Natalia Belemets1, Nazarii Kobyliak2, Oleksandr Virchenko1, Tetyana Falalyeyeva1, Tsyryuk Olena1, Petro Bodnar3, Oleksiy Savchuk1, Tetyana Galenova1, Martin Caprnda4, Luis Rodrigo5, Lubomir Skladany6, Delian Delev7, Radka Opatrilova8, Peter Kruzliak9, Tetyana Beregova1, Lyudmyla Ostapchenko1. 1. Taras Shevchenko National University, Kyiv, Ukraine. 2. Bogomolets National Medical University, Kyiv, Ukraine. Electronic address: nazariikobyliak@gmail.com. 3. Bogomolets National Medical University, Kyiv, Ukraine. 4. 2nd Department of Internal Medicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia. 5. Faculty of Medicine, University of Oviedo, Central University Hospital of Asturias (HUCA), Oviedo, Spain. 6. Department of Internal Medicine, F. D. Roosvelt Hospital, Banska Bystrica, Slovakia. 7. Department Pharmacology and Clinical Pharmacology, Medical Faculty, Medical University of Plovdiv, Plovdiv, Bulgaria. 8. Department of Chemical Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Brno, Czechia. 9. Department of Chemical Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Brno, Czechia; 2nd Department of Surgery, Faculty of Medicine, Masaryk University, Brno, Czechia. Electronic address: kruzliakpeter@gmail.com.
Abstract
BACKGROUND: One of the pathogenic mechanisms of the progression non-alcoholic liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH) is the accumulation of reactive oxygen species (ROS). So, antioxidant therapy is necessary for successful treatment of the liver injury. We have paid attention to melanin produced by yeast Nadsoniella nigra strain X-1 as novel antioxidant and anti-inflammatory agents with low toxicity. In current study we aimed to investigate the preventive effect of melanin on the monosodium glutamate (MSG) induced NAFLD model in rats. METHODS: The study was carried out on 45 Wistar rats that were divided into 3 groups: intact, MSG- and MSG+melanin groups (n=15 in each group). Newborn rats of MSG- and MSG+melanin groups were administered with MSG (4mg/g, 8μl/g, subcutaneously) at 2nd-10th days of life. Since the age of 1 month, rats of MSG-group were treated with water (0.25ml/100g), rats of MSG+melanin groups-with melanin (1mg/kg) dissolved in water (0.25ml/100g). INTRODUCTION: had been performed intermittently (two-week courses alternated with two-week breaks) for 3 months. In 4-month rats anthropometrical parameters and visceral adipose tissue (VAT) mass were estimated. To assess morphological changes in liver we used NAS (NAFLD activity score). The content of pro-inflammatory cytokines (interleukin (IL)-1β, IL-12Bp40, interferon (INF)-γ) and anti-inflammatory cytokines (IL-4, IL-10, tumor growth factor (TGF)-β) were measured by ELISA. RESULTS: We found significantly lower total score (1.0±0.19 vs 3.33±0.36, p<0.001), degree of steatosis (0.73±0.18 vs 1.80±0.17, p<0.001) and manifestation of lobular inflammation (0.27±0.11 vs 1.20±0.17, p<0.001) due to NAFLD activity score in MSG+melanin group compared to MSG-obesity. NASH we confirmed only in 33.3% of rats with MSG-obesity that was significantly higher than after melanin (6.7%) administration (p=0.033). Melanin administration reduce amount of visceral fat on 44.5% (p<0.001) as compared to MSG-obesity group. Melanin reduced the content of IL-1β in rat serum and restored the level of anti-inflammatory cytokines (IL-10, TGF-β) to the control values. CONCLUSION: Thus, the administration of melanin can prevent development of NAFLD/NASH in rats with MSG-induced obesity and can be considered as possible novel therapeutic agents but further studies to confirm its action needed.
BACKGROUND: One of the pathogenic mechanisms of the progression non-alcoholic liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH) is the accumulation of reactive oxygen species (ROS). So, antioxidant therapy is necessary for successful treatment of the liver injury. We have paid attention to melanin produced by yeastNadsoniella nigra strain X-1 as novel antioxidant and anti-inflammatory agents with low toxicity. In current study we aimed to investigate the preventive effect of melanin on the monosodium glutamate (MSG) induced NAFLD model in rats. METHODS: The study was carried out on 45 Wistar rats that were divided into 3 groups: intact, MSG- and MSG+melanin groups (n=15 in each group). Newborn rats of MSG- and MSG+melanin groups were administered with MSG (4mg/g, 8μl/g, subcutaneously) at 2nd-10th days of life. Since the age of 1 month, rats of MSG-group were treated with water (0.25ml/100g), rats of MSG+melanin groups-with melanin (1mg/kg) dissolved in water (0.25ml/100g). INTRODUCTION: had been performed intermittently (two-week courses alternated with two-week breaks) for 3 months. In 4-month rats anthropometrical parameters and visceral adipose tissue (VAT) mass were estimated. To assess morphological changes in liver we used NAS (NAFLD activity score). The content of pro-inflammatory cytokines (interleukin (IL)-1β, IL-12Bp40, interferon (INF)-γ) and anti-inflammatory cytokines (IL-4, IL-10, tumor growth factor (TGF)-β) were measured by ELISA. RESULTS: We found significantly lower total score (1.0±0.19 vs 3.33±0.36, p<0.001), degree of steatosis (0.73±0.18 vs 1.80±0.17, p<0.001) and manifestation of lobular inflammation (0.27±0.11 vs 1.20±0.17, p<0.001) due to NAFLD activity score in MSG+melanin group compared to MSG-obesity. NASH we confirmed only in 33.3% of rats with MSG-obesity that was significantly higher than after melanin (6.7%) administration (p=0.033). Melanin administration reduce amount of visceral fat on 44.5% (p<0.001) as compared to MSG-obesity group. Melanin reduced the content of IL-1β in rat serum and restored the level of anti-inflammatory cytokines (IL-10, TGF-β) to the control values. CONCLUSION: Thus, the administration of melanin can prevent development of NAFLD/NASH in rats with MSG-induced obesity and can be considered as possible novel therapeutic agents but further studies to confirm its action needed.