الفهرس 
Lists of AbbreviationsOnly 14 pages are availabe for public view
 |  | from | 144 |  |  |
| | | from | 144 | | |
Abstract
Summary & conclusions
The human skin color is one of the most perceptible phenotypic variations among humans and is determined primarily by the type and amount of melanin synthesized within melanosomes and the pattern of melanosome distribution within the melanocytes. Getting a lighter skin tone always draws a lot of interest, fair or light skin color has been a symbol of prominence, superiority and higher social ranking. A lot is known about topical skin whitening agents, but systemic skin whitening agents which are slowly gaining popularity do not have much evidence to their credit in the scientific literature
Glutathione is a low molecular weight thiol-tripeptide that plays a prominent role in maintaining intracellular redox balance. In addition to its remarkable antioxidant properties, the discovery of its anti-melanogenic properties has led to its promotion as a skin-lightening agent. It is formed by three amino acids glutamate, cysteine and glycine. It is a compound with a biologically active sulfhydryl group contributed by the cysteine moiety that acts as the active part of the molecule. This sulfhydryl group allows for interaction with a variety of biochemical systems, hence the abbreviation “GSH” for its active form. Various mechanisms for the hypo pigmentary effect of glutathione have been proposed, with inhibition of tyrosinase being the most important .Skin color is determined mainly by the quantity of melanin synthesized by the melanocyte and its distribution pattern in the surrounding keratinocytes.
The purpose of the current study was to evaluate the safety and efficacy of parenteral glutathione as skin whitening agent. During this study, glutathione was injected intra-peritoneal in Guinea pigs in a dose of (46.5 mg) every week for 4 weeks (active treatment group). Another group was evaluated 1 month after glutathione stoppage (recovery group).
The current study showed marked and significant reduction in (eumelanin) pigment stained by Fontana Masson stain within the basal layer of the squamous epithelium and in hair follicles in the treated group (group 2) while in the recovery group eumelanin pigment started to increase significantly in contrast to treated group 2 but it still lower than those of the control group 1.
By Warthin Starry stain, there were numerous dense melanin pigment granules (pheomelanin) within the keratinocytes and hair and hair follicles. in the recovery group there was relative significant decrease in the density of melanin pigment granules (pheomelanin) within the keratinocytes and hair & hair follicles in contrast to group 2 but it still more dense than those demonstrated in group 1.
By Tyrosinase immunohistochemistry, there was positive reaction of the melanocytes in the treated group and in the recovery group with a relatively small cell body and few and short processes in the recovery group in contrast with treated group that show no apparent processes.
Grossly there were some hairs in the dark brown area start to become lighter became lighter in color in glutathione treated group compared to the control and the recovery group.
Laboratory investigations results of SGOT, SGPT, FSH, LH, Prolactin, E2, TSH, Testosterone not significantly different from the control group indicating the safety of GHS when used systemically in this dose used in this study.
Conclusions
Parenteral glutathione injection might be effective at reducing skin pigmentation in Guinea pigs. It was associated with a reduction in both eumelanin pigmentation and number of tyrosinase positive cells, with increase in pheomelanin granules. Laboratory investigations results indicated that the tested dose of glutathione was not harmful to liver, kidney and thyroid gland of animals. Based on the present results, parenteral glutathione might be considered a safe and effective systemic whitening agent.