ABSTRACT
ObjectiveThe law of fertilizer requirement serves as the basis for the fertilization of medicinal plants， development of special fertilizer， and high-quality medicinal materials. MethodThis study aims to explore the optimal potassium application rate for Panax ginseng to achieve high yield and quality of the medicinal material and targeted management of potassium fertilizer. To be specific， 6 concentration gradients （0， 2， 4， 8， 10， and 12 mmol·L-1） of potassium sulfate （potassium fertilizer） were designed and applied to the 4-year-old P. ginseng in CK， C1， C2， C3， C4， and C5 treatments， respectively. Thereby， the influence of potassium concentration on P. ginseng was observed. ResultWhen potassium sulfate was applied at 8 mmol·L-1， P. ginseng had the chlorophyll content of 32.13%， net photosynthetic rate of 2.548 8 µmol·m-2·s-1， and activities of superoxide dismutase （SOD）， peroxidase （POD）， and catalase （CAT） significantly higher than those in the CK， C1， C4， and C5 treatments （P<0.05）. The average fresh weight of P. ginseng roots was 6.25 g， 134% up from the CK， and the content of ginsenoside Rg1 （5.24 mg·g-1） and Re （4.17 mg·g-1） and total saponins （12.33 mg·g-1） was significantly higher than that in CK and other treatments （P<0.05）. Thus， 8 mmol·L-1 potassium sulfate was most favorable for the growth and effective component accumulation of four-year-old P. ginseng. ConclusionThis study expounds the effect of potassium fertilizer on the yield and quality of P. ginseng， which is expected to help guide the precise application of potassium fertilizer in P. ginseng production in the field and lay a theoretical basis for the development of special fertilizer for P. ginseng and the optimization of fertilization technology.
ABSTRACT
The obstacle to successful remyelination in demyelinating diseases, such as multiple sclerosis, mainly lies in the inability of oligodendrocyte precursor cells (OPCs) to differentiate, since OPCs and oligodendrocyte-lineage cells that are unable to fully differentiate are found in the areas of demyelination. Thus, promoting the differentiation of OPCs is vital for the treatment of demyelinating diseases. Shikimic acid (SA) is mainly derived from star anise, and is reported to have anti-influenza, anti-oxidation, and anti-tumor effects. In the present study, we found that SA significantly promoted the differentiation of cultured rat OPCs without affecting their proliferation and apoptosis. In mice, SA exerted therapeutic effects on experimental autoimmune encephalomyelitis (EAE), such as alleviating clinical EAE scores, inhibiting inflammation, and reducing demyelination in the CNS. SA also promoted the differentiation of OPCs as well as their remyelination after lysolecithin-induced demyelination. Furthermore, we showed that the promotion effect of SA on OPC differentiation was associated with the up-regulation of phosphorylated mTOR. Taken together, our results demonstrated that SA could act as a potential drug candidate for the treatment of demyelinating diseases.