Beneficial effects of dried pomegranate juice concentrated powder on ultraviolet B-induced skin photoaging in hairless mice

Abstract

The present study investigated the anti-aging effects of pomegranate juice concentrated powder (PCP) in hairless mice following 15 weeks of UVB irradiation (three times a week; 0.18 J/cm2). Skin moisturizing effects were evaluated through skin water, collagen type I and hyaluronan contents, as well as collagen type I and hyaluronan synthesis-related transcript levels. Wrinkle formation and edema scores (skin weights) were also assessed, along with skin matrix metalloproteinase (MMP)-1, MMP-9 and MMP-13 transcript levels. To determine the anti-inflammatory effects of PCP, myeloperoxidase (MPO) activity, interleukin (IL)-1β and IL-10 contents were observed. Caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) were used as an apoptotic index in epidermal keratinocytes. To determine the anti-oxidative effects of PCP, nitrotyrosine and 4-hydroxynonenal immunoreactive cells were detected and glutathione (GSH) content, malondialdehyde levels, superoxide anion production, Nox2, and GSH reductase mRNA expression were all measured. The results indicated that skin wrinkles induced by photoaging were significantly reduced by PCP, whereas skin water contents, collagen type I and hyaluronan contents all increased. Furthermore, IL-1β levels in the PCP-treated groups were lower than those in the UVB-exposed control group. UVB-induced GSH depletion was also inhibited by PCP. Taken together, the results of the current study suggest that PCP has favorable protective effects against UVB-induced photoaging through anti-apoptotic effects, MMP activity inhibition and ECM (COL1 and hyaluronan) synthesis-related moisturizing, anti-inflammatory and anti-oxidative effects.

Keywords: anti-inflammatory effect; antioxidant effect; apoptosis; dried pomegranate juice concentrated powder; photoaging; skin moisturizing effect; ultraviolet B.

Figures

Figure 1.

Representative gross images of dorsal back skin (top panel) and replicas (bottom panel) taken from unexposed intact or UVB-exposed hairless mice. (A) Unexposed normal vehicle control hairless mice treated with distilled water; (B) UVB-exposed vehicle control hairless mice administered distilled water; (C) UVB-exposed hairless mice administered 2 ml/kg PCS; (D) UVB-exposed hairless mice administered 100 mg/kg PCP; (E) UVB-exposed hairless mice administered 200 mg/kg PCP; (F) UVB-exposed hairless mice administered 400 mg/kg PCP. Scale bars=10 mm; UVB, ultraviolet B; PCP, dried pomegranate juice concentrated powder; PCS, pomegranate juice concentrated solution.

Figure 2.

Changes in the mean length and depth of wrinkles in skin replicas following 15 weeks continuous oral administration of PCP or PCS in UVB-exposed mice. Significant increases in (A) mean length and (B) average depth of skin wrinkles were detected in the skin replicas of UVB control mice compared with the intact controls. Values are expressed as the mean ± standard deviation (n=8). P-values were determined by the least significant difference test. *P†P<0.01 vs. UVB control. UVB, ultraviolet B; PCP, dried pomegranate juice concentrated powder; PCS, pomegranate juice concentrated solution.

Figure 3.

Changes in skin edema scores. The graph presents the 6-mm diameter skin weights following 15 weeks continuous oral administration of PCP or PCS in UVB-exposed mice. Values are expressed the mean ± standard deviation (n=8). P-values were determined by the least significant difference test. *P†P<0.01 vs. UVB control. UVB, ultraviolet B; PCP, dried pomegranate juice concentrated powder; PCS, pomegranate juice concentrated solution.

Figure 4.

Representative histological images of dorsal back skin tissues taken from unexposed intact or UVB exposed hairless mice. (A) Intact vehicle control; (B) UVB control; (C) UVB-exposed mice treated with 2 ml/kg PCS; (D) UVB-exposed mice treated with 100 mg/kg PCP; (E) UVB-exposed mice treated with 200 mg/kg PCP; (F) UVB-exposed mice treated with 400 mg/kg PCP. Arrows indicate microfolds formed. Scale bars=100 µm. UVB, ultraviolet B; MT, Masson's trichrome; PCP, dried pomegranate juice concentrated powder; PCS, pomegranate juice concentrated solution.

Figure 5.

Representative immunohistochemistrical images of dorsal back skin tissues, taken from unexposed intact or UVB-exposed hairless mice. (A) Intact vehicle control; (B) UVB control; (C) UVB-exposed mice treated with 2 ml/kg PCS mice; (D) UVB-exposed mice treated with 100 mg/kg PCP; (E) UVB-exposed mice treated with 200 mg/kg PCP; (F) UVB-exposed mice treated with 400 mg/kg PCP. All avidin-biotin complex immunostaining. Scale bars=50 µm. UVB, ultraviolet B; 4-HNE, 4-hydroxynonenal; PARP, cleaved poly(ADP-ribose) polymerase; MMP-9, matrix metalloproteinase 9; PCP, dried pomegranate juice concentrated powder; PCS, pomegranate juice concentrated solution.