Safety and efficacy of parenteral glutathione as a promising skin lightening agent: A controlled assessor blinded pharmacohistologic and ultrastructural study in an animal model.

Hyperpigmentation was induced in the skin of experimental animals using UVB at 6 J/cm three times a week for three consecutive weeks. Subsequently, glutathione was injected intraperitoneally in the experimental animals at doses of 10, 20, and 40 mg/kg body weight three times a week for three consecutive weeks. At the end of the experiment, blood samples and lung, kidney, liver, and skin tissue specimens were collected from animals for hematological, biochemical, histological, and electron microscopy examination. Glutathione at 40 mg/kg body weight/day reduced skin hyperpigmentation significantly, except at low doses. The skin lightening effect assessed by a chromameter was dose-dependent. There were no statistically significant differences among the mean values of AST, ALT, creatinine, BUN, and CBC counts across the four groups. Lung, kidney, and liver tissue specimens did not show any histological toxic changes. The number of melanin granules was significantly lower in the group treated with the highest dose of glutathione compared to that in the control. Electron microscopy proved that glutathione at 20 and 40 mg/kg body weight/day was able to reduce the number of melanized cells significantly compared to that in the control. Parenteral glutathione was effective as a skin lightening agent and did not provoke any toxic effects in the employed animal model. The limitation of the study was conducted in guinea pigs and was of short-term duration.