Corresponding detection kit

After 10 days of hemp growth, seedlings of uniform growth were selected for four different treatments: (1) control treatment for 4 days (nutrient solution only); (2) cadmium stress treatment for 4 days (nutrient solution containing 100 µmol/LCdCl2); (3) proanthocyanidin treatment for 4 days (nutrient solution containing 50 mg/L proanthocyanidin concentration); (4) proanthocyanidin pretreatment for 12 h (same treatment as step 3), followed by cadmium treatment for 4 days (same treatment as step 2). Six biological replicates were set up for each group, and plants of uniform growth were selected for subsequent trials.
To conduct the GSH and SOD assay methods, a homogenate (10%) was prepared as follows. Plant tissue assay site tissue was weighed (g), combined with PBS (phosphate-buffered saline) buffer (mL; 1:9), and homogenized. The homogenate was centrifuged and the supernatant was taken for use in the assay. An equal volume of precipitant from a kit was added to the supernatant, mixed well, and centrifuged. The supernatant was used as the sample to be tested. GSH and SOD were detected according to the instructions using the corresponding detection kit (Nanjing Jiancheng Bioengineering Institute, Nanjing, China), and the GSH and SOD contents were quantified colorimetrically at 405 nm.

The blood samples were collected by using a vacuum collection tube and immediately frozen and transported to the laboratory. Then, the blood samples were centrifuged (−4°C, 3000 rpm, 10 min) to obtain plasma. In addition, the tissue was weighed and washed with 0.9% NaCl. Subsequently, plasma and tissue samples were stored at −80°C. According to corresponding detection kit (Jiancheng Bioengineering Institute, Nanjing, China), Malondialdehyde (MDA), total antioxidant capacity (T-AOC) and glutathione (GSH) were detected to test for the levels of oxidative stress. In addition, the remainder of the kidney was stored in formalin for histological evaluation.

Hemocyanin concentrations were determined by a UV-Spectrophotometric (Beijing Purkinje General Instrument Co., Ltd) at 335 nm with 10 μL of serum diluted in 990 μL distilled water in a quartz cuvette, manually calibrated with distilled water. Hemocyanin concentrations (mmol/L) = 2.69 E (1%, 1 cm) mmol/L (35 (link)).
The acid phosphatase (ACP), alkaline phosphatase (ALP) were measured by a UV-spectrophotometer (Beijing Purkinje General Instrument Co., Ltd) at 520 nm with corresponding detection kits (Nanjing Jiancheng Bioengineering Institute, Nanjing, China) according to the manufacturer's protocols.