Protective Effect of Ginseng on Salivary Dysfunction Following Radioiodine Therapy in a Mouse Model.

BACKGROUND: Following radioiodine (RI) therapy, oxidative stress is a putative damage mechanism resulting in salivary gland (SG) dysfunction. Since ginseng is a known anti-oxidative herb, we examined the SG radioprotective effects of Korea red ginseng (KRG) in a mouse model, when administered prior to RI.

METHODS: Four-week-old mice (n = 60) were divided into four groups: (1) normal control, (2) RI only treated (0.01 mCi/g, orally), (3) KRG administered (0.2 mg/g, intraperitoneal injection) 0.5 and 24 hours before RI, and (4) amifostine-treated group (0.2 mg/g, intraperitoneally) 0.5 hour before RI. The salivary lag times and flow rates were assessed, and sampled tissues were subjected to histologic examinations including hematoxylin and eosin and immunohistochemical staining. Apoptosis was examined by the terminal deoxynucleotidyl transferase biotin-dUDP nick end labeling (TUNEL) assay, and excretion changes in salivary 99m Tc pertechnetate were evaluated by single-photon emission computed tomography.

RESULTS: The body weight of the KRG group was similar to the control group. Salivary lag times and flow rates in the RI + KRG group were faster than in the RI only group. There was no significant intergroup difference in the SG weight. The RI + KRG group exhibited more mucin-containing parenchyma and less fibrotic tissues than the RI only group. Salivary epithelial (aquaporin 5) and myoepithelial (smooth muscle actin) cells of the RI + KRG group were protected from radiation damage. Low 8-OhdG (oxidative stress biomarker) and high superoxide dismutase 2 (reactive oxygen species scavenger) immunostaining reactivity was detected in the RI + KRG group when compared with the RI only group. Fewer apoptotic cells were observed in the RI + KRG or amifostine group compared to the RI only group in the TUNEL assay. The 99m Tc pertechnetate excretion level recovered in the KRG group.

CONCLUSION: Pretreatment with KRG before RI therapy is potentially beneficial in protecting against RI-induced salivary dysfunction.