Asian J Beauty Cosmetol. 2012; 10(4): 887-891.
The Protective Effect of Extracts of Bifidobacterium longum against Ultraviolet B in Human Dermal Fibroblasts
ABSTRACT
Bifidobacterium longum (B. longum ) is a species of gram-positive anaerobic bacterium which can be found
intestines of humans. B. longum , a potential probiotic used in the food industry, promotes the health of
human intestinal tract by reduction of harmful gram-negative bacteria and toxic molecules. Also, B. longum
has numerous biological effects, such as anti-cancer, activation of immune response and reduction of DNA
damage. Ultraviolet (UV) irradiation has many adverse effects on skin, including inflammation, alteration in the
extracellular matrix, cellular senescence and apoptosis. In this study, we investigated the protective effect of B.
longum extracts against UVB-induced cellular damage in human dermal fibroblasts (HDFs). B. longum extracts
at concentration 0.01 ~ 0.02% (w/v) did not affect cell viability in HDFs. When UVB-exposed HDFs were treated
with B. longum extracts, cell viability was substantially enhanced in a dose-dependent manner. To investigate
inhibitory effects against cellular senescence of B. longum extracts in HDFs, we performed SA-β-gal staining.
UVB-exposed HDFs with B. longum extracts were decreased SA-β-gal positive cells approximately 40% at
the concentration of 0.02% (w/v). Flow cytometry was used to determine changes of cell cycle in B. longum
extracts treated-HDFs. UVB irradiation slightly increased the percentage of cell population in the sub-G1
phase. However, the proportion of cells in sub-G1 phase were decreased approximately 50% by treatment with
B. longum extracts. These results suggest that B. longum extracts reduce UVB-induced cellular senescence
and apoptosis in HDFs. Thus, B. longum extracts might be used as a potential agents for protection of UVBinduced
skin cell damage.
Keywords :
B ifidobacterium longum , Ultraviolet, Senescence, Apoptosis, Protection, Human dermal fibroblast
