Assessment of Pharmacological Potential of Novel Exopolysaccharide Isolated from Marine Kocuria sp. Strain AG5: Broad-Spectrum Biological Investigations

Abstract

With more than 17 clinically approved Drugs and over 20 prodrugs under clinical investigations, marine bacteria are believed to have a potential supply of innovative therapeutic bioactive compounds. In the current study, Kocuria sp. strain AG5 isolated from the Red Sea was identified and characterized by biochemical and physiological analysis, and examination of a phylogenetic 16S rRNA sequences. Innovative exopolysaccharide (EPS) was separated from the AG5 isolate as a major fraction of EPS (EPSR5, 6.84 g/L−1). The analysis of EPSR5 revealed that EPSR5 has a molecular weight (Mw) of 4.9 × 104 g/mol and number average molecular weight (Mn) of 5.4 × 104 g/mol and contains sulfate (25.6%) and uronic acid (21.77%). Analysis of the monosaccharide composition indicated that the EPSR5 fraction composes of glucose, galacturonic acid, arabinose, and xylose in a molar ratio of 2.0:0.5:0.25:1.0, respectively. Assessment of the pharmacological potency of EPSR5 was explored by examining its cytotoxicity, anti-inflammatory, antioxidant, and anti-acetylcholine esterase influences. The antioxidant effect of EPSR5 was dose- and time-dependently increased and the maximum antioxidant activity (98%) was observed at 2000 µg/mL after 120 min. Further, EPSR5 displayed a significant repressive effect regarding the proliferation of HepG-2, A-549, HCT-116, MCF7, HEP2, and PC3 cells with IC50 453.46 ± 21.8 µg/mL, 873.74 ± 15.4 µg/mL, 788.2 ± 32.6 µg/mL, 1691 ± 44.2 µg/mL, 913.1 ± 38.8 µg/mL, and 876.4 ± 39.8 µg/mL, respectively. Evaluation of the inhibitory activity of the anti-inflammatory activity of EPSR5 indicated that EPSR5 has a significant inhibitory activity toward lipoxygenase (5-LOX) and cyclooxygenase (COX-2) activities (IC50 15.39 ± 0.82 µg/mL and 28.06 ± 1.1 µg/mL, respectively). Finally, ESPR5 presented a substantial hemolysis suppressive action with an IC50 of 65.13 ± 0.89 µg /mL, and a considerable inhibitory activity toward acetylcholine esterase activity (IC50 797.02 μg/mL). Together, this study reveals that secondary metabolites produced by Kocuria sp. strain AG5 marine bacteria serve as an important source of pharmacologically active compounds, and their impact on human health is expected to grow with additional global work and research.

Degradation of Cell Wall Polysaccharides during Traditional and Tank Fermentation of Chinese Liupao Tea

“…For example, Kocuria sp. has been reported to produce exopolysaccharides . Our team found that the fungal predominant bacteria Blastobotrys can produce EPS, and the EPS produced has a bile acid binding ability.…”

“…has been reported to produce exopolysaccharides. 40 Our team found that the fungal predominant bacteria Blastobotrys can produce EPS, and the EPS produced has a bile acid binding ability. In conclusion, microorganisms play an important role in the degradation and transformation of polysaccharides in the cell wall of Liupao tea.…”

In vitro studies on the pharmacological potential, anti-tumor, antimicrobial, and acetylcholinesterase inhibitory activity of marine-derived Bacillus velezensis AG6 exopolysaccharide

“…had a suppressive impact on the growth of cancer cells. 12 The highest IC 50s was (1691.00 ± 44.20 μg mL −1 ) for MCF-7, and the lowest was (453.46 ± 21.80 μg mL −1 ) for HepG-2. An exopolysaccharide from Bacillus albus DM-15 isolated from Indian Ayurvedic had an IC 50 value of 20 ± 0.97 μg mL −1 against lung cancer cell line (A549), and cellular staining showed necrotic, apoptotic properties in damaged A549 cells.…”

Tapping the biosynthetic potential of marine Bacillus licheniformis LHG166, a prolific sulphated exopolysaccharide producer: structural insights, bio-prospecting its antioxidant, antifungal, antibacterial and anti-biofilm potency as a novel anti-infective lead

“…Following our findings, EPSR5, an acidic microbial exopolysaccharide extracted from marine Kocuria sp., its highest DPPH radical scavenging of 98% was recorded after 120 min at a concentration of 2000 μg/mL ( Alshawwa et al, 2022 ). Also, Another EPS isolated from B. subtilis AG4 exhibited 97.6% DPPH scavenging activity at 1500 μg/mL, IC 50 = 300 μg/mL, and 64.8% H 2 O 2 scavenging, IC 50 = 1,500 μg/mL at the same tested concentration ( Abdel-Wahab et al, 2022 )—another EPS from Bacillus sp.…”

“…These compounds exhibited promising therapeutic potential. For instance, they inhibit the proliferation of pathogenic bacteria and fungi ( Selim et al, 2022 ), impede the proliferation of malignant cells ( Abdel-Wahab et al, 2022 ), scavenge reactive oxygen species ( Alshawwa et al, 2022 ), diminish inflammation ( Alharbi et al, 2023 ), and expedite the process of wound repair ( Zaghloul and Ibrahim, 2022 ). These microbial bioactive metabolites encompass a diverse range of chemical structures, including peptides, lipopeptides, polypeptides, lactones, fatty acids, polyketides, isocoumarins, terpenoids, and exopolysaccharides ( Zhou et al, 2019 ).…”