## 4 Discussion  
This research demonstrated that shikonin enhanced hGF proliferation and migration when its concentration was appropriately adjusted. It also notably decreased IL-1\(\beta\)-induced inflammatory cytokine production and ROS induction. In addition, shikonin treatment significantly decreased the IL-1\(\beta\)-induced upregulation of miR-146a expression in hGFs. Natural compounds have different effects depending on the target cells and the concentration used, with the same compound reacting differently at high and low concentrations [24]. The effect of shikonin, a naturally occurring compound extracted from _Lithospermrum erythorhizon_, is concentration-dependent, and many inhibitory effects on malignant tumors have been reported when used at high concentrations. In a previous study, it was reported that the use of 2.5 \(\upmu\)M shikonin induced autophagy in human hepatocellular carcinoma cells [25]. Studies have also shown that shikonin, at doses of 2.5, 5, and 7.5 \(\upmu\)M, suppressed the proliferation of human malignant glioma U87 and U251 cell lines in a manner that was both time- and concentration-dependent [26]. However, several studies have shown that low concentrations of shikonin are not toxic and have a beneficial effect on cells. In a previous report, 1 \(\upmu\)M of shikonin was reported to promote wound healing by inducing transforming growth factor \(\beta\) (TGF-\(\beta\)) in the intestinal epithelial cell line [27]. It has also been reported that 1 \(\upmu\)M of shikonin promotes wound healing by promoting the proliferation of normal human keratinocyte cells [28]. The results of this study showed that for hGFs, 0.1 \(\upmu\)M of shikonin was most effective for proliferation and migration. Concentrations above 10 \(\upmu\)M were cytotoxic. These results indicate that there is an optimum concentration of shikonin and that it is important to determine it for each tissue, depending on the intended use. The anti-inflammatory effects of shikonin have been studied for many years, and many reports have been published [29]. [PERSON] et al. demonstrated that the administration of shikonin reduces the secretion of IL-6, IL-8, and MMP in a dose-dependent manner in synovial fibroblasts stimulated by IL-1\(\beta\)-induced inflammation [30]. [PERSON] et al. reported that shikonin-treated murine bone marrow-derived dendritic cells showed a decrease in the release levels of IL-4, IL-5, IL-13, and tumor necrosis factor (TNF)-\(\alpha\), which were induced by ovalbumin and thymic stromal lymphopoietin (TSLP) [31]. Research has shown that shikonin demonstrates efficacy in addressing inflammatory conditions, such as neuroinflammation [32] and colitis [33], owing to its anti-inflammatory properties. The inhibition of the nuclear factor-kB (NF-kB) pathway by shikonin has been widely reported as one of the important mechanisms for this anti-inflammatory effect [34; 35]. NF-\(\kappa\)B is  
Figure 5: The effects of shikonin on oxidative stress and miR-146a levels. (**a**) ROS fluorescence intensity was evaluated. Fluorescence staining was performed using a fluorescence microscope (scale bar: 200 \(\upmu\)m). (**b**) miR-146a expression was determined at 72 h after IL-1\(\beta\) stimulation. Statistically significant enhancements compared to the control group are denoted by * \(p<0.05\). A statistically significant reduction relative to the control group is indicated by \({}^{\dagger\dagger}p<0.01\). known as a mediator of immunity and is one of the signaling pathways that play an important role in the regulation of inflammatory responses [36]. It has been reported that shikonin suppresses inflammation in vivo by inhibiting the release of TNF-\(\alpha\) by rat macrophage cells and by inhibiting the migration of lipopolysaccharide-mediated NF-\(\kappa\)B to the nucleus [37]. The anti-inflammatory effects of shikonin have also been reported in periodontal tissues. [PERSON] et al.