ABSTRACT
In this study, we investigated the anti-osteoporotic activity and mechanism of action of extract of Panax quiquefolium L. based on zebrafish model combined with metabolomics technology. A zebrafish model of prednisolone-induced osteoporosis was used to compare the anti-osteoporotic activity of Panax quiquefolium L., and the expression of osteoblast-associated genes and osteoclast-associated genes in zebrafish was detected by quantitative real-time PCR (qRT-PCR), using bone fluorescence area and fluorescence density as evaluation indexes. Metabolomics based on ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) was used to explore the change patterns of biomarkers and the metabolic pathways affected. The results showed that the 50% ethanol extracts of Panax quiquefolium L. from Jilin, Canada, Wenden and the United States can significantly improve the bone fluorescence area of zebrafish compared with model group. Furthermore, four sources 50% ethanol extracts of Panax quiquefolium L. except United States also can significantly improve the bone fluorescence density of zebrafish. In addition, PCR showed that extract of Panax quiquefolium L. can significantly up-regulated the expression of vitamin D receptor b (vdrb), collagen type I α2 (col1a2) and cysteine-rich acidic secreted protein (sparc) genes, and down-regulated the expression of matrix metalloproteinase 9 (mmp9), anti-tartrase acid phosphatase (trap) and cathepsin K (ctsk) genes. Metabolomic analysis identified 24 key differential metabolites. Furthermore, pathway analysis showed that Panax quiquefolium L. could regulate the levels of 10 key biomarkers by participating in purine metabolism, tricarboxylic acid cycle and pentose phosphate metabolism and improve the osteoporosis status of zebrafish. This study preliminically revealed the anti-osteoporosis mechanism of 50% ethanol extract from Panax quiquefolium L. through multi-component, multi-target and multi-pathway and also provides theoretical basis for clinical development and utilization of anti-osteoporosis products of Panax quiquefolium L. This experiment was approved by the Experimental Animal Welfare Ethics Committee of the Institute of Biology, Shandong Academy of Sciences (approval number: SWS20181002).
ABSTRACT
The present study observed the regulatory effect of total flavonoids of Ziziphora clinopodioides on autophagy and the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)/mammalian target of rapamycin(mTOR) signaling pathways in ApoE~(-/-) mice and explored the mechanism of total flavonoids of Z. clinopodioides against atherosclerosis(AS). ApoE~(-/-) mice were fed on a high-fat diet for eight weeks to induce an AS model. The model mice were randomly divided into a model group, a positive control group, and low-, medium-and high-dose groups of total flavonoids of Z. clinopodioides, while C57BL/6J mice fed on a common diet were assigned to the blank group. The serum and aorta samples were collected after intragastric administration for 12 weeks, and the serum levels of total cholesterol(TC), triglyceride(TG), low density lipoprotein-cholesterol(LDL-C), and high density lipoprotein-cholesterol(HDL-C) were detected by an automatic biochemical analyzer. The serum expression levels of intercellular adhesion molecule-1(ICAM-1), vascular cell adhesion molecule-1(VCAM-1), matrix metalloproteinase-2(MMP-2), and matrix metalloprotei-nase-9(MMP-9) were detected by enzyme-linked immunosorbent assay(ELISA). Oil red O staining was used to observe the aortic plaque area in mice. Hematoxylin-eosin(HE) staining was used to observe the aortic plaque and pathological changes in mice. The expression of P62 and LC3 in the aorta was detected by the immunofluorescence method. The protein expression of LC3Ⅱ/Ⅰ, Beclin-1, P62, p-PI3K, p-Akt, and p-mTOR in the aorta of mice was detected by Western blot. The results showed that compared with the blank group, the serum levels of TC, TG, LDL-C, ICAM-1, VCAM-1, MMP-2 and MMP-9 in the model group were significantly increased(P<0.01 or P<0.05), the content of HDL-C was decreased(P<0.05), intra-aortic plaque area was enlarged(P<0.01), the expression of LC3 in the aorta was significantly down-regulated, P62 expression was up-regulated(P<0.01 or P<0.05), the expressions of LC3Ⅱ/Ⅰ and Beclin-1 in the aortic lysate were significantly down-regulated, and the expressions of p-PI3K, p-Akt, p-mTOR and P62 were significantly increased(P<0.01). The medium-and high-dose groups of total flavonoids of Z. clinopodioides could reduce the serum levels of TC, TG, LDL-C, ICAM-1, VCAM-1, MMP-2, and MMP-9 in AS model mice(P<0.01 or P<0.05), and increase the content of HDL-C(P<0.01 or P<0.05). The aortic plaque area of mice after middle and high doses of total flavonoids of Z. clinopodioides was significantly reduced(P<0.01), the content of foam cells decrease, and the narrowing of the lumen decreased. The total flavonoids of Z. clinopodioides significantly increased the expression of LC3 in the aorta and the expression of LC3Ⅱ/Ⅰ and Beclin-1 in the lysate, and decreased the expression of P62 in the aorta and the expression of p-PI3K, p-Akt, p-mTOR and P62 in the lysate(P<0.01 or P<0.05). The results showed that the total flavonoids of Z. clinopodioides could improve the content of blood lipids and inflammatory factors, and reduce the generation of foam cells and plaques in aortic tissue, and the mechanism may be related to the regulation of PI3K/Akt/mTOR signaling pathway.