## 2 Results and Discussion
### Effect of Administration
#### 2.2.3 Influence on Antioxidant Biomarkers  
Enzymes  
Antioxidants can act by ROS scavenging or inhibiting lipid peroxidation. Endogenous antioxidant enzymes such as SOD, GPx and CAT provide protection against ROS. Among marine algae, the Sargassaceae family has been found to exhibit the highest radical scavenging activity [29]. In the present study, we determined the activities of the antioxidant enzymes SOD, GPx and CAT in liver and red blood cells of the rats in relation to administration of the _S. muticum_ extract. The total amount of lipid peroxidation products was assayed by quantifying thiobarbituric acid reactive substances (TBARS), which are often used as oxidation markers. Data in Table 3 summarize the influence of the extract on the lipid peroxidation and antioxidant enzymes. Results indicate a significant reduction of 62.68% in liver GPx (U-mg\({}^{-1}\) prot.) and of 45.27% in TBARS levels for the SmE fed rats at 0.5 and 1 g Kg\({}^{-1}\), respectively, but no effect was shown on SOD activity in either liver or erythrocytes. In a similar study, erythrocyte TBARS levels of diabetic patients supplemented with seaweeds were lower than in controls; catalase and GSH-Px activities were higher in the treated group than in controls, but SOD was not affected by the seaweed supplement [27]. Catalase affects cellular resistance to toxicity induced by hydrogen peroxide and it is responsible for eliminating H\({}_{2}\)O\({}_{2}\). The ROS scavenging activity of SOD is therefore consistent with the action of CAT because SOD generates H\({}_{2}\)O\({}_{2}\), which must be scavenged by CAT [24; 30]. However, significant variations in catalase activity were not observed in either liver or erythrocytes of rats administered the _Sargassum_ extracts. The antioxidant effects of diverse substances may be particularly low under conditions of stress, but possibly do not have any effect under conditions of no stress. \begin{table}
\begin{tabular}{l c c c c} \hline
**Serum Parameters** & **Control** & **0.5 g kg\({}^{-1}\)** & **1 g kg\({}^{-1}\)** & **2 g kg\({}^{-1}\)** \\ \hline CHO total (mg dL\({}^{-1}\)) & 121.50 \(\pm\) 3.96 & 118.17 \(\pm\) 3.24 & 118.50 \(\pm\) 5.36 & 114.83 \(\pm\) 2.96 \\ HDL (mg dL\({}^{-1}\)) & 49.50 \(\pm\) 1.30 & 48.80 \(\pm\) 1.53 & 48.10 \(\pm\) 2.09 & 45.33 \(\pm\) 1.15 \\ LDL (mg dL\({}^{-1}\)) & 51.70 \(\pm\) 2.94 & 50.70 \(\pm\) 1.71 & 45.08 \(\pm\) 2.27 & 46.43 \(\pm\) 2.14 \\ Triglycerides (mg dL\({}^{-1}\)) & 105.75 \(\pm\) 6.21 & 98.23 \(\pm\) 6.23 & 86.50 \(\pm\) 5.70 & 97.17 \(\pm\) 8.19 \\ BUN (mg dL\({}^{-1}\)) & 11.25 \(\pm\) 0.34 & 11.33 \(\pm\) 0.76 & 13.00 \(\pm\) 0.71 & 12.00 \(\pm\) 0.95 \\ Total protein (g dL\({}^{-1}\)) & 5.40 \(\pm\) 0.05 & 5.57 \(\pm\) 0.08 & 5.50 \(\pm\) 0.11 & 5.37 \(\pm\) 0.09 \\ Albumin (g dL\({}^{-1}\)) & 4.15 \(\pm\) 0.058 & 4.30 \(\pm\) 0.05 & 4.13 \(\pm\) 0.12 & 4.13 \(\pm\) 0.03 \\ GOT (UI L\({}^{-1}\)) & 127.50 \(\pm\) 8.14 & 157.83 \(\pm\) 11.46 & 167.50 \(\pm\) 24.46 & 164.67 \(\pm\) 19.81 \\ GPT (UI L\({}^{-1}\)) & 23.25 \(\pm\) 2.28 & 21.83 \(\pm\) 4.00 & 26.00 \(\pm\) 1.71 & 29.00 \(\pm\) 3.97 \\ Glucose (mg dL\({}^{-1}\)) & 100.80 \(\pm\) 3.28 & 95.83 \(\pm\) 3.06 & 90.78 \(\pm\) 2.76 & 82.40 \(\pm\) 2.55 \\ \hline \end{tabular}  
* Serum parameter abbreviations: CHO, total cholesterol; HDL, high density lipoprotein cholesterol; LDL, low density lipoprotein cholesterol; BUN, blood urea nitrogen; GOT, glutamic oxaloacetic transaminase; GPT, glutamic pyruvic transaminase.  
\end{table} 
Table 2: Serum parameters in control rats and _Sargassum muticum_ extract treated groups. Values are mean \(\pm\) SEM. Number of animals per group = 6.