Augmentation of macrophage functions by an aqueous extract isolated from Platycodon grandiflorum

Platycodon grandiflorum root extract inhibits Aβ deposition by breaking the vicious circle linking oxidative stress and neuroinflammation in Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease accompanied by irreversible cognitive impairment. A deleterious feedback loop between oxidative stress and neuroinflammation in early AD exacerbates AD-related pathology. Platycodon grandiflorum root extract (PGE) has antioxidant and anti-inflammatory effects in several organs. However, the mechanisms underlying the effects of PGE in the brain remain unclear, particularly regarding its impact on oxidative/inflammatory damage and Aβ deposition. Thus, we aim to identify the mechanism through which PGE inhibits Aβ deposition and oxidative stress in the brain by conducting biochemical and histological analyses. First, to explore the antioxidant mechanism of PGE in the brain, we induced oxidative stress in mice injected with scopolamine and investigated the effect of PGE on cognitive decline and oxidative damage. We also assessed the effect of PGE on reactive oxygen species (ROS) generation and the expressions of antioxidant enzymes and neurotrophic factor in H2O2- and Aβ-treated HT22 hippocampal cells. Next, we investigated whether PGE, which showed antioxidant effects, could reduce Aβ deposition by mitigating neuroinflammation, especially microglial phagocytosis. We directly verified the effect of PGE on microglial phagocytosis, microglial activation markers, and pro-inflammatory cytokines in Aβ-treated BV2 microglial cells. Moreover, we examined the effect of PGE on neuroinflammation, inducing microglial responses in Aβ-overexpressing 5XFAD transgenic mice. PGE exerts antioxidant effects in the brain, enhances microglial phagocytosis of Aβ, and inhibits neuroinflammation and Aβ deposition, ultimately preventing neuronal cell death in AD. Taken together, our findings indicate that the therapeutic potential of PGE in AD is mediated by its targeting of multiple pathological processes.

Polysaccharides from Platycodon grandiflorum: A review of their extraction, structures, modifications, and bioactivities

Platycodon grandiflorum (P. grandiflorum) has long been used as a food and traditional herbal medicine. As a food, P. grandiflorum is often transformed into pickles for consumption, and as a traditional Chinese medicine, P. grandiflorum clears the lung, nourishes the pharynx, dispels phlegm, and discharges pus. Polysaccharides are among the main active components of P. grandiflorum. Recent literature has described the preparation, identification, and pharmacological activity of these polysaccharides. Studies have shown that these polysaccharides exhibit a variety of significant biological effects in vitro and in vivo, such as immune stimulation and antioxidant, anti-liver injury, anti-apoptosis and antitumour effects. However, there is no systematic summary of the related research articles on P. grandiflorum polysaccharide, which undoubtedly brings some difficulties to the future research. The purpose of this review is to comprehensively describe research progress on the extraction, purification, structural characterization, modification, and biological activity of P. grandiflorum polysaccharides. The shortcomings of recent research are summarized, further research on their biological activity is proposed to provide new reference value for the application of P. grandiflorum polysaccharides in drugs and health products in the future.

Sambucus ebulus (Elderberry) Fruits Modulate Inflammation and Complement System Activity in Humans

Sambucus ebulus (SE) fruits are used for immune stimulation and amelioration of gastrointestinal inflammatory conditions. Currently, there is no scientific evidence of their effects on various aspects of the immune response mechanisms in humans. The purpose of this study was to evaluate the immunomodulatory potential of SE fruit infusion intake in healthy humans. Anthocyanin content was determined with UPLC-ESI-MS/MS. Fifty-three volunteers enrolled in a 4-week SE infusion intake intervention. Blood count, serum total protein, Interleukin 1 beta (IL-1β), Interleukin 6 (IL-6), Tumor Necrosis Factor Alpha (TNFα), High-sensitivity C-reactive protein (hs-CRP), C3, and C4 levels were measured on automatic analyzers, and Interleukin 8 (IL-8) was measured manually with an ELISA kit. Cyanidin-3-O-galactoside (48.15 mg/g DW), followed by cyaniding-3-sambubioside (43.41 ± 1.07 mg/g DW), were the most abundant anthocyanins in SE samples. A significant decrease in total protein (2.82%), IL-6 (20.15%), TNFα (5.38%), IL-8 (5.50%), C3 (4.16%), and C4 (14.29%) was established in the whole group. Total protein, IL-8, TNFα, and C4 decreased in women (3.11%, 4.76%, 5.09%, and 11.11%), and IL-6 decreased (40.61%) in men. Hb (1.20%) and hematocrit (1.55%) levels decreased in the whole group and in the women group (1.61% and 2.20%). SE fruits exert immune-modulatory activity as revealed by decreased pro-inflammatory status and complement activity markers in healthy volunteers after a 4-week intervention.

Biotransformation of Platycosides, Saponins from Balloon Flower Root, into Bioactive Deglycosylated Platycosides

Platycosides, saponins from balloon flower root (Platycodi radix), have diverse health benefits, such as antioxidant, anti-inflammatory, anti-tussive, anti-cancer, anti-obesity, anti-diabetes, and whitening activities. Deglycosylated platycosides, which show greater biological effects than glycosylated platycosides, are produced by the hydrolysis of glycoside moieties in glycosylated platycosides. In this review, platycosides are classified according to the chemical structures of the aglycone sapogenins and also divided into natural platycosides, including major, minor, and rare platycosides, depending on the content in Platycodi radix extract and biotransformed platycosides. The biological activities of platycosides are summarized and methods for deglycosylation of saponins, including physical, chemical, and biological methods, are introduced. The biotransformation of glycosylated platycosides into deglycosylated platycosides was described based on the hydrolytic pathways of glycosides, substrate specificity of glycosidases, and specific productivities of deglycosylated platycosides. Methods for producing diverse and/or new deglycosylated platycosides are also proposed.

Platycodon grandiflorus polysaccharides deeply participate in the anti-chronic bronchitis effects of platycodon grandiflorus decoction, a representative of “the lung and intestine are related”

Platycodon grandiflorus (Jacq.) A. DC. (PG) root is one of the most commonly used medicine-food materials for respiratory discomfort in Asia, usually in the form of a decoction or leaching solution. As everyone knows, both of decoction and leaching solution is a polyphase dispersion system, containing low-molecular-weight water-soluble active ingredients and hydrophilic macromolecules. This study aimed to discuss the synergistic effect of Platycodon grandiflorus polysaccharide (PGP) and platycodin D (PD) in PG decoction against chronic bronchitis (CB) and the mechanism underlying. A series of PGP, PD, and PGD + PD suspensions were administrated to CB model rats, on the levels of whole animal and in situ intestinal segment with or without mesenteric lymphatic vessels ligation. It exhibited that PGP exhibited synergistic effects with PD, on improving the histopathological abnormity, mucus secretion excess, and immunological imbalance in lung of CB model rat, closely associated with its modulations on the mucosal immunity status in small intestine. The polysaccharide macromolecules in PG decoction or leaching solution should be responsible for the modulation of pulmonary immune state, possibly through the common mucosal immune between small intestine and lung. These results might be a new perspective that illustrates the classical theory of “the lung and intestine are related” in traditional Chinese medicine.

Stauntonia hexaphylla leaf extract (YRA-1909) suppresses inflammation by modulating Akt/NF-κB signaling in lipopolysaccharide-activated peritoneal macrophages and rodent models of inflammation

Background

Inflammation is emerging as a key contributor to many vascular diseases and furthermore plays a major role in autoimmune diseases, arthritis, allergic reactions, and cancer. Lipopolysaccharide (LPS), which is a component constituting the outer membrane of Gram-negative bacteria, is commonly used for an inflammatory stimuli to mimic inflammatory diseases. Nuclear factor-kappa B (NF-κB) is a transcription factor and regulates gene expression particularly related to the inflammatory process. Stauntonia hexaphylla (Lardizabalaceae) is widely used as a traditional herbal medicine for rheumatism and osteoporosis and as an analgesic, sedative, and diuretic in Korea, Japan, and China.

Objective

The purpose of this study was to investigate the anti-inflammatory activity of YRA-1909, the leaf aqueous extract of Stauntonia hexaphylla using LPS-activated rat peritoneal macrophages and rodent inflammation models.

Results

YRA-1909 inhibited the LPS-induced nitric oxide (NO) and proinflammatory cytokine production in rat peritoneal macrophages without causing cytotoxicity and reduced inducible NO synthase and prostaglandin E₂ levels without affecting the cyclooxygenase-2 expression. YRA-1909 also prevented the LPS-stimulated Akt and NF-κB phosphorylation and reduced the carrageenan-induced hind paw edema, xylene-induced ear edema, acetic acid-induced vascular permeation, and cotton pellet-induced granuloma formation in a dose-dependent manner in mice and rats.

Conclusions

S. hexaphylla leaf extract YRA-1909 had anti-inflammatory activity in vitro and in vivo that involves modulation of Akt/NF-κB signaling. Thus, YRA-1909 is safe and effective for the treatment of inflammation.

Production of Bioactive Deapiosylated Platycosides from Glycosylated Platycosides in Balloon Flower Root Using the Crude Enzyme from the Food-Available Fungus Rhizopus oryzae

Extract from balloon flower root (Platycodi radix) containing platycosides as saponins is a beneficial food additive and is used for their savory taste and the alleviation of respiratory diseases. Deglycosylated platycosides show greater pharmacological effects than glycosylated platycosides. However, there are no reports on the conversion of glycosylated platycosides into deapiosylated platycosides. In this study, we showed that the crude enzyme from Rhizopus oryzae, a generally recognized as safe (GRAS) fungus isolated from meju (fermented soybean brick), completely converted glycosylated platycosides in Platycodi radix extract into deapiosylated platycosides: deapiosylated platycodin D (deapi-PD), deapiosylated platycodin A (deapi-PA), deapiosylated polygalacin D (deapi-PGD), and deapiosylated platyconic acid A (deapi-PCA). Among these, deapi-PA and deapi-PCA were first identified using liquid chromatography/mass spectrometry. The anti-inflammatory and antioxidant effects of deapiosylated platycosides were greater than those of the precursor glycosylated platycosides. These deapiosylated platycosides could improve the properties of functional food additives.

Kakkonto, shosaikoto, Platycodon grandiflorum root, and gypsum (a Japanese original combination drug known as saikatsugekito): Pharmacological review of its activity against viral infections and respiratory inflammatory conditions and a discussion of its applications to COVID ‐19

Aim

Traditional Japanese (Kampo) medicine has been used to treat viral infectious diseases. In particular, saikatsugekito (a combination drug of kakkonto, shosaikoto, Platicodon glandiflorum root, and gypsum) has been reported to be useful during the past influenza pandemic. The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has spread worldwide, causing the novel coronavirus disease (COVID‐19) to emerge as a pandemic. In this article, we conducted a literature review on the pharmacological activities of the components present in saikatsugekito against viral infection and respiratory inflammation.

Methods

We searched PubMed and the Cochrane Library for English articles, as well as Ichushi and J‐stage for Japanese articles. Articles published until January 1, 2000 were retrieved using the keywords ‘kakkonto’, ‘shosaikoto’, ‘Platycodon’, and ‘gypsum’. We then extracted articles on basic research investigating viral infections, inflammation, cytokine, the immune response, and lung tissue damage.

Results

We extracted 28 eligible articles. Kampo medicines have antiviral activities by interfering with the attachment, internalization, replication, progeny virion release, and cell‐to‐cell spreading of single‐strand RNA viruses. They also enhance the immunomodulating activities of the host, including cytokine production, regulation of multiple immune cells, and protection from lung tissue injury. Furthermore, Kampo medicine has been found to regulate body temperature and airway mucin release.

Conclusion

The results demonstrated that Kampo medicine has therapeutic activities against single‐strand RNA virus infections and respiratory inflammation, and may also have activities against SARS‐CoV‐2. Further research is required to investigate the activity of Kampo medicines, such as saikatsugekito, against SARS‐CoV‐2.

Characterization of β-Glycosidase from Caldicellulosiruptor owensensis and Its Application in the Production of Platycodin D from Balloon Flower Leaf

Platycodin D has diverse pharmacological activities. An efficient and economical mechanism for obtaining platycosides (platycodin D in particular) would be very useful. Balloon flower leaf extract (BFLE) was obtained by recycling leaves discarded from Platycodi radix production, as they have a high platycoside E content. A recombinant β-glycosidase from Caldicellulosiruptor owensensis was characterized and applied to BFLE for platycoside bioconversion. The enzyme specifically hydrolyzed the glucose residue at the C-3 position in platycosides and was suitable for platycodin D production. Under optimized reaction conditions, β-glycosidase from C. owensensis completely converted platycoside E from BFLE into platycodin D with the highest concentration and productivity reported so far. These results greatly improve the production process for deglycosylated platycosides.

Enzymatic Biotransformation of Balloon Flower Root Saponins into Bioactive Platycodin D by Deglucosylation with Caldicellulosiruptor bescii β-Glucosidase

Platycodin D (PD), a major saponin (platycoside) in Platycodi radix (balloon flower root), has higher pharmacological activity than the other major platycosides; however, its content in the plant root is only approximately 10% (w/w) and the productivities of PD by several enzymes are still too low for industrial applications. To rapidly increase the total PD content, the β-glucosidase from Caldicellulosiruptor bescii was used for the deglucosylation of the PD precursors platycoside E (PE) and platycodin D3 (PD3) in the root extract into PD. Under the optimized reaction conditions, the enzyme completely converted the PD precursors into PD with the highest productivity reported so far, increasing the total PD content to 48% (w/w). In the biotransformation process, the platycosides in Platycodi radix were hydrolyzed by four pathways: deapiosylated (deapi)-PE → deapi-PD3 → deapi-PD, PE → PD3 → PD, polygalacin D3 → polygalacin D, and 3″-O-acetyl polygalacin D3 → 3″-O-acetyl polygalacin D.

Biotransformation of Food-Derived Saponins, Platycosides, into Deglucosylated Saponins Including Deglucosylated Platycodin D and Their Anti-Inflammatory Activities

The Platycodon grandiflorum root, Platycodi radix, a common vegetable, and its extract with glycosylated saponins, platycosides, have been used as food items and food health supplements for pulmonary diseases and respiratory disorders. Enzymes convert glycosylated saponins into deglycosylated saponins, which exhibit higher biological activity than glycosylated saponins. In this study, β-glucosidase from the hyperthermophilic bacterium Dictyoglomus turgidum converted platycosides in the Platycodi radix extract into deglucosylated platycosides. In addition, the enzyme completely converted platycoside E (PE), platycodin D₃ (PD₃), and platycodin D (PD) in Platycodi radix extract into deglucosylated platycodin D (deglu PD), which was first identified by nuclear magnetic resonance. The anti-inflammatory activities of deglu PD and deglucosylated Platycodi radix extract were higher than those of PE, PD₃, PD, Platycodi radix extract, and baicalein, an anti-inflammatory agent. Therefore, deglucosylated Platycodi radix extract is expected to be used as improved functional food supplements.

Anti-Inflammatory Effects of a Stauntonia hexaphylla Fruit Extract in Lipopolysaccharide-Activated RAW-264.7 Macrophages and Rats by Carrageenan-Induced Hind Paw Swelling

The fruit of Stauntonia hexaphylla is commonly used as a traditional anthelmintic in Korea, Japan, and China. However, its anti-inflammatory activity and the underlying mechanisms have not been studied systematically. In the present study, we examined the anti-inflammatory activities of an aqueous extract of S. hexaphylla fruit (SHF) in lipopolysaccharide (LPS)-activated RAW 264.7 cells. The SHF extract contained anti-inflammatory compounds, such as neochlorogenic acid, chlorogenic acid, and cryptochlorogenic acid. The extract inhibited protein levels of inducible nitric oxide synthase and the activity of cyclooxygenase enzyme, with concomitant reductions in the production of nitric oxide and prostaglandin E₂ in LPS-activated RAW 264.7 cells. Additionally, the SHF extract reduced the production of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. The SHF extract attenuated LPS-induced nuclear factor-κB (NF-κB) activation by decreasing the phosphorylation of its inhibitor, IκBα. Furthermore, the SHF extract showed a significant anti-inflammatory effect in vivo by reducing the volume of carrageenan-induced paw edema in rats. Our results suggest that the SHF extract exerts potential anti-inflammatory properties against LPS-activated RAW 254.7 cells, and in an animal model of inflammation.

Immune Enhancing Activity of β-(1,3)-Glucan Isolated from Genus Agrobacterium in Bone-Marrow Derived Macrophages and Mice Splenocytes

An effective method for activating macrophages and deriving a Th1 immune response could be used to improve the defenses of hosts. In this study, we investigated the immunomodulation effect and the related signaling mechanism of [Formula: see text]-(1,3)-glucan, isolated from the Agrobacterium species. Here, we found that [Formula: see text]-(1,3)-glucan predominantly induced the tumor necrosis factor (TNF)-[Formula: see text], interleukin (IL)-1[Formula: see text], IL-6, IL-12p70, and nitric oxide, which was dependent on mitogen-activated protein kinases (MAPK) and nuclear factor (NF)-[Formula: see text]B signaling. Additionally, [Formula: see text]-(1,3)-glucan treatment significantly up-regulated the expression of the co-stimulatory molecules CD80 and CD86, and also significantly increased the expression of iNOS and Dectin-1, which is a transmembrane protein that binds [Formula: see text]-glucan and associates with macrophage activation. Importantly, the splenic T cells co-cultured with [Formula: see text]-(1,3)-glucan-treated macrophages produced the a Th1 cytokine profile that includes high levels of IFN-[Formula: see text], but not IL-4 (Th2 cytokine), indicating that [Formula: see text]-(1,3)-glucan contributes to Th1 polarization of the immune response. Taken together, our results suggest that [Formula: see text]-(1,3)-glucan isolated from Agrobacterium species can induce macrophage activation through the MAPK and NF-[Formula: see text]B signaling pathway, as well as Th1 polarization.

Platycodon grandiflorus - an ethnopharmacological, phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Platycodon grandiflorus (Jacq.) A. DC., the sole species in genus Platycodon A. DC. (Campanulaceae) has a long history of use as a traditional herbal medicine for the treatments of cough, phlegm, sore throat, lung abscess, chest pain, dysuria, and dysentery. As a legal medicine and dietary supplement, it is also frequently used as an ingredient in health foods and vegetable dishes. The aim of this review is to provide up-to-date information on the botanical characterization and distribution, ethnopharmacology, phytochemistry, pharmacology, and toxicity of Platycodon grandiflorus based on literature published in recent years. It will build a foundation for further study of the mechanism of action and the development of better therapeutic agents and healthy products from Platycodon grandiflorus.

MATERIAL AND METHODS

All of the available information on Platycodon grandiflorus was collected via electronic search (using PubMed, SciFinder Scholar, CNKI, TPL (www.theplantlist.org), Google Scholar, Baidu Scholar, and Web of Science).

RESULTS

A comprehensive analysis of the literature obtained through the above-mentioned sources confirmed that ethno-medical uses of Platycodon grandiflorus have been recorded in China, Japan, Mongolia, and Korea for thousands of years. A phytochemical investigation revealed that this product contains steroidal saponins, flavonoids, polyacetylenes, sterols, phenolics, and other bioactive compounds. Crude extracts and pure compounds isolated from Platycodon grandiflorus exhibited significant anti-inflammatory and immunostimulatory effects. They also showed valuable bioactive effects, such as anti-tumor, anti-oxidant, anti-diabetic, anti-obesity, hepatoprotective and cardiovascular system effects, among others.

CONCLUSIONS

In light of its long traditional use and the modern phytochemical and pharmacological studies summarized here, Platycodon grandiflorus has been demonstrated to show a strong potential for therapeutic and health-maintaining uses. Both the extracts and chemical components isolated from the plant showed a wide range of biological activities. Thus, more studies on the pharmacological mechanisms of its main active compounds (e.g., platycodin D, D2) need to be conducted. In addition, as one of the most popular traditional herbal medicines, clinical studies of the main therapeutic aspects, toxicity and adverse effects of Platycodon grandiflorus will also undoubtedly be the focus of future investigation.

Platycosides from the Roots of Platycodon grandiflorum and Their Health Benefits

The extracts and pure saponins from the roots of Platycodon grandiflorum (PG) are reported to have a wide range of health benefits. Platycosides (saponins) from the roots of PG are characterized by a structure containing a triterpenoid aglycone and two sugar chains. Saponins are of commercial significance, and their applications are increasing with increasing evidence of their health benefits. The biological effects of saponins include cytotoxic effects against cancer cells, neuroprotective activity, antiviral activity, and cholesterol lowering effects. Saponins with commercial value range from crude plant extracts, which can be used for their foaming properties, to high purity saponins such as platycodin D, which can be used for its health applications (e.g., as a vaccine adjuvant). This review reveals that platycosides have many health benefits and have the potential to be used as a remedy against many of the major health hazards (e.g., cancer, obesity, alzheimer's) faced by populations around the world. Methods of platycoside purification and analysis are also covered in this review.

Glycosylated platycosides: identification by enzymatic hydrolysis and structural determination by LC-MS/MS

In this study, enzymatic hydrolysis and chemometric methods were utilized to discriminate glycosylated platycosides in the extract of Platycodi Radix by LC-MS. Laminarinase, whose enzymatic activity was evaluated using gentiobiose and laminaritriose, was a suitable enzyme to identify the glycosylated platycosides. The laminarinase produced deapi-platycodin D and platycodin D from the isolated deapi-platycoside E and platycoside E through the loss of two glucose units by enzymatic reaction, respectively. After hydrolyzing a crude extract by laminarinase, the reconstructed total ion chromatogram generated by a chemometric technique sorted peaks of deglycosylated platycosides easily. Structural information of the glycosylated isomers was revealed through fragment ions generated by the sodiated C0β ion corresponding to reduced disaccharides in the positive MS(4) spectra. Characteristic fragment ions of Glc-(1→6)-Glc moieties were observed through ring cleavages of (0,2)A0β, (0,3)A0β, and (0,4)A0β, whereas Glc-(1→3)-Glc moieties produced only (0,3)A0β ions. Lithium-adducted platycosides allowed more detailed structural analysis of glycosidic bond cleavage corresponding to Y1β and B1β in addition to ring cleavage.

The Evaluation of the Body Weight Lowering Effects of Herbal Extract THI on Exercising Healthy Overweight Humans: A Randomized Double-Blind, Placebo-Controlled Trial

We investigated the effects of herbal extracts, a mixture of Scutellariae Radix and Platycodi Radix containing the active ingredients Baicalin and Saponin (target herbal ingredient (THI)), on lowering body weight. The present study was a prospective, randomized, double-blind, and placebo-controlled trial carried out at the outpatient department of a hospital over a period of 2 months. Group 1 patients (n = 30) received THI, and group 2 patients (n = 23) received placebo three times a day before meals. Weight, waist circumference, BMI, total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and glucose were measured at baseline and again at the 2nd month. For safety evaluation, various hematological and biochemical parameters were assessed. Values of mean change of weight in the THI-treated group were -1.16 ± 1.41 kg and in the placebo-treated group were -0.24 ± 1.70 kg, respectively. The difference in mean change of weight in the THI-treated group compared with that in the placebo-treated group was statistically significant (P < 0.05). The incidence of subjective and objective adverse drug reactions was insignificant (P > 0.05). THI was statistically significant in its effectiveness on the weight loss.

The procyanidin trimer C1 induces macrophage activation via NF-κB and MAPK pathways, leading to Th1 polarization in murine splenocytes

Numerous studies have shown various relationships between foods with a high nutritional value and a robust immune response, particularly studies that have focused on host protection and cytokine networks. This study aimed to clarify the role played by the procyanidin trimer C1 in innate and adaptive immunity. Procyanidin C1 did not exert cytotoxicity at concentrations ranging from 7.8 to 62.5 μg/ml in macrophage cells; therefore, concentration of 62.5 μg/ml was used as the maximum dose of procyanidin C1 throughout subsequent experiments. Procyanidin C1 enhanced inducible nitric oxide synthase-mediated nitric oxide production in a concentration-dependent manner. In addition, procyanidin C1 functionally induced macrophage activation by augmenting the expression of cell surface molecules (CD80, CD86, and MHC II) and proinflammatory cytokine production (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) via activation of mitogen-activated protein kinase (MAPK), e.g., p38, ERK, and JNK and nuclear factor (NF)-κB signaling pathways. Interestingly, procyanidin C1 effectively polarized T helper type 1 (Th1) by secreting Th1-mediated cytokines (interferon-γ, IL-12p70, and IL-2) and inducing splenocyte proliferation, indicating that procyanidin C1 contributes to Th1 polarization of the immune response. Accordingly, these findings confirms that the procyanidin C1 induces macrophage activation via NF-κB and MAPK pathways, leading to Th1 polarization in murine splenocytes, which suggests that procyanidin C1 regulates innate and adaptive immunity by macrophage activation and Th1 polarization.

Improvement of atopic dermatitis-like skin lesions by Platycodon grandiflorum fermented by Lactobacillus plantarum in NC/Nga mice

Atopic dermatitis (AD) is characterized as a multi-factorial inflammatory skin disease that has been increasing worldwide. Previously, we demonstrated that FPG, which is Platycodon grandiflorum (PG) fermented by Lactobacillus plantarum (LP), increases the level of interferon (IFN)-gamma in mouse splenocytes in vitro. In this study, we investigated the effects of FPG in an animal model of AD, with a particular emphasis on its effects on T helper (Th)1 and Th2 immune responses. To assess the potential use of FPG for the inhibition of AD, we established a model of AD-like skin lesions in NC/Nga mice. Immunoglobulin isotypes (Igs) and Th1/Th2 cytokines in the sera and spleens of AD-like mice were examined. In addition, histological examination was also performed. AD symptoms in skin lesions improved following oral administration of FPG. IgE secretion was significantly down-regulated, and this was accompanied by decreased levels of interleukin (IL)-4 and IgG1 and increased serum levels of IL-12p40 and IgG2a in FPG-treated animals. In splenocytes, the production of the Th1 cytokines IL-12p40 and IFN-gamma was up-regulated, while the levels of the Th2 cytokines IL-4 and 5 were down-regulated by FPG treatment. These results suggest that FPG inhibits the development of AD-like skin lesions in NC/Nga mice by suppressing the Th2 cell response and increasing the Th1 cell responses. Our results indicate that FPG is safe and effective for the prevention of AD-like skin lesions.

The procyanidin trimer C1 inhibits LPS-induced MAPK and NF-κB signaling through TLR4 in macrophages

Natural products and dietary components rich in polyphenols have been shown to reduce inflammation; however, the molecular mechanisms underlying this anti-inflammatory activity are not completely characterized, and many features remain to be elucidated. This research was carried out to clarify the potential role of procyanidin trimer C1 in the anti-inflammatory effect of polyphenols. Procyanidin C1 inhibited inducible nitric oxide synthase-mediated nitric oxide production and the release of pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor-α) in lipopolysaccharide (LPS)-induced macrophages. Treatment with procyanidin C1 resulted in a significant decrease in prostaglandin E2 and cyclooxygenase-2 levels, as well as the expression of cell surface molecules (CD80, CD86, and MHC class II), which was induced by LPS. Furthermore, our data demonstrated that the anti-inflammatory effect of procyanidin C1 occurs through inhibition of mitogen-activated protein kinase (p38 and c-Jun N-terminal kinase) and nuclear factor-κB signaling pathways. These 2 factors play a major role in controlling inflammation, through toll-like receptor 4, suggesting that procyanidin C1 plays a potent role in promoting anti-inflammatory activity in macrophages. These results represent a novel and effective therapeutic intervention for the treatment of inflammatory disease.

Herbal extract THI improves metabolic abnormality in mice fed a high-fat diet

Target herbal ingredient (THI) is an extract made from two herbs, Scutellariae Radix and Platycodi Radix. It has been developed as a treatment for metabolic diseases such as hyperlipidemia, atherosclerosis, and hypertension. One component of these two herbs has been reported to have anti-inflammatory, anti-hyperlipidemic, and anti-obesity activities. However, there have been no reports about the effects of the mixed extract of these two herbs on metabolic diseases. In this study, we investigated the metabolic effects of THI using a diet-induced obesity (DIO) mouse model. High-fat diet (HFD) mice were orally administered daily with 250 mg/kg of THI. After 10 weeks of treatment, the THI-administered HFD mice showed reduction of body weights and epididymal white adipose tissue weights as well as improved glucose tolerance. In addition, the level of total cholesterol in the serum was markedly reduced. To elucidate the molecular mechanism of the metabolic effects of THI in vitro, 3T3-L1 cells were treated with THI, after which the mRNA levels of adipogenic transcription factors, including C/EBPα and PPARγ, were measured. The results show that the expression of these two transcription factors was down regulated by THI in a dose-dependent manner. We also examined the combinatorial effects of THI and swimming exercise on metabolic status. THI administration simultaneously accompanied by swimming exercise had a synergistic effect on serum cholesterol levels. These findings suggest that THI could be developed as a supplement for improving metabolic status.

Effects of dietary supplementation of Chinese medicinal herbs on polymorphonuclear neutrophil immune activity and small intestinal morphology in weanling pigs

The purpose of this study was to evaluate the effects of dietary Chinese medicinal herbs (CMH) supplementation composed of Panax ginseng, Dioscoreaceae opposite, Atractylodes macrocephala, Glycyrrhiza uralensis, Ziziphus jujube and Platycodon grandiflorum, on the performance, intestinal tract morphology and immune activity in weanling pigs. Two hundred and forty weaned pigs were assigned randomly to four dietary groups including the negative control (basal diet), 0.1% CMH, 0.3% CMH and 0.114% antibiotic (Chlortetracycline calcium Complex, Sulfathiazole and Procaine Penicillin G) supplementation groups for a 28-day feeding trial. Results indicated that both CMH supplementation groups had a better gain and feed/gain than control group (CT) during the first 2 weeks of the experimental period. The 0.3% CMH had a significant decrease in the diarrhoea score in first 10 days of experimental period when compared with other groups. The CMH supplementation groups had a higher villous height, increased lactobacilli counts in digesta of ileum and decreased coliform counts in colon compared with CT. The immune activities of polymorphonuclear leucocytes (PMNs), including the respiratory burst and Salmonella-killing ability, were significantly enhanced in CMH supplementation groups at day 7 of experiment period. The CMH and antibiotic supplementations increased the nutrient digestibility such as dietary dry matter, crude protein and gross energy in weanling pigs. In conclusion, the dietary CMH supplementation improved intestinal morphology and immune activities of PMNs, thus giving rise to nutrient digestibility and reduce diarrhoea frequency in weanling pigs.

Inhibitory effect of Platycodon grandiflorum on T(H)1 and T(H)2 immune responses in a murine model of 2,4-dinitrofluorobenzene-induced atopic dermatitis-like skin lesions

BACKGROUND

Platycodon grandiflorum is a traditional Asian medicine that is used to treat pulmonary and respiratory allergic disorders.

OBJECTIVE

to investigate the effects of P grandiflorum in vivo in an animal model of atopic dermatitis (AD), with particular emphasis on its effects on T(H)1 and T(H)2 immune responses.

METHODS

we established a model of AD-like skin lesions in NC/Nga mice. After oral administration of P grandiflorum, we measured cytokine and immunoglobulin profiles along with histologic examination of skin.

RESULTS

P grandiflorum was nontoxic in a 2,4-dinitrofluorobenzene-induced model of AD-like skin lesions in NC/Nga mice. AD symptoms in skin lesions improved after oral administration of P grandiflorum. IgE secretion was significantly downregulated in P grandiflorum-treated animals, accompanied by decreased levels of interleukin (IL) 4 and IgG1 and increased serum levels of IL-12p40 and IgG2a. In isolated splenocytes, the production of the T(H)1 cytokines IL-12p40 and interferon-γ was upregulated by P grandiflorum, whereas the levels of the T(H)2 cytokines IL-4 and IL-5 were downregulated in a mouse model of AD-like skin lesions.

CONCLUSIONS

these results suggest that P grandiflorum inhibits the development of AD-like skin lesions in NC/Nga mice by suppressing the T(H)2 cell response and increasing the T(H)1 cell responses. Our results indicate that P grandiflorum is safe and effective as a natural herbal medicine for the treatment of AD-like skin lesions.

Platycodin D inhibits adipogenesis of 3T3-L1 cells by modulating Kruppel-like factor 2 and peroxisome proliferator-activated receptor gamma

In this study, platycodin D was found to inhibit intracellular triglyceride accumulation in 3T3-L1 cells with an IC(50) of 7.1 microM. The expression levels of genes involved in lipid metabolism such as fatty-acid-binding protein 4 and lipoprotein lipase were significantly downregulated following treatment with platycodin D. Treatment with platycodin D also resulted in a reduction of Peroxisome proliferator-activated receptor(PPAR)gamma expression and its binding to target DNA sequence. Among the various upstream regulators of PPARgamma, the expression of Kruppel-like factor(KLF)2, an anti-adipogenic factor, was significantly upregulated following platycodin D treatment. When the upregulation of KLF2 was inhibited by KLF2 siRNA, the expression and binding of PPARgamma to its target sequence were significantly recovered under these conditions. The results of this study suggested that anti-adipogenic effect of platycodin D involves the upregulation of KLF2 and subsequent downregulation of PPARgamma.

Saponins from the roots of Platycodon grandiflorum stimulate osteoblast differentiation via p38 MAPK- and ERK-dependent RUNX2 activation

Changkil (CK), the aqueous extract of the roots of Platycodon grandiflorum, has been used as a traditional oriental medicine for the treatment of chronic adult diseases. Although a saponin fraction derived from CK (CKS) has been suggested to have a variety of functional effects, its effect on bone is unknown. In the present study, the effects of CKS on osteoblast differentiation and function were determined by analyzing the activity of alkaline phosphatase (ALP), an osteoblast marker, and the regulation of RUNX2, a master gene of osteoblast differentiation, in a mesenchymal stem cell line. CKS upregulated ALP activity and the expression of osteogenic marker genes in C2C12 cells. In addition, CKS increased the expression and transcriptional activity of RUNX2. To determine which signaling pathways are involved in the osteogenic effects of CKS, we tested the effect of inhibitors of kinases known to regulate RUNX2. CKS-induced enhancement of RUNX2 and ALP was inhibited by treatment with a p38 inhibitor (SB203580) and an ERK inhibitor (U0126). These findings suggest that CKS stimulates osteoblast differentiation by activation of RUNX2 via mechanisms related to the p38 MAPK and ERK signaling pathways. The regulation of RUNX2 activation by CKS may be an important therapeutic target for osteoporosis.

Metallothionein-III provides neuronal protection through activation of nuclear factor-kappaB via the TrkA/phosphatidylinositol-3 kinase/Akt signaling pathway

Metallothionein (MT)-III is associated with resistance to neuronal injury. However, the underlying mechanism for its effects is unclear. The present study investigated the mechanisms of MT-III protection of neuronal cells from hypoxia or DNA damage-induced cell death. MT-III reduced the hydrogen peroxide- or DNA damage-induced effects on neuronal cells, including the cell death, the activation of caspase-3 and -9, and the release of mitochondrial cytochrome c to the cytoplasm in a dose-dependent manner. MT-III also increased the activation of Akt, the phosphorylation and degradation of IkappaB, the nuclear translocation/accumulation and the transcriptional activity of nuclear factor-kappaB (NF-kappaB) in neuronal cells in a dose-dependent manner. The MT-III-induced antiapoptotic effects and increase in NF-kappaB activity were blocked by specific inhibitors of TrkA, phosphatidylinositol-3 kinase (PI3K), Akt, or NF-kappaB, indicating that MT-III provides neuronal protection by activating NF-kappaB through the TrkA/PI3K/Akt signaling pathway.

Inhibitory effect of Platycodi Radix on ovalbumin-induced airway inflammation in a murine model of asthma

Asthma is a chronic inflammatory disease of the airways characterized by an associated increase in airway responsiveness. In this study, we investigated the inhibitory effect of an aqueous extract from the root of Platycodi Radix (Changkil: CK) on airway inflammation in a murine model of asthma. Mice were sensitized and challenged by ovalbumin (OVA) inhalation to induce chronic airway inflammation and airway remodeling. CK markedly decreased the number of infiltrated inflammatory cells and the levels of Th1 and Th2 cytokines and chemokines compared with those in the OVA-induced group. In addition, CK reduced OVA-specific IgE levels in bronchoalveolar lavage (BAL) fluid. Based on lung histopathological studies, inflammatory cell infiltration and mucus hypersecretion were inhibited by CK administration compared to that in the OVA-induced group. Lung weight was reduced after CK administration. Also, increased generation of ROS in BAL fluid, as well as NF-kappaB nuclear translocation, by inhalation of OVA was diminished by CK. Moreover, CK reduced the OVA-induced upregulation of matrix metalloproteases activity. These findings indicate that oxidative stress may play a crucial role in the pathogenesis of bronchial asthma induced by OVA and that CK may be useful as an adjuvant therapy for the treatment of bronchial asthma.

A promising balanced Th1 and Th2 directing immunological adjuvant, saponins from the root of Platycodon grandiflorum

The haemolytic activities and adjuvant potentials of Platycodon grandiflorum saponin (PGS) and its fractions on the cellular and humoral immune responses of ICR mice against ovalbumin (OVA) were evaluated. PGS was subjected to silica gel column chromatography to afford four fractions, and two fractions PGSC and PGSD selected for testing for activities because of containing dominant saponin peaks. PGS, PGSC, and PGSD showed a slight haemolytic effect, with their HD50 value being 37.91+/-2.24, 21.30+/-1.22, 37.58+/-1.86 microg/ml against 0.5% rabbit red blood cell, respectively. ICR mice were immunized subcutaneously with OVA 100 microg alone or with OVA 100 microg dissolved in saline containing Alum (200 microg), Quil A (10 microg), PGS (50, 100 or 200 microg), PGSC, or PGSD (25, 50 or 100 microg) on days 1 and 15. Two weeks later (day 28), concanavalin A (Con A)-, pokeweed (PWM)-, and OVA-stimulated splenocyte proliferation and OVA-specific antibodies in serum were measured. PGS and PGSC significantly enhanced the Con A-, PWM-, and OVA-induced splenocyte proliferation in OVA-immunized mice at three doses (P<0.01 or P<0.001). However, no significant differences (P>0.05) were observed among the OVA group, OVA/Alum group and OVA/PGSD group. OVA-specific IgG, IgG1, and IgG2b antibody levels in serum were significantly enhanced by PGS, PGSC, and PGSD compared with OVA control group (P<0.05, P<0.01, or P<0.001). Moreover, the adjuvant effects of PGSC (50 or 100 microg) on the OVA-specific IgG, IgG1, and IgG2b antibody responses to OVA in mice were more significant than those of Alum. In conclusion, PGS seem to be a promising balanced Th1 and Th2 directing immunological adjuvants which can enhance the immunogenicity of vaccine.

Platycodin D induces apoptosis and decreases telomerase activity in human leukemia cells

Platycodin D (PD) is a major constituent of triterpene saponins found in the root of Platycodon grandiflorum. Recent studies have demonstrated that PD is a potentially interesting candidate for use in cancer chemotherapy. However, the molecular mechanisms responsible for PD-induced telomerase inhibition remain to be poorly known. In this study, we examined the effects of PD treatment on telomerase activity in different human leukemia cell lines. At concentrations between 10 and 20 microM, PD exerted a dose-dependent direct cytotoxic effect and inhibition of telomerase activity via downregulation of hTERT expression. Because c-Myc and Sp1 are known to directly regulate transcription of hTERT, we also evaluated the expression and DNA binding activity of these proteins. PD treatment reduced c-Myc and Sp1 protein levels and DNA binding activities in a dose-dependent manner. We also observed that PD treatment downregulates the activation of Akt, thereby reducing the phosphorylation and nuclear translocation of hTERT. We conclude that PD has direct cytotoxic effect on human leukemia cells and suppresses telomerase activity through transcriptional and posttranslational suppression of hTERT.

Modified Arabinoxylan Rice Bran (Mgn-3/Biobran) Enhances Intracellular Killing of Microbes by Human Phagocytic Cells in Vitro

Phagocytic cells, comprised of neutrophils and moncytyes/macrophages, play a key role in the innate immune response to infection. Our earlier study demonstrated that arabinoxylan rice bran (MGN-3/Biobran) activates murine peritoneal macrophage and macrophage cell lines. In this study, we investigated whether MGN-3 can upregulate the phagocytic activity of human phagocytes in peripheral blood to phagocytize Escherichia coli (E. coli), trigger the oxidative burst and produce cytokines. Phagocytic cells were pre-labeled with dichlorofluorescin diacetate dye and were incubated with phycoerythrin-labeled E. coli in the presence or absence of MGN-3. Phagocytosis and oxidative burst were assessed by flow cytometry. Results showed that treatment with MGN-3 enhanced the phagocytosis of E. coli by neutrophils and moncytes. This was associated with an increased oxidative burst. In addition, it caused a significant induction of cytokines (TNF-α, IL-6, IL-8 and IL-10); the effect was detected at 1 μg/ml and increased in a dose-dependent manner (P≤ 0.01). Notably, MGN-3 alone had no effect on the growth of 31 strains of bacteria suggesting that MGN-3 modulates phagocytic cellular function. These findings may have applications in the treatment of infections in the elderly and in immunocompromised patients.

Fish oil increases cholesterol storage in white adipose tissue with concomitant decreases in inflammation, hepatic steatosis, and atherosclerosis in mice

Although fish oil has hypolipidemic and antiatherosclerotic properties, the potential for white adipose tissue (WAT) to mediate these effects has not been studied. LDL-receptor deficient (LDLR-/-) mice were fed high fat, olive oil-containing diets supplemented with additional olive oil or with fish oil for 12 wk. Fish oil feeding significantly reduced plasma lipid levels. In contrast, lipid storage in WAT was increased in fish oil-fed mice as evidenced by increased total fat (P < 0.05) and perigonadal WAT mass (P < 0.05), increased cholesterol storage (P < 0.001), and adipocyte hypertrophy. Despite increased adipose tissue mass, WAT-specific inflammation and insulin sensitivity were improved (P < 0.05), concomitant with reduced macrophage infiltration. Furthermore, fish oil increased WAT and plasma levels of adiponectin. In addition, fish oil feeding decreased the formation of proinflammatory F2- isoprostanes, markers of oxidative stress (P < 0.05). The increased WAT lipid storage in fish oil-fed mice was associated with reduced lipid accumulation in liver (P < 0.05) and decreased atherosclerotic lesion area (P < 0.05). Taken together, these data highlight the specific role of WAT in regulating dietary fish oil-mediated improvement in systemic lipid homeostasis and atherosclerosis.

Inflammatory effect of endosulfan via NF-κB activation in macrophages

Macrophages are essential for the inflammatory response process because they release a wide variety of proinflammatory mediators. Endosulfan is extremely toxic to invertebrates and has been implicated in various mammalian toxicities. However, its influence on production of cytokine or on the functions of macrophages is unclear. This study examined the effects of endosulfan on the production of nitric oxide (NO) and proinflammatory cytokines (IL-1beta, IL-6, TNF-alpha), and examined the molecular mechanism in macrophages. Exposing macrophages to endosulfan induced the production of NO and proinflammatory cytokines and the expression of these genes. The transient transfection and electrophoretic mobility shift assays with the NF-kappaB binding sites showed that the NF-kappaB transcription factor mediated the endosulfan-induced increase in the expression levels of iNOS and proinflammatory cytokines. These results show that endosulfan stimulates the production of NO and proinflammatory cytokines and can up-regulate the gene expression levels through NF-kappaB transactivation. Overall, these results suggest that endosulfan has inflammatory potential.

Antihyperglycemic effects of Platycodon grandiflorum (Jacq.) A. DC. extract on streptozotocin-induced diabetic mice

The root of Platycodon grandiflorum (Jacq.) A. DC has been reported to have a wide range of health benefits in oriental food. This study examined the hypoglycemic effects of Platycodon grandiflorum (Jacq.) A. DC aqueous-ethanol extract (PGE) in streptozotocin (STZ) -induced diabetic ICR mice (STZ diabetic mice) for the first time. The effects of PGE on blood glucose, plasma insulin levels and body weight were investigated. A significant decrease in blood glucose levels was observed after single administration of PGE. Furthermore, Glibenclamide and PGE significantly suppressed the rise in blood glucose after 30 min in the acute glucose tolerance test. Treatment with glibenclamide and PGE resulted in a reduction in blood glucose levels from the 2nd week, and this reduction was maintained until the 4th week of treatment. The body weight changed slightly in glibenclamide and PGE treated mice in comparison with the STZ control group. Plasma insulin levels were increased with glibenclamide treatment in STZ diabetic mice, whereas such effect was not observed with PGE. These results indicated that PGE could induce hypoglycemic effects without stimulating insulin secretion.

Qualitative and quantitative determination of ten major saponins in Platycodi Radix by high performance liquid chromatography with evaporative light scattering detection and mass spectrometry

Saponins in Platycodi Radix (platycosides) exhibit potent biological activities in mammalian systems, including several beneficial effects such as anti-inflammatory, immunomodulatory and anti-obesity activities. In this study, we developed a new HPLC separation coupled with evaporative light scattering detector (ELSD) for the simultaneous quantitative determination of ten major saponins in Platycodi Radix. Simultaneous separation of these saponins was achieved on a C18 analytical column. The mobile phase consisted of a gradient of aqueous acetonitrile. The method was validated for linearity, precision, accuracy, limit of detection and quantification. Electrospray ionization mass spectrometry (ESI-MS) and liquid chromatography coupled with on-line mass spectrometry (LC-ESI MS/MS) were applied to identify platycosides in the purified fractions and in the crude extract. Under ESI-MS/MS conditions, the fragmentation patterns of [M-H]- ions exclusively show signals corresponding to cleavage of the glycosidic bonds, thus allowing a rapid identification of saponins in the crude extract of Platycodi Radix. The validated HPLC method provides a new basis of overall assessment on quality of Platycodi Radix, and ESI-MS/MS and LC-ESI MS/MS approaches offers analytical tools for a rapid screening of platycosides in the crude extract.

Chemopreventive effect of saponins derived from roots ofPlatycodon grandiflorum on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung tumorigenesis in A/J mice

This study examined the chemopreventive effect of saponins that were isolated from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil saponins (CKS), against the tobacco-specific carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), -on lung tumorigenesis in A/J mice. The mice were treated with a single NNK dose (100 mg/kg b.w., i.p.). CKS (0.5, 1,4 mg/kg body wt.) was administered orally daily for 3 days/week beginning 1 day after the NNK treatment and was maintained throughout the experiment. The administration of CKS suppressed the NNK-induced increase in the level of proliferating cell nuclear antigen, which are a marker of cell proliferation, in the lungs of the mice 4 weeks after the NNK injection. Twenty-five weeks after the NNK treatment, the mice were sacrificed and the number of surface lung tumors was measured. CKS significantly reduced the number of lung tumors induced by NNK in a dose dependent manner. These results suggest that CKS suppresses the development of lung tumors and has a chemopreventive effect against NNK-induced mouse lung tumorigenesis.

Inhibition of tumor invasion and metastasis by aqueous extract of the radix of Platycodon grandiflorum

Platycodon grandiflorum is a traditional oriental herbal medicine that is known for its immunostimulatory and anti-tumor effects. This study examined the anti-metastatic activities of an aqueous extract from the root of P. grandiflorum (Changkil: CK) using in vitro and in vivo metastasis assays. CK inhibited the invasion of B16-F10 melanoma cells through a reconstituted basement membrane (Matrigel)-coated filter, and strongly inhibited the adhesion of B16-F10 melanoma cell to extracellular matrices such as Matrigel, fibronectin and laminin substrates. CK also inhibited an experimentally induced lung cancer and prolonged the survival time in vivo. In addition, CK augmented NK cell activity. These results show that CK can reduce the extent of a lung metastasis of B16-F10 melanoma cells by inhibiting the adhesion of tumor cells to the basement membrane possibly and activating NK cells.

Cholesterol-lowering effect of platycodin D in hypercholesterolemic ICR mice

This study investigates the in vivo hypocholesterolemic action of platycodin D and its in vitro evidence for the cholesterol-lowering properties. In order to examine the effects of platycodin D on hypercholesterolemia in male ICR mice, platycodin D with doses of 15, 30 or 50 mg/kg was orally administered for 8 weeks. Changes in body weight and daily food intake were measured regularly during the experimental period. Final contents of triglyceride and different types of cholesterol in the serum, livers and feces were determined. The effects of platycodin D on cholesterol metabolism were further investigated with several in vitro assays, including antioxidant effect on low density lipoprotein oxidation, inhibition of human acyl-coenzyme A:cholesterol acyltransferase (hACAT) and serum lipoprotein associated-phospholipase A(2) (Lp-PLA(2)), as well as the regulation of farnesoid X receptor. The formation of insoluble complex between platycodin D and cholesterol was also investigated. Following an eight week experimental period, the body weights of platycodin D-fed mice were less than those of control mice on a high cholesterol diet by 11.2+/-5% (P<0.01) with 15 mg/kg platycodin D, 11.7+/-5% (P<0.01) with 30 mg/kg platycodin D, and 23.4+/-7.9% (P<0.0001) with 50 mg/kg platycodin D, respectively. A decrease in daily food consumption was also noted in most of the treated animals. Triglyceride and cholesterol concentrations were decreased in serums and livers, but increased in feces. Some of the in vitro observations revealed that the hypocholesterolemic effect of platycodin D is partly associated with inhibition to hACAT activity and antagonism to the farnesoid X receptor as well as the formation of insoluble complex with between platycodin D and cholesterol. Both in vivo and in vitro results demonstrate a potential value of platycodin D as a novel cholesterol-lowering and anti-atherogenic candidate.

Platycodin D-induced apoptosis through nuclear factor-κB activation in immortalized keratinocytes

Platycodi Radix is the root of Platycodon grandiflorum and it is widely used in the traditional Oriental medicine as an expectorant for pulmonary diseases and a remedy for respiratory disorders. Platycodin D is the major constituent of triterpene saponins in the root. This study investigates apoptosis by platycodin D in immortalized human keratinocytes (HaCaT). Platycodin D-induced apoptosis in HaCaT cells was confirmed by DNA fragmentation, caspase-3 activation, and caspase-8 activation. Platycodin D could activate inhibitor of nuclear factor-kappaB kinase (IKK)-beta in the nuclear factor-kappaB (NF-kappaB) activation of upstream level, but not IKK-alpha. Pretreated-N-tosyl-l-phenylalanine chloromethyl ketone (TPCK), a potent NF-kappaB inhibitor, could suppress the induction of apoptosis and activation of NF-kappaB of HaCaT cells by platycodin D. We also demonstrated that platycodin D-mediated apoptosis of HaCaT cells upregulates Fas receptor and Fas ligand (FasL) expression, but did not exhibit p53 activation. HaCaT cells were also transfected with pFLF1, which preserves the promoter region of Fas receptor gene containing NF-kappaB binding site. On incubation with platycodin D, the NF-kappaB activity related to Fas receptor increased in a dose-dependent manner. Among the major transcription elements on Fas receptor and FasL promoter, NF-kappaB activation was shown to have an essential role in the expression of the death receptor such as FasL. These results suggest that platycodin D has the ability to induce apoptosis in HaCaT cells through the upregulation of Fas receptor and FasL expression via to NF-kappaB activation in the transcriptional level. These results demonstrate that the NF-kappaB activation plays a crucial role in the induction of apoptosis in human HaCaT cells on treatment with platycodin D.

The role of lipolysis in mediating the proinflammatory effects of very low density lipoproteins in mouse peritoneal macrophages

Hypertriglyceridemia is an important risk factor for atherosclerosis, especially in obesity. Macrophages are one of the primary cell types involved in atherogenesis and are thought to contribute to lesion formation through both lipid accumulation and proinflammatory gene expression. In this study, we sought to determine the direct impact of triglyceride (TG)-rich VLDL-induced lipid accumulation on macrophage proinflammatory processes. Incubation of mouse peritoneal macrophages with 100 microg/ml VLDL for 6 h led to 2.8- and 3.7-fold increases in intracellular TGs and FFAs, respectively (P < 0.05). The inflammatory proteins tumor necrosis factor-alpha, interleukin-1beta, monocyte chemoattractant protein-1, intercellular adhesion molecule-1, matrix metalloproteinase 3 (MMP3), and macrophage inflammatory protein-1alpha (MIP-1alpha) were all upregulated by at least 2-fold (P < 0.05) in a dose-dependent manner in VLDL-treated macrophages. The increase in inflammatory gene expression coincided with the phosphorylation of the mitogen-activated protein kinase (MAPK) pathway members extracellular signal-regulated kinase (ERK) 1/2, stress-activated protein kinase/c-Jun NH2-terminal kinase, and p38 MAPK and was ameliorated by U0126, an inhibitor of ERK1/2. Inhibition of extracellular TG hydrolysis with tetrahydrolipstatin (Orlistat) resulted in the absence of intracellular TG and FFA accumulation and was accompanied by the amelioration of ERK1/2 phosphorylation and MIP-1alpha gene expression. These data indicate that VLDL hydrolysis, and the subsequent accumulation of intracellular FFAs and TGs, plays a substantive role in mediating the proinflammatory effects of VLDL. These data have important implications for the direct proatherogenic effects of VLDL on macrophage-driven atherosclerosis.