In silico evaluation of potential breast cancer receptor antagonists from GC-MS and HPLC identified compounds in Pleurotus ostreatus extracts

Abstract

Introduction: Pharmacotherapeutic targets for breast cancer include the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (EGFR). Inhibitors of these receptors could be interesting therapeutic candidates for the treatment and management of breast cancer (BC). Aim: This study used GC-MS and HPLC to identify bioactive compounds in Pleurotus ostreatus (P. ostreatus) extracts and applied in silico methods to identify potent EGFR, ER, and PR inhibitors from the compounds as potential drug candidates. Method: GC-MS and HPLC were used to identify bioactive chemicals in P. ostreatus extracts of aqueous (PO-A), methanol (PO-M), ethanol (PO-E), chloroform (PO-C), and n-hexane (PO-H). The ER, PR, and EGFR model optimization and molecular docking of compounds/control inhibitors in the binding pocket were simulated using AutoDock Vina in PyRx. The drug-likeness, pharmacokinetic, and pharmacodynamic features of prospective docking leads were all anticipated. Result: The results indicated the existence of 29 compounds in PO-A, 36 compounds in PO-M and PO-E, 42 compounds in PO-C, and 22 compounds in PO-H extracts. With ER, only o-tolylamino-acetic acid (4-nitro-benzylidene)-hydrazide (-7.5 kcal mol^-1) from the ethanolic extract could bind to the receptor. PR and EGFR, on the other hand, identified several compounds with higher binding affinities than the control. Ergotaman-3',6',18-trione (-8.1 kcal mol^-1), 5,10-diethoxy-2,3,7,8-tetrahydro-1H,6H-dipyrrolo[1,2-a:1',2'-d]pyrazine (-7.8 kcal mol^-1) from the aqueous extract; o-tolylamino-acetic acid (4-nitro-benzylidene)-hydrazide (-8.4 kcal mol^-1) from the ethanolic extract had better binding affinity compared to progesterone (-7.7 kcal mol^-1). Likewise, ergotaman-3',6',18-trione (-9.7 kcal mol^-1) from the aqueous extract and phenol, 2,4-bis(1,1-dimethyl ethyl) (-8.2 kcal mol^-1) from the chloroform extract had better binding affinities compared to the control, gefitinib (-7.9 kcal mol^-1) with regards to EGFR. None of the PO-H or PO-M extracts outperformed the control for any of the proteins. Phenols and flavonoids such as quercetin, luteolin, rutin, chrysin, apigenin, ellagic acid, and naringenin had better binding affinity to PR and EGFR compared to their control. Conclusion: The identified compounds in the class of phenols and flavonoids were better lead molecules due to their ability to strongly bind to the proteins' receptors. These compounds showed promising drug-like properties; they could be safe and new leads for creating anticancer medicines.

Fig. 1. (a and b): P. ostreatus mushroom. (a): P. ostreatus growing on its substrate. (b): P. ostreatus freshly harvested.

Fig. 2. The intermolecular interactions between 10531 (A); 565346 (B) and PR.

Fig. 3. The intermolecular interactions between 6876597 and PR.

Fig. 4. The intermolecular interactions between 5280343 (A); 5280445 (B); 439246 (C) and PR.

Fig. 5. The intermolecular interactions between 5280343 (A); 5280443 (B); 5281855 (C) and PR.

Fig. 6. The intermolecular interactions between 6876597 and ER.

Fig. 7. The intermolecular interactions between 10531 and EGFR.

Fig. 8. The intermolecular interactions between 93344 and EGFR.

Fig. 9. The intermolecular interactions between 5280343 (A); 5280445 (B); 5280805 (C); 5281607 (D) and EGFR.

Fig. 10. The intermolecular interactions between 5281855 (A); 5280343 (B); 5280443 (C) and EGFR.