Protopanaxadiols Eliminate Behavioral Impairments and Mitochondrial Dysfunction in Parkinson's Disease Mice Model.

Currently, there are no effective therapies to cure Parkinson's disease (PD), which is the second most common neurodegenerative disease primarily characterized by motor dysfunction and degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc). Protopanaxadiols (PPDs), including 20 (R)- protopanaxadiol (R-PPD) and 20 (S)- protopanaxadiol (S-PPD), are main metabolites of ginsenosides. The role of ginsenosides in neurodegenerative diseases has been thoroughly studied, however, it is unknown whether PPDs can attenuate behavioral deficits and dopaminergic neuron injury in PD model mice to date. Here, we administered PPDs to MPTP-induced PD model mice and monitored the effects on behavior and dopaminergic neurons to investigate the effects of R-PPD and S-PPD against PD. Our results showed that R-PPD and S-PPD (at a dose of 20 mg/kg, i.g.) treatment alleviated MPTP (30 mg/kg, i.p.) induced behavioral deficits. Besides, R-PPD and S-PPD protected MPP+-induced neuron injury and mitochondrial dysfunction, and reduced the abnormal expression of Cyt C, Bax, caspase-3 and Bcl-2. These findings demonstrate that R-PPD and S-PPD were potentially useful to ameliorate PD.

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.

Cycloastragenol upregulates SIRT1 expression, attenuates apoptosis and suppresses neuroinflammation after brain ischemia.

Cycloastragenol (CAG) is the active form of astragaloside IV isolated from Astragalus Radix, which displays multiple pharmacological effects. Silent information regulator 1 (SIRT1), a class III histone deacetylase, has been shown to play an important role in neuroprotection against cerebral ischemia. In this study, we investigated whether CAG protected against ischemic brain injury and, if so, whether the beneficial effects were associated with the regulation of SIRT1 in the ischemic brain. Mice were subjected to 45 min of middle cerebral artery occlusion (MCAO) followed by reperfusion. CAG (5, 10, 20 mg/kg) was injected intraperitoneally at the onset of reperfusion, 12 h later and then twice daily for up to three days. CAG dose-dependently reduced brain infarct volume, significantly ameliorated functional deficits, and prevented neuronal cell loss in MCAO mice. Meanwhile, CAG significantly reduced matrix metalloproteinase-9 activity, prevented tight junction degradation and subsequently ameliorated blood-brain barrier disruption. Moreover, CAG significantly upregulated SIRT1 expression in the ischemic brain but did not directly activate its enzymatic activity. Concomitant with SIRT1 upregulation, CAG reduced p53 acetylation and the ratio of Bax to Bcl-2 in the ischemic brain. CAG also inhibited NF-κB p65 nuclear translocation. As a result, CAG suppressed the mRNA expression of pro-inflammatory cytokines, including TNF-α and IL-1ß, and inhibited the activation of microglia and astrocytes in the ischemic brain. Our findings suggest that CAG is neuroprotective against ischemic brain injury in mice and that its beneficial effect may involve SIRT1 upregulation and the inhibition of apoptosis and neuroinflammation in the ischemic brain.

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.

Protopanaxadiol alleviates obesity in high-fat diet-fed mice via activation of energy-sensing neuron in the paraventricular nucleus of hypothalamus.

Obesity is one of the most important health problems worldwide. Panax ginseng has been reported to exert anti-obesity effect. However, the active constituents and the underlying mechanism remained uncertain. This study uncovered the anti-obesity effect of protopanaxadiol (PPD) and its potential mechanism. To investigate the anti-obesity effect of PPD, high-fat diet induced obesity (DIO) C57BL/6 mice were treated with PPD by both intraperitoneal injection (i.p.) and oral administration. Body weight and food intake were recorded. Energy expenditure was measured by CLAMS metabolic cages. For mechanism study, C-Fos in the hypothalamus of the mice was stained following the intracerebroventricular (i.c.v.) injection of PPD. Our results showed that with both injection and feeding, PPD reduced body weight, inhibited food intake, increased energy expenditure and improved liver damage in DIO mice. Mechanistically, i.c.v. injection of PPD inhibited feeding and increased C-Fos expression in paraventricular nucleus of the hypothalamus (PVH). The results suggest that PPD may reduce body weight of DIO mice via the activation of PVH neurons and PPD is a potential therapeutic candidate for the treatment of obesity.

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.

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.

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.

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.

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.

Ginsenoside metabolite compound K suppresses T-cell priming via modulation of dendritic cell trafficking and costimulatory signals, resulting in alleviation of collagen-induced arthritis.

Ginsenoside metabolite compound K (CK; 20-O-d-glucopyranosyl-20(S)-protopanaxadiol), a novel ginsenoside metabolite, belongs to the dammarane-type triterpene saponins, according to its structure. The anti-inflammatory activity of CK has been identified in several studies. Our study demonstrated that CK exerted an anti-inflammatory effect in collagen-induced arthritis (CIA) and adjuvant-induced arthritis animal models, and this effect was due to inhibition of the abnormal activation and differentiation of T cells. However, the mechanism of CK in suppressing T-cell activation remains unclear. In this study, CK had a therapeutic effect in mice with CIA, decreased the percentage of activated T cells and dendritic cells (DCs), and increased the percentage of naive T cells in lymph nodes. The inhibitory effect on T-cell activation of CK was related to suppression of accumulation of DCs in lymph nodes. CK decreased CCL21 levels in lymph nodes and CCR7 expression in DCs and suppressed CCL21/CCR7-mediated migration of DCs, thus reducing accumulation of DCs in lymph nodes. In addition, signals for T-cell activation including major histocompatibility complex class II and costimulatory molecules, such as CD80 and CD86, were suppressed by CK, and the proliferation of T cells induced by DCs was inhibited by CK. In conclusion, this study demonstrated that CK downregulated DC priming of T-cell activation in CIA, and suppression of CCL21/CCR7-mediated DC migration and signaling between T cells and DCs might be the potential mechanism. These results provide an interesting, novel insight into the potential mechanism by which CK contributes to the anti-inflammatory effect in autoimmune conditions.

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.

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.

20(S)-protopanaxadiol-aglycone downregulation of the full-length and splice variants of androgen receptor.

As a public health problem, prostate cancer engenders huge economic and life-quality burden. Developing effective chemopreventive regimens to alleviate the burden remains a major challenge. Androgen signaling is vital to the development and progression of prostate cancer. Targeting androgen signaling via blocking the production of the potent ligand dihydrotestosterone has been shown to decrease prostate cancer incidence. However, the potential of increasing the incidence of high-grade prostate cancers has been a concern. Mechanisms of disease progression after the intervention may include increased expression of androgen receptor (AR) in prostate tissue and expression of the constitutively active AR splice variants (AR-Vs) lacking the ligand-binding domain. Thus, novel agents targeting the receptor, preferentially both the full-length and AR-Vs, are urgently needed. In the present study, we show that ginsenoside 20(S)-protopanaxadiol-aglycone (PPD) effectively downregulates the expression and activity of both the full-length AR and AR-Vs. The effects of PPD on AR and AR-Vs are manifested by an immediate drop in proteins followed by a reduction in transcripts, attributed to PPD induction of proteasome-mediated degradation and inhibition of the transcription of the AR gene. We further show that although PPD inhibits the growth as well as AR expression and activity in LNCaP xenograft tumors, the morphology and AR expression in normal prostates are not affected. This study is the first to show that PPD suppresses androgen signaling through downregulating both the full-length AR and AR-Vs, and provides strong rationale for further developing PPD as a promising agent for the prevention and/or treatment of prostate cancer.

Oestrogen receptor α agonist improved long-term ovariectomy-induced spatial cognition deficit in young rats.

Ovariectomy is known as 'surgical menopause' with decreased levels of oestrogen in female rodents and its reported risks and adverse effects include cognitive impairment. In the brain, oestrogen exerts effects through its receptors, oestrogen receptor α (ERα) and ß (ERß). However, the role of ERα or ERß in ovariectomy-induced cognitive impairment needs further investigation. Here, we observed that bilaterally ovariectomized 3-month-old rats showed obvious spatial learning and memory deficits in the Morris water maze with significant loss of neurons and synapses in the hippocampus. In addition to the rapid decline in serum oestradiol levels, the expression of ERα, but not ERß, was decreased in the hippocampus starting 1 wk after ovariectomy. Prompt 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol (PPT) treatment (1 mg/kg.d), an agonist of ERα, improved the spatial learning and memory ability of ovariectomized rats and rescued ovariectomy-induced neuron loss by up-regulating the level of BCLxl, an important anti-apoptosis protein. Furthermore, PPT treatment also improved ovariectomy-induced hippocampal synapse loss and up-regulated the levels of synaptic proteins (synapsin I, NR2A and GluR1) and the activates of CaMK Πα, ERK and Akt. Thus, these results demonstrated that ERα plays an important role in neuroprotection and that prompt ERα rescue is effective to improve hippocampal-dependent cognition deficit after long-term ovariectomy.

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.

Pharmacokinetics and pharmacodynamics of Rh2 and aPPD ginsenosides in prostate cancer: a drug interaction perspective.

Ginsenoside Rh2 and its aglycon (aPPD) are one of the major metabolites from Panax ginseng. Preclinical studies suggest that Rh2 and aPPD have antitumor effects in prostate cancer (PCa). Our aims in this review are (1) to describe the pharmacokinetic (PK) properties of Rh2 and aPPD ginsenosides; 2) to provide an overview of the preclinical findings on the use of Rh2 and aPPD in the treatment of PCa; and (3) to highlight the mechanisms of its PK and pharmacodynamic (PD) drug interactions. Increasing evidence points to the potential efficacy of Rh2 or aPPD for PCa treatment. Based on the laboratory studies, Rh2 or aPPD combinations revealed an additive or synergistic interaction or enhanced sensitivity of anticancer drugs toward PCa. This review reveals that enhanced anticancer activities were demonstrated in preclinical studies through interactions of Rh2 and/or aPPD with the proteins related to PK (e.g., cytochrome P450 enzymes, transporters) or PD of the other anticancer drugs or PCa signaling pathways. In conclusion, combining Rh2 or aPPD with anti-prostate cancer drugs leads to PK or PD interactions which could facilitate either therapeutically beneficial or toxic effects.

A novel oral dosage formulation of the ginsenoside aglycone protopanaxadiol exhibits therapeutic activity against a hormone-insensitive model of prostate cancer.

This study focuses on determining the pharmacokinetics, biodistribution, and efficacy of the ginsenoside aglycone protopanaxadiol (aPPD) administered as a single agent in a novel oral dosage formulation. To obtain these data and to characterize the stability of aPPD, appropriate analytical assay development was carried out. The solubility and stability of aPPD were determined, and the compound was formulated for oral gavage. aPPD levels in blood and tissues following oral administration to nu/nu nude mice were determined using liquid chromatography-mass spectrometry/mass spectrometry. The efficacy of aPPD was determined upon oral administration to nu/nu nude mice bearing PC-3 human prostate cancer xenograft tumors. Immunohistochemical analysis of tumor tissues was performed to establish apoptotic indices and Ki-67 expression as markers of proliferation. The maximum solubility of aPPD in ethanol was 68.4 mg/ml. aPPD administered at a dose of 70 mg/kg yielded a T(max) of approximately 40 min and a C(max) value of 3.9 ± 1.4 µg/ml, and no toxicity was observed. aPPD accumulated largely in the stomach and small intestine and was also present in the brain. This dose engendered a significant delay in PC-3 tumor growth, an increase in apoptotic index, and a decrease in Ki-67 levels. We have shown that aPPD is a stable compound that can be formulated for oral gavage. Pharmacokinetic studies demonstrate the ability of this compound to be absorbed after oral administration. Future studies will assess the activity and pharmacokinetics of aPPD when administered in combination with standard chemotherapy.

Snailase preparation of ginsenoside M1 from protopanaxadiol-type ginsenoside and their protective effects against CCl4-induced chronic hepatotoxicity in mice.

To investigate the protective effects of protopanaxadiol-type ginsenoside (PDG) and its metabolite ginsenoside M1 (G-M1) on carbon tetrachloride (CCl(4))-induced chronic liver injury in ICR mice, we carried out conversion of protopanaxadiol-type ginsenosides to ginsenoside M1 using snailase. The optimum time for the conversion was 24 h at a constant pH of 4.5 and an optimum temperature of 50 °C. The transformation products were identified by high-performance liquid chromatography and electrospray ion-mass spectrometry. Subsequently, most of PDG was decomposed and converted into G-M1 by 24 h post-reaction. During the study on hepatoprotective in a mice model of chronic liver injury, PDG or G-M1 supplement significantly ameliorated the CCl(4)-induced liver lesions, lowered the serum levels of select hepatic enzyme markers (alanine aminotransferase, ALT, and aspartate aminotransferase, AST) and malondialdehyde and increased the activity of superoxide dismutase in liver. Histopathology of the liver tissues showed that PDG and G-M1 attenuated the hepatocellular necrosis and led to reduction of inflammatory cell infiltration. Therefore, the results of this study show that PDG and G-M1 can be proposed to protect the liver against CCl(4)-induced oxidative injury in mice, and the hepatoprotective effect might be attributed to amelioration of oxidative stress.