## 3 Results
### Effects of FRB on Spleen Cell Proliferation  
FRB at doses of 50, 100, and 200 \(\mathrm{\SIUnitSymbolMicro g}\)/mL was added to spleen cells (treated with concanavalin A (Con A) or lipopolysaccharide (LPS)) and then incubated for 48 h. Negative control (without the addition of FRB samples, Con A, or LPS) was prepared as described in the materials and methods section.  
Con A-treated splenocyte proliferation was further increased by the addition of FRB (\(p<0.001\)) (Figure 2A). These findings suggest that FRB is effective in cellular immune responses by promoting T cell proliferation.  
Figure 1: GPC Analysis of RB and FRB. Processed Rice Bran (RB; (**a**)) and Fermented Rice Bran (FRB; (**b**)).  
We also evaluated the effect of FRB on LPS-induced B cell proliferation by adding FRB (50, 100, and 200 \(\upmu\)g/mL) to the culture medium with LPS. FRB supplementation stimulated cell proliferation in a dose-dependent manner (\(p<0.01\) and \(p<0.001\)) (Figure 2B). These findings suggest that FRB may have an immunostimulatory effect affecting the humoral immune response.  
Effects of FRB and RB Administrations on Body Weight and Immune-Related Organ Weight in Animal Model  
When CY is applied to lymphocyte cells, their immune system is negatively affected, since CY is a well-defined alkylating agent [31]. Alkylation inhibits DNA synthesis and impairs the functions in T and B cells and eventually reduces their immune response [29; 31; 32]. Therefore, in this research we evaluated whether this immunosuppression method can be improved by the co-administration of CY and FRB.  
FRB (0.5 g/kg-bw) or RB (0.5 g/kg-bw) was administered for 14 days. CY was intraperitoneallyally administrated as a single dose of 100 mg/kg 5 days before sacrifice. As a result, significant differences were observed in the weight of thymus and spleen according to CY administration, and significant differences were also measured between the FRB and RB treatment groups (Table 5). The weight of both thymus and spleen related to immunity was significantly reduced in all groups administered CY, triggering immune decline due to CY (Table 5). More specifically, the weight of thymus decreased by 41% in the CY control group but showed a difference between the FRB- and the RB-treated groups by about 2.3% and 18%, suggesting a tendency to recover immune function. The spleen weight of the CY control group decreased (17%) compared to normal control. FRB with the CY administration group significantly increased spleen weight by 11% compared to the spleen weight of the CY control group. The above results suggest that FRB supplementation may help restore the weight of the spleen and thymus relevant for immunity, possibly by enhancing and protecting CY-induced damage in the immune system.  
Overall, our findings suggest that FRB treatment could increase the weight of both spleen and thymus, and recover the CY-induced immunosuppression.  
Figure 2: Changes in splenocytes proliferation induced by Con A (**A**), LPS (**B**), and FRB. Mouse Splenocytes were stimulated with Con A (15 \(\upmu\)g/mL), LPS (500 \(\upmu\)g/mL) in the presence of various concentrations of FRB for 48 h. MTT assay was performed to evaluate the splenocytes proliferation. The results were expressed as the mean \(\pm\) standard deviation of different experiments. Statistical significances of Con A and LPS groups were determined by Student’s \(t\)-test (**\(p<0.01\), ***\(p<0.001\)).