Antimicrobial Mechanism and Identification of the Proteins Mediated by Extracts from Asphaltum punjabianum and Myrtus communis

Kawther Aabed; Afrah E Mohammed; Hicham Benabdelkamel; Afshan Masood; Assim A Alfadda; Ibrahim O Alanazi; Eman A Alnehmi

doi:10.1021/acsomega.0c04047

Antimicrobial Mechanism and Identification of the Proteins Mediated by Extracts from Asphaltum punjabianum and Myrtus communis

ACS Omega. 2020 Nov 23;5(48):31019-31035. doi: 10.1021/acsomega.0c04047. eCollection 2020 Dec 8.

Authors

Kawther Aabed¹, Afrah E Mohammed¹, Hicham Benabdelkamel², Afshan Masood², Assim A Alfadda³, Ibrahim O Alanazi⁴, Eman A Alnehmi⁵

Affiliations

¹ Department of Biology, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia.
² Proteomics Unit, Obesity Research Center, College of Medicine, King Saud University, P.O. Box 2925 (98), Riyadh 11461, Saudi Arabia.
³ Proteomics Unit, Obesity Research Center, Department of Medicine, College of Medicine, King Saud University, P.O. Box 2925 (98), Riyadh 11461, Saudi Arabia.
⁴ The National Center for Biotechnology (NCB), Life Science and Environment Research Institute, King Abdulaziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 12354, Saudi Arabia.
⁵ Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.

Abstract

Myrtus communis ("myrtle") and Asphaltum punjabianum ("shilajeet") are a medicinal plant and a long-term-humified dead plant material, respectively. We studied their antibacterial and anticandidal activities against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Candida albicans. The activities of the aqueous extracts of the studied materials were measured using agar-well diffusion methods. Furthermore, proteomic analysis of treated microbial cells was conducted to identify affected proteins. The results showed both antibacterial and anticandidal activities for the myrtle extract (ME), while the shilajeet extract (SE) showed antibacterial activity only. The highest antimicrobial activity was observed against E. coli among the microbes tested; therefore, it was taken as the model for the proteomic analysis to identify the antimicrobial mechanism of ME and SE using two-dimensional electrophoresis. Upregulation of expression of 42 proteins and downregulation of expression of 6 proteins were observed in E. coli treated with ME, whereas 12 upregulated and 104 downregulated proteins were detected in E. coli treated with SE, in comparison with the control. About 85% of identified expressed proteins were from the cytoplasm and 15% from microbial cell walls, indicating the penetration of extracts inside cells. A higher percentage of expressed proteins was recorded for enzymatic activity. Our findings suggest that the major targets of the antibacterial action were proteins involved in the outer membrane, oxidative stress, and metabolism. Our data might reveal new targets for antimicrobial agents.