In silico screening and in vitro activity measurement of javamide analogues as potential p38 MAP kinase inhibitors.

Authors: Park, Jae

Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2017
Publication Date: 12/13/2017
Citation: Park, J.B. 2017. In silico screening and in vitro activity measurement of javamide analogues as potential p38 MAP kinase inhibitors. International Journal of Molecular Sciences. 18(12)pii:E2704. https://doi.org/10.3390/ijms ijms18122704.
DOI: https://doi.org/10.3390/ijms18122704

Interpretive Summary: Currently, there is a great need to elucidate the biological activities of many phytochemicals whose health effects are still unknown. In silico screening (a computer-aided virtual screening) is one of the useful and alternative approaches complementing conventional high throughput screening which is often expensive and time-consuming. Because in silico screening can identify new inhibitors for targeted molecules with velocity and rationality, it has emerged as a more suitable screening method in finding candidate compounds than traditional high throughput screening. P38 mitogen-activated protein kinase (p38 MAPK) is a protein kinase critically involved in inflammation/stress-associated diseases. Our data suggested that javamide-I/-II found in coffee may contain strong anti-inflammation activity, but there is no information regarding their efficacy as p38 MAPK inhibitors. Therefore, in this paper, the effects of thirty javamide analogues on p38 MAPK were investigated using in silico screening and in vitro p38 MAPK assay methods. The combinination of in silico screening and in vitro p38 MAPK assay methods identified javamide-II-O-ethyl ester as a most potent p38 MAPK among tested compounds. This study provided new information about javamide-II-O-ethyl ester as a most potent p38 MAPK inhibitor and the combination of in silico and in vitro assay approaches which may be a useful and efficient solution as a functional screening approach.

Technical Abstract: P38 mitogen-activated protein kinase (p38 MAPK) is a protein kinase critically involved in the progress of inflammation/stress-associated diseases. Our data suggested that javamide analogues may contain strong anti-inflammation activity, but there is little information about their effect on p38 MAPK. Therefore, in this paper, the effects of thirty javamide analogues on p38 MAPK were investigated using in silico screening and in vitro p38 MAPK assay methods. The javamide analogues were synthesized and their chemical structures were confirmed using NMR spectroscopic methods. After that, javamide analogues were screened using an in silico modeling program. The screened analogues demonstrated a wide range of binding energy (E = -20 to -39) and some analogues with E = -37 to -39 showed a strong binding affinity to p38 MAPK. In the in vitro p38 MAPK assay, the kinase was significantly inhibited by the analogues with great binding energy (E = -37 to -39) and in silico scores (Avg. score = -28.9 to -29.3). Furthermore, the comparative analysis of both the in silico and in vitro assay data showed a positive correlation between the in silico scores and p38 MAPK inhibition. In fact, the javamide analogues with the top five in silico scores (Avg. score = -27.5 to -29.3) were found to inhibit p38 MAPK by 27-31% (P < 0.05) better than those with less scores (E < -27.5). Especially, javamide-II-O-ethyl ester with relatively a high in silico score (Avg. score = -37) inhibited p38 MAPK greatly (IC50 = 9.9µM) compared to the other analogues. In summary, this study suggests that javamide-II-O-ethyl ester may be a most potent p38 MAPK inhibitor among the tested compounds and the combination of in silico and in vitro assay approaches may be a useful and efficient solution as a functional screening approach in searching new lead compounds for targeted molecules.