Effects of 7-MEGATM 500 on Oxidative Stress, Inflammation, and Skin Regeneration in H2O2-Treated Skin Cells

Abstract

Environmental stimuli can lead to the excessive accumulation of reactive oxygen species (ROS), which is one of the risk factors for premature skin aging. Here, we investigated the protective effects of 7-MEGA^TM 500 (50% palmitoleic acid, 7-MEGA) against oxidative stress-induced cellular damage and its underlying therapeutic mechanisms in the HaCaT human skin keratinocyte cell line (HaCaT cells). Our results showed that treatment with 7-MEGA prior to hydrogen peroxide (H₂O₂)-induced damage significantly increased the viability of HaCaT cells. 7-MEGA effectively attenuated generation of H₂O₂-induced reactive oxygen species (ROS), and inhibited H₂O₂-induced inflammatory factors, such as prostaglandin E₂ (PGE₂), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β). In addition, cells treated with 7-MEGA exhibited significantly decreased expression of matrix metalloproteinase-1 (MMP-1) and increased expression of procollagen type 1 (PCOL1) and Elastin against oxidative stress by H₂O₂. Interestingly, these protective activities of 7-MEGA were similar in scope and of a higher magnitude than those seen with 98.5% palmitoleic acid (PA) obtained from Sigma when given at the same concentration (100 nL/mL). According to our data, 7-MEGA is able to protect HaCaT cells from H₂O₂-induced damage through inhibiting cellular oxidative stress and inflammation. Moreover, 7-MEGA may affect skin elasticity maintenance and improve skin wrinkles. These findings indicate that 7-MEGA may be useful as a food supplement for skin health.

Keywords: 7-MEGA; Anti-inflammation; Anti-oxidantion; Palmitoleic acid; Skin regeneration.

Fig. 1

Cytotoxicity and DPPH radical scavenging ability of 7-MEGA in HaCaT cells. (A) Viability of HaCaT cells after treatment with increasing concentrations of 7-MEGA (1~100 nL/mL) for 24 hr. (B) DPPH radical scavenging ability of 7-MEGA. Data are expressed as the mean ± SEM of three independent experiments, ***p < 0.001 vs. PA.

Fig. 2

Protective effect of 7-MEGA on cell viability against oxidative stress induced by H₂O₂ in HaCaT cells. Viability of HaCaT cells after treatment with increasing concentrations of H₂O₂ (0.1~1.5 mM) for 24 hr. (B) Viability of HaCaT cells after treatment with 1.0mM H₂O₂ for 24 hr after pretreatment with 7-MEGA (10~100 nL/mL) for 1 hr. Data are expressed as the mean ± SEM of three independent experiments, *p<0.05, **p < 0.01, ***p < 0.001 vs CON, ^#p<0.05, ^##p< 0.01, ^###p <0.001 vs. H₂O₂, ^$p< 0.05 vs. PA100.

Fig. 3

Effect of 7-MEGA on reactive oxygen species (ROS) generation and anti-oxidative activity (SOD, GSH) in H₂O₂-treated HaCaT cells. (A) HaCaT cells were pretreated with 7-MEGA (10~100 nL/mL) for 1 hr, then oxidative stress was induced using H₂O₂ (1.0 mM) for 5min. ROS generation was evaluated by DCF-DA. (B–C) HaCaT cells were pretreated with 7-MEGA (10~100 nL/mL) for 1 hr, then oxidative stress was induced using H₂O₂ (1.0mM) for 24 hr. SOD and GSH expression were measured in cell lysates by ELISA. Data are expressed as the mean± SEM of three independent experiments, **p< 0.01, ***p< 0.001 vs. CON, ^#p<0.05, ^##p<0.01, ^###p< 0.001 vs. H₂O₂, ^$p< 0.05 vs. PA100.

Fig. 4

Effect of 7-MEGA on the protein expression of pro-inflammatory markers (TNF-α, IL-1β), COX-2, and PGE₂ in H₂O₂-treated HaCaT cells. HaCaT cells were pretreated with 7-MEGA (10~100 nL/mL) for 1 hr, then oxidative stress was induced using H₂O₂ (1.0 mM) for 24 hr. (A–B) Whole cell lysates were subjected to Western blot analysis to evaluate COX-2 and PGE₂ expression. (C–D) IL-1β and TNF-α were measured in the culture supernatant by ELISA. Data are expressed as the mean ± SEM of three independent experiments, ***p< 0.001 vs. CON, ^#p<0.05, ^##p< 0.01, ^###p< 0.001, vs. H₂O₂, ^$p< 0.05 vs. PA100.

Fig. 5

Effect of 7-MEGA on MMP-1, procollagen type 1, Elastin protein expression in H₂O₂-treated HaCaT cells. HaCaT cells were pretreated with 7-MEGA (10~100 nL/mL) for 1 hr, then oxidative stress was induced using H₂O₂ (1.0 mM) for 24 hr. (A–C) Whole cell lysates were subjected to Western blot analysis to evaluate MMP-1, PCOL1 and Elastin expression. Data are expressed as the mean ± SEM of three independent experiments, ***p< 0.001 vs. CON, ^#p< 0.05, ^##p<0.01, ^###p< 0.001, vs. H₂O₂, ^$p< 0.05 vs. PA100.