Efek asam alpha-lipoat pada sintesis kolagen fibroblas kulit normal manusia yang dipajan sinar ultraviolet B

KRISMI, Arum, dr. Satiti Retno Pudjiati, Sp.KK(K)

2010 | Tesis | S2 Ilmu Kedokteran Klinik

Pajanan sinar ultraviolet B (SUVB) berulang pada kulit manusia dapat mempercepat penuaan dini karena SUVB terbukti dapat menurunkan deposisi dan meningkatkan degradasi kolagen. Uji klinis membuktikan bahwa asam alphalipoat (alpha-lipoic acid / A-LA) 5% topikal dapat memperbaiki tampilan kulit menua dini, namun efek A-LA pada deposisi dan degradasi kolagen kultur fibroblas kulit normal manusia belum pernah dilaporkan. Penelitian ini dilakukan untuk mengetahui efek A-LA pada deposisi dan degradasi kolagen kultur fibroblas kulit normal manusia yang dipajan SUVB.Kultur fibroblas kulit normal manusia diterapi dengan A-LA 0, 125, 250, 500 μM yang dilarutkan dalam DMEM dan dipajan UVB 300 mJ/cm2. Kadar deposisi dan degradasi kolagen diukur menggunakan metode Sirius Red, dibaca secara spektrofotometris dengan SpectraMax™ 550 nm. Perbedaan rerata densitas optis (DO) deposisi kolagen dianalisis dengan uji Wilcoxon dan uji Friedman,sedangkan degradasi kolagen dianalisis dengan uji t berpasangan dan ANOVA satu arah (p<0,05).Alpha-lipoic acid 125 μM menghambat penurunan rerata deposisi kolagen secara bermakna (p=0,050), namun konsentrasi selanjutnya tidak memberikan hambatan yang bermakna. Alpha-lipoic acid menghambat peningkatan rerata degradasi kolagen secara tidak bermakna (p>0,05). Sebagai simpulan, A-LA dapat menghambat penurunan deposisi, tetapi tidak dapat menghambat peningkatan degradasi kolagen kultur fibroblas kulit normal manusia yang dipajan SUVB.

Repeated ultraviolet B (UVB) irradiation on human skin has considered responsible in premature aging processes because UVB has proved to inhibits collagen deposition and accelerates collagen degradation. Clinical studies showed that topical usage of 5% alpha-lipoic acid (A-LA) improved the clinical appearance of photoaged skin. However, the effect of A-LA on collagen deposition and degradation in UVB-irradiated normal human skin fibroblasts culture has not been reported. We investigated the effect of A-LA on collagen deposition and degradation in UVB-irradiated cultured normal human skin fibroblasts.Cultured normal human skin fibroblasts were treated with 0, 125, 250, 500 μM A-LA diluted in complete DMEM and irradiated with 300 mJ/cm2 UVB. The mean collagen deposition and degradation’s level were measured by Sirius Red assay, read spectrophotometrically by SpectraMax™ at 550 nm. Mean differences of collagen deposition optical densities (OD) were analyzed by Wilcoxon signedranks test and Friedman test, while collagen degradation by paired-sample t test and one way ANOVA (p<0,05). Alpha-lipoic acid 125 μM inhibited mean collagen deposition decrement significantly (p=0,050), though higher concentrations did not. Alpha-lipoic acid inhibited mean collagen degradation increment insignificantly (p>0,05). In conclusions, A-LA inhibits mean collagen deposition decrement, but does not inhibit mean collagen degradation increment in UVB-irradiated cultured normal human skin fibroblasts.

Kata Kunci : Alpha,lipoic,Kolagen,Fibroblas kulit normal manusia,Ultraviolet B