(20S)-Protopanaxatriol

Arzneimittelforschung. 2011;61(3):148-52.

Effect of 20(S)-protopanaxatriol and its epimeric derivatives on myocardial injury induced by isoproterenol.[Pubmed: 21528638]

It was reported Panax ginseng had diverse components and multifaceted pharmacological functions. This study aims to investigate the effect of (20S)-Protopanaxatriol (PT, CAS 179799-20-3) and its epimeric derivatives (20S, 24R-epoxy-dammarane-3beta, 6alpha, 12beta, 25-tetraol, PTD1 and 20S, 24S-epoxy-dammarane-3beta, 6alpha, 12beta, 25-tetraol, PTD2) on myocardial injury induced by isoproterenol in rats.
METHODS AND RESULTS:
Male Wistar rats were administered orally 20(S)-protopanaxatriol or its epimeric derivatives for 7 days. Four days after treatment, all rats, except those in the control group, were subcutaneously injected with isoproterenol (20 mg/kg) for 3 consecutive days. Two hours after the last isoproterenol injection, the rats were anaesthetized and sacrificed. The biochemical parameters were assayed and pathological examination of the heart tissues was performed. Administration of PT and PTD1 resulted in a reduction in creatine kinase and lactate dehydrogenase. PT and PTD1 Inhibited not only the elevation of malondialdehyde content, but also the reduction of superoxide dismutase activity, glutathione peroxidase and total antioxIdant capacity. The pathohistological changes induced by isoproterenol were also ameliorated by PT and PTD1.
CONCLUSIONS:
The present findings suggest that PT and PTD1 exerted cardioprotective effects against myocardial ischemic injury by enhancing the anti-free-radical actions of heart tissues. Furthermore the results indicated that the configuration of C-24 of the funan ring was involved in the phannacological action of the epimeric derivatives of 20(S)-protopanaxatriol.

J Exp Clin Cancer Res . 2019 Mar 15;38(1):129.

Co-administration of 20(S)-protopanaxatriol (g-PPT) and EGFR-TKI overcomes EGFR-TKI resistance by decreasing SCD1 induced lipid accumulation in non-small cell lung cancer[Pubmed: 30876460]

Abstract Background: Non-small cell lung cancer (NSCLC) patients with sensitive epidermal growth factor receptor (EGFR) mutations are successfully treated with EGFR tyrosine kinase inhibitors (EGFR-TKIs); however, resistance to treatment inevitably occurs. Given lipid metabolic reprogramming is widely known as a hallmark of cancer and intimately linked with EGFR-stimulated cancer growth. Activation of EGFR signal pathway increased monounsaturated fatty acids (MUFA) and lipid metabolism key enzyme Stearoyl-CoA Desaturase 1 (SCD1) expression. However the correlation between EGFR-TKI resistance and lipid metabolism remains to be determined. Methods: In this study the differences in lipid synthesis between paired TKI-sensitive and TKI-resistant patient tissues and NSCLC cell lines were explored. Oleic acid (OA, a kind of MUFA, the SCD1 enzymatic product) was used to simulate a high lipid metabolic environment and detected the affection on the cytotoxic effect of TKIs (Gefitinib and osimertinib) in cell lines with EGFR-activating mutations. (20S)-Protopanaxatriol (g-PPT), an aglycone of ginsenosides, has been reported to be an effective lipid metabolism inhibitor, was used to inhibit lipid metabolism. Additionally, synergism in cytotoxic effects and signal pathway activation were evaluated using CCK-8 assays, Western blotting, flow cytometry, Edu assays, plate clone formation assays and immunofluorescence. Furthermore, two xenograft mouse models were used to verify the in vitro results. Results: Gefitinib-resistant cells have higher lipid droplet content and SCD1 expression than Gefitinib-sensitive cells in both NSCLC cell lines and patient tissues. Additionally oleic acid (OA, a kind of MUFA, the SCD1 enzymatic product) abrogates the cytotoxic effect of both Gefitinib and osimertinib in cell lines with EGFR-activating mutations. As a reported effective lipid metabolism inhibitor, g-PPT significantly inhibited the expression of SCD1 in lung adenocarcinoma cells, and then down-regulated the content of intracellular lipid droplets. Combined treatment with Gefitinib and g-PPT reverses the resistance to Gefitinib and inhibits the activation of p-EGFR and the downstream signaling pathways. Conclusions: Our findings uncover a link between lipid metabolic reprogramming and EGFR-TKI resistance, confirmed that combination target both EGFR and abnormal lipid metabolism maybe a promising therapy for EGFR-TKI resistance and highlighting the possibility of monitoring lipid accumulation in tumors for predicting drug resistance. Keywords: EGFR-TKI resistance; Lipid droplet; Lipid metabolism; NSCLC; Oleic acid; SCD1.

Int J Mol Sci . 2018 Apr 2;19(4):1053.

20(S)-Protopanaxadiol-Induced Apoptosis in MCF-7 Breast Cancer Cell Line through the Inhibition of PI3K/AKT/mTOR Signaling Pathway[Pubmed: 29614812]

Abstract 20(S)-Protopanaxadiol (PPD) is one of the major active metabolites of ginseng. It has been reported that 20(S)-PPD shows a broad spectrum of antitumor effects. Our research study aims were to investigate whether apoptosis of human breast cancer MCF-7 cells could be induced by 20(S)-PPD by targeting the Phosphatidylinositol 3-kinase/Protein kinase B/Mammalian target of rapamycin (PI3K/AKT/mTOR) signal pathway in vitro and in vivo. Cell cycle analysis was performed by Propidium Iodide (PI) staining. To overexpress and knock down the expression of mTOR, pcDNA3.1-mTOR and mTOR small interfering RNA (siRNA) transient transfection assays were used, respectively. Cell viability and apoptosis were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-test and Annexin V /PI double-staining after transfection. The antitumor effect in vivo was determined by the nude mice xenograft assay. After 24 h of incubation, treatment with 20(S)-PPD could upregulate phosphorylated-Phosphatase and tensin homologue deleted on chromosome 10 (p-PTEN) expression and downregulate PI3K/AKT/mTOR-pathway protein expression. Moreover, G0/G1 cell cycle arrest in MCF-7 cells could be induced by 20(S)-PPD treatment at high concentrations. Furthermore, overexpression or knockdown of mTOR could inhibit or promote the apoptotic effects of 20(S)-PPD. In addition, tumor volumes were partially reduced by 20(S)-PPD at 100 mg/kg in a MCF-7 xenograft model. Immunohistochemical staining indicated a close relationship between the inhibition of tumor growth and the PI3K/AKT/mTOR signal pathway. PI3K/AKT/mTOR pathway-mediated apoptosis may be one of the potential mechanisms of 20(S)-PPD treatment. Keywords: 20(S)-Protopanaxadiol; MCF-7; PI3K/AKT/mTOR; apoptosis.

J Pharm Biomed Anal. 2014 Jan;88:497-508.

Identification of 20(S)-protopanaxatriol metabolites in rats by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry and nuclear magnetic resonance spectroscopy.[Pubmed: 24184656]

(20S)-Protopanaxatriol (PPT), one of the aglycones of ginsenosides, has been shown to exert cardioprotective effects against myocardial ischemic injury. However, studies on PPT metabolism have rarely been reported.
METHODS AND RESULTS:
This study is the first to investigate the in vivo metabolism of PPT following oral administration by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS) and nuclear magnetic resonance (NMR) spectroscopy. The structures of the metabolites were identified based on the characteristics of their MS data, MS(2) data, and chromatographic retention times. A total of 22 metabolites, including 17 phase I and 5 phase II metabolites, were found and tentatively identified by comparing their mass spectrometry profiles with those of PPT. Two new monooxygenation metabolites, (20S,24S)-epoxy-dammarane-3,6,12,25-tetraol and (20S,24R)-epoxy-dammarane-3,6,12,25-tetraol, were chemicallly synthesized and unambiguously characterized according to the NMR spectroscopic data. The metabolic pathways of PPT were proposed accordingly for the first time. Results revealed that oxidation of (1) double bonds at Δ((24,25)) to form 24,25-epoxides, followed by rearrangement to yield 20,24-oxide forms; and (2) vinyl-methyl at C-26/27 to form corresponding carboxylic acid were the predominant metabolic pathways. Phase II metabolic pathways were proven for the first time to consist of glucuronidation and cysteine conjugation.
CONCLUSIONS:
This study provides valuable and new information on the metabolism of PPT, which is indispensable for understanding the safety and efficacy of PPT, as well as its corresponding ginsenosides.