Methylcobalamin Protects Melanocytes from H2O2-Induced Oxidative Stress by Activating the Nrf2/HO-1 Pathway

Abstract

Purpose: Oxidative stress is considered a major determinant in the pathogenesis of vitiligo. Methylcobalamin (MeCbl) is an activated form of vitamin B12 that regulates inflammatory factors, counters oxidative stress, and reduces apoptosis in many disease models. However, the specific mechanism of MeCbl repigmentation against vitiligo is unknown. In this study, we explored the effect of MeCbl on melanocytes following hydrogen peroxide (H 2 O 2 )induced oxidative stress. Methods: We established an oxidative stress model using the immortalized human normal melanocyte cell line PIG1. We used a Cell Counting Kit-8 (CCK-8) to detect drug cytotoxicity, and we measured the melanin content of cells using the NaOH method. Intracellular oxidative damage was assessed by flow cytometry and antioxidant enzyme detection kits. In addition, we assessed the presence of apoptosis by flow cytometry and Western blots. We explored the underlying mechanisms of MeCbl during oxidative stress in melanocytes by analyzing the results of experiments based on real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, and laser scanning confocal immunofluorescence microscopy. Finally, we repeated the experiments after applying an inhibitor to block the Nrf2 pathway. Results: We found that MeCbl treatment enhanced cell viability, increased melanin content, reduced intracellular reactive oxygen species (ROS) accumulation, increased the activities of antioxidant enzyme superoxide dismutase (SOD) and catalase (CAT), reduced melanocyte apoptosis, and up-regulated the expression of the Nrf2/HO-1 pathway. Moreover, the protective effects of MeCbl were significantly weakened after inhibiting the Nrf2/HO-1 pathway. Conclusion:Our results indicate that MeCbl attenuated the H 2 O 2 -induced oxidative stress in melanocytes by activating the Nrf2/HO-1 pathway, this suggests that MeCbl may be an effective treatment against vitiligo.

Ischemic Stroke and Dietary Vitamin B12 Deficiency in Old-Aged Females: Impaired Motor Function, Increased Ischemic Damage Size, and Changed Metabolite Profiles in Brain and Cecum Tissue

“…Additionally, in the mitochondria, vitamin B12 is involved in the regulation of mitochondrial metabolism. Recent data suggest that vitamin B12 plays an important antioxidant role in the body and, when levels are reduced, there is more oxidation present [ 42 , 43 ]. The increased levels of oxidation lead to the activation of nuclear factor–erythroid factor 2-related factor (Nrf-2) [ 43 ], an important transcription factor involved in the cellular response to oxidative stress.…”

“…Recent data suggest that vitamin B12 plays an important antioxidant role in the body and, when levels are reduced, there is more oxidation present [ 42 , 43 ]. The increased levels of oxidation lead to the activation of nuclear factor–erythroid factor 2-related factor (Nrf-2) [ 43 ], an important transcription factor involved in the cellular response to oxidative stress. Ischemic stroke also results in oxidative stress and increased levels of Nrf-2 [ 44 ].…”

Ischemic stroke and dietary vitamin B12 deficiency in old-aged females impaired motor function, increased ischemic damage size, and changed metabolite profiles in brain and cecum tissue

“…Additionally, in the mitochondria, vitamin B12 is involved in the regulation of mitochondrial metabolism. Recent data suggests that vitamin B12 plays an important antioxidant role in the body and, when levels are reduced, there is more oxidation present (An et al, 2021; van de Lagemaat et al, 2019). The increased levels of oxidation lead to the activation of nuclear factor-erythroid factor 2-related factor (Nrf-2) (An et al, 2021), an important transcription factor involved in cellular response to oxidative stress.…”

“…Recent data suggests that vitamin B12 plays an important antioxidant role in the body and, when levels are reduced, there is more oxidation present (An et al, 2021; van de Lagemaat et al, 2019). The increased levels of oxidation lead to the activation of nuclear factor-erythroid factor 2-related factor (Nrf-2) (An et al, 2021), an important transcription factor involved in cellular response to oxidative stress. Ischemic stroke also results in oxidative stress and increased levels of Nrf-2 (Farina et al, 2021).…”

Research status of vitiligo models

“…Various endogenous or exogenous stimuli can disrupt the balance of the oxidative-antioxidant system, which may increase the level of Reactive Oxygen Species (ROS) in MCs. ROS can destroy macromolecular substances including lipids, nucleic acids and proteins, leading to lipid peroxidation, DNA fragmentation, oxidative decomposition of proteins and activation or inactivation of various enzymes [7]. Moreover, ROS may also cause a decrease in mitochondrial membrane potential, abnormalities in mitochondrial membrane lipid composition, and impairment of the integrity of the respiratory chain.…”