Antiviral actions of flavanoid-derived compounds on dengue virus type-2
Authors: Rohana Yusof
Mudiana Muhamad
Noorsaadah Abd Rahman
Lee Yean Kee
Journal: International Journal of Biological Sciences (2010)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Dengue virus type-2; cytophatic effects; flavanoid; in vitro inhibition; inhibitory activity
Affiliations: Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. 

Abstract:  Dengue viruses, mosquito-borne members of the Flaviviridae family, are the causative agents of dengue fever and its associated complications, dengue haemorrhagic fever and dengue shock syndrome. To date, more than 2.5 billion people in over 100 countries are at risk of infection, and approximately 20 million infections were reported annually. There is currently no treatment or vaccine available for dengue infection. This study employed a whole-cell organism model or in vitro methods to study the inhibitory property of the flavanoid-derived compounds against DENV2 activity. Results showed that at concentration not exceeding the maximum non-toxic dose (MNTD), these compounds completely prevented DENV2 infection in HepG2 cells as indicated by the absence of cytophatic effects. The in vitro antiviral activity assessed in HepG2 cells employing virus inhibition assay showed high inhibitory activity in a dose dependent manner. At concentration below MNTD, compounds exhibited inhibitory activity against DENV2 with a range of potency strengths of 72% to 100%. The plaque forming unit per ml (pfu/ml) was reduced prominently with a maximum reduction of 98% when the infected HepG2 cells were treated with the highest non-toxic dose of compounds. The highly potent activity of the compounds against DENV2 infection strongly suggests their potential as a lead antiviral agent for dengue. 

Retracted: No

PubPeer comments:
 I have been examining the raw data for this publication located at http: dx.doi.org 10.5061 dryad.895b2 1 and I noticed some oddities in the data, listed below. 1. There appear to be some duplicated rows, shown below. However, since all the fields in them are the same, including the Replicate, Source Colony and Trial Order, etc. they may merely be an error where the same row was entered twice into the spreadsheet. ![file] ![file] ![file] 2. There are some rows where they are partially duplicated, shown below. In these, all the information about the Replicate, Source Colony, Trial Order, etc. is the same, but some of the data values are different (highlighted in orange). If this was an example of the same data entered twice, one would expect the rows to be totally identical, as in the previous duplicated rows. ![file] ![file] ![file] 3. Biologically implausible data: unusually large webs. The methods of the paper state: u201cAfter the three initial assays, each colony container was fastened to a hookbush acacia (A. mellifera) branch with clothes pins in the early evening hours (20.00u201321.30).u201d u2026. u201cThe following morning (05.45u201306.00), we measured the capture web area produced by estimating its general shape (triangle, rectangle, etc.) and then recording the appropriate dimensions to estimate its area using a tape measure. u201c The data of the two largest webs are highlighted below. The sizes of these webs, 10712 cm^2 (=1.0712 m^2) and 7452 cm^2 (=0.7452 m^2) seem quite large for spiders to construct overnight, even a colony of 30 of them. ![file] 4. Biologically implausible data: unusually fast spiders. The methods of the paper state: u201cThe aversive stimulus was implemented by striking the branch to which the colony was attached with a blunt probe. This stimulus sends a vibration throughout the web, which caused spiders to disperse from the simulated prey item and run back into their retreat. We measured the latency for the first and the last individual to enter the retreat following this stimulus.u201d The data for the unusually large webs also have unusually fast spiders. If I am interpreting the data correctly, the spiders were attracted to a stimulus 38 cm from the retreat, and then upon the aversive stimulus, returned to the retreat in 1 second. This seems unusually fast, especially given the other measurements in the dataset of spiders taking much longer to retreat from much shorter distances. ![file] One might expect spiders that retreat from further distances to generally take longer to retreat, but as the graph below shows, this is not the case. ![file] 5. I cannot reconstruct the factorial design. The methods state: u201cWe constructed artificial colonies of S. dumicola of two different sizes (10 or 30 individuals) and four different personality compositions (all bold, all shy, 50 : 50 bold and shy, or all individuals of u2018averageu2019 boldness) in a fully factorial design (n = 64 experimental units, n u2248 8 of each treatment combination).u201d However, I find myself unable to reconstruct the data in a way that shows 8 of each treatment. As an example, below are all the rows that list a size of 10 and u201cBoldu201d composition. I do not see how to come up with 8 replicates from this data. Similar issues occur with the others size boldness compositions. ![file] 6. Finally, there is a lot of data that is not reported. The methods state: u201cPrior to personality assays, we measured the body mass and prosoma width of each spider with a digital scale and digital callipers, respectively.u201d However, there are no boldness, mass, or prosoma measurements provided in the data. Could the authors please explain? , 
 Expression of Concern issued 29 April 2020: https: doi.org 10.1098 rspb.2020.0848  Following the publication of u2018Personality composition is more important than group size in determining collective foraging behaviour in the wildu2019 Proc. R. Soc. B 281, 20141424. Published 7 December 2014, it has been brought to the attention of the Editorial team that there are concerns regarding this study. An investigation into these aspects is under way, and the journal is, therefore, issuing an expression of concern and will notify readers as to the results of our investigation as soon as possible. , 
 Thanks for posting a link to the expression of concern. This is why I did not respond to your previous comment - these errors are already being dealt with in collaboration with a group of editors at *Proceedings B*. , 
 I prefer to work alongside reliable journal editors rather than be bullied by an anonymous sunflower. , 
 From the pubpeer FAQ : ![file] , 
 For this paper specifically, can you address the apparent and unexpected overlap with Keiser et al. (2015)  Warring arthropod societies: Social spider colonies can delay annihilation by predatory ants via reduced apparency and increased group size - https: pubpeer.com publications FC7DBE8B572C1F0D54CB8087CAADC2#1 ,