Hepatocarcinogenesis: How Do Peroxisome Proliferators Relate?

1992 ◽  
Vol 11 (3) ◽  
pp. 363-367 ◽  
Author(s):  
Emmanuel Farber

There is an increasing awareness that many peroxisome proliferators are being introduced into our environment and many of these have shown carcinogenic activity in some rodent species. The agents involved include drugs (e.g., hypolipdemic agents of several chemical structures including HMG CoA reductase inhibitors) and industrial chemicals. The neoplasms seen are mainly in the liver with a variable incidence in the pancreas. The association between peroxisome proliferation and neoplasms is impressive. Yet, there are several seemingly fundamental differences between carcinogenic peroxisome proliferators and mutagenic or genotoxic chemical carcinogens. Peroxisome proliferators in general are neither mutagenic nor genotoxic and do not induce precancerous hepatic lesions and liver cell cancer until they have reached the late stage. With many agents, it appears that a considerable degree of peroxisome proliferation must take place for them to be carcinogenic. One poorly documented speculation is that peroxisome proliferators induce cancer by acting mainly as promoters, presupposing that the animals being tested are “preinitiated,” a conclusion that is scientifically indefensible. This presentation covers a comparison between the key requirements for cancer development with genotoxic agents and those seen with peroxisome proliferators, and discusses the methylation of genes for selective enzymes of the resistance phenotype induced by mutagenic carcinogens.

2018 ◽  
Vol 23 (46) ◽  
pp. 7027-7039 ◽  
Author(s):  
Georgia Vogiatzi ◽  
Evangelos Oikonomou ◽  
Gerasimos Siasos ◽  
Sotiris Tsalamandris ◽  
Alexandros Briasoulis ◽  
...  

Background: Chronic inflammation and immune system activation underlie a variety of seemingly unrelated cardiac conditions including not only atherosclerosis and the subsequent coronary artery disease but also peripheral artery disease, hypertension with target organ damage and heart failure. The beneficial effects of HMG-CoA reductase inhibitors or statins are mainly attributed to their ability to inhibit hepatic cholesterol biosynthesis. Beyond their lipid lowering activity, ample evidence exists in support of their potent anti-inflammatory properties which initiate from the inhibition of GTPase isoprenylation, activating a cataract of secondary pathways and extend to the inhibition and blocking of immune cell activation and interaction. </P><P> Objective: To summarize the anti-inflammatory mechanisms of statins in clinical and experimental settings in cardiovascular disease. </P><P> Methods: A systematic search of PubMed and the Cochrane Database was conducted in order to identify the majority of trials, studies, current guidelines and novel articles related to the subject. </P><P> Results: In vitro, statins have immuno-modulatory and anti-inflammatory effects, and they can exert antiatherosclerotic effects independently of their hypolipidemic actions. In addition, positive results have emerged from mechanistic and experimental studies on the active role of HMG-CoA reductase inhibitors in HF. By extrapolating those data in clinical setting, we further understand how HMG-CoA reductase inhibitors can beneficially affect not only systolic but also diastolic HF. </P><P> Conclusion: In this review article, we present the basic pathophysiologic data supporting the anti-inflammatory actions of statins in clinical and experimental settings and we link these mechanisms with confirmatory clinical data on the potent non lipid lowering effects of HMG-CoA reductase inhibitors.


2019 ◽  
Vol 16 (10) ◽  
pp. 1130-1137
Author(s):  
Hayrettin Ozan Gulcan ◽  
Serkan Yigitkan ◽  
Ilkay Erdogan Orhan

High cholesterol and triglyceride levels are mainly related to further generation of lifethreating metabolism disorders including cardiovascular system diseases. Therefore, hypercholesterolemia (i.e., also referred to as hyperlipoproteinemia) is a serious disease state, which must be controlled. Currently, the treatment of hypercholesterolemia is mainly achieved through the employment of statins in the clinic, although there are alternative drugs (e.g., ezetimibe, cholestyramine). In fact, the original statins are natural products directly obtained from fungi-like molds and mushrooms and they are potent inhibitors of hydroxymethylglutaryl-CoA reductase, the key enzyme in the biosynthesis of cholesterol. This review focuses on the first identification of natural statins, their synthetic and semi-synthetic analogues, and the validation of hydroxymethylglutaryl-CoA reductase as a target in the treatment of hypercholesterolemia. Furthermore, other natural products that have been shown to possess the potential to inhibit hydroxymethylglutaryl-CoA reductase are also reviewed with respect to their chemical structures.


2020 ◽  
Vol 16 (4) ◽  
pp. 473-485
Author(s):  
David Mary Rajathei ◽  
Subbiah Parthasarathy ◽  
Samuel Selvaraj

Background: Coronary heart disease generally occurs due to cholesterol accumulation in the walls of the heart arteries. Statins are the most widely used drugs which work by inhibiting the active site of 3-Hydroxy-3-methylglutaryl-CoA reductase (HMGCR) enzyme that is responsible for cholesterol synthesis. A series of atorvastatin analogs with HMGCR inhibition activity have been synthesized experimentally which would be expensive and time-consuming. Methods: In the present study, we employed both the QSAR model and chemical similarity search for identifying novel HMGCR inhibitors for heart-related diseases. To implement this, a 2D QSAR model was developed by correlating the structural properties to their biological activity of a series of atorvastatin analogs reported as HMGCR inhibitors. Then, the chemical similarity search of atorvastatin analogs was performed by using PubChem database search. Results and Discussion: The three-descriptor model of charge (GATS1p), connectivity (SCH-7) and distance (VE1_D) of the molecules is obtained for HMGCR inhibition with the statistical values of R2= 0.67, RMSEtr= 0.33, R2 ext= 0.64 and CCCext= 0.76. The 109 novel compounds were obtained by chemical similarity search and the inhibition activities of the compounds were predicted using QSAR model, which were close in the range of experimentally observed threshold. Conclusion: The present study suggests that the QSAR model and chemical similarity search could be used in combination for identification of novel compounds with activity by in silico with less computation and effort.


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