Cycloastragenol protects against glucocorticoid-induced osteogenic differentiation inhibition by activating telomerase.

Glucocorticoid-induced osteoporosis (GIOP) that is mainly featured as low bone density and increased risk of fracture is prone to occur with the administration of excessive glucocorticoids. Cycloastragenol (CAG) has been verified to be a small molecule that activates telomerase. Studied showed that up-regulated telomerase was associated with promoting osteogeneic differentiation, so we explored whether CAG could promote osteogenic differentiation to protect against GIOP and telomerase would be the target that CAG exerted its function. Our results demonstrated that CAG prominently increased the ALP activity, mineralization, mRNA of runt-related transcription factor 2, osteocalcin, osteopontin, collagen type I in both MC3T3-E1 cells and dexamethasone (DEX)-treated MC3T3-E1 cells. CAG up-regulated telomerase reverse transcriptase and the protective effect of CAG was blocked by telomerase inhibitor TMPyP4. Moreover, CAG improved bone mineralization in DEX-induced bone damage in a zebrafish larvea model. Therefore, the study showed that CAG could alleviate the osteogenic differentiation inhibition induced by DEX in vitro and in vivo, and CAG might be considered as a candidate drug for the treatment of GIOP.

Dammarane sapogenins attenuates stress-induced anxiety-like behaviors by upregulating ERK/CREB/BDNF pathways.

Dammarane sapogenins (DS), an extract derived from ginseng by alkaline hydrolysis of total ginsenosides, possesses high pharmacological activity and higher bioavailability than ginsenosides. The present study was designed to investigate the anxiolytic-like effects of DS in a mouse model of chronic social defeat stress (CSDS). DS (40 and 80 mg/kg) significantly ameliorated social avoidance and anxiety-like behavior in four test models of CSDS, showing increased time in the interaction zone in the social interaction test and in the center of the field in the open field test, an increased percentage of entries and open arm time in the elevated plus maze, and reduced latency to eat in the novelty-suppressed feeding test. Biochemical analyses showed that DS significantly reduced serum corticosterone levels and increased brain concentration of neurotransmitter 5-HT and noradrenaline in CSDS mice. Treatment with DS significantly upregulated BDNF (brain-derived neurotrophic factor), p-CREB/CREB and p-ERK1/2/ERK1/2 protein expression in the hippocampus and prefrontal cortex of CSDS mice. Collectively, these results suggest that DS exerts anxiolytic-like effects in CSDS model mice and the action is mediated, at least in part, by modulating the HPA (hypothalamic-pituitary-adrenal) axis and monoamine neurotransmitter levels, and via ERK/CREB/BDNF signaling pathway.

Ginsenoside metabolite 20(S)-protopanaxatriol from Panax ginseng attenuates inflammation-mediated NLRP3 inflammasome activation.

ETHNOPHARMACOLOGICAL RELEVANCE: Panax ginseng C.A. Meyer (Araliaceae), has been used in traditional medicine for preventive and therapeutic purposes in Asian countries. One of the active ginsenoside metabolites, 20(S)-Protopanaxatriol (PPT), has been associated with diverse pharmacological effects, including anti-inflammatory properties. AIM OF THE STUDY: Although the capacity of PPT as an anti-inflammatory agent has been studied, this study aimed to explore the intrinsic mechanism of PPT in regulating inflammasome activation-mediated inflammatory responses in experimental models. MATERIALS AND METHODS: Lipopolysaccharide (LPS)-primed peritoneal macrophages in vitro was used to study the role of PPT on inflammasome activation. LPS-induced septic shock and monosodium urate (MSU)-induced murine peritonitis models were employed for in vivo evaluations. RESULTS: PPT attenuated NLRP3 inflammasome activation and also reduced ASC oligomerization, leading to attenuation of interleukin (IL)-1ß secretion. Further, PPT inhibited IL-1ß secretion in both LPS-induced septic shock and MSU-induced mouse peritonitis models. CONCLUSIONS: This study revealed that ginsenoside metabolite PPT, inhibits inflammation-mediated inflammasome activation and supported the traditional use of ginseng in treating various inflammatory disorders.

Antidepressant-like effects of 20(S)-protopanaxadiol in a mouse model of chronic social defeat stress and the related mechanisms.

20(S)-Protopanaxadiol (PPD) is a basic aglycone of the dammarane triterpenoid saponins and exerts antidepressant-like effects on behaviour in the forced swimming test (FST) and tail suspension test (TST) and in rat olfactory bulbectomy depression models. However, the antidepressant effects of PPD have not been studied thoroughly. The objective of the present study was first to investigate the effect of PPD on depression behaviours induced by chronic social defeat stress (CSDS) in mice. The results showed that CSDS was effective in producing depression-like behaviours in mice, as indicated by decreased responses in the social interaction test, sucrose preference test, TST, and FST, and that this effect was accompanied by noticeable alterations in the levels of oxidative markers (superoxide dismutase, catalase, and lipid peroxidation) and monoamines (5-HT and NE) in the hippocampus and serum corticosterone levels. Additionally, western blot analysis revealed that CSDS exposure significantly downregulated BDNF, p-TrkB/TrkB, p-Akt/Akt, and p-mTOR/mTOR protein expression in the hippocampus. Remarkably, chronic PPD treatment significantly ameliorated these behavioral and biochemical alterations associated withCSDS-induced depression. Our results suggest that PPD exerts antidepressant-like effects in mice with CSDS-induced depression and that this effect may be mediated by the normalization of neurotransmitter and corticosterone levels and the alleviation of oxidative stress, as well as the enhancement of the PI3K/Akt/mTOR-mediated BDNF/TrkB pathway.

Inhibition of NLRP3 inflammasome-mediated pyroptosis in macrophage by cycloastragenol contributes to amelioration of imiquimod-induced psoriasis-like skin inflammation in mice.

Psoriasis is a common chronic inflammatory skin disease, and the infiltrated macrophages in psoriatic skin lesions play a key role in the progression of this uncontrolled cutaneous inflammation. However, the current therapeutic strategies for patients with psoriasis are not satisfactory. Here, we report that cycloastragenol (CAG), a natural active small compound isolated from Astragalus membranaceus, significantly ameliorated imiquimod (IMQ)-induced psoriasiform dermatitis in mice by targeting proinflammatory macrophages. CAG significantly reduced the clinical scores, decreased the epidermal thickness, and ameliorated the deteriorating histopathology observed in IMQ-induced mice. CAG treatment specifically reduced the dermal infiltration of macrophages, rather than of dendritic cells, neutrophils, or T lymphocytes, into psoriatic skin. CAG dose-dependently decreased the level of proinflammatory cytokines, including IL-1ß, TNF-α and IL-6, in murine psoriatic skin and serum, as well as in IMQ-stimulated, bone-marrow-derived macrophages. When compared to the control group, CAG significantly decreased IMQ-triggered NLRP3 inflammasome activation and gasdermin D-mediated cell pyroptosis in these proinflammatory macrophages. CAG also suppressed the assembly of the NLRP3 inflammasome complex. Taken together, the results show that CAG selectively modulates macrophage function by inhibiting NLRP3 inflammasome-mediated pyroptosis to ameliorate IMQ-induced psoriasis-like skin inflammation in mice. Our findings also identify an effective drug candidate for the treatment of psoriasis.

LC-MS/MS determination of ginsenoside compound K and its metabolite 20 (S)-protopanaxadiol in human plasma and urine: applications in a clinical study.

AIM: Ginsenoside compound K (CK) is considered to be a potential therapeutic drug for rheumatoid arthritis because of its good anti-inflammatory activity. The purpose of this work was to establish a rapid, sensitive and specific method for determination of CK and its active metabolite 20(S)-protopanaxadiol (20(S)-PPD). Materials & methods: The analytes and internal standards were extracted by liquid-liquid extraction. Then, were separated by high performance liquid phase and determined by triple quadrupole mass spectrometry. RESULTS: A LC-MS/MS using liquid-liquid extraction was developed for determining CK over the concentration range 1.00-1002.00 ng/ml and 0.15-54.30 ng/ml for 20(S)-PPD. The lower limits of quantification for CK and 20(S)-PPD were 1.00 and 0.15 ng/ml, respectively. CONCLUSION: This method was successfully validated for detecting both CK and 20(S)-PPD in the human plasma and urine, and was proved to be suitable for the pharmacokinetic study of CK in healthy Chinese volunteers. CLINICAL TRIAL REGISTRATION NUMBER: ChiCTR-TRC-14004824.

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.

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.

Ginsenoside 20(S)-protopanaxadiol inhibits triple-negative breast cancer metastasis in vivo by targeting EGFR-mediated MAPK pathway.

Metastasis is the primary cause of cancer recurrence and cancer related mortality in triple-negative breast cancer (TNBC). EGFR overexpression is in 50-75% TNBC and EGFR-mediated signaling has potential as an attractive therapeutic target in some specific subtypes of breast cancer due to its significant association with tumor metastasis and poor prognosis. Therefore, identification of promising therapeutic strategies targeting EGFR with higher specificity toward cancer metastasis is urgently needed. 20(S)-protopanaxadiol (PPD), one of the major active metabolites from Panax ginseng, has been widely reported to possess pleiotropic anticancer activities in various cancers. In this study, we investigated the effect of PPD against cancer metastasis and the related molecular mechanisms in TNBC in vitro and in vivo. PPD (>30 µM) suppressed cell proliferation by arresting cell cycle in G0/1 phase and triggering cells apoptosis as shown by cell viability assay, flow cytometry analysis and colony formation assay, whereas lower dose of PPD (<20 µM) decreased metastatic potential of MDA-MB-231 and SUM159 cells through direct inhibition of cell adhesion, motility and invasiveness. In TNBC xenograft and syngeneic models, PPD treatment markedly decreased tumor growth and lung metastasis. PPD reversed epithelial-mesenchymal transition (EMT), decreased the expression and activity of matrix metalloproteinases (MMPs) while increased the expression of tissue inhibitors of metalloproteinases (TIMPs) as shown by Western blot and gelatin zymography. Cell signaling pathways that control the expression or activation of these processes were investigated by Western blot and ELISA assay. PPD treatment reduced the phosphorylation of EGFR and down-regulated the activation ERK1/2, p38 and JNK signaling, which was further validated by using the agonists or inhibitors of EGFR and MAP kinases family. Collectively, these findings suggest that PPD holds therapeutic potential against the tumor metastasis of TNBC via targeting EGFR-mediated MAPK pathway.

Protective effects of protopanaxatriol on acute liver injury induced by concanavalin A.

The purpose of this study was to explore the protective effect of protopanaxatriol (PPT) on acute liver injury induced by concanavalin A (ConA). In this study, mice were randomly separated into four groups. The first group received PBS (i.v.). The second group was given PPT (50 mg/kg body weight, i.p.) for 3 days before PBS (i.v.) injection. The third group received ConA (15 mg/kg body weight, i.v.). The fourth group was administered PPT (50 mg/kg body weight, i.p.) for 3 days before ConA (i.v.) injection. The serum levels of ALT and AST were detected after 20 h of ConA injection. The pathological changes of liver were observed by H/E staining. The expression of inflammatory factors was measured by ELISA and qRTPCR, and the changes of the signaling pathway were detected by western blot. Histopathological changes and blood transaminase elevation indicated significant liver injury after ConA injection. However, PPT pretreatment obviously reversed these changes. The ELISA and qRT-PCR results indicated that PPT preconditioning significantly inhibited the production of inflammatory factors. In addition, this inhibitory effect of PPT was mainly mediated by regulation of the nuclear factor-κB (NF-κB) signaling pathway. The active ingredient of ginseng, PPT, exerts an obvious protective effect on acute liver injury caused by ConA through inhibiting the inflammatory response.

Antidepressant effects of dammarane sapogenins in chronic unpredictable mild stress-induced depressive mice.

Depression is a common, dysthymic, and psychiatric disorder, resulting in enormous social and economic burden. Dammarane sapogenins (DS), an active fraction from oriental ginseng, has shown antidepressant-like effects in chronic restraint rats and sleep interruption-induced mice, and the present study aimed to further confirm the antidepressant effects of DS in a model of chronic unpredictable mild stress (CUMS) and to explore the underlying mechanism. Oral administration of DS (20, 40, and 80 mg/kg) markedly improved depressant-like behaviors, increasing the sucrose intake in the sucrose preference test and reducing the latency in the novelty-suppressed feeding test, and decreasing the immobility time in both the tail suspension and forced swimming tests, compared with the CUMS mice. Biochemical analysis of brain tissue and serum showed that DS treatment restored the decreased hippocampal neurotransmitter concentrations of serotonin, dopamine, norepinephrine (noradrenaline), and gamma-aminobutyric acid, and decreased the elevated of serum hormone levels (corticotrophin releasing factor, adrenocorticotrophic hormone, and corticosterone) induced by CUMS. Our findings confirm that DS exerts an antidepressant-like effect in the CUMS model of depression in mice, and suggest it may be mediated by regulation of neurotransmitters and hypothalamic-pituitary-adrenal axis.

Neuroprotective effects of 20(S)-protopanaxatriol (PPT) on scopolamine-induced cognitive deficits in mice.

20(S)-protopanaxatriol (PPT), one of the ginsenosides from Panax ginseng, has been reported to have neuroprotective effects and to improve memory. The present study was designed to investigate the protective effect of PPT on scopolamine-induced cognitive deficits in mice. Male Institute of Cancer Research mice were pretreated with 2 different doses of PPT (20 and 40 µmol/kg) for 27 days by intraperitoneal injection, and scopolamine (0.75 mg/kg) was injected intraperitoneally for 9 days to induce memory impairment. Thirty minutes after the last pretreatment, the locomotor activity was firstly examined to evaluate the motor function of mice. Then, memory-related behaviors were evaluated, and the related mechanism was further researched. It was founded that PPT treatment significantly reversed scopolamine-induced cognitive impairment in the object location recognition experiment, the Morris water maze test, and the passive avoidance task, showing memory-improving effects. PPT also significantly improved cholinergic system reactivity and suppressed oxidative stress, indicated by inhibition of acetylcholinesterase activity, elevation of acetylcholine levels, increasing superoxide dismutase activity and lowering levels of malondialdehyde in the hippocampus. In addition, the expression levels of Egr-1, c-Jun, and cAMP responsive element binding in the hippocampus were significantly elevated by PPT administration. These results suggest that PPT may be a potential drug candidate for the treatment of cognitive deficit in Alzheimer's disease.

Cycloastragenol improves hepatic steatosis by activating farnesoid X receptor signalling.

Non-alcoholic fatty liver disease (NAFLD) has become a global health problem. However, there is no approved therapy for NAFLD. Farnesoid X receptor (FXR) is a potential drug target for treatment of NAFLD. In an attempt to screen FXR agonists, we found that cycloastragenol (CAG), a natural occurring compound in Astragali Radix, stimulated FXR transcription activity. In animal studies, we demonstrated that CAG treatment resulted in obvious reduction of high-fat diet induced lipid accumulation in liver accompanied by lowered blood glucose, serum triglyceride levels and hepatic bile acid pool size. The stimulation of FXR signalling by CAG treatment in DIO mice was confirmed via gene expression and western blot analysis. Molecular docking data further supported the interaction of CAG and FXR. In addition, CAG alleviated hepatic steatosis in methionine and choline deficient L-amino acid diet (MCD) induced non-alcoholic steatohepatitis (NASH) mice. Our data suggest that CAG ameliorates NAFLD via the enhancement of FXR signalling.

Anti-fatigue Effects of 20(S)-Protopanaxadiol and 20(S)-Protopanaxatriol in Mice.

Ginseng (Panax ginseng C.A. MEYER, Araliaceae), which contains protopanaxadiol-type and protopanaxatriol-type ginsenosides, has been used for inflammation, fatigue, stress, and tumor in Asian countries. Orally administered ginsenosides are metabolized to their aglycones 20(S)-protopanaxadiol (PPD) and 20(S)-protopanaxatriol (PPT) by gut microbiota. However, their anti-fatigue effects have not been studied thoroughly. Therefore, we investigated the anti-fatigue activities of PPD and PPT in mice, using the weight-loaded swimming (WLS) and the rota-rod tests. Ginseng water extract (GW), ginseng saponin fraction (GWS) and ginseng polysaccharide fraction (GWP) at concentrations of 50 and 100 mg/kg and PPD and PPT at 5 and 10 mg/kg were orally administered to mice once daily for 5 d. GW, GWS, and PPT significantly increased the WLS time, however, GWP and PPD did not cause any significant change. PPT induced the most significant increase in WLS time. PPD (10 mg/kg) and PPT (5 and 10 mg/kg) inhibited the WLS-induced increase in corticosterone, lactate, lactate dehydrogenase (LDH), and creatinine levels as well as the reduction in glucose level. PPT increased the riding time in the rota-rod test, and also inhibited corticosterone, lactate, and creatinine levels. These findings suggest that the anti-fatigue effect of ginseng may be attributable to its saponins, particularly PPT, rather than to its polysaccharides.

Anti-stress effects of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol in immobilized mice.

Panax ginseng C.A. MEYER (Araliaceae), which contains ginsenosides as its main components, has been shown to have various biological effects, including anti-inflammatory, anxiolytic, anti-stress, and anti-tumor effects. Orally administered ginsenoside Rb1 and Re are metabolized to 20(S)-protopanaxadiol (PPD) and compound K via ginsenoside Rd and 20(S)-protopanaxatriol (PPT) and ginsenoside Rh1 via ginsenoside Rg1 by gut microbiota, respectively. Therefore, we investigated the anti-stress effects of these metabolites, PPD and PPT, by measuring their anxiolytic and anti-inflammatory effects in immobilized mice. Treatment with PPD and PPT prior to immobilization stress increased the time spent in open arms and open arm entries in the elevated plus-maze (EPM) test. The anxiolytic effects of PPD (10 mg/kg) and PPT (10 mg/kg) were comparable to that of buspirone (1 mg/kg). This observed anxiolytic effect of PPD was significantly blocked by flumazenil or bicuculline, and the effect of PPT was blocked by WAY-100635. Treatment with PPD also potently suppressed immobilization stress-induced serum levels of corticosterone and interleukin (IL)-6 by the enzyme-linked immunosorbent assay. However, PPT treatment did not suppress them. Based on these findings, PPD and PPT may exhibit the anxiolytic effect via γ-aminobutyrateA (GABAA) receptor(s) and serotonergic receptor(s), respectively, and PPD may have an anti-inflammatory effect that is more potent than that of PPT.

TRAIL pathway is associated with inhibition of colon cancer by protopanaxadiol.

Among important components of American ginseng, protopanaxadiol (PPD) showed more active anticancer potential than other triterpenoid saponins. In this study, we determined the in vivo effects of PPD in a mouse cancer model first. Then, using human colorectal cancer cell lines, we observed significant cancer cell growth inhibition by promoting G1 cell cycle redistribution and apoptosis. Subsequently, we characterized the downstream genes targeted by PPD in HCT-116 cancer cells. Using Affymetrix high density GeneChips, we obtained the gene expression profile of the cells. Microarray data indicated that the expression levels of 76 genes were changed over two-fold after PPD, of which 52 were upregulated while the remaining 24 were downregulated. Ingenuity pathway analysis of top functions affected was carried out. Data suggested that by regulating the interactions between p53 and DR4/DR5, the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) pathway played a key role in the action of PPD, a promising colon cancer inhibitory compound.

Natural products and chemotherapeutic agents on cancer: prevention vs. treatment.

Natural products play an important role in cancer therapeutics, and lately more attentions have been paid to the prevention of major lethal malignancies, such as colorectal cancer (CRC). After oral ingestion, botanicals' parent compounds can be converted to their metabolites by the enteric microbiome, and these metabolites may have different bioactivities and variable bioavailability. In this study, we used an active ginseng metabolite, protopanaxadiol (PPD), as an example to assess its colon cancer preventive effect by comparing its effect with the treatment effect of fluorouracil (5-FU). A xenograft tumor nude mouse model with human colon cancer cell inoculation was used. After preventive PPD or treatment 5-FU administration with the same dose (30 mg/kg), tumor growth inhibition was evaluated by both a Xenogen bioluminescence imaging technique and manual tumor size measurement. Our data showed that preventive PPD very significantly inhibited the tumor growth compared to 5-FU (p < 0.01). Our data suggest that the PPD is a promising cancer prevention agent. More studies are needed to explore the chemopreventive actions of PPD and its potential clinical utility.

20(S)-protopanaxadiol triggers mitochondrial-mediated apoptosis in human lung adenocarcinoma A549 cells via inhibiting the PI3K/Akt signaling pathway.

20(S)-Protopanaxadiol (PPD), an aglycone saponin ginsenoside isolated from Panax quinquefolium L, has been shown to inhibit the growth and proliferation in several cancer lines. However, the underlying molecular mechanisms remain poorly understood. In this study, we investigated the apoptosis-induced effects and the mechanism of 20(S)-PPD on human lung adenocarcinoma A549 cells. 20(S)-PPD showed a potent antiproliferative activity against A549 cells by triggering apoptosis. 20(S)-PPD-induced apoptosis was characterized by a dose-dependent loss of the mitochondrial membrane, release of cytochrome c, second mitochondria-derived activator of caspase (Smac) and apoptosis-inducing factor (AIF), activation of caspase-9/-3, and cleavage of poly (ADP-ribose) polymerase (PARP). Caspase-dependence was indicated by the ability of the pan-caspase inhibitor z-VAD-fmk to attenuate 20(S)-PPD-induced apoptosis. After treatment with 20(S)-PPD, the proportion of A549 cells at the G0/G1 phase increased, while cells at the S and G2/M phases decreased. Furthermore, 20(S)-PPD also triggered down-regulation of phosphorylated Akt (Ser473/Thr308) and glycogen synthase kinase 3ß (GSK 3ß). Knockdown of GSK 3ß with siRNA promoted the apoptotic effects of 20(S)-PPD. These results revealed an unexpected mechanism of action for this unique ginsenoside: triggering a mitochondrial-mediated, caspase-dependent apoptosis via down-regulation of the PI3K/Akt signaling pathway in A549 cells. Our findings encourage further studies of 20(S)-PPD as a promising chemopreventive agent against lung cancer.

Bioactivity of five components of Chinese herbal formula Jiangzhi granules against hepatocellular steatosis.

OBJECTIVE: This study aims to evaluate the bioactivity of five components of the traditional Chinese medicine complex prescription Jiangzhi granules against hepatocellular steatosis. METHODS: The five major components, including protopanaxadiol, tanshinone IIA, emodin, chlorogenic acid, and nuciferine, were extracted from Jiangzhi granules. Their cytotoxicity was assessed to determine the safe dose of each component for HepG2 cells. HepG2 cellular steatosis was induced using 1 mmol/L of free fatty acids (FFAs) for 24 h, and then treated with each component at high, intermediate, and low doses (500, 50, and 5 µmol/L), respectively for another 24 h. The effects on HepG2 steatosis were observed directly under optical phase microscopy, or through oil red O staining and Nile red assays. In addition, the levels of reactive oxygen species (ROS) in the steatotic HepG2 cells with and without high-dose protopanaxadiol treatment were measured using fluorescent dye 2',7'-dichlorodihydrofluorescein diacetate staining. RESULTS: No obvious cytotoxicity was observed in the HepG2 cells incubated with each of the five components at up to 500 µmol/L. At 24 h after incubation with FFAs, the HepG2 cells swelled and many lipid droplets accumulated. The lipid content was attenuated after 24 h of incubation with protopanaxadiol, tanshinone IIA, and emodin at 500 or 50 µmol/L (P < 0.05), especially with 500 µmol/L protopanaxadiol (P < 0.01). In addition, the ROS level was elevated in steatotic cells, but decreased after intervention with 500 µmol/L protopanaxadiol (P < 0.05). CONCLUSION: Protopanaxadiol, tanshinone IIA, and emodin alleviate hepatocellular steatosis in a dose-dependent manner, and oxidative stress regulation may partially contribute to the effects of protopanaxadiol.

Ginseng saponin metabolite 20(S)-protopanaxadiol inhibits tumor growth by targeting multiple cancer signaling pathways.

Plant-derived active constituents and their semi-synthetic or synthetic analogs have served as major sources of anticancer drugs. 20(S)-protopanaxadiol (PPD) is a metabolite of ginseng saponin of both American ginseng (Panax quinquefolius L.) and Asian ginseng (Panax ginseng C.A. Meyer). We previously demonstrated that ginsenoside Rg3, a glucoside precursor of PPD, exhibits anti-proliferative effects on HCT116 cells and reduces tumor size in a xenograft model. Our subsequent study indicated that PPD has more potent antitumor activity than that of Rg3 in vitro although the mechanism underlying the anticancer activity of PPD remains to be defined. Here, we investigated the mechanism underlying the anticancer activity of PPD in human cancer cells in vitro and in vivo. PPD was shown to inhibit growth and induce cell cycle arrest in HCT116 cells. The in vivo studies indicate that PPD inhibits xenograft tumor growth in athymic nude mice bearing HCT116 cells. The xenograft tumor size was significantly reduced when the animals were treated with PPD (30 mg/kg body weight) for 3 weeks. When the expression of previously identified Rg3 targets, A kinase (PRKA) anchor protein 8 (AKAP8L) and phosphatidylinositol transfer protein α (PITPNA), was analyzed, PPD was shown to inhibit the expression of PITPNA while upregulating AKAP8L expression in HCT116 cells. Pathway-specific reporter assays indicated that PPD effectively suppressed the NF-κB, JNK and MAPK/ERK signaling pathways. Taken together, our results suggest that the anticancer activity of PPD in colon cancer cells may be mediated through targeting NF-κB, JNK and MAPK/ERK signaling pathways, although the detailed mechanisms underlying the anticancer mode of PPD action need to be fully elucidated.

Paraptosis and NF-κB activation are associated with protopanaxadiol-induced cancer chemoprevention.

BACKGROUND: Protopanaxadiol (PPD) is a triterpenoid that can be prepared from steamed ginseng. PPD possesses anticancer potential via caspase-dependent apoptosis. Whether paraptosis, a type of the caspase-independent cell death, is also induced by PPD has not been evaluated. METHODS: Cell death, the cell cycle and intracellular reactive oxygen species (ROS) were analyzed by flow cytometry after staining with annexin V/PI, PI/RNase or H2DCFDA. We observed morphological changes by crystal violet staining assay. Mitochondrial swelling was measured by ultraviolet-visible spectrophotometry. The activation of NF-κB was measured by luciferase reporter assay. RESULTS: At comparable concentrations of 5-fluorouracil, PPD induced more cell death in human colorectal cancer cell lines HCT-116 and SW-480. We demonstrated that PPD induced paraptosis in these cancer cells. PPD treatment significantly increased the percentage of cancer cells with cytoplasmic vacuoles. After the cells were treated with PPD and cycloheximides, cytoplasmic vacuole generation was inhibited. The paraptotic induction effect of PPD was also supported by the results of the mitochondrial swelling assay. PPD induced ROS production in cancer cells, which activated the NF-κB pathway. Blockage of ROS by NAC or PS-1145 inhibited the activation of NF-κB signaling. CONCLUSIONS: PPD induces colorectal cancer cell death in part by induction of paraptosis. The anticancer activity of PPD may be enhanced by antioxidants such as green tea, which also inhibit the activation of NF-κB signaling.