Comparison of structure and the synergistic anti-hepatocellular carcinoma effect of three polysaccharides from vinegar-baked Radix Bupleuri.

Three polysaccharides from Vinegar-baked Radix Bupleuri (VR) and their combined effects were studied. VRP3-3 was a branched polysaccharide with a molecular weight (Mw) of 16.05 kDa characterized by 1,5 linked-α-Araf, 1,2,4 linked-α-Rhap and 1,4 linked-α-GalpA as main chain with a small amount of esterification and acetylation groups. And side chains were connected to the O-3 of Araf, O-4 of Rhap. VRP2-3 had a Mw of 95.35 kDa, its backbone comprised of 1,2 linked-α-Galp, 1,4 linked-ß-GalpA(O-Ac), 1,2,4 linked-α-Rhap and 1,5 linked α-Araf. The residues of 1,4 linked-ß-Galp,1,3 linked-ß-Galp and 1,6 linked-ß-D-Galp were connected at O-4 of α-L-Rhap and O-3 of α-L-Araf as its side chain. VRP2-4 was a pectin polysaccharide with a Mw of 57.90 kDa. Its main chain was constituted of 1,4 linked-α-Galp, 1,4 linked-α-GalpA(OMe), 1,4 linked-α-GalpA and 1,2,4 linked-α-Rhap, with some acetylation. As the major side chain, 1,5 linked-α-Araf was connected to O-4 of α-Rhap, a small amount of t-α-Galp and t-α-Manp were also included. VRP3-3 showed superior synergistic effect in combination with paclitaxel, methotrexate and cisplatin than the other two polysaccharides. The VR polysaccharide with a ~16 kDa molecular weight, a larger polymerization degree of arabinan in the backbone and the triple helix structure are the key structures for activity. Together, our findings clarify the pharmacodynamic basis of VR and provide promising adjuvants for Hepatocellular Carcinoma (HCC) chemotherapy.

A novel pectin polysaccharide from vinegar-baked Radix Bupleuri absorbed by microfold cells in the form of nanoparticles.

Polysaccharides of vinegar-baked Radix Bupleuri (VBCP) have been reported to exhibit liver-targeting and immunomodulatory activities through oral administration, but the absorption behavior and mechanism of VBCPs have not been extensively studied. In this study, a novel HG type pectin polysaccharide, VBCP1-4, with a high molecular weight of 2.94 × 106 Da, was separated from VBCP. VBCP1-4 backbone was contained 1,4-α-D-GalpA, 1,4-α-D-GalpA6OMe, 1,3,4-α-D-GalpA and 1,2,4-α-D-Rhap. The branches were mainly contained 1,5-α-L-Araf, 1,3,5-α-L-Araf, t-α-L-Araf and t-α-D-Galp, which linked to the 3 position of 1,3,4-α-D-GalpA and the 4 position of 1,2,4-α-D-Rhap. VBCP1-4 could self-assemble to nanoparticles in water, with CMC values of 106.41 µg/mL, particle sizes of 178.20 ± 2.82 nm and zeta potentials of -23.19 ± 1.44 mV. The pharmacokinetic study of VBCP1-4, which detected by marking with FITC, revealed that it could be partially absorbed into the body through Peyer's patches of the ileum. In vitro absorption study demonstrated that VBCP1-4 was difficult to be absorbed by Caco-2 cell monolayer, but could be absorbed by M cells in a time and concentration dependent manner. The absorption mechanism was elucidated that VBCP1-4 entered M cells through clathrin-mediated endocytosis in the form of nanoparticles. These findings provide valuable insights into the absorption behavior of VBCP and contribute to its further development.

Vinegar-baked Radix Bupleuri enhances the liver-targeting effect of rhein on liver injury rats by regulating transporters.

OBJECTIVE: This study aimed to explore whether the liver-targeting enhancing effect of vinegar-baked Radix Bupleuri (VBRB) on rhein was achieved by affecting transporters, metabolism enzymes as well as hepatocyte nuclear factor 1α/4α (HNF1α/HNF4α) in liver injury. METHODS: The effect of VBRB on the efficacy of rhein was performed with the LPS-induced acute liver injury rat model. Aspartate aminotransferase (AST), alanine transaminase (ALT) and superoxide dismutase (SOD) levels were determined and histopathological examination was taken. Drug concentrations in tissues were determined by high performance liquid chromatography (HPLC). The protein expressions of drug transporters, metabolic enzymes and hepatic nuclear factors were determined by Western blotting and ELISA assays. KEY FINDING: VBRB improved the liver protecting effect of rhein, which was consistent with its promoting effect on targeted enrichment of rhein in the liver. VBRB or in combination with rhein inhibited P-glycoprotein (Pgp) and multi-resistance related protein 2 (MRP2), while increased organic anion transporting polypeptide 2 (OATP2), which might be the reason why VBRB promoted liver-targeting effect of rhein. CONCLUSION: VBRB enhances the liver-protecting effect of rhein by down-regulating Pgp, MRP2, and up-regulating OATP2.

Polysaccharides of vinegar-baked radix bupleuri promote the hepatic targeting effect of oxymatrine by regulating the protein expression of HNF4α, Mrp2, and OCT1.

ETHNOPHARMACOLOGICAL RELEVANCE: Vinegar-baked Radix Bupleuri (VBRB) is a processed form of Bupleurum chinense DC. As a well-known meridian-guiding drug, it is traditionally used as a component of traditional Chinese medicine formulations indicated for the treatment of liver diseases. However, the liver targeting component in VBRB remains unclear. Therefore, this study aims to explore the efficacy and mechanism of PSS (polysaccharides in Vinegar-baked Radix Bupleuri) in enhancing liver targeting. MATERIALS AND METHODS: Drug distribution of OM alone or combined with PSS was investigated in vivo. Relative uptake efficiency (RUE) and relative targeting efficiency (RTE) were calculated to evaluate liver targeting efficiency. The mRNA and protein expression of organic cation transporter 1 (OCT1), multi-drug resistance protein 2 (Mrp2), and hepatocyte nuclear factor 4α (HNF4α) in the liver were determined by q-PCR and Western blot. Then, AZT, the inhibitor of OCT1 and BI6015, the inhibitor of HNF4α were used to investigate regulatory mechanisms involved in the uptake of OM in the cell. At last, the role of PSS in the anti-hepatitis B virus (HBV) was explored on HepG2.2.15. RESULTS: PSS increased the AUC of OM in the liver and increase the RUE and RTE in the liver which indicated a liver targeting enhancing effect. The mRNA and protein expression of OCT1 was increased while Mrp2 and HNF4α decreased. PSS could increase the uptake of OM in HepG2 by increasing the protein expression of HNF4α and OCT1, while inhibited Mrp2. Moreover, PSS combined with OM could enhance the anti-HBV effect of OM. CONCLUSION: PSS enhanced the liver targeting efficiency and the underlying mechanism related to up-regulating the expression of OCT1 and HNF4α, while down-regulating of Mrp2. These results suggest that PSS may become a potential excipient and provide a new direction for new targeted research.

Polysaccharide from vinegar baked radix bupleuri as efficient solubilizer for water-insoluble drugs of Chinese medicine.

The development of solubilizers with high efficiency, high safety and simple technology is one of the important fields in modern pharmaceutical industry. Our previous study found that vinegar baked Radix Bupleurum polysaccharides (VBCP) was a potential candidate. This study aimed to clarify which polysaccharide in VBCP had solubility enhancement effect and its solubilizing mechanism. Here, we reported that a novel acidic branched polysaccharide from VBCP, VBCP-3-A, which was non-toxic and had high solubility to baicalin and rhein. It was much better than that of Tween 80. The solubilization mechanism might be that VBCP-3-A self-assembled to form micelle-like aggregates in water, which can encapsulate water-insoluble constituents through the interaction of both hydrogen bonding and hydrophobic forces. in vivo pharmacokinetic study showed that VBCP-3-A increased Cmax and AUC (0-t) of baicalin and rhein. Those results suggested that VBCP-3-A was a potential solubilizer with high efficiency and high safety.

Enhanced liver-targeting via coadministration of 10-Hydroxycamptothecin polymeric micelles with vinegar baked Radix Bupleuri.

BACKGROUND: Vinegar baked Radix Bupleuri (VBRB) is a wildly used traditional Chinese medicine, it could be used as a meridian guided drug to enhance liver targeting efficiency of the delivered drug in addition to its therapeutic effect. PURPOSE: To investigate the liver targeting effect induced by VBRB via coadministration with 10-Hydroxycamptothecin loaded polymeric micelles. METHODS: First of all, the inhibitory effect of VBRB on the activity of glutathione S-transferase (GST) was investigated in vitro to select the most effective extract. After oral administration of 10-Hydroxycamptothecin (HCPT) polymeric micelles with low, medium and high doses of VBRB, pharmacokinetic parameters, including the ratio of Cmax in the liver (Ce) and the relative uptake efficiency (RUE), were employed to assess the liver targeting efficiency. RESULTS: It was found that VBRB extract BC1 has the strongest inhibition effect on GST activity in the five extracts. By coadministration of HCPT loaded micelles with three doses of BC1, the AUC0-t of HCPT in the liver raised by 42.5%, 23.0%, -0.2%, with RUE 1.45, 1.23, 1.02 for low, medium and high dose groups, respectively, indicating that low and medium dose of BC1 presented better liver-targeting enhancing effect than that of the high dose, which corresponded to the commonly used dose of VBRB in traditional Chinese medicine formulae. CONCLUSIONS: VBRB could effectively enhance the liver-targeting efficiency of HCPT loaded polymeric micelles after oral coadministration. Such a simple but effective strategy may enlighten on the potential use of meridian guided drug together with modern drug delivery system to achieve better active drug targeting.

Integrative hepatoprotective efficacy comparison of raw and vinegar-baked Radix Bupleuri using nuclear magnetic resonance-based metabolomics.

Radix Bupleuri (RB), with a Chinese name Chaihu, is one of the most popular Traditional Chinese herbal drug. It can be baked with vinegar to afford vinegar-baked Radix Bupleuri (VBRB), which is used in Traditional Chinese Medicine (TCM) for liver diseases treatment. In the present study, nuclear magnetic resonance-based metabolomic approach was used to compare the liver protective effect of RB and two types of VBRBs, which were prepared by two kinds of vinegar. The contents of 14 metabolites in the liver of carbon tetrachloride (CCl4) treated mice were significantly altered in comparison with control group, and VBRB prepared by Shanxi vinegar showed best effect as revealed by the amount and regulatory degree of the perturbed metabolites. The metabolism pathways analysis showed that the liver protective effect was related with the energy metabolism, lipid metabolism, ketone body metabolism, glutathione metabolism, amino acids metabolism and nucleotide synthesis. The results presented here showed that metabolomic approach made it possible to disclose the subtle biological difference between two types of VBRB, which highlight the potential of metabolomic approach to quantitatively compare the pharmacological effect of the herbal drugs.

Vinegar amount in the process affected the components of vinegar-baked Radix Bupleuri and its hepatoprotective effect.

BACKGROUND: Bupleuri Radix (in Chinese Chaihu), the dried roots of Bupleurum Chinense DC, is a traditional Chinese medicine widely used to treat fever, hepatitis, jaundice, nephritis, dizziness. When baked with vinegar, its effect is more focused on liver related disease. This paper was undertaken to determine the best vinegar amount in the processing and explore its key efficacy components. METHODS: Hepatoprotective effects of Radix Bupleuri after processing with different amount of vinegar (1:5, 2:5, 3:5) were investigated on liver hurt rats, and the change of constituents were analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). RESULTS: With the increasing amount of vinegar, the hepatoprotective effects of vinegar-baked Radix Bupleuri (VBRB) and the content of saikosaponin b2 increased. CONCLUSION: These results suggested that vinegar amount in the process affected the pharmacological effect of VBRB significantly and saikosaponin b2 may be the key efficacy component of it.

Modulatory effects of extracts of vinegar-baked Radix Bupleuri and saikosaponins on the activity of cytochrome P450 enzymes in vitro.

1. In this article, the modulatory effects of extracts from vinegar-baked Radix Bupleuri (VBRB) and saikosaponins on the activity of CYP1A2, CYP2C9 and CYP3A4 were investigated in vitro. 2. Microsomal in vitro incubation method was utilized to simulate metabolic reaction under physiological environment by incubating the marker with liver microsomes in the absence or presence of VBRB and saikosaponins. The contents of 4-acetamidophenol, 6ß-hydroxyltestosterone and 4-hydroxydiclofenac, the metabolites of phenacetin, testosterone and diclofenac, which were selected as specific probe drugs of CYP1A2, CYP2C9 and CYP3A4, respectively, were analyzed by high-performance liquid chromatography. 3. The production of the metabolites was incubation time dependent. The modulatory effects of different VBRB extracts and saikosaponins on CYP isoforms increased with concentration. Among all the extracts studied, BC1 has a strong inhibition effect compared to the three CYP isoforms tested, while the others have only significant inhibition on the activity of CYP2C9. 4. This in vitro study demonstrated that various extracts of VBRB tested in this study have negligible potential to interfere with CYP1A2- and CYP3A4-metabolized drugs; risk of herb-drug interaction might occur when VBRB is concurrently taken with CYP2C9 substrates.

Effect of saikosaponins and extracts of vinegar-baked Bupleuri Radix on the activity of ß-glucuronidase.

In Traditional Chinese Medicine, liver targeting is usually achieved by coadministration with Vinegar-baked Radix Bupleuri (VBRB), but the mechanism is unclear. In this paper, the influence of VBRB on the activity of ß-glucuronidase was investigated and compared with that of saikosaponins. The activity of ß-glucuronidase was measured by microplate reader using a 4-nitrophenyl-ß-d-glucuronide substrate. The change of 4-nitrophenol content was used to characterize the activity of ß-glucuronidase. Bupleurum chinenes were found to be the inhibitor of ß-glucuronidase. The inhibition rate of Bupleurum chinenes extracts BC1 (high molecular weight polysaccharides), BC2 (ethanol soluble/water insoluble component), BC3 (extracted by n-butanol, soluble in water), and BC4 (low molecular weight water soluble parts) on the activity of ß-glucuronidase was found to be 45.15%, 33.94%, 24.94%, and 34.54%, respectively, after 1 h incubation, with BC1 showing the highest inhibition rate. In contrast, the saikosaponins were demonstrated to be the promoter of ß-glucuronidase, with promotion rates of 333.56%, 217.04%, 247.87%, 149.75%, and 92.50% for saikosaponin standard samples A, B, B2, C, and D, respectively, (p<0.05). In conclusion, inhibiting the activity of ß-glucuronidase might be one of the reasons why VBRB could influence drug distribution upon its coadministration with other drugs. Since saikosaponins and VBRB extracts have opposite effect, more attention should be paid to the content of saikosaponins in the extracts upon its application.