Anti-senescence effects of Rhodiola crenulate extracts on LO2 cells and bioactive compounds.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhodiola crenulata (Rc) is a traditional herb, used in Tibetan medicine, has shown promise efficacy in physical performance improvement, work capacity enhancement, fatigue elimination, and altitude sickness prevention. Also, Rc exhibited therapeutic effects on aging-related diseases. However, relevant researches on Rc and their bioactive components are quite few and needs further investigation. AIM OF THE STUDY: The objective of this study was to understand the relationship between phytochemical profiles and their activities of Rc extracts. MATERIALS AND METHODS: Rc extracts prepared by solvents with various hydrophilicity (i.e. aqueous ethanol (70%, v/v), water, and ethyl acetate), and their chemical compositions and specific compounds were analyzed by chemical analysis method and ultra-performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-QTOF-MS). The regulate effects of Rc extracts on senescence and antioxidant activity were evaluated using the models of LO2 cells and Caenorhabditis elegans. RESULTS: The 70% ethanol extracts exhibited better regulating effects on senescence via the assays of senescence -associated ß-galactosidase (SAßG) staining and lifespan, which was consistent with the higher antioxidant activities observed based on the results of antioxidant assays. A total of 14 phytochemicals have been identified in 70% ethanol extracts, whereas the other two extracts contained much fewer compounds in varieties. Phytochemical profile of water extract was similar to the first half (polar compounds, running time: 0-6 min) of 70% ethanol extract profile, while those of ethyl acetate extract was consistent with its second half (more nonpolar compounds, running time: 6-12 min). CONCLUSIONS: The 14 phytochemicals in Rc might exhibit additive or synergistic effects on senescence regulating and antioxidant activities, providing theoretical basis for daily administration of Rc.

[Effect of fertilization combinations of nitrogen, phosphorus, and potassium on four phenolic compounds of cultivated Rhodiola crenulata].

This study is aimed to explore the effect of nitrogen, phosphorus and potassium combined application on the active components of Rhodiola crenulata. R. crenulata was used as the research object, "3414" fertilization experiment were conducted with regular fertilization of NPK(N 60 kg·hm⁻², P2O5 100 kg·hm⁻²,KCl 160 kg·hm⁻²) to study the effect of different rates of NPK fertilization on the total amount of 4 phenolic constituents of gallic acid, salidroside, tyrol and ethyl gallate through field test. The results show that the content of salidroside was higher in the treatment of N1P2K1 and N1P2K2, andthe total amount of four phenols was higher in the treatment of N1P2K2 and N2P2K2. The suitable level of nitrogen, phosphorus and potassium promoted the accumulation of the 4 kinds of phenols.The amount of fertilizer recommended by the three factor fertilizer effect equation,(N 0 kg·hm⁻²,P2O5 150 kg·hm⁻²,KCl 31.71 kg·hm⁻²) obtained the highest content of salidroside, and it was 1.54%.（N 35.54 kg·hm⁻²,P2O5 150 kg·hm⁻²,KCl 237.73 kg·hm⁻²ï¼‰obtained the highest content of 4 kinds of phenolic compounds, and it was 1.93%. This study provides a reference for the standardization of artificial planting of endangered Tibetan medicine.