This study investigated newly synthesized of chitosan-St-TPGS-NPs and chitosan-Sd-TPGS-NPs (CStNPs and CSdNPs) produced by a combination of sonication and emulsification/solvent evaporation method and in combination with the ionic gelation method with slight modifications. The newly synthesized CStNPs and CSdNPs were characterized by several technical methods such as SEM, TEM and FT-IR. In this study, 60 male Wistar rats were divided randomly into six groups. Each group included 10 animals with control group, stevia group (St), stevioside group (Sd), CNPs group, chitosan-stevia-TPGS nanoparticles (CStNPs) group, chitosan-stevioside-TPGS nanoparticles (CSdNPs) group. All the groups received their daily dosages orally for two months. After the end of the experiment, a blood sample was collected for estimation of the liver enzyme concentration (ALT, AST, ALP, and TSB), lipids profile (TC, TG, LDL-C, VLDL-C, and HDL-C), hematological parameters (RBCs, WBCs, Hb, and PCV, also FAS, FBG, and TyG index). Analysis was performed to assess the average change (AFC) in PPAR-α gene expression in all study groups. The results suggested that there is a significant difference in FAS (pg/mL) levels between the control group (494.2 ± 15.8) and the St or free Sd groups at the end of 2nd month (511.6 ± 16.2, and 561.7 ± 17.2), respectively. In addition the highly significant differences were registered between the Sd group in comparison with CNPs, CStNPs, and CSdNPs groups at the end of the experiment. On the other hand, the results of this study suggested that there is a significant difference in AFC between the control group (5.86 ± 0.58) and St or free Sd groups at the end of the 2nd month (3.00 ± 0.22, and 1.86 ± 0.12), respectively. In addition, highly significant differences were found between the Sd group (1.86 ± 0.12) and the CNPs, CStNPs, and CSdNPs groups at the end of the experiment (4.98 ± 0.25, 3.91 ± 0.24, and 4.02 ± 0.45). This study concluded that St and in large form Sd have harmful effects on the male liver of male rats. The newly synthesized (CStNPs and CSdNPs) should attenuate the risk of St and Sd via the activation of PPAR-α gene expression and inhibition of FAS.