## 3 Results  
### Ginensoides Rb1 and Rg3 Enhanced the Differentiation of 3T3-L1 Preadipocytes  
To determine the effect of ginsengs Rb1 and Rg3 on adipocyte differentiation, 3T3-L1 preadipocytes were induced to differentiate with the standard hormonal inducers (MDI)  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & & **Primer Sequences (5\({}^{\prime}\)\(\rightarrow\)3\({}^{\prime}\))** \\ \hline \multirow{2}{*}{PPAR\(\gamma\)} & Forward & CCA GAG TCT GCT GAT CTG CG \\  & Reverse & GCC ACC TCT TIG CTC TGA TC \\ \hline \multirow{2}{*}{C/EBP \(\alpha\)} & Forward & GGT GCG CAA GAG CCCG AGA TAA AG \\  & Reverse & AGT TCA CGG CTC AGC TGT TCC AC \\ \hline \multirow{2}{*}{aP2} & Forward & GAC CTG CAA ACT CGT CTC CA \\  & Reverse & CAT GAC ACA TTC CAC CAC CA \\ \hline \multirow{2}{*}{GLUT4} & Forward & TAC TCA TTC TTG GAC GGT TC \\  & Reverse & TGA TGT AGA GGT ATC TGG GG \\ \hline \multirow{2}{*}{adiponectin} & Forward & AAG GAC AAG GCCCG TTC TCT \\  & Reverse & TAT GGG TAG TTG CAG TCA GIT GG \\ \hline \multirow{2}{*}{IRS-1} & Forward & TCG TCA ATA GCG TAA CTG GA \\  & Reverse & AGA ACG TGC AGT TCA GTC AA \\ \hline \multirow{2}{*}{PI3K} & Forward & CAT GTT CTG CAA ACT TCA CCA \\  & Reverse & CCT GGG AAA ACA TAA ACT TG \\ \hline \multirow{2}{*}{Akt} & Forward & AGA GAT GGG GAT AGG TGT CT \\  & Reverse & ACT CAC ACA GGT CTG CAT A \\ \hline \multirow{2}{*}{\(\beta\)-actin} & Forward & AGG CTG TGC TGT CCC TGT ATG C \\  & Reverse & ACC CAAG CAA GGC TGG AAA \\ \hline \hline \end{tabular}
\end{table}
Table 1: Gene-specific primers used for RT-PCR.  
in the absence or presence of ginsenosides Rb1 or Rg3 (1, 10, and 50 uM), as described in the Methods. The range of concentrations was chosen to consider physiologically achievable doses (1 and 10 uM) and a nontoxic high dose of ginsenosides (50 uM) [40; 41; 42]. As shown in Figure 1, both ginsenosides Rb1 and Rg3 enhanced lipid accumulated during differentiation of 3T3-L1 preadipcytes. Ginsenoside Rb1 induced a dose-dependent increase in lipid acquisition in 3T3-L1 cells. However, ginsenoside Rg3 exerted its maximal effect at 1 uM as well as a dose-dependent decrease in lipid accumulation.  
PPAR\({}_{\forall}\) is known as a master transcription regulator of adipocyte differentiation, and orchestrates with C/EBP\(\alpha\) to regulate downstream target genes such as adipocyte protein 2 (aP2). It is well known that PPAR\({}_{\forall}\) is also a nuclear receptor for anti-diabetic drugs. Consistent with the effect on adipocyte differentiation, ginsenoside Rb1 dose-dependently enhanced the expression of PPAR\({}_{\forall}\), CEBP\(\alpha\), and aP2 mRNAs at all concentrations used (Figure 2). Moreover, ginsenoside Rg3 exerted its maximal stimulatory effect at 1 uM for the expression of PPAR\({}_{\forall}\), C/EBP\(\alpha\), and aP2 mRNAs during the differentiation of 3T3-L1 adipocytes. In contrast, Rg3 at a high concentration (50 uM) showed inhibitory effects on the expression of C/EBP\(\alpha\) and aP2 mRNA, but did not reach statistical significance compared to the control. These results indicate that the effects of the ginsenosides are comparable with respect to morphological changes and molecular responses.  
Figure 1: Effect of ginsenoside Rb1 and Rg3 on adipocyte conversion during the differentiation of 3T3-L1 preadipocytes. (**a**) Oil red O staining at day 0, 4, and 6 with or without ginsenoside Rb1 and Rg3. (**b**) Lipid accumulation determined by absorbance at 490 nm. Values are the means \(\pm\) SDs of four samples. \({}^{\text{a}\text{-}\text{c}}\) Bars with different letters indicate statistically significant differences among groups at \(p<0.05\).  
Figure 2: Changes in the expression of PPAR\({}_{\forall}\), CEBP\(\alpha\), and aP2 mRNAs by ginsenosides Rb1 and Rg3 during the differentiation of 3T3-L1 preadipocytes. Values are the means \(\pm\) SDs of four samples. \({}^{\text{a}\text{-}\text{d}}\) Bars with different letters indicate statistically significant differences among groups at \(p<0.05\).