Polysaccharide and ethanol extracts of Anoectochilus formosanus Hayata: Antioxidant, wound-healing, antibacterial, and cytotoxic activities

Thi-Phuong Nguyen; Han N Phan; Thang Duc Do; Giap Dang Do; Long Hoang Ngo; Hoang Dang Khoa Do; Khoa Thi Nguyen

doi:10.1016/j.heliyon.2023.e13559

Polysaccharide and ethanol extracts of Anoectochilus formosanus Hayata: Antioxidant, wound-healing, antibacterial, and cytotoxic activities

Heliyon. 2023 Feb 14;9(3):e13559. doi: 10.1016/j.heliyon.2023.e13559. eCollection 2023 Mar.

Authors

Thi-Phuong Nguyen¹, Han N Phan¹, Thang Duc Do², Giap Dang Do², Long Hoang Ngo¹, Hoang Dang Khoa Do¹, Khoa Thi Nguyen¹

Affiliations

¹ NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, Ho Chi Minh City, Viet Nam.
² Department of Plantcell Biotechnology, Institute of Tropical Biology, Vietnam Academy of Science and Technology (VAST), Ho Chi Minh City, Vietnam.

Abstract

Introduction: Polysaccharide and alcohol extracts of Anoectochilus formosanus Hayata have attracted great attention as they exhibit noteworthy properties such as prebiotic and anti-hyperglycemic effects. However, the antioxidant and wound-healing activities of the polysaccharide extract as well as the antibacterial and cytotoxic effects of the ethanol extracts have not been thoroughly uncovered. Therefore, our study investigated these bioactivities of the two extracts prepared from Anoectochilus formosanus to broaden understandings of medical benefits of the plant.

Methods: The monosaccharide composition was analyzed by HPAEC-PAD. The antioxidant and wound-healing activities of the polysaccharide extract were evaluated by ABTS and scratch assays, respectively. The broth dilution method was used to determine the antibacterial ability of the ethanol extract. Additionally, the cytotoxic and mechanistic effects of this extract against hepatocellular carcinoma HUH-7 cells was assessed by MTT assay, qRT-PCR and Western blotting methods.

Results: The polysaccharide extract possessed an effective free radical scavenging ability in an ABTS assay (IC₅₀ = 44.92 μg/ml). The extract also ameliorated wound recovery in a fibroblast scratch assay. Meanwhile, the ethanol extract was able to inhibit the growth of Staphylococcus aureus (MIC = 2500 μg/ml), Bacillus cereus (MIC = 2500 μg/ml), Escherichia coli (MIC = 2500 μg/ml), and Pseudomonas aeruginosa (MIC = 1250 μg/ml). Additionally, it repressed the viability of HUH-7 cells (IC₅₀ = 53.44 μg/ml), possibly through upregulating the expression of caspase 3 (CASP3), CASP8, and CASP9 at both mRNA and protein levels.

Conclusion: The polysaccharide extract of A. formosanus exhibited the antioxidant and wound-healing properties whereas the ethanol extract showed the antibacterial activity and cytotoxicity against HUH-7 cells. These findings specify notable biological effects of the two extracts which could be of potential use in human healthcare.

Keywords: Anoectochilus formosanus; Antibacterial; Antioxidant; Cytotoxic; Wound-healing.