The levels of cAMP, cGMP, and cAMP/cGMP in serum. (a) cAMP, df = 59, F = 5.88. Compared with the normal group, the serum cAMP of the model group was lower. Compared with the model group, the serum cAMP of the high dose, middle dose, and positive group was higher. (b) cGMP, df = 59, F = 8.951. Compared with the normal group, the cGMP content of the model group was higher. Compared with the model group, the cGMP content of the high dose group, the middle dose group, and the positive group was lower (c) cAMP/cGMP, df = 59, F = 8.067. Compared with the normal group, the cAMP/cGMP of the model group was lower. Compared with the model group, the serum cAMP/cGMP of the high dose group, the middle dose group, the low dose group, and the positive group was higher. ELISA was performed according to the manufacturer's protocol. The data of each group were expressed as mean ± standard deviation (SD). ##P < 0.01 and #P < 0.05 versus normal group; ∗∗P < 0.01 and ∗P < 0.05 versus model group. NG: normal group, MG: model group, HDG: high dose group, MDG: middle dose group, LDG: low dose group, PG: positive group.