Resveratrol is a naturally occurring polyphenol which has various beneficial effects, such as ant... more Resveratrol is a naturally occurring polyphenol which has various beneficial effects, such as anti-inflammatory, anti-tumor, anti-aging, antioxidant, and neuroprotective effects, among others. The anti-cancer activity of resveratrol has been related to alterations in sphingolipid metabolism. We analyzed the effect of resveratrol on the enzymes responsible for accumulation of the two sphingolipids with highest functional activity—apoptosis promoting ceramide (CER) and proliferation-stimulating sphingosine-1-phosphate (S1P)—in human lung adenocarcinoma A549 cells. Resveratrol treatment induced an increase in CER and sphingosine (SPH) and a decrease in sphingomyelin (SM) and S1P. Our results showed that the most common mode of CER accumulation, through sphingomyelinase-induced hydrolysis of SM, was not responsible for a CER increase despite the reduction in SM in A549 plasma membranes. However, both the activity and the expression of CER synthase 6 were upregulated in resveratrol-treat...
Photobiomodulation, Photomedicine, and Laser Surgery, 2020
Background: Cellular senescence is one of the major factors contributing to the aging process. Ph... more Background: Cellular senescence is one of the major factors contributing to the aging process. Photobiomodulation (PBM) is known to trigger an array of cellular responses, but there are no data on how it affects the process of cellular senescence. In this study, we analyze the effect of PBM on the cellular senescence and telomere dynamics. Methods: Human dermal fibroblasts were irradiated by a panel of light-emitting diodes with 590 nm and dose 30 J/cm2 accumulated over 1200 sec repeated in 4-day cycle within 40 days. After the last cycle of PBM treatment, the difference in number of senescent cells between PBM treated groups end nontreated control groups was measured by senescent sensitive β-galactosidase assay, and the difference in average telomere length between the experimental end control groups was analyzed using relative human telomere length quantitative Polymerase Chain Reaction (qPCR) assay. Results: After 10 cycles of irradiation, the percentage of senescent cells in PBM-treated cultures was 19.7% ± 4.5%, p < 0.05 smaller than the percentage of senescent cells in the control group, and their relative telomere length was 1.19 ± 0.09-fold, p < 0.05 greater than nontreated controls. Conclusions: Our study demonstrates for the first time that PBM with appropriate parameters can delay the attrition of the telomeres and the entry of cells into senescence, suggesting a potential involvement of telomerase reactivation. A hypothetical mechanism for this light-induced antiaging effect is discussed.
Combinations of anti-cancer drugs can overcome resistance to therapy and provide new more effecti... more Combinations of anti-cancer drugs can overcome resistance to therapy and provide new more effective treatments. In this work we have analyzed the effect of the polyphenol quercetin and the anti-cancer sphingosine analog fingolimod on the sphingolipid metabolism in HepG2 cells, since sphingolipids are recognized as mediators of cell proliferation and apoptosis in cancer cells. Treatment of hepatocellular carcinoma HepG2 cells with quercetin and fingolimod, alone or in combination, induced different degrees of sphingomyelin (SM) reduction and a corresponding activation of neutral sphingomyelinase (nSMase). Western blot analysis showed that only treatments containing quercetin induced up-regulation of nSMase expression. The same treatment caused elevation of ceramide (CER) levels, whereas the observed alterations in sphingosine (SPH) content were not statistically significant. The two tested drugs induced a reduction of the pro-proliferative sphingolipid, sphingosine 1 phosphate (S1P),...
THE ROLE OF LOW MOLECULAR ANTIOXIDANT N-ACETYL-L-CYSTEINE ON THE PHOSPHOLIPID COMPOSITION OF THE ... more THE ROLE OF LOW MOLECULAR ANTIOXIDANT N-ACETYL-L-CYSTEINE ON THE PHOSPHOLIPID COMPOSITION OF THE ALVEOLAR SURFACTANT IN SEPTIC RESPIRATORY DISTRESS SYNDROME CAUSED BY EXPERIMENTAL FEC L PERITONITIS S. Lazarov, R. Nicolov, E. Yanev, A. Momtchilova and R. Pankov Department of Pathophysiology, Medical Faculty – Sofia Department of Pharmacology and Toxicology, Medical Faculty – Sofia Institute of Biophysics, Bulgarian Academy of Sciences Department of Biology, Sofia University “Sv. Kliment Ohridski”
Адрес за кореспонденция: Д-р Симеон Лазаров, Катедра по патологична физиология, Медицински факулт... more Адрес за кореспонденция: Д-р Симеон Лазаров, Катедра по патологична физиология, Медицински факултет, МУ – София, Група по белодробна патология и сърфактантология, бул. “Св. Георги Софийски” 1, 1341 София, GSM: 0897 75 14 93 ***** Address for correspondence: Simeon Lazarov, MD, Department of Pathophysiology, Group of Lung Pathology and Survactants, Medical Faculty, Medical University – Sofia, 1 Sv. G. Sofiyski str., Bg-1431 Sofia, GSM: 0897 75 14 93
The polyphenol quercetin is associated with numerous beneficial health effects in various patholo... more The polyphenol quercetin is associated with numerous beneficial health effects in various pathologies such as oxidative stress, neurodegenerative disorders, inflammation, neoplastic processes, age-...
Resveratrol is a naturally occurring polyphenol which has various beneficial effects, such as ant... more Resveratrol is a naturally occurring polyphenol which has various beneficial effects, such as anti-inflammatory, anti-tumor, anti-aging, antioxidant, and neuroprotective effects, among others. The anti-cancer activity of resveratrol has been related to alterations in sphingolipid metabolism. We analyzed the effect of resveratrol on the enzymes responsible for accumulation of the two sphingolipids with highest functional activity—apoptosis promoting ceramide (CER) and proliferation-stimulating sphingosine-1-phosphate (S1P)—in human lung adenocarcinoma A549 cells. Resveratrol treatment induced an increase in CER and sphingosine (SPH) and a decrease in sphingomyelin (SM) and S1P. Our results showed that the most common mode of CER accumulation, through sphingomyelinase-induced hydrolysis of SM, was not responsible for a CER increase despite the reduction in SM in A549 plasma membranes. However, both the activity and the expression of CER synthase 6 were upregulated in resveratrol-treat...
Photobiomodulation, Photomedicine, and Laser Surgery, 2020
Background: Cellular senescence is one of the major factors contributing to the aging process. Ph... more Background: Cellular senescence is one of the major factors contributing to the aging process. Photobiomodulation (PBM) is known to trigger an array of cellular responses, but there are no data on how it affects the process of cellular senescence. In this study, we analyze the effect of PBM on the cellular senescence and telomere dynamics. Methods: Human dermal fibroblasts were irradiated by a panel of light-emitting diodes with 590 nm and dose 30 J/cm2 accumulated over 1200 sec repeated in 4-day cycle within 40 days. After the last cycle of PBM treatment, the difference in number of senescent cells between PBM treated groups end nontreated control groups was measured by senescent sensitive β-galactosidase assay, and the difference in average telomere length between the experimental end control groups was analyzed using relative human telomere length quantitative Polymerase Chain Reaction (qPCR) assay. Results: After 10 cycles of irradiation, the percentage of senescent cells in PBM-treated cultures was 19.7% ± 4.5%, p < 0.05 smaller than the percentage of senescent cells in the control group, and their relative telomere length was 1.19 ± 0.09-fold, p < 0.05 greater than nontreated controls. Conclusions: Our study demonstrates for the first time that PBM with appropriate parameters can delay the attrition of the telomeres and the entry of cells into senescence, suggesting a potential involvement of telomerase reactivation. A hypothetical mechanism for this light-induced antiaging effect is discussed.
Combinations of anti-cancer drugs can overcome resistance to therapy and provide new more effecti... more Combinations of anti-cancer drugs can overcome resistance to therapy and provide new more effective treatments. In this work we have analyzed the effect of the polyphenol quercetin and the anti-cancer sphingosine analog fingolimod on the sphingolipid metabolism in HepG2 cells, since sphingolipids are recognized as mediators of cell proliferation and apoptosis in cancer cells. Treatment of hepatocellular carcinoma HepG2 cells with quercetin and fingolimod, alone or in combination, induced different degrees of sphingomyelin (SM) reduction and a corresponding activation of neutral sphingomyelinase (nSMase). Western blot analysis showed that only treatments containing quercetin induced up-regulation of nSMase expression. The same treatment caused elevation of ceramide (CER) levels, whereas the observed alterations in sphingosine (SPH) content were not statistically significant. The two tested drugs induced a reduction of the pro-proliferative sphingolipid, sphingosine 1 phosphate (S1P),...
THE ROLE OF LOW MOLECULAR ANTIOXIDANT N-ACETYL-L-CYSTEINE ON THE PHOSPHOLIPID COMPOSITION OF THE ... more THE ROLE OF LOW MOLECULAR ANTIOXIDANT N-ACETYL-L-CYSTEINE ON THE PHOSPHOLIPID COMPOSITION OF THE ALVEOLAR SURFACTANT IN SEPTIC RESPIRATORY DISTRESS SYNDROME CAUSED BY EXPERIMENTAL FEC L PERITONITIS S. Lazarov, R. Nicolov, E. Yanev, A. Momtchilova and R. Pankov Department of Pathophysiology, Medical Faculty – Sofia Department of Pharmacology and Toxicology, Medical Faculty – Sofia Institute of Biophysics, Bulgarian Academy of Sciences Department of Biology, Sofia University “Sv. Kliment Ohridski”
Адрес за кореспонденция: Д-р Симеон Лазаров, Катедра по патологична физиология, Медицински факулт... more Адрес за кореспонденция: Д-р Симеон Лазаров, Катедра по патологична физиология, Медицински факултет, МУ – София, Група по белодробна патология и сърфактантология, бул. “Св. Георги Софийски” 1, 1341 София, GSM: 0897 75 14 93 ***** Address for correspondence: Simeon Lazarov, MD, Department of Pathophysiology, Group of Lung Pathology and Survactants, Medical Faculty, Medical University – Sofia, 1 Sv. G. Sofiyski str., Bg-1431 Sofia, GSM: 0897 75 14 93
The polyphenol quercetin is associated with numerous beneficial health effects in various patholo... more The polyphenol quercetin is associated with numerous beneficial health effects in various pathologies such as oxidative stress, neurodegenerative disorders, inflammation, neoplastic processes, age-...
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