Krishna Mohan Surapaneni
Kasturba Medical College & Hospital, Manipal University; Li Ka Shing Faculty of Medicine, Institute of Medical & Health Sciences Education (IMHSE), Hong Kong, The University of Hong Kong; Maastricht University, The Netherlands and Suez Canal University, Egypt; Saveetha Medical College & Hospital, Saveetha University;
PhD (Medical)., CIMHSE., MHPE., PGDPHI., PGDPHN
Associate Professor & Vice Principal, Department of Biochemistry & Research
Saveetha Medical College & Hospital, Saveetha University
Favourite thing to do in my job: To invent bio marker to diagnose liver failure in people who does not take alcohol
I am a teacher and researcher, teaching biochemistry to medical students, doing research on liver diseases in people who do not take any alcohol or little alcohol
SUMMARY OF RESEARCH WORK
AIM AND SCOPE OF THE STUDY:
The objective of the present study is to establish an experimental model of NASH and identify safe and effective agents to treat NASH. The present study is concerned with exploring the potential effects of the three drugs of choice viz. Pioglitazone – an insulin sensitizer, Quercitin – hepatoprotectant, an antioxidant and hydroxy citric acid –lipid regulator in experimental model of non alcoholic steatohepatitis (NASH).
Hence a study on the following topics has been considered appropriate and this study was undertaken in two distinct phases.
PHASE – I: ESTABLISHMENT OF EXPERIMANTAL MODEL OF NASH IN RATS:
A high-fat diet (HFD) is used to create a model of NASH. Thus, this model mimics the most common features of NASH in humans and provides an ideal tool to study the role of events involved in the pathogenesis of NASH and to define any future experimental therapy, which ameliorated the degree of liver injury. Liver biopsy is the only way to confirm the presence or absence of NASH in a person with features of NASH. It also remains the “gold standard” for fibrotic severity.
PHASE – II: COMPARATIVE STUDY OF PROTECTIVE ROLE OF PIOGLITAZONE, QUERCITIN AND HYDROXY CITRIC ACID:
Since the pathogenesis of NASH involved interplay of 3 possible mechanisms such as hyper insulinemia, lipotoxicity and oxidative stress, we have chosen 3 categories of drugs, pioglitazone as insulin sensitizer, quercetin as hepato protectant & antioxidant and hydroxy citric acid as an lipid lowering agent & Antiobesity agent.
This study is designed to study the comparative protective role of the three drugs of choice by histopathological studies and SEM studies. Various biochemical experiments have been carried out to analyze the possible mechanisms involved in the pathology of NASH by assessing liver marker enzymes, serum liver function test parameters, general biochemical parameters, hepatic lipid profile, serum lipoprotein levels, enzymatic and non enzymatic antioxidants levels in liver tissue, ECM Components, various inflammatory markers and other biochemical parameters with regard to liver diseases. The study is also designed to perform separation of phospholipids by TLC, RT-PCR analysis to assess expression of VEGF mRNA, immunoblot analysis for the detection of cytochrome P450 2E1 (CYP2E1) enzyme levels in liver, quantification of cytochrome P450 2E1 (CYP2E1) enzyme levels in liver by immunoblot analysis, immunohistochemistry of CK-18, quantification of CK-18 & comparison with ALD, estimation of “TPSA” as a diagnostic marker for NASH by ELISA & comparison with ALD were also carried out.
The comparative study of pioglitazone (insulin sensitizer), quercetin (hepatoprotectant and antioxidant) and hydroxy citric acid (hypolipidemic and anti obesity agent) were carried out in modified experimental model of NASH in rats. In this study, by analyzing various biochemical, histopathological, immuno histochemical, PCR studies etc, we can understand the mechanism of drugs showing better therapeutic action on NASH.
The findings of this research study can be summarized as follows:
Experimental NASH model in rats, which mimics NASH in humans, was produced by feeding high fat diet ad libitum for 8 weeks, confirmed by the histopathological studies and supported by the scanning electron microscopy studies.The hepatoprotective action of the three drugs of choice (pioglitazone, quercetin and hydroxy citric acid) was observed by treating the rats with high fat diet for 4 weeks, then feeding them high fat diet simultaneously with intra gastric administration of pioglitazone, quercetin and hydroxy citric acid, for another 4 weeks. The hepatoprotective action of pioglitazone, quercetin and hydroxy citric acid was confirmed by biochemical parameters and NASH biomarkers.
The hepatoprotective action of the three drugs of choice (pioglitazone, quercetin and hydroxy citric acid) was observed by treating the rats with high fat diet for 4 weeks, then feeding them high fat diet simultaneously with intra gastric administration of pioglitazone, quercetin and hydroxy citric acid, for another 4 weeks. The hepatoprotective action of pioglitazone, quercetin and hydroxy citric acid was confirmed by biochemical parameters and NASH biomarkers.
ALT, AST, GGT and LDH levels are fluctuated in experimentally induced NASH group when compared to rats in control group. The ratio between ALT and AST has also been found to have predictive value. The protective effect of quercetin on experimental NASH showed more significant reduction of these liver enzymes in comparison with pioglitazone and hydroxy citric acid therapy.
A significant increase in the levels of total bilirubin, creatinine, urea, uric acid and glucose was noticed in experimental NASH group whereas in quercetin, hydroxy citric acid and pioglitazone treated groups normalize these parameters.
Serum lipid profile such as total cholesterol, free cholesterol, esterified cholesterol, phospholipids, triglycerides and free fatty acids levels raised significantly in experimental NASH. Hydroxy citric acid and pioglitazone showed much reduction in lipid levels when compared to quercetin treated groups.
Significant elevation of lipoproteins such as HDL, LDL, VLDL, HDL:LDL, TC:HDL were observed in experimental NASH, indicating that the disease progression was directly proportional to the lipoprotein levels. Protective effect of quercetin and hydroxy citric acid was noticed significantly when compared to experimental NASH. Significant reduction was also observed in pioglitazone treated rats.
The levels of non-enzymatic and enzymatic antioxidants were assessed in experimental NASH rats, and found to be decreased. The antioxidant property of quercetin and hydroxy citric acid could be more beneficial in treatment of NASH when compared to pioglitazone treated rats.
The imbalanced production of pro- and anti inflammatory adipokines secreted from fat contributes to the pathogenesis of NASH was observed. Adiponectin is an important adipokine decreased significantly, whereas the levels of hyaluronic acid and leptin were increased significantly in experimentally induced NASH group, compared to control group. Quercetin appeared to protect against liver injury and reverse the levels of hyaluronic acid, leptin and adiponectin towards normal. The same protective effect was observed in pioglitazone treated groups and hydroxy citric acid significantly.
TNF-α and MPO have long been recognized for their pro-inflammatory properties and their role in NASH progression was clearly established. TNF-α and MPO were highly expressed in experimentally induced NASH group, compared to control group. Quercetin and pioglitazone offers protection against NASH by ameliorating the inflammation (hepatitis), a principle and key feature of NASH, whereas hydroxy citric acid offers very little protection against NASH.
Quantitative real-time polymerase chain reaction (RT-PCR) analysis of vascular endothelial growth factor (VEGF) messenger RNA (VEGF mRNA) was analyzed in all the groups. Enhanced expression of VEGF mRNA was detected in experimental NASH group whereas reduced expression of VEGF mRNA was observed in quercetin, pioglitazone and hydroxy citric acid treated groups. Quercetin showed an effective inhibition of VEGF mRNA expression and perhaps only smaller inhibition of VEGF mRNA level seen in hydroxy citric acid and pioglitazone treated rats.
Cytochrome P450 2E1 (CYP2E1) enzyme levels in liver was detected by immunoblot analysis. Increased expression of this enzyme is involved in the pathogenesis of NASH was observed through the generation of oxidative stress. Reduced expression of functional CYP2E1 protein was observed in quercetin, pioglitazone and hydroxy citric acid treated groups.
Cytokeratin-18 (CK-18), a potential biomarker for NASH was detected by immunohistochemical study. Increased expression of CK-18 was observed in experimentally induced NASH than in control group. The over expressed CK- 18 levels in NASH were markedly reduced by treatment with pioglitazone, quercetin and HCA suggesting their role to prevent cell death. The maximum significant protection was shown against NASH by quercetin compared to pioglitazone and HCA. Quercetin showed very less expression of CK-18 when compared to pioglitazone & hydroxy citric acid treated groups.
Noninvasive panels of serological markers have been developed to evaluate the presence of steatosis and hepatic necro-inflammation to avoid liver biopsy.
Tissue polypeptide specific antigen (TPSA) has recently been proposed as diagnostic marker of apoptosis in NASH and elevated levels were observed in experimental NASH when compared to control group, whereas TPSA was not expressed in alcoholic liver disease (ALD).
Thus, the results of the present investigation have fulfilled the objective and scope of this study.
NASH can be cured by reducing the oxidative stress and free radical production. It is earnestly hoped that the results obtained have opened up newer horizons of research in the area of NASH and its management by quercetin, pioglitazone and hydroxy citric acid. Present study conclusively demonstrated that quercetin, possessing potent radical scavenging, antioxidant, hepatoprotective and anti-inflammatory properties, could be safely developed as hepatoprotective drug for NASH. Future studies are required for clinical trials to try this protective mechanism of quercetin for NASH suffering patients.
My Typical Day
teaching, research and administration
As a teacher:
I teach biochemistry for students of medical, dental, nursing and other health science disciplines.
As a Researcher:
I work on my on going research projects on day-to-day basis
As Vice Principal (Administration):
I have supervise many administrative activities of the college, ex: Organizing a Lecture and a workshop
What I'd do with the prize money
I would want to donate this to an “Orphanage Home” and “Blind School”
1. To spend on a research project related to AUTISM children
2. Donate to old age home
How would you describe yourself in 3 words?
Sincere, Honest and Hardworking
What's the best thing you've done in your career?
I have contributed significantly to the existing information in the literature, leading to the advancement of the science
What or who inspired you to follow your career?
Dr. A P J ABDUL KALAM
Were you ever in trouble at school?
If you weren't doing this job, what would you choose instead?
I want to be a bank employee
Who is your favourite singer or band?
A R REHAMAN
What's your favourite food?
South Indian Food
What is the most fun thing you've done?
I don’t remember
If you had 3 wishes for yourself what would they be? - be honest!
1. Publish a research paper in “British Medical Journal (BMJ)” 2. To visit “ANTARCTICA” 3. To build an “OLD AGE HOME & ORPHANAGE”