Novel Stable Protease Inhibitor from Phoenix dactylifera (L.) Flowers with Antimicrobial and Antitumoral Activities

• Published in: ACS omega 2024-03, Vol.9 (11), p.13332-13341
• Main Authors: Jemel, Ikram, Krayem, Najeh, Ben Bacha, Abir, Alonazi, Mona, Horchani, Habib, Ghamgui, Hanène
• Format: Article
• Language: English
• ISSN: 2470-1343; 2470-1343
• DOI: 10.1021/acsomega.3c10287

A novel protease inhibitor isolated from date palm Phoenix dactylifera (L.) flowers (PIDF) was purified and characterized. A heat and acidic treatment step followed by ethanol precipitation and reverse-phase high-performance chromatography was applied to purify this natural protease inhibitor to homogeneity with a single band of about 19 kDa. The stability study depicted that PIDF was fully stable at 40 °C and retained 65% of its initial activity after heating at 50 °C for 24 h. Its thermal stability at 70 °C was markedly enhanced by adding calcium, bovine serum albumin, and sorbitol as well as by metal divalent cations, especially Mg2+ and Hg2+. This protease inhibitor showed high inhibitory activity against therapeutic proteases, including pepsin, trypsin, chymotrypsin, and collagenase, and acted as a potent inhibitor of some commercial microbial proteases from Aspergillus oryzae, Bacillus. sp, and Bacillus licheniformis. Moreover, a potent antibacterial spectrum against Gram (+) and Gram (−) bacterial strains and an efficient antifungal effect were observed. Its cytotoxicity toward human colorectal cancer cell LoVo and HCT-116 lines suggested that PIDF could serve as a new therapeutic target inhibiting human colorectal cancer.