Protective effect of sesamol against myocardial infarction caused by isoproterenol in Wistar rats
Authors: Kodukkur Viswanathan Pugalendi
Lakshmanan Vennila
Journal: Redox Report (2010)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: cardioprotective effect; sesamol; isoproterenol-induced myocardial infarction; albino Wistar rats; marker enzymes
Affiliations: Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar 608 002, Tamilnadu, India.

Abstract:  This study was designed to investigate the cardioprotective effect of sesamol on isoproterenol (ISO)-induced myocardial infarction in adult male albino Wistar rats. The heart damage induced by ISO was indicated by elevated levels of the marker enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase-MB (CK-MB) and the levels of troponin T and I in the plasma. In addition, lipid peroxidative markers such as thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and lipid hydroperoxides (LHP) significantly increased in the plasma and heart. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) significantly decreased in the heart and (non-enzymic antioxidants) vitamin C, vitamin E and reduced glutathione (GSH)) levels significantly decreased in the plasma and heart in ISO-rats. Histopathological observations correlated with the biochemical parameters. Administration of sesamol at different doses 50, 100 and 200 mg/kg body weight intraperitoneally for 7 days prevented the above changes and improved towards normality; the 50 mg dose was more effective than the other two doses. 

Retracted: No

PubPeer comments:
 This paper is one of several from this research group at the Department of Biochemistry and Biotechnology at Annamalai University that report measurements with an unexpectedly narrow range of standard deviations (SDs). Together, these cast serious doubts over the existence of real, replicate measurements in studies by this group. Tables 1 through 4 in this paper together show 138 measurements with SDs. Here, for example, is a screenshot of Table 2. ![file] The majority of the SDs are between 5 and 11% of the mean value they belong to. Here is a histogram of the SD percentages, showing an unexpected narrow range of values, with no SD over 14%. ![file] This is a very unusual distribution of SDs in biological measurements. Could the authors please provide the raw data? , 
 Figure 2. The same dark-colored spots appear to be visible three times in two different panels. Shown with blue circles. Could the authors please provide an explanation what happened here? ![file] , 
 Update for comment #1: For comparison, here is a collage of 12 papers from other research groups to show the expected range of SDs. All of these use groups of 6 to 8 rats, and do similar measurements. I graphed their SDs in the same way as the graph above, but with the X axis up to 100%. Each of these graphs show a much wider and more even spread of SDs than the graph above. ![file] , 
 #2 Two of the panels also appeared (with horizontal compression) in Fig 2 of [Selvaraj Pugalendi (2010)] -- here at top. ![file] The purported experiments involved  six groups of eight rats each in this study, and  six groups of six rats each in the other paper, so they were emphatically different projects - not two concurrent projects using the same control groups. ,