## 4 Discussion  
Excessive fat accumulation in the body leads to a disease we call 'obesity', which is affected by changes in various economic, lifestyle, and nutritional conditions, and can be exposed to obesity and related diseases in all life cycles [21,22]. In addition, in the recent health functional food market, demand and interest in weight control foods for a healthy and ideal body is peaking. To satisfy these demands, research on the development of various natural materials that suppress fat accumulation or help in weight control is actively conducted [23, 24, 25]. TJ is a plant that is widely distributed in Asian countries and some Western countries and has been widely used for medicinal purposes [26]. In addition, according to a recent investigation, active substances such as polyphenols, trapain, 1,2,3,6-tetra-O-galloyl-\(\beta\)-d-glucopyranoside, and eugenin were found in TJ [16]. In particular, the antidiabetic effect of TJ was prominent among several studies [27], and the result of controlling glucose metabolism is expected to be effective in the prevention or treatment of obesity. In our preliminary study, we confirmed the presence of ellagic acid in a component analysis test of TJ (data not shown). Ellagic acid is a dimeric derivative of gallic acid that is found in woody plants, nuts, grapes, and berries [28]. It is reported to exhibit key biological activities such as radical scavenging, chemopre, and antiviral [29]. Our study aimed to determine whether TJ exerts effects on the adipogenesis, lipogenesis, and lipolysis mechanisms of differentiated 3T3-L1 cells. Prior to this experiment, we conducted a cell viability test. 3T3-L1 cells treated with TJ were confirmed to be non-toxic up to the maximum concentration (200 ug/mL) used in the main experiment. Furthermore, we used green tea catechin as a positive control in this experiment. Green tea is one of the most popular teas in Asia and is known as a drink useful for weight control [30]. One of its active ingredients, catechin, has been reported as a substance that promotes fat oxidation, regulates body composition, and inhibits fat synthesis in the 3T3-L1 cell model [31]. To clarify the effect of the TJ on the adipogenesis and lipogenesis mechanisms during the differentiation period of adipocytes, we confirmed the expression and activity levels of adipogenesis- and lipogenesis-related proteins. Adipogenesis is the progress by which  
Figure 8: Effects of the TJ on lipolysis-related proteins in 3T3-L1 cells: **(A)** Western blot showing the expression levels of the proteins, **(B)** p-AMPK/AMPK, **(C)** UCP1/actin, **(D)** PKA/actin, **(E)** PDE3B/actin, **(F)** perilipin A/actin, **(G)** ATGL/actin, **(H)** p-HSL/HSL and **(I)** CPT1A/actin. NC, normal control; DC, differentiated control; PC1, catechin 100 ug/mL; PC2, catechin 200 ug/mL; TJ (10, 50, 100, or 200 ug/mL). The data are shown as mean \(\pm\) standard deviation (SD; n = 3), and statistical analyses were conducted by [PERSON]’s multiple range tests after one-way ANOVA. Each lowercase alphabet indicates within-figure differing significance (\(p<0.05\)). the differentiation of 3T3-L1 cells (preadipocytes) matures into adipocytes [32]. It begins with a reduction in cAMP levels and activation of CREB, which stimulates the expression of transcription factors such as PPAR\(\gamma\) and C/EBPa [33]. Adipogenesis is regulated by these transcription factors that are also called the master regulators in the final step of differentiation [34]. PPAR\(\gamma\), called a ligand-activated transcription factor, can induce the expression of C/EBPa, which in turn mediates the expression levels of adipogenesis-related genes, including adiponectin, FABP4, G6 Pase, and leptin [35; 36]. In our previous study, we confirmed that the activity of cAMP and MAPK decreased in the adipogenesis-induced model, and the expression levels of C/EBP\(\beta\), C/EBPa, and PPAR\(\gamma\) increased when adipocytes were differentiated [20].