• BMB Reports
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• 제55권10호
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• pp.481-487
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• 2022

Over the past few years, hydrogen sulfide (H₂S) has been shown to exert several biological functions in mammalian. The endogenous production of H₂S is mainly mediated by cystathione β-synthase, cystathione γ-lyase and 3-mercaptopyruvate sulfur transferase. These enzymes are broadly expressed in liver tissue and regulates liver function by working on a variety of molecular targets. As an important regulator of liver function, H₂S is critically involved in the pathogenesis of various liver diseases, such as non-alcoholic steatohepatitis and liver cancer. Targeting H₂S-generating enzymes may be a therapeutic strategy for controlling liver diseases. This review described the function of H₂S in liver disease and summarized recent characterized role of H₂S in several cellular process of the liver.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.125-125
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• 2001

Peroxynitrite (ONOO), a potent cytotoxic oxidant formed by the reaction of nitric oxide (ㆍNO) and superoxide radical (ㆍO$_2$), reacts rapidly to cause of oxidization and nitration process. The importance of the regulation of ONOO$^{-}$ has been recently recognized because of the lack of specific endogenous enzymes against ONOO$^{-}$. Coffee that is a complex mixture containing a variety of components has been reported to have both beneficial and hazardous effects.

• 한국축산식품학회지
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• 제41권4호
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• pp.589-607
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• 2021

Meat proteolytic systems play a crucial role in meat tenderisation. Understanding the effects of processing technologies and post-mortem storage conditions on these systems is important due to their crucial role in determining the quality characteristics of meat and meat products. It has recently been proposed that tenderisation occurs due to the synergistic action of numerous endogenous proteolytic systems. There is strong evidence suggesting the importance of μ-calpain during the initial post-mortem aging phase, while m-calpain may have a role during long-term aging. The caspase proteolytic system is also a candidate for cell degradation in the initial stages of conversion of muscle to meat. The role of cathepsins, which are found in the lysosomes, in post-mortem aging is controversial. Lysosomes need to be ruptured, through aging, or other forms of processing to release cathepsins into the cytosol for participation in proteolysis. A combination of optimum storage conditions along with suitable processing may accelerate protease activity within meat, which can potentially lead to improved meat tenderness. Processing technologies such as high pressure, ultrasound, and shockwave processing have been reported to disrupt muscle structure, which can facilitate proteolysis and potentially enhance the aging process. This paper reviews the recent literature on the impacts of processing technologies along with post-mortem storage conditions on the activities of endogenous proteases in meat. The information provided in the review may be helpful in selecting optimum post-mortem meat storage and processing conditions to achieve improved muscle tenderness within shorter aging and cooking times.

• Environmental Analysis Health and Toxicology
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• 제30권
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• pp.6.1-6.7
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• 2015

Objectives This study aimed to estimate the effects of 4-nonylphenol (NP), a ubiquitously present surfactant in aquatic environments, on the anti-oxidant systems of the liver in the Far Eastern catfish Silurus asotus. Methods Changes in biochemical parameters involved in glutathione (GSH)-related and other anti-oxidant systems were analyzed following 4 weeks of 4-NP administration (0.1 and 1.0 mg/kg diet) via a formulated diet to catfish. Results 4-NP exposure induced an elevation in hepatic lipid peroxide levels and an accompanying decrease in reduced state GSH after 2 weeks, suggesting pro-oxidant effects of the chemical in catfish. This oxidative stress was associated with an inhibition of the GSH-utilizing enzyme glutathione peroxidase at the same time point. This inhibition was restored after 4 weeks. The activities of other anti-oxidant enzymes, i.e., glutathione reductase, superoxide dismutase and catalase were increased after 4 weeks. These enzyme increases occurred more strongly at the higher 4-NP concentration (1.0 mg/kg diet). Conclusions 4-NP given to catfish at 0.1 to 1.0 mg/kg diet, concentrations relevant to environmental levels, depletes the endogenous anti-oxidant molecule GSH and temporarily inhibits GSH-related anti-oxidant enzymes. Such declines in anti-oxidant capacity and elevated oxidative stress seem to be compensated eventually by subsequent activation of various anti-oxidant enzyme systems.

• Journal of Plant Biotechnology
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• 제36권2호
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• pp.149-156
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• 2009

Application of exogenous polyamines (PAs) reduced the paraquat (PQ)-induced cotyledon injuries in radish seedling plants with 1 mM spermidine (Spd) being the most effective protectant. PQ injury symptoms in the cotyledons, e.g., large accumulation of $H_2O_2$, and losses of fresh weight, chlorophyll, and proteins, were significantly alleviated. Likewise, analysis of $H_2O_2$-scavenging enzymes such as catalase (CAT) and guaiacol peroxidase (GPX) showed that pretreatment with Spd among PAs remarkably increased total CAT activity and strongly retarded PQ-induced rapid decline in total GPX activity. In a native gel assay, one CAT isozyme (CAT1) and two GPX isozymes (GPX1 and a newly synthesized GPX isozyme) proved to be more responsible for PQ tolerance, as manifested by the strong increases in their activities by Spd pretreatment. Based on these results, we can suggest that PAs (especially 1 mM Spd) may function as antioxidant protectors by invoking CAT and GPX enzymes which control the endogenous $H_2O_2$ level in radish cotyledons exposed to PQ.

• Journal of Ginseng Research
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• 제22권1호
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• pp.1-10
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• 1998

In the present study, to determine whether the antioxidative components of Korean red ginseng protect against radiation damage and the possible relationship among the radioprotective effects and antioxidant actions, the effects of total saponin (200 mg/kg, ip) and lipophilic fraction (200 mg/kg, oral) preferment of mice on the survival ratio, major antioxidant enzymes (SOD, catalase and glutathione peroxidase) activities, glutathione levels and lipid peroxidation in the liver were exiled for 2 weeks after whole ${\gamma}$-body ${\gamma}$-irradiation (6.5 Gy). The 30-day survival ratio increased from 10% to 57% and 40% for mice treated with total saponin and lipophilic fraction, respectively. On day 14 after ${\gamma}$-irradiation, the ginseng total saponin pretreatment produced a slight increase of antioxidant enzymes activities and significantly Increased reduced glutathione (GSH) contents (p<0.05) in the liver compared with non-treated group. Pretreatment with ginseng total saponin significantly deceased GSSG/total GSH ratio (p<0.05) without change of GSSG in the liver and inhibited the radiation-induced incense in the hepatic malondialdehyde levels. (p<0.05) In these results, GSH plays an important role in the liver in several detoxifications and the reduction of lipid peroxides. Thus, it appears that total saponin of red ginseng exerts its radioprotective effect by accelerating the production of endogenous antioxidants, such as glutathione from radiation induced damages and thereby oxygen free radicals.

• 식물조직배양학회지
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• 제22권2호
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• pp.71-76
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• 1995

자리공 모상근에서 광처리에 따른 항산화효소의 활성을 조사하였다. Catalasa superoxide dismutasae, ascorbate oxidase (AO)의 활성은 광도가 2,000 lx까지 증가할수록 감소하였으며, 특히 AO활성은 2,000 lx에서 암상태보다 92% 감소하였다. Glutathione reductase, glutathione peroxidase (GPO), ascorbate peroxidase 그리고 peroxidase의 활성도는 500 lx까지는 광도가 높아질수록 증가하였으나 그 이상의 높은 광도에서는 현저하게 감소하였다. GPO의 활성은 AO처럼 2,000 lx에서 암상태보다 85%감소하였다. 광파장에 따른 항산화효소의 활성은 청색광의 파장에서 가장 많이 억제되었으며, AO의 활성은 25%까지 감소하였다. 청색광 파장의 광도에 따른 항산화효소의 활성도는 30 lx까지는 증가하다가 200 lx에서는 암상태보다 21-71%까지 감소하는 경향을 나타내었다. AO의 활성은 청색 파장의 광도(300-200 lx)가 증가할수록 급격히 감소하여 200 lx에서는 70%까지 억제되었다. 자리공 모상근의 항산화효소 활성은 청색광 파장의 높은 광도에서 주로 생성된 유해산소 의하여 억제되고 있음을 확인하였다. 광상태하에서 모상근의 생장과 betalain 합성을 향상시키기 위해서는 모상근에서 생성되는 산화제의 효율적인 제거가 요구됨이 시사되었다.

• BMB Reports
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• 제40권5호
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• pp.708-714
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• 2007

The two-component signal transduction, which typically consists of a histidine kinase and a response regulator, is used by bacterial cells to sense changes in their environment. Previously, the SphS-SphR histidine kinase and response regulator pair of phosphate sensing signal transduction has been identified in Synechocystis sp. PCC 6803. In addition, some response regulators in bacteria have been shown to be cross regulated by low molecular weight phosphorylated compounds in the absence of the cognate histidine kinase. The ability of an endogenous acetyl phosphate to phosphorylate the response regulator, SphR in the absence of the cognate histidine kinase, SphS was therefore tested in Synechocystis sp. PCC 6803. The mutant lacking functional SphS and acetate kinase showed no detectable alkaline phosphatase activity under phosphate-limiting growth conditions. The results suggested that the endogenous acetyl phosphate accumulated inside the mutants could not activate the SphR via phosphorylation. On the other hand, exogenous acetyl phosphate could allow the mutant lacking functional acetate kinase and phosphotransacetylase to grow under phosphate-limiting conditions suggesting the role of acetyl phosphate as an energy source. Reverse transcription PCR demonstrated that the transcripts of acetate kinase and phospho-transacetylase genes in Synechocystis sp. PCC 6803 is up-regulated in response to phosphate limitation suggesting the importance of these two enzymes for energy metabolism in Synechocystis cells

• 생명과학회지
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• 제34권3호
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• pp.199-207
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• 2024

CYP 효소는 내인성 및 외인성 화학물질의 대사에 핵심적인 역할을 담당한다. 특히, 약물, 자연생성물 및 환경 독성 화학물질 등은 조직에 따라 특이적 CYP 효소 유전자의 발현을 조절하며, 이는 체내 유입된 약물과 독성물질 등과 같은 화학물질들 사이의 상호작용을 유발하여 이들의 대사에 영향을 줌으로써, 결국 치료 효과와 독성 효과에 변화를 초래한다. 이 분야에 대한 지난 수십 년 동안의 집중적인 연구는, 이러한 CYP 효소 유전자의 발현조절을 매개하는 분자적 기전을 이해하는 데 상당한 진전을 가져왔다. 이제는 구체적인 CYP 효소 유전자의 발현 유도를 조절하는 화합물들뿐만 아니라, 이를 감지하여 특정 CYP 유전자의 발현 조절을 매개하는 데 관여하는 수용체들과 이들의 신호전달 경로들이 비교적 상세히 밝혀졌다. 본 총설에서는, 다양한 화학물질의 노출에 반응하여 CYP 효소 유전자들의 발현 유도를 매개하는 것으로 알려진 주요 외인성 물질-감지 수용체들과 기타 조절인자들의 분자적 작용기전을 요약한다.

• 대한예방한의학회지
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• 제12권1호
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• pp.73-87
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• 2008

In recent years, there has been a globally increasing application of herbal medicines and dietary supplements to treat various chronic diseases and to promote health. However, there are increasing clinical reports on the organ toxicities associated with consumption of herbal medicines. In general, most xenobiotics are metabolized by Phase I reaction(the main enzyme : cytochrome P450) and Phase II reaction. However, reactive oxygen species, free radicals and electrophils are produced inevitably during xenobiotics metabolism. These toxic species and metabolites are increased whenever the endogenous substances and enzymes for Phase II reaction not available. In addition, herbal-drug interactions are pharmacokinetic, with most actually or theoretically affecting the metabolism of the affected product by way of the cytochrome P450 enzymes. This review updated the knowledge on metabolic activation of herbal components and its clinical and toxicological implications. Also, the possible way for preventing the side-effects by herbal-medicine use was suggested.