Optimizing the Extraction and Enrichment of Luteolin from Patrinia villosa and Its Anti-Pseudorabies Virus Activity.

Luteolin from Patrinia villosa exhibits strong antiviral activity. Here, the conditions for extracting and enriching luteolin from P. villosa were optimized. Response surface methodology was used to determine the optimal extraction parameters in terms of reflux time, solvent ratio, extraction temperature, material-to-liquid ratio, and number of extractions. Thereafter, a macroporous resin method was used to enrich luteolin from P. villosa. Finally, the following optimal extraction and enrichment conditions were established: an extraction time of 43.00 min, a methanol/hydrochloric acid solvent ratio of 13:1, an extraction temperature of 77.60 °C, a material/liquid ratio of 1:22, and a total of two extractions. NKA-9 was determined to be the most appropriate resin for enrichment. The ideal adsorption conditions were as follows: a pH of 5.0, a temperature of 25 °C, an initial luteolin concentration of 19.58 µg/mL, a sample loading volume of 2.9 BV, and a sample loading rate of 2 BV/h. The ideal desorption conditions were as follows: distilled water, 30% ethanol and 80% ethanol elution, and 5 BV at a flow rate of 2 BV/h. After optimization, the enrichment recovery rate was 80.06% and the luteolin content increased 3.8-fold. Additionally, the enriched product exhibited a significant inhibitory effect on PRV (Porcine pseudorabies virus) in vitro and in vivo, providing data for developing and applying luteolin from P. villosa.

Comparison of Cd subcellular distribution and Cd detoxification between low/high Cd-accumulative rice cultivars and sea rice.

Salt-tolerant rice cultivar (sea rice) is a research hotspot worldwide due to its high yield in high salinity soil. However, knowledge regarding the cadmium (Cd) effects on the growth of sea rice is limited. To determine the short-term and long-term impact of Cd stress, relatively low/high Cd-accumulative rice cultivars and sea rice were grown to compare their growth responses to Cd stress over time. The results showed that sea rice presented the highest Cd concentrations in the root, stem, and leaves under 32-days of Cd stress. Cd stress shortened and thickened the rice root, and decreased the proportion of root diameters in the 0-0.2 mm range. Cd stress remarkably increased the Cd and Fe concentration in dithionite-citrate-bicarbonate (DCB) extracts, and the DCB-Cd and DCB-Fe concentrations were the highest in sea rice. The subcellular distribution of Cd in the rice roots indicated that Cd accumulated the most in the soluble fraction and cell wall. The contents of pectin and hemicellulose 2 in the root cell wall of the low-Cd accumulative rice variety CL755 were higher than those in MXZ and sea rice. Collectively, this work provides a general understanding of the Cd effects on sea rice growth and indicates that sea rice has a relatively high Cd accumulation compared with the other two rice cultivars. However, the specifically-related mechanism remains to be further studied.