Background: NF-kB signaling pathway is a key point in the regulation of inflammatory responses. Inhibiting or limiting the NF-kB pathway may be useful in the disease control. There are a vast list of inhibitory agents for targeting the NF-kB signaling. However, herbal ingredients have been shown to exert anti-inflammatory effects. The aim is to evaluate and compare the interacting potency of a synthetic NF-kB agent, 3-Chloro-4-nitro-N-(5-nitro-2-thiazolyl)-benzamide (NTB), with two natural derived ingredients including curcumin and epigallocatechin gallate. The approach was virtual analysis and computer base investigation.
Material and method: The cheminformatics structures of curcumin, epigallocatechin gallate and NTB, a synthetic NF-kB inhibitor, were obtained from zinc docking repository. NF-kB chain A structure was obtained from protein data bank database with the PDB code=1nfi. Using Molegro Virtual Docker cheminformatics and PDB structures were interacted by an algorithm of energy minimization method. Docking scores were compared using analysis of variances (ANOVA).
Results: There were two hot-points for interaction of selected molecules with the chain A of NF-kB. Herbal ingredients were more potent than synthetic material for interaction in this two hot point. Curcumin (the best MoleDock score= -152.731; Mean±SD=-133.447±9.17 for 17 positions) was more potent than epigallocatechin gallate (the best MoleDock score= -146.47; Mean±SD= -116.36±17.598 for 34 positions). The best MoleDock score for NTB equal -120.332; Mean±SD= -108.25±8.66 for 16 positions. There were significant docking scores among curcumin and epigallocatechin gallate and NTB (CI=0.95; P-value=0.000). But, epigallocatechin gallate was not meaningfully different with NTB when comparing mean docking scores (P=0.147).
Discussion: Herbal ingredients such as curcumin and epigallocatechin gallate may interact with NFkB chain A subunit and inhibit it more potent than synthetic agents such as NTB and so forth. Then, anti-inflammatory effects of herbal ingredients may be desirable by the facts shown in the current in silico study. Furthermore, we suggest pure curcumin and epigallocatechin gallate as probable drugs for controlling acute phase of diseases. However, experimental and animal trials may be next steps of the current study.