## 3 Results and Discussion
### Lysozyme and Myeloperoxidase Activity  
In the present study, serum lysozyme activity in fish treated with _C. aerea_ extract significantly increased from 7 to 21 days (\(p<0.05\)) post treatment. Maximum lysozyme activity was found in the T2 group on the 28 th day after treatment compared with controls (Figure 2). Similar findings have also been reported in other studies. In one of our previous studies, treatment with methanolic extract of _C. antenmina_ significantly increased serum lysozyme level in _L. rolita_[24]. It has been reported that Fucoidan-rich seaweed (_Sargassum wightii_) extract at 2% dietary level significantly increased serum lysozyme activity in _L. rolita_[39]. Lysozyme constitute an important part of various defense molecules of  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multirow{2}{*}{**Groups**} & \multicolumn{4}{c}{**Days**} \\ \cline{3-6}  & & **0 Days** & **7 Days** & **14 Days** & **21 Days** & **28 Days** \\ \hline \multirow{4}{*}{Neutrophil Activity} & Control & 0.098 \({}^{\circ}\) \(\pm\) 0.013 & 0.134 \({}^{\mathrm{bc}}\)\(\pm\) 0.00632 & 0.156 \({}^{\mathrm{d}}\)\(\pm\) 0.00272 & 0.143 \({}^{\mathrm{c}}\)\(\pm\) 0.0034 & 0.123 \({}^{\mathrm{b}}\)\(\pm\) 0.0014 \\ \cline{2-6}  & T1 & 0.093 \({}^{\mathrm{a}}\)\(\pm\) 0.00033 & 0.185 \({}^{\mathrm{c}}\)\(\pm\) 0.0022 & 0.187 \({}^{\mathrm{c}}\)\(\pm\) 0.00323 & 0.164 \({}^{\mathrm{b}}\)\(\pm\) 0.0035 & 0.125 \({}^{\mathrm{b}}\)\(\pm\) 0.0014 \\ \cline{2-6}  & T2 & 0.096 \({}^{\mathrm{a}}\)\(\pm\) 0.0012 & 0.166 \({}^{\mathrm{b}}\)\(\pm\) 0.0023 & 0.226 \({}^{\mathrm{c}}\)\(\pm\) 0.00214 & 0.201 \({}^{\mathrm{a}}\)\(\pm\) 0.0033 & 0.143 \({}^{\mathrm{b}}\)\(\pm\) 0.00434 \\ \cline{2-6}  & T3 & 0.091 \({}^{\mathrm{a}}\)\(\pm\) 0.00134 & 0.145 \({}^{\mathrm{c}}\)\(\pm\) 0.00343 & 0.168 \({}^{\mathrm{c}}\)\(\pm\) 0.013 & 0.184 \({}^{\mathrm{b}}\)\(\pm\) 0.001854 & 0.132 \({}^{\mathrm{b}}\)\(\pm\) 0.00524 \\ \hline \multirow{4}{*}{Lysozyme Activity} & Control & 609.4 \({}^{\mathrm{c}}\)\(\pm\) 0.39 & 565.4 \({}^{\mathrm{b}}\)\(\pm\) 0.43 & 678.3 \({}^{\mathrm{d}}\)\(\pm\) 0.582 & 545.3 \({}^{\mathrm{b}}\)\(\pm\) 0.34 & 464.3 \({}^{\mathrm{a}}\)\(\pm\) 0.212 \\ \cline{2-6}  & T1 & 612.4 \({}^{\mathrm{a}}\)\(\pm\) 0.423 & 745.54 \({}^{\mathrm{b}}\)\(\pm\) 0.48 & 798.45 \({}^{\mathrm{a}}\)\(\pm\) 0.743 & 612.43 \({}^{\mathrm{a}}\)\(\pm\) 0.85 & 600.3 \({}^{\mathrm{a}}\)\(\pm\) 0.88 \\ \cline{2-6  
the immune system. They mediate resistance against the microbial attack of gram-positive bacteria [40] as well as gram-negative bacteria [41] by destroying cellular walls of bacteria. Lysoszymes split the linkages between the \(\beta\) (1\(\rightarrow\)4) linking N-acetyl muramic acid and N-acetyl glucosamine in gram-positive bacteria's cell walls. In the case of gram-negative bacteria, the lysoszymes mediate other enzymes to interrupt the outer cell wall, thus exposing the inner peptidoglycan layer [40,41]. Lysozyme also plays a role to regulate immune cell differentiation and proliferation, and stimulates phagocytic activity [42]. Methanol extracts of various herbs (i.e., _Ocimum sanctum_, _Myristica fragrans_, and _Withania somifera_ have significantly improved several immune parameters, including serum bactericidal and phagocytic activity, leukocrit and the albumin-globulin ratio, against bacterial infection induced by _Vibrio harveyi_ in larvicultured juvenile _Epinephus tauvina_, a grouper fish species [43]. It has been shown that _L. rohita_ cultured on a diet with 0.5% _Achynanthes asperna_ seeds exhibit enhanced lysozyme activity [44]. In addition, serum lysozyme activity increased significantly in rainbow trout (_Oncorhynchus mykiss_) cultured on food containing a marine algae, _Dunaliella salina_[45].