Molecular Docking Studies, Chemical Composition, Antioxidant, Cytotoxicity, Antibacterial and Antifungal Activities of Globularia alypum Extract

Background: Globularia alypum L. is a Mediterranean plant of the Globulariaceae family which has been used in folk medicine to cure several diseases. Different studies have been done in vitro and in vivo using diverse G. alypum extracts to understand this traditional use. Methods: In this study, Tunisian G. alypum leaf methanol extract (GAME) was chemically identified using LC-ESI-MS, then examined in vitro for its antioxidant, antibacterial, and antifungal activities. Besides, a molecular docking study was also conducted. Results: Nineteen phenolic compounds were detected, with trans-cinnamic acid (45.14%) and luteolin 7-O-glucoside (19.82%) being the dominant ones. The GAME demonstrated important antioxidant activities, especially against 2, 2-diphenyl-l-1-picrylhydrazil (DPPH) radical (IC50 = 16.1±1.1 μg.ml^-1) and exhibited an anti-proliferative effect against Vero cells with (IC50 2091 ± 177 μg.ml^-1). Data also reveals that the GAME inhibited the growth of oral bacteria, in particular Streptococcus oralis (MICs value ranged from 2560 to 20480 μg.ml^-1). In addition, GAME has a significant antifungal action, especially against Candida albicans ATCC 90028 (MIC=2560 μg.ml^-1). Docking study identified one of the major molecules (luteolin 7-O-glucoside) present in the GAME extract, displaying a good interaction with tyrosinase (docking score -9.6 kcal.mol^-1) and other antibacterial (tyrosyl-tRNA synthetase, gyrase, deformylase) and antifungal (n-myristoyltransferase, chitinase) target proteins. Conclusion: This study illustrates that GAME has potent sources of antioxidants and antimicrobials useful in combating oral bacteria. Hence GAME can be of reasonable use in food technology, processing, as well as the medical field.