Thais savignyi tissue extract: bioactivity, chemical composition, and molecular docking

Abstract

Context: Thais savignyi Deshayes (Muricidae) is widely distributed in the Red Sea. Its abundance and the history of Muricidae in traditional medicine make it a tempting target for investigation.

Objective: To investigate the chemical profile and biological activities of T. savignyi tissue extracts.

Materials and methods: Methanol, ethanol, acetone, and ethyl acetate extracts from T. savignyi tissue were compared in their antioxidant by total antioxidant capacity, DPPH free radical scavenging, and total phenolic content. In addition, the antimicrobial, and antibiofilm properties (at 250 µg/mL) of the extracts were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumoniae, Staphylococcus aureus, and Candida albicans. The antioxidant extract with greatest activity was assessed for cytotoxicity (range 0.4-100 µg/mL) against 3 human cancer cell lines (UO-31, A549 and A431), and its chemical composition was investigated using GC-MS. Moreover, docking simulation was performed to predict its constituents' binding modes/scores to the active sites of thymidylate kinase.

Results: The ethyl acetate extract (Ts-EtOAc) showed the highest total antioxidant capacity (551.33 mg AAE/g dry weight), total phenolics (254.46 mg GAE/g dry weight), and DPPH scavenging (IC₅₀= 24.0 µg/mL). Ts-EtOAc exhibited strong antibacterial (MIC: 3.9 µg/mL against K. pneumoniae), antibiofilm (MIC: 7.81 µg/mL against S. aureus), and antifungal (MIC: 3.9 µg/mL against C. albicans) activities and considerable cytotoxicity against cancer cells (UO-31: IC₅₀= 19.96 ± 0.93, A549: IC₅₀= 25.04 ± 1.15 μg/mL). GC-MS identified multiple bioactive metabolites in Ts-EtOAc extract belonging to miscellaneous chemical classes. Molecular docking studies revealed that the constituents of Ts-EtOAc have antibacterial potential.

Discussion and conclusions: T. savignyi extract has considerable antimicrobial and cytotoxic activities. Further studies are needed to isolate the active constituents of this snail for comprehensive drug discovery tests.

Keywords: Antioxidant; antimicrobial; bioactive compounds; cytotoxicity; marine snails.

Figure 1.

Biofilm inhibitory activities of different solvent extracts of Thais savignyi snails.

Figure 2.

Cytotoxicity of Ts-EtOAc extract against different human cancer cell lines after 24 h of treatment. (A) UO-31: Human kidney renal cell carcinoma; (B) A549: Adenocarcinomic human alveolar basal epithelial cells; (C) A431: Human epidermoid carcinoma cells (X-axis: Log concentrations of the extract from 0.4 to 100 μg/mL and Y-axis: the percentage of cell viability). (D): The comparison of average IC₅₀ of the extract vs. staurosporine as a positive control. Data represent the mean ± SD of three independent experiments.

Figure 3.

GC-MS chromatogram of Ts-EtOAc extract.

Figure 4.

Chemical structures of some major identified compounds in Ts-EtOAc extract.

Figure 5.

The two-dimensional (A) and three-dimensional (B) suggested binding modes of redocked ligand within the binding pocket of TMK (PDB: 4QGG).

Figure 6.

The two-dimensional (left panel) and three-dimensional (right panel) suggested binding modes of compounds 1 (A), 2 (B) and 3 (C) within the binding pocket of TMK (PDB: 4QGG).

Figure 7.

The two-dimensional (A) and three-dimensional (B) suggested binding modes of compound 4 within the binding pocket of TMK (PDB: 4QGG).

Figure 8.

The two-dimensional (left panel) and three-dimensional (right panel) suggested binding modes of compounds 5 (D), 6 (E) and 7 (F) within the binding pocket of TMK (PDB: 4QGG).