## 4 Discussion
reported that shikonin reduced IL-6 and IL-8 production in human periodontal ligament cells induced by IL-1\(\beta\) and TNF-\(\alpha\)[15]. [PERSON] et al. also reported that shikonin exhibited anti-inflammatory effects in lipopolysaccharide-acrylamide (LPS)-stimulated human periodontal ligament cells by inhibiting the transduction of ERK and NF-\(\kappa\)B signaling pathways [38]. The results of this study showed that 0.1 \(\mu\)M of shikonin significantly reduced the production of inflammatory cytokines IL-6 and IL-8 in the hGFs induced by IL-1\(\beta\). This is consistent with previous findings, suggesting that the shikonin concentration that promotes proliferation and migration also exerts anti-inflammatory effects on human gingival fibroblasts, potentially offering beneficial effects for periodontitis. The presence of reduced oxygen in their structure makes ROS extremely reactive, enabling them to inflict damage on cellular components like proteins [6]. To maintain cellular survival, activation, and organ function, the body regulates the induction of ROS in order to preserve the redox balance. But the induction of ROS is increased by inflammation, UV radiation, and trauma, and excessive induction leads to redox imbalance and oxidative stress [39]. Inflammatory pathways involving pro-inflammatory cytokines increase the induction of intracellular ROS [40]. In a state of oxidative stress with excessive ROS expression, significant damage is caused to various tissues, affecting the entire body [41]. Oxidative stress contributes to the onset and progression of various systemic diseases, including lifestyle-related diseases, neurodegenerative disorders, and chronic inflammatory diseases [42]. Previously, the naphthoquinone moiety in the structure of shikonin has been shown to have radical-scavenging activity [43], and the antioxidant effects of shikonin have been reported in various diseases. Acute liver damage was mitigated by the administration of shikonin, which functioned by suppressing oxidative stress and inflammatory processes [14]. Shikonin also improves dopaminergic neuronal apoptosis by inhibiting oxidative stress and neuroinflammation in [PERSON]'s disease [44]. Furthermore, [PERSON] demonstrated how treatment with shikonin upregulated the antioxidant system in response to ROS in diabetes [45]. The antioxidation of periodontal tissues is also important in periodontal disease because ROS, which significantly contributes to the development and progression of periodontal disease, induces tissue destruction and stimulates inflammatory processes, such as collagen degradation and cell damage [40]. In the present study, shikonin significantly reduced IL-1\(\beta\)-induced ROS in human gingival fibroblasts. Shikonin suppresses oxidative stress against ROS induction in periodontitis and is expected to contribute to the prevention and treatment of periodontal diseases. MicroRNAs (miRNAs) are a type of non-coding RNA molecule and are responsible for regulating the post-transcriptional expression of numerous messenger RNAs (mRNAs) [16]. Researchers have extensively investigated the various disorders influenced by these miRNAs. In recent years, a growing body of evidence has indicated that compounds found in nature may offer therapeutic benefits for certain conditions by modulating miRNA expression. In the past, the naturally occurring substance berberine has been reported to promote the expression of miR-29a, miR-152, and miR-429 and to have potential in the prevention and treatment of colorectal cancer [46]. Resveratrol also inhibits inflammatory factors by downregulating the expression of miR-155 and promoting the expression of its target gene, which is a suppressor of cytokine signaling [47]. Tanshinone IIA has been reported to exert anti-inflammatory effects by downregulating the expression of miR-29b, miR-34c, miR-155, miR-147, and miR-184 [48].