemotherapy compared to those who did not develop dysgeusia. In both subjective and objective assessments, the patients with dysgeusia performed significantly worse than those without dysgeusia. Six of the eight patients who developed dysgeusia were administered Novelzine, which did not improve the taste disorder despite the improvement of serum zinc levels. CONCLUSION: The combined approach using subjective and objective taste assessment methods was useful in assessing chemotherapy-induced dysgeusia. Mechanisms other than hypozincemia should be considered as contributors to taste disorders caused by platinum-based drugs.

Antibacterial activity of peptides derived from the C-terminal region of a hemolytic lectin, CEL-III, from the marine invertebrate Cucumaria echinata.

Several synthetic peptides derived from the C-terminal domain sequence of a hemolytic lectin, CEL-III, were examined as to their action on bacteria and artificial lipid membranes. Peptide P332 (KGVIFAKASVSVKVTASLSK-NH(2)), corresponding to the sequence from residue 332, exhibited strong antibacterial activity toward Gram-positive bacteria. Replacement of each Lys in P332 by Ala markedly decreased the activity. However, when all Lys were replaced by Arg, the antibacterial activity increased, indicating the importance of positively charged residues at these positions. Replacement of Val by Leu also led to higher antibacterial activity, especially toward Gram-negative bacteria. The antibacterial activity of these peptides was correlated with their membrane-permeabilizing activity toward the bacterial inner membrane and artificial lipid vesicles, indicating that the antibacterial action is due to perturbation of bacterial cell membranes, leading to enhancement of their permeability. These results also suggest that the hydrophobic region of CEL-III, from which P332 and its analogs were derived, may play some role in the interaction with target cell membranes to trigger hemolysis.