الفهرس | Only 14 pages are availabe for public view |
Abstract Chemical peeling is a procedure used for cosmetic improvement of skin or for treatment of some skin disorders. The chemical exfoliating agent is applied to the skin to destruct portions of epidermis and/or dermis with subsequent regeneration and rejuvenation of the tissues Alpha-hydroxy acids (Such as Glycolic acid and lactic acid) have been recognized as important adjunctive therapeutic elements in a variety of skin disorders including actinic damage, seborrheic keratosis, photodamage, hyperpigmentation and acne Alpha-hydroxy acids (AHAs) cause a superficial exfoliation by keratinocyte dyscohesion of pathologically sticky cells at the level of stratum granulosum in the epidermis .This allows the pathologic cells to become loose and shed and therefore helps to correct an abnormally thickened stratum corneum In addition, AHAs applications on the skin increase the epidermal thickness, the hyaluronic acid, collagen I, procollagen I and mucopolysaccharides; and reduce the fragmentation of elastic fibers Glycolic acid (G A) has effect on the induction of cell cycle arrest and induction of apoptosis in human keratinocytes Topical lactic acid (L A) increases the number of apoptotic cells and increase secretion of vascular endothelial growth factor in human reconstructed epidermis Apoptosis is a controlled form of cell death through the interaction of many proteins including Bcl-2. Bcl-2 gene is an antiapoptotic membrane associated molecule that resides in the nuclear envelope and mitochondria. The expression of Bcl-2 prevents apoptotic cell death The Bcl-2 protein has been shown to suppress cell death and protects cell against apoptosis induced by different death-inducing signals. The expression of Bcl-2 protein is high in malignant tumors of the skin such as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), as well as in the precancerous lesion as actinic keratosis (AK) and in benign tumor such as seborrheic Keratosis (SK, . |