Anti-inflammatory potential of an ethyl acetate fraction isolated from Justicia gendarussa roots through inhibition of iNOS and COX-2 expression via NF-κB pathway
Authors: Shobha Bhaskar
Kripa Krishnan
Kavitha S Kumar
Viji Vijayan
A Helen
V Shalini
Journal: Cellular Immunology (2012)
Discipline: IMMUNOLOGY
Keywords: Justicia gendarussa; anti-inflammatory; mechanism of action; ethyl acetate fraction; rats
Affiliations: Department of Biochemistry, University of Kerala, Kariavattom Campus, Thiruvananthapuram 695581, Kerala, India.

Abstract:  Justicia gendarussa Burm.f. (J. gendarussa) is a plant used as traditional medicine in different parts of India and China to treat inflammatory disorders like rheumatoid arthritis. But its mechanism of anti-inflammatory action is still unclear. Hence in this context, the objective of our study is to reveal the mechanism of anti-inflammatory activity of J. gendarussa which would form an additional proof to the traditional knowledge of this plant. The anti-inflammatory function and mechanism(s) of action was studied in an ethyl acetate fraction isolated from methanolic extract of J. gendarussa roots (EJG). Anti-inflammatory studies were conducted on rats using partitioned fractions isolated from methanolic extract of J. gendarussa roots. In carrageenan-induced rat paw edema, ethyl acetate fraction brought about 80% and 93% edema inhibition at 3rd and 5th hour at a dose of 50 mg/kg, when compared to other extracts and Voveran. We investigated whether EJG inhibits the release of cycloxygenase (COX), 5-lipoxygenase (5-LOX), interleukin-6 (IL-6) and nuclear factor kappa B (NF-κB) in LPS stimulated human peripheral blood mononuclear cells (hPBMCs). Results shows that EJG dose dependently inhibited LPS-activated COX, 5-LOX, IL-6, and NF-κB in hPBMCs. EJG also reduced LPS induced levels of iNOS and COX-2 mRNA expression in hPBMCs. This study provides an insight into the probable mechanism(s) underlying the anti-inflammatory activity of EJG and therefore, we report the first confirmation of the anti-inflammatory potential of this traditionally employed herbal medicine in vitro. 

Retracted: No

PubPeer comments:
 The housekeeping gene, GAPDH was duplicated in the same publication. The bar graphs of the two figures are exactly similar values. Could the authors clarify the unexpected similarity with their raw data? ![file] , 
 #1 It appears that there has been some confusion. A careful examination of the Material and Methods section 2.8 would indicate that the conditions for RNA preparation and RTu2013PCR analysis are exactly the same for COX2, iNOS, and GAPDH. I am adding the snapshot of section 2.8 below for the readers to see. ![file] In fact, this can also be confirmed from the legends of Figures 5 and 6. I am also attaching a snapshot of the two figure legends for the readers to see. ![file] Now, if the experimental conditions are exactly the same then reusing the same housekeeping gene GAPDH at both places seems reasonable. Also, in this case, it is entirely up to authors whether they want to show both COX2 and iNOS along with GAPDH in the same figure or they want to split the figure (as it has been done) and show the two genes separately along with the same housekeeping gene. I am also not convinced with the point The bar graphs of the two figures are exactly similar values. A closer examination indicates that the height of the bar graph for LPS in both plots is different. Also, the error bars in Fig 5 are different from the error bars in Fig 6 and the apparent similarities are expected to some extent. ![file] The concerns raised by the commenter in #1 do not dilute the results and conclusions reported in Figures 5 and 6. ,