Periodontitis is a chronic inflammatory condition primarily triggered by bacterial infections, with periodontopathogens such as Porphyromonas gingivalis playing a pivotal role. We evaluated the antioxidant and anti-inflammatory effects of ethanol extract of Salvia plebeia R. Br. (SP-E) on human gingival fibroblasts (hTERT-hNOF) stimulated with P. gingivalis -derived lipopolysaccharide (LPS). Dried S. plebeia was extracted using 70% ethanol, yielding a 10.5% extract. Inflammation in hTERT-hNOF cells was induced using P. gingivalis LPS in conjunction with LPS-binding protein and CD14. SP-E was administered at concentrations ranging from 25 to 100 μg/mL. Antioxidant capacity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and superoxide dismutase (SOD) activity assay. Inflammatory cytokine expression and secretion were analyzed via reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Results demonstrated a concentrationdependent antioxidant effect, with 62.98% radical scavenging activity observed at 200 μg/mL SP-E. In hTERT-hNOF cells, SOD activity increased from 4.88% (LPS-treated) to 45.78% with 100 μg/mL SP-E. RT-PCR analysis showed significant downregulation of interleukin (IL)-1β, IL-6, and IL-8 mRNA expression following SP-E treatment. ELISA confirmed a reduction in tumor necrosis factor (TNF)-α (312.83 → 178.22 pg/mL), IL-6 (453.97 → 170.83 pg/mL), and IL-8 (480.14 → 276.86 pg/mL) levels with 100 μg/mL SP-E. These findings suggest that SP-E may offer therapeutic potential for preventing and managing periodontal disease by mitigating oxidative stress and modulating inflammatory cytokine expression. Further studies are warranted to elucidate the underlying molecular mechanisms and validate these effects in vivo .

Introduction
Materials and Methods
    1. Preparation of natural extract
    2. Preparation of LPS
    3. Cell culture
    4. Cell cytotoxicy measurement
    5. Radical scavenging capacity measurement
    6. Assessment of superoxide dismutase activity
    7. mRNA expression changes of pro-inflammatorycytokines
    8. Protein expression changes of pro-inflammatorycytokines
Results
    1. Extraction yield of SP-E
    2. Cytotoxicity of SP-E
    3. Antioxidant activity of SP-E
    4. Inhibitory effect of SP-E on mRNA expression ofpro-inflammatory cytokines
    5. Inhibitory effect of SP-E on protein expression ofpro-inflammatory cytokines
Discussion
Funding
Conflicts of Interest
References

• Joong-Ki Kook(Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju 61452, Republic of Korea, Oral Bacterial Pathogen Resource Specialized Bank and Korean Collection for Oral Microbiology, Chosun University, Gwangju 61452, Republic of Korea) Corresponding author
• Chaekwang Rim(RCK Co., Ltd. Research Institute, Hwasun 58141, Republic of Korea)
• Hyeonjun Cho(RCK Co., Ltd. Research Institute, Hwasun 58141, Republic of Korea, Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju 61452, Republic of Korea)