In Vitro Assessment of Antistaphylococci, Antitumor, Immunological and Structural Characterization of Acidic Bioactive Exopolysaccharides from Marine Bacillus&nbsp; cereus Isolated from Saudi Arabia

Samy Selim; Mohammed S Almuhayawi; Mohanned Talal Alharbi; Mohammed K Nagshabandi; Awadh Alanazi; Mona Warrad; Nashwa Hagagy; Ahmed Ghareeb; Abdallah S Ali

doi:10.3390/metabo12020132

In Vitro Assessment of Antistaphylococci, Antitumor, Immunological and Structural Characterization of Acidic Bioactive Exopolysaccharides from Marine Bacillus  cereus Isolated from Saudi Arabia

Metabolites. 2022 Feb 1;12(2):132. doi: 10.3390/metabo12020132.

Authors

Samy Selim¹, Mohammed S Almuhayawi², Mohanned Talal Alharbi³, Mohammed K Nagshabandi³, Awadh Alanazi¹, Mona Warrad⁴, Nashwa Hagagy^{5

6}, Ahmed Ghareeb⁷, Abdallah S Ali⁸

Affiliations

¹ Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka 72341, Saudi Arabia.
² Department of Medical Microbiology and Parasitology, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
³ Department of Medical Microbiology and Parasitology, Faculty of Medicine, University of Jeddah, Jeddah 23218, Saudi Arabia.
⁴ Department of Clinical Laboratory Sciences, College of Applied Medical Sciences at Al-Quriat, Jouf University, Al-Quriat 77454, Saudi Arabia.
⁵ Department of Biology, College of Science and Arts at Khulis, University of Jeddah, Jeddah 21959, Saudi Arabia.
⁶ Botany and Microbiology Department, Faculty of Science, Suez Canal University, Ismailia 41522, Egypt.
⁷ Botany and Microbiology Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
⁸ Department of Microbiology, Faculty of Agriculture, Cairo University, Giza 12613, Egypt.

Abstract

A strain of Bacillus cereus was isolated from the Saudi Red Sea coast and identified based on culture features, biochemical characteristics, and phylogenetic analysis of 16S rRNA sequences. EPSR3 was a major fraction of exopolysaccharides (EP_S) containing no sulfate and had uronic acid (28.7%). The monosaccharide composition of these fractions is composed of glucose, galacturonic acid, and arabinose with a molar ratio of 2.0: 0.8: 1.0, respectively. EPSR3 was subjected to antioxidant, antitumor, and anti-inflammatory activities. The results revealed that the whole antioxidant activity was 90.4 ± 1.6% at 1500 µg/mL after 120 min. So, the IC₅₀ value against DPPH radical found about 500 µg/mL after 60 min. While using H₂O₂, the scavenging activity was 75.1 ± 1.9% at 1500 µg/mL after 60 min. The IC₅₀ value against H₂O₂ radical found about 1500 µg/mL after 15 min. EPSR3 anticytotoxic effect on the proliferation of (Bladder carcinoma cell line) (T-24), (human breast carcinoma cell line) (MCF-7), and (human prostate carcinoma cell line) (PC-3) cells. The calculated IC50 for cell line T-24 was 121 ± 4.1 µg/mL, while the IC₅₀ for cell line MCF-7 was 55.7 ± 2.3 µg/mL, and PC-3 was 61.4 ± 2.6 µg/mL. Anti-inflammatory activity was determined for EPSR3 using different methods as Lipoxygenase (LOX) inhibitory assay gave IC₅₀ 12.9 ± 1.3 µg/mL. While cyclooxygenase (COX-2) inhibitory test showed 29.6 ± 0.89 µg /mL. EPSR3 showed potent inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci. The exposure times of EPSR3 for the complete inhibition of cell viability of methicillin resistant S. aureus was found to be 5% at 60 min. Membrane stabilization inhibitory gave 35.4 ± 0.67 µg/mL. EPSR3 has antitumor activity with a reasonable margin of safety. The antitumor activity of EPSR3 may be attributed to its content from uronic acids with potential for cellular antioxidant and anticancer functional properties.

Keywords: Antistaphylococci; Bacillus cereus; Exopolysaccharide; MRSA; anti-inflammatory; antioxidant; antitumor.

Grants and funding

DSR-2021-01-0348/Al Jouf University