There are serval concerns raised in the paper. First, the paper is titled as “Effect of DA-9701, a novel prokinetic agent, on postoperative ileus in rats.” What the novelty of the study is when compared to the literature about DA-9701 is this study regarding DA-9701 on POI. Many literatures on DA-9701 have already been acknowledged with its prokinetic effect in gut motility.4 Whilst, this study is mimic a post-operation ileus (by using minor surgery) to compare the changes of GIT, fecal weight, and ghrelin that are affected by DA-9701.
In the procedures as shown in Figure 1, the acclimatization period for rats was 7 days, and DA-9701 was gavaged once respectively before and after operation, without vehicle or agent as a control. It is unclear why the 7 days acclimatization is necessary without time course scaling comparison; also, it is hard to believe that any effect or change, without a control, resulted from DA-9701 instead of mechanical delivery. A rational explanation needs to be addressed by the authors.
To look up GIT parameters and stool weight as shown in Figure 2, the effect from DA-9701 could be categorized as no surgery/no medication (NSNM) versus no surgery/medication (NSM), surgery/no medication (SNM) versus surgery/medication (SM). As the results show in Figure 2A there is no change between NSNM and NSM, and significant changes between SNM and SM. We question how to understand DA-9701 selectively effect on SM, but not NSM? In Figure 2B, we are more confused as to why the authors compared between no surgery, and surgery + no medication, especially the critical comparison of SNM and SM is not significantly changed. It suffers from a number of weaknesses in drawing their conclusions.
Active ghrelin levels were used as an indication of POI in the paper. As shown in the
Notably, the data in the paper reveals some information indicating DA-9701 as a prokinetic medication in promoting bowel peristalsis. The argument can be made for such study since it lacks vehicle control for DA-9701 that may increase a difficulty for data interpretation even difference existed in. We appreciate the authors’ work and believe the DA-9701 research will be followed up in more detail in terms of mechanisms such as ghrelin levels and ghrelin receptor changes under DA-9701. Although data analyses is somewhat not comparable, it is informative and encouraging to clinicians.