Mitigating cadmium accumulation in dicotyledonous vegetables by iron fertilizer through inhibiting Fe transporter IRT1-mediated Cd uptake.

The solubility of cadmium (Cd) in soil and its transfer to plants are influenced by soil pH. While increasing soil pH reduces Cd solubility and accumulation in rice plants grown in acidic soils, its effect on Cd accumulation in vegetables remains inconclusive. Here, we investigated the impact of soil pH on Cd accumulation in dicotyledonous vegetables and elucidated the underlying molecular mechanisms. Soils collected from various locations were supplemented with varying quantities of lime to achieve soil pH values of around 5.0, 6.0, 7.0, and 8.0. Raising soil pH from around 5.0 to 8.0 markedly decreased extractable Cd. However, increasing soil pH tended to promote shoot Cd accumulation in dicotyledonous vegetable species including lettuce, pakchoi, and Chinese cabbage, and the model dicotyledonous plant Arabidopsis thaliana. Conversely, soil pH increase resulted in a monotonic decrease in rice Cd accumulation. In our hydroponic experiments, we discovered that iron (Fe) deficiency substantially increased Cd uptake and accumulation in dicotyledonous plants but not in rice. Increasing soil pH reduced soil Fe availability and induced the Fe transporter gene IRT1 expression in dicotyledonous vegetables roots, which led to an increase in IRT1-mediated Cd uptake and subsequently increased Cd accumulation as soil pH increases. A comprehensive model incorporating extractable Cd and root IRT1 expression better explained Cd accumulation in vegetable shoots. The application of 50 mg/kg of Fe fertilizer in neutral or alkaline soils resulted in a significant reduction in Cd accumulation by 34-58% in dicotyledonous vegetables. These findings reveal that increasing soil pH has two opposite effects, decreasing soil Cd availability while promoting Cd uptake through IRT1 upregulation, reconciling the inconsistency in its effect on Cd accumulation in dicotyledonous plants. Our findings provide important insights for understanding the factors affecting Cd uptake in plants and offer a practical solution to mitigate Cd contamination in vegetables.

Chemical composition, properties, and antimicrobial activity of the water-soluble pigments from Castanea mollissima shells.

Agricultural residues Castanea mollissima shells represent a promising resource for natural pigments for the food industry. This study provides a comprehensive and systematic evaluation of water-soluble pigments (CSP) from C. mollissima shells, which were obtained by 50% ethanol with microwave-assisted extraction. Spectroscopic techniques (UV, FT-IR, (13)C NMR), elemental analysis, and chromatographic techniques (HPAEC, GPC) revealed that the main components in the CSP were flavonoids procyanidin B3 (condensed tannin), quercetin-3-O-glycoside, and steroidal sapogenins. As a consequence, CSP was water-soluble and presented significant DPPH scavenge capacity (EC50 value was 0.057 mg/mL). Specially, CSP gave excellent antibacterial activity, and even better than 5% aqueous phenol in some case. Moreover, CSP was practically nontoxic and exhibited good stability with temperature, natural light, and metal ions. These outstanding properties will enlarge the application of CSP for natural food additives production.

[Effect of Danshen root compound on blood lipid and bone biomechanics in mice with hyperlipemia-induced osteoporosis].

OBJECTIVE: To observe the effects of Danshen root compound (DSC) on blood lipid and bone biomechanics in mice with hyperlipemia-induced osteoporosis. METHODS: Forty Kunming mice were randomized into 5 equal groups, and were given intragastric administration with distilled water (control), lipid emulsion (LE) at the daily dose of 5 ml/kg, LE plus simvastatin, LE plus DSC at 5.0 g/kg (DSC-L group), and LE plus DSC at 10.0 g/kg (DSC-H group), respectively. Serum TC, TG, and HDL-c levels and left femur hydroxyproline, calcium and phosphate contents were measured in the rats, with the right femur taken for bone biomechanical test. RESULTS: Compared with those in the control group, serum TC, LDL-c and AI of the mice increased and HDL-c, Hyp and bone calcium decreased significantly (P<0.01) with lowered bone biomechanical properties. Compared with those of the LE model group, AI decreased and HDL-c increased significantly in DSC-L and DSC-H groups (P<0.01), and the bone biomechanics in DSC-H group was improved. CONCLUSION: Long-term intragastric administration of lipid emulsion causes lipid metabolic disorder and induces osteoporosis due to hyperlipemia in mice. DSC can significantly increase HDL-c and partially prevent the occurrence of osteoporosis in mice.

[Effect of a compound Danshen preparation in preventing long-term gastric lipid emulsion administration-induced nonalcoholic steatohepatitis in rats].

OBJECTIVE: To investigate the preventive effects of a compound Danshen preparation (DSC) on long-term gastric lipid emulsion administration-induced nonalcoholic steatohepatitis in rats. METHODS: Twenty-seven 3-month-old SD rats were randomized equally into 3 groups and subjected to daily intragastric administration for 20 weeks of distilled water (control), lipid emulsion at 5 ml/kg (model group), and lipid emulsion plus DSC at 5.0 g/kg (DSC treatment group). After blood glucose (BG) determination, the rats were sacrificed for measurement of serum TC, TG, HDL-c, AST, and ALT, and the liver was weighed and pathologically examined. RESULTS: Compared with the control group, the rats in the model group showed significantly increased BG, TC, LDL-c, arteriosclerosis index (AI), AST, ALT, liver weight, and liver index (P<0.01) and decreased HDL-c (P<0.01), while TG remained unchanged. Fatty degeneration, hydropic degeneration and necrosis with inflammatory cell infiltration were observed in the liver of the rats in the model group. Compared with the model group, the rats in DSC groups showed decreased BG, AI (P<0.01), liver weight, liver index, AST, and ALT (P<0.05) and increased HDL-c, with milder pathological changes in the liver. CONCLUSIONS: Long-term gastric perfusion of lipid emulsion causes lipid metabolic disorder and nonalcoholic fatty liver disease in rats characterized by increased TC and decreased HDL-c. DSC can significantly increase HDL-c and provide partial protection of the liver against the damages by the lipid emulsion.