균주 적용 자몽추출발효물의 생리활성 특성 = Characterization of Biological Activities of Fermented Grapefruit Extract by Leuconostoc mesenteroides

다국어 초록 (Multilingual Abstract)

This study systematically evaluated the biological activities of grapefruit (Citrus paradisi) extract following biotransformation by Leuconostoc mesenteroides CJNU 0147, with particular focus on its antimicrobial, anti-inflammatory, anticancer, and wound-healing properties. After fermentation, the grapefruit extract was fractionated and assessed for antimicrobial efficacy against the pathogenic microorganisms Staphylococcus aureus and Candida albicans. In addition, its effects on cell proliferation and wound repair were examined using human keratinocyte (HaCaT) models, while cytotoxic and anticancer activities were evaluated in human colon cancer (HT-29) cells. The biotransformed grapefruit extracts exhibited significantly enhanced antimicrobial activity compared with non-fermented extracts. In HaCaT cells, treatment with the fermented extract promoted cellular proliferation and markedly accelerated wound closure, achieving complete healing within 24 h. Selective cytotoxicity toward HT-29 cells was observed, with stronger growth inhibition at 500 µg/mL than at 1000 µg/mL, indicating a dose-dependent but non-linear response. Furthermore, the biotransformed extract demonstrated notable anti-inflammatory effects, as evidenced by the downregulation of pro-inflammatory cytokines IL-1β and TNF-α. Overall, these findings demonstrate that L. mesenteroides–mediated biotransformation significantly enhances the biofunctional properties of grapefruit extract, highlighting its promising potential for application in nutraceutical and cosmeceutical formulations.

목차 (Table of Contents)

• I. Introduction 1
• 1.1 Biotransformation and Its Role in Enhancing Bioactivity 2
• 1.2 Leuconostoc mesenteroides: A Functional Fementative Agent 3
• 1.3 Functional Implications of Grapefruit Fermentation 4
• 1.4 Antimicrobial, Anticancer, and Regenerative Potential 5
• 1.5 Research Gap and Aim of the Present Study 6
• II. Material and Methods 8
• 2.1 Preparation of Grapefruit Extracts and Fermentation 8
• 2.2 Microbial Strains and Cell Lines 9
• 2.3 Cell Culture Conditions 9
• 2.4 Screening Against Colon Cancer Cell Line HT-29 and Epidermal Keratinocyte Cell Line (HaCaT) 9
• 2.5 Production of exopolysaccharides by L. mesenteroides CJNU 0147 10
• 2.6 Antimicrobial Assay 11
• 2.7 Determination of Cell Cytotoxicity in HT-29 and Cell Proliferation in HaCaT cells using MTT assay 11
• 2.8 Effect of Biotransformed Grapefruit Extract on Cell Migration in HT-29 and Wound Healing in HaCaT Cells 12
• 2.9 Anti-inflammatory Effect of Bio-transformed Grapefruit Extract 13
• 2.10 Evaluation of the Effect of Bio-transformed Grapefruit Extract on Apoptosis Markers in HT-29 14
• III. Results 15
• 3.1 Screening Against Colon Cancer Cell Line HT-29 and Epidermal Keratinocyte Cell Line (HaCaT) 15
• 3.2 Production of exopolysaccharides by L. mesenteroides CJNU 0147 16
• 3.3 Antimicrobial Activity 17
• 3.4 Dose-dependent Effect of Bio-transformed Grapefruit Extract on HaCaT Cell Viabiliy 19
• 3.5 Wound Healing Effect of Bio-transformed Grapefruit Extract on HaCaT Cell Line 20
• 3.6 Anti-inflammatory Effect of Bio-transformed Grapefruit Extract 22
• 3.7 Dose-dependent Anticancer Effect on Colon Cancer Cell Line HT-29 23
• 3.8 Effect of Bio-transformed Grapefruit Extract on HT-29 Cell Migration 24
• 3.9 Effect of Bio-transformed Grapefruit on Apoptosis 25
• IV. Discussion 28
• 4.1 Implications and Future Direction 34
• V. Conclusion 36