The possible therapeutic effect of platelet-rich plasma versus its derived exosomes in a hydrogen peroxide–induced depigmentation model in adult guinea pigs: a histological study

Vitiligo is a pigmentary disorder characterized by the loss of functional melanocytes, leading to depigmented skin patches and significant psychological burden. Platelet-rich plasma (PRP) and its derived exosomes have recently gained attention as potential regenerative therapies due to their immunomodulatory and antioxidant effects.To evaluate the therapeutic effects of platelet-rich plasma (PRP) versus its derived exosomes in a hydrogen peroxide-induced depigmentation model in guinea pigs.Forty-two adult male guinea pigs were divided into control, depigmentation, PRP-treated, and PRP-exosome-treated groups. Depigmentation was induced using topical H₂O₂. A recovery group was included to assess spontaneous repigmentation after discontinuation of H₂O₂. Histological, immunohistochemical, histomorphometric, and biochemical analyses were performed.The depigmentation group showed progressive spongiosis in the epidermis with significant increase in the epidermal thickness. Significant decrease in melanin pigment and significant decrease in the number of melanocytes were noticed in the epidermis and hair follicles. Administration of PRP and PRP-Exosomes reversed these histological alterations with significant reduction in epidermal thickness and negative CD3 reaction in the dermis. More improvement was observed in PRP-exosome group compared to PRP group, as evidenced by significant increased amount of melanin granules and number of melanocytes in exosome group.Within the limitations of this oxidative stress-induced depigmentation model, both PRP and its derived exosomes were associated with histological improvement, with greater changes observed in the exosome-treated group. However, further studies are needed to confirm these findings in models more representative of human vitiligo.