Abstract:

To investigate the protective effect of low molecular weight chitosan (LMWC) against cadmium-induced
toxicological activity, the freshwater crab Sinopotamon henanense was challenged with LMWC (20, 40 mg/L and 80 mg/L) and
or cadmium (29, 58 mg/L and 87 mg/L). Cadmium accumulation, superoxide dismutase (SOD) activity, malondialdehyde
(MDA) content, glutathione S-transferase (GST) activity and glutathione (GSH) content were measured in hepatopancreas
of S. henanense. The results showed that Cd2+ (58 mg/L) significantly decreased SOD activity and increased MDA
content in hepatopancreas of the crabs compared to the control group (P ＜ 0.05), whereas LMWC did not change SOD
activity and MDA content in hepatopancreas. Also, there was an apparent accumulation of Cd2+ in hepatopancreas, which
was lessened in the presence of LMWC in a concentration-dependent manner. In addition, Cd2+ significantly decreased
the hepatopancreas GST activity and GSH content in the crabs relative to the control (P ＜ 0.05). Co-treatment with
LMWC enhanced the GST activity and GSH content in hepatopancreas tissues compare with the crabs exposed to Cd2+
alone. According to these results, it can be concluded that LMWC has protective function against the adverse influence of
cadmium on Sinopotamon henanense.

Key words: Sinopotamon henanense, low molecular weight chitosan, malondialdehyde, superoxide dismutase, glutathione S-transferase, glutathione, cadmium