Effect of dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'- dicarboxylate (DDB) on chemical-induced liver injury

Interactions Between Natural Products and Tamoxifen in Breast Cancer: A Comprehensive Literature Review

Introduction: Tamoxifen (TAM) is the most commonly used hormone therapeutic drug for the treatment of estrogen receptor-positive (ER+) breast cancer. 30%–70% of clinical breast cancer patients use natural products, which may increase the likelihood of drug interactions.

Objective: To evaluate the evidence for the interactions between natural products and TAM in breast cancer.

Methods: Electronic databases, including PubMed, CINAHL Plus (via EbscoHost), European PMC, Medline, and Google Scholar, were searched for relevant publications. The search terms include complementary and alternative medicine, natural products, plant products, herbs, interactions, tamoxifen, breast cancer, and their combinations.

Results: Various in vitro and in vivo studies demonstrated that the combined use of natural products with TAM produced synergistic anti-cancer effects, including improved inhibition of tumor cell growth and TAM sensitivity and reduced side effects or toxicity of TAM. In contrast, some natural products, including Angelica sinensis (Oliv.) Diels [Apiaceae], Paeonia lactiflora Pall., Rehmannia glutinosa (Gaertn.) DC., Astragalus mongholicus Bunge, and Glycyrrhiza glabra L. [Fabaceae], showed estrogen-like activity, which may reduce the anti-cancer effect of TAM. Some natural products, including morin, silybin, epigallocatechin gallate (EGCG), myricetin, baicalein, curcumin, kaempferol, or quercetin, were found to increase the bioavailability of TAM and its metabolites in vivo. However, three are limited clinical studies on the combination of natural products and TAM.

Conclusion: There is evidence for potential interactions of various natural products with TAM in pre-clinical studies, although the relevant clinical evidence is still lacking. Further studies are warranted to evaluate the potential interactions of natural products with TAM in clinical settings.

Antihyperlipidemic, anti-inflammatory, analgesic, and antipyretic activities of "dimethyl dimethoxy biphenyl dicarboxylate" in male Wistar rats

Dimethyl dimethoxy biphenyl (DDB) dicarboxylate has been applied as a therapeutic modality for curing liver diseases, particularly hepatitis virus. The objective of this study was to assess the protective potential against Triton X-100 induced abnormal fat metabolism in addition to anti-inflammatory, analgesic, and antipyretic effects of DDB. The anti-inflammatory, antinociceptive, and antipyretic of DDB were investigated through induction of paw edema, pain, and fever in experimental rats. DDB decreased cholesterol and triglyceride contents. DDB resulted in inhibition of inflammation, nociception, and fever in the experimental models. DDB improved lipid profile, as evidence of hypolipidemic potential. It also showed anti-inflammatory, analgesic, and antipyretic properties.

Efficacy and Safety of Biphenyl Dimethyl Dicarboxylate and Ursodeoxycholic Acid Combination in Chronic Hepatitis Related to Metabolic Syndrome Components

Backgrounds/Aims

Steatohepatitis related to metabolic syndrome is a chronic liver disease prevalent in patients not only with non-alcoholic steatohepatitis but also with alcoholic liver disease and chronic viral hepatitis. On the other hand, there is limited data on the effects of hepatotonic agents in these patients. Therefore, this study evaluated the efficacy of a combined hepatotonic agent in this population.

Methods

Thirty-three adults with chronic hepatitis and one or more components of metabolic syndrome were assigned randomly to receive biphenyl dimethyl dicarboxylate/ursodeoxycholic acid or a placebo for 24 weeks. The primary outcome was the normalization of ALT (≤40 U/L). The secondary outcomes were the change in controlled attenuation parameter, transient elastography, and Chronic Liver Disease Questionnaire score.

Results

The 33 patients were assigned randomly to two groups. Eight (50%) of 16 patients who received the intervention drug showed the normalization of ALT, whereas only one (6%) of 17 patients in the placebo group did so. In contrast, the change in controlled attenuation, transient elastography, and Chronic Liver Disease Questionnaire were similar in the two groups. ALT was changed significantly during the four assessment periods, and this change was affected by the group. The interaction between the group and time was also significant. AST was changed significantly during the same period. This change was not affected by the group.

Conclusions

Biphenyl dimethyl dicarboxylate/ursodeoxycholic acid combination reduced ALT in chronic liver disease related to metabolic syndrome. On the other hand, there is no evidence that this leads to improved hepatic steatosis and fibrosis within 6 months.

Possible carcinogenic potential of dimethyl dimethoxy biphenyl dicarboxylate in experimental animals

Dimethyl dimethoxy biphenyl dicarboxylate (DDB) has been extensively used in the treatment of liver diseases accounting for 1–6% of the global disease burden. Cell replication, DNA synthesis, and proliferation, providing significant information about behavior of cells were examined in mice exposed to subchronic administration with DDB. Conventional liver functions specifically gamma-glutamyltransferase (γ-GT), a marker expressing liver canceration was also investigated. Normal mice were allocated into two groups each of 10 mice. The 1^st and 2^nd groups were treated with DDB in a dose of 50 mg/kg/day, 5 days/week for 1 month and 3 months, respectively. Comparable groups of normal mice were left without treatment as controls. Compared to normal control group, animals receiving DDB for 3 months showed marked elevations of both alanine aminotransferase and γ-GT, significant inhibition in cytochrome P450, a significant increase in the mean ploidy and 4C with moderate to marked increase in S-phase populations and the number of proliferating cell nuclear antigen-positive cells. In conclusion, this is the first report on the potential relationship between the subchronic administration of DDB and the increase in the hepatocyte proliferation, cell replication and DNA synthesis that may raise an alarm regarding possible DDB insult on the biological behavior of cells.

Study on four polymorphs of bifendate based on X-ray crystallography

Bifendate, a synthetic anti-hepatitis drug, exhibits polycrystalline mode phenomena with 2 polymorphs reported (forms A and B). Single crystals of the known crystalline form B and 3 new crystallosolvates involving bifendate solvated with tetrahydrofuran (C), dioxane (D), and pyridine (E) in a stoichiometric ratio of 1:1 were obtained and characterized by X-ray crystallography, thermal analysis, and Fourier transform infrared (FT-IR) spectroscopy. The differences in molecular conformation, intermolecular interaction and crystal packing arrangement for the four polymorphs were determined and the basis for the polymorphisms was investigated. The rotation of single bonds resulted in different orientations for the biphenyl, methyl ester and methoxyl groups. All guest solvent molecules interacted with the host molecule via an interesting intercalative mode along the [1 0 0] direction in the channel formed by the host molecules through weak aromatic stacking interactions or non-classical hydrogen bonds, of which the volume and planarity played an important role in the intercalation of the host with the guest. The incorporation of solvent-augmented rotation of the C–C bond of the biphenyl group had a striking effect on the host molecular conformation and contributed to the formation of bifendate polymorphs. Moreover, the simulated powder X-ray diffraction (PXRD) patterns for each form were calculated on the basis of the single-crystal data and proved to be unique. The single-crystal structures of the four crystalline forms are reported in this paper.

[Comparison on the efficacy and safety of biphenyl dimethyl dicarboxylate and ursodeoxycholic acid in patients with abnormal alanine aminotransferase: multicenter, double-blinded, randomized, active-controlled clinical trial]

BACKGROUND/AIMS

Chronic hepatocellular damage is closely associated with hepatic fibrosis and fatal complication in most liver diseases. The aim of this study is to compare the efficacy and safety of biphenyl dimethyl dicarboxylate (DDB) and ursodeoxycholic acid (UDCA) in patients with abnormal ALT.

METHODS

One-hundred thirty-five patients with elevated ALT were randomized to receive either 750 mg/day of DDB or 300 mg/day of UDCA for 24 weeks in 4 referral hospitals. Ninety-three (69%) patients had non-alcoholic steatohepatitits, 27 (20%) had alcoholic hepatitis, and 15 (11%) had chronic hepatitis. The primary end point was the rate of ALT normalization at week 24. The secondary endpoints were changes in AST, liver stiffness, and the incidence of adverse events.

RESULTS

A total of 101 patients completed 24 weeks of therapy. ALT normalization at week 24 was observed in 44 (80.0%) patients in DDB group and 16 (34.8%) in UDCA group (p<0.001). Higher mean reduction of ALT levels from baseline to 24 weeks was seen in DDB group compared with UDCA group (-70.0% vs. -35.9%, p<0.001). Normalization of AST level (p=0.53) and change in the liver stiffness (p=0.703) were not significantly different between the two groups. Severe adverse drug reaction occurred in 1 patient in DDB group but the subject continued therapy during the study period.

CONCLUSIONS

DDB was not inferior to UDCA for normalizing ALT level. Furthermore it was safe and well tolerated by patients with abnormal ALT.

Dimethyl dimethoxy biphenyl dicarboxylate attenuates hepatic and metabolic alterations in high fructose-fed rats

High fructose consumption is currently linked to metabolic disorders including insulin resistance and dyslipidemia as well as hepatic steatosis. Dimethyl dimethoxy biphenyl dicarboxylate (DDB) is a hepatoprotectant with antioxidant and anti-inflammatory properties. The aim of this study therefore is to evaluate the effect of DDB on high fructose-induced metabolic disturbances and hepatic steatosis in a rat model. Male Wistar rats were allocated into three groups: control, fructose-fed (10% in drinking water and 10% in diet), and fructose-fed DDB (300 mg/kg, orally)-treated groups. Rats were fed a high-fructose diet for 6 weeks, while DDB was administered for an additional 2 weeks. High-fructose consumption elevated serum glucose and insulin levels and impaired oral glucose tolerance test, revealing insulin resistance. It also increased serum triglycerides and alanine aminotransferase as well as visceral fat content and decreased serum high-density lipoprotein. Additionally, histopathological examination revealed that high fructose intake induced hepatic steatosis. These alterations were associated with increased serum uric acid as well as hepatic content of malondialdehyde and nitric oxide (NO) in addition to overexpression of inducible NO synthase (iNOS). DDB administration significantly ameliorated the high fructose-induced hepatic and metabolic alterations. In conclusion, DDB ameliorates high fructose-induced metabolic disorders and hepatic steatosis in rats. Such protection is, at least in part, due to the inhibition of lipid peroxidation, decrease in iNOS overexpression, and reduction of elevated uric acid.

Spectroscopic study on the interaction of catalase with bifendate and analogs

The interactions of bifendate (DDB) or analogs (Bicyclol, I, II and III) with catalase are analyzed by spectrophotometric methods. The fluorescence spectra results show the intrinsic fluorescence of catalase is strongly quenched by DDB or analogs with a static quenching procedure. The binding constants are obtained at three temperatures. The thermodynamics parameters (ΔH, ΔS, ΔG) indicate the hydrophobic and electrostatic interactions play a major role in the interaction. The results of synchronous fluorescence, UV-vis absorption and three-dimensional fluorescence spectra demonstrate that the microenvironments of Trp residue of catalase are disturbed by the analogs. Thermodynamic results showed that DDB is the strongest quencher and bind to catalase with the highest affinity among five compounds.

Contribution of a significant first-pass effect of dimethyl-4,4′-dimethoxy-5,6,5′,6′-dimethylene dioxybiphenyl-2,2′-dicarboxylate in the liver to its poor bioavailability in rats

Objectives

The objective of this study was to investigate the mechanism responsible for the poor oral bioavailability of dimethyl-4′,4′-dimethoxy-5,6,5′,6′-dimethylene dioxy-biphenyl-2,2′-dicarboxylate (DDB), a hepatoprotective agent, in rats.

Methods

DDB was intravenously administered to rats at doses of 0.2-1 mg/kg. To determine the hepatic first-pass effect in rats, DDB (1 mg/kg) was administered via the pyloric vein and the femoral vein. Direct measurement of intestinal permeability was attempted using Caco-2 cell monolayers and rat intestinal epithelium.

Key findings

A moment analysis indicated that the volume of distribution and clearance remained unchanged with the magnitude of the dose, indicating that DDB exhibited linear pharmacokinetics. When the area under the curve for DDB after administration to the pyloric vein was compared with that after femoral vein administration, the ratio (FH) was found to be 0.294, indicating a significant first-pass effect for DDB. The permeability of DDB was high in the rat intestine (1.78 ± 0.229 × 10−5 cm/s) and in Caco-2 cell monolayers (6.8 ± 0.70 × 10−5 cm/s), suggesting that DDB, in soluble form, was readily permeable across the intestinal epithelium.

Conclusions

These observations indicated that despite the fact that DDB was readily permeable to the intestinal epithelium, a significant first-pass metabolism was associated with its pharmacokinetics in rats.

Diphenyl Dimethyl Bicarboxylate in the Treatment of Viral Hepatitis, Adjuvant or Curative?

Diphenyl dimethyl bicarboxylate (DDB) has been used in some countries as hepatoprotectant adjuvant in the treatment of liver diseases, such as chronic viral hepatitis, chemical or drug induced hepatic damage. Its early confirmed efficacy is to normalize elevated blood alanine aminotransferase (ALT) from different etiologies, however, it can rarely affect the rest hepatic enzymes. In addition, the lowering or normalization of ALT in most cases occurs during DDB treatment, withdrawal of DDB administration results in ALT re-elevated. Hence, for a long time, it has been only used as adjuvant of liver disease therapy. It is still controversial that whether DDB can be beneficial to liver histology. The normalization of ALT in hepatitis does not indicate therapeutic efficacy if without substantial liver histology improvement. In recent years, more studies showed that DDB might have new therapeutical potentials in liver diseases, it may have the effect of anti-viral, anti-malignancy. These new findings were mostly based on the in vitro or animal experiments, more basic studies and clinical trials are needed to ascertain these efficacies, prior to that stage, it is recommended to be cautious to apply DDB clinically for anti-virus and anti-malignancy purposes.

Wuweizisu C from Schisandra chinensis decreases membrane potential in C6 glioma cells

AIM

To study the effects of dibenzocyclooctadiene lignans isolated from Schisandra chinensis, such as wuweizisu C, gomisin N, gomisin A, and schisandrin, on the membrane potential in C6 glioma cells.

METHODS

The membrane potential was estimated by measuring the fluorescence change in DiBAC-loaded glioma cells.

RESULTS

Wuweizisu C decreased the membrane potential in a concentration-dependent manner. Gomisin N and gomisin A, however, showed differential modulation and no change was induced by schisandrin or dimethyl- 4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate, a synthetic drug derived from dibenzocyclooctadiene lignans. We found no involvement of G(i/o ) proteins, phospholipase C, and extracellular Na(+) on the wuweizisu C-induced decrease of the membrane potential. Wuweizisu C by itself did not change the intracellular Ca(2+)[Ca(2+)](i) concentration, but decreased the ATP-induced Ca(2+) increase in C6 glioma cells. The 4 lignans at all concentrations used in this study did not induce any effect on cell viability. Furthermore, we found a similar decrease of the membrane potential by wuweizisu C in PC12 neuronal cells.

CONCLUSION

Our results suggest that the decrease in the membrane potential and the modulation of [Ca(2+)](i) concentration by wuweizisu C could be important action mechanisms of wuweizisu C.

A simple HPLC method for the determination of bifendate: Application to a pharmacokinetic study of bifendate liposome

A rapid, sensitive and simple high-performance liquid chromatographic (HPLC) method with ultraviolet detector (UV) has been developed for the determination of bifendate in 100 microl plasma of rats. Sample preparation was carried out by deproteinization with 100 microl of acetonitrile. A 20 microl of supernatant was directly injected into the HPLC system with methanol-double distilled water (65/35, v/v) as the mobile phase at a flow rate of 1.0 ml/min. Separation was performed with a microBondapak C(18) column at 30 degrees C. The peak was detected at 278 nm. The calibration curve was linear (r(2)=0.9989) in the concentration range of 0.028-2.80 microg/ml in plasma. The intra- and inter-day variation coefficients were not more than 6.55% and 6.07%, respectively. The limit of detection was 5 ng/ml. The mean recoveries of bifendate were ranged from 94.53% to 99.36% in plasma. The present method has been successfully applied to the pharmacokinetic study of bifendate liposome in rats.

Liquiritigenin, an aglycone of liquiritin in Glycyrrhizae radix, prevents acute liver injuries in rats induced by acetaminophen with or without buthionine sulfoximine

Glycyrrhizae radix has been used as one of the oldest and most frequently employed botanicals in both western and oriental countries. Previously, we showed that liquiritigenin (LQ), an aglycone of liquiritin in G. radix, exerts cytoprotective effects against heavy metal-induced toxicity in vitro. This study investigated in vivo protective effects of LQ against acute liver injuries induced by acetaminophen (APAP) or APAP plus buthionine sulfoximine (BSO). Liver injuries were assessed by blood biochemistry and histopathology in rats administered with LQ purified from the acid hydrolyates of liquiritin singly (p.o. or i.v., 2-4 days) or in combination with dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'-dicarboxylate (DDB), a synthetic derivative of Schisandrin C in Fructus shizandrae, and exposed to APAP or APAP + BSO. LQ treatments (oral) effectively decreased liver injuries induced by a single dose of APAP, as evidenced by decreases in hepatic necrosis and inflammation as well as plasma alanine aminotransferase and lactate dehydrogenase activities. LQ, when intravenously applied, enhanced hepatoprotective effect with a greater potency. APAP + BSO led to severe liver injuries, resulting in lethality. LQ pretreatments significantly reduced the potentiated liver necrosis, decreasing mortality. In spite of the improvement in blood biochemistry, DDB failed to protect the liver from injuries induced by APAP or APAP + BSO. Combined treatments of rats with LQ and DDB showed some additive protective effect. The present study demonstrates that LQ efficaciously protects the liver from acute injuries induced by APAP or from APAP-induced severe injuries during GSH deficiency, indicating that LQ is one of the principal cytoprotective components comprised in G. radix.

The metabolism and excretion of 2-methylaminoethoxycarbonyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2'-carboxylic acid (DDB-S) in rats and human

The metabolism and excretion of 2-methylaminoethoxycarbonyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2'-carboxylic acid (DDB-S) were investigated in both rats and humans using liquid chromatography/electrospray ion trap mass spectrometry (LC/ESI-MS/MS). In rats, DDB-S was rapidly eliminated from the body after a single 50 mg/kg intravenous injection, with urine being a major excretion route. DDB-S was metabolically stable; approximately 96% of the administered dose was recovered in the form of the parent compound. Nevertheless, 12 metabolites were detected in the urine and feces collected from DDB-S-treated rats. The structural characterizations of the metabolites were elucidated from the MS(n) spectral analysis. Because DDB-S has a pseudo-symmetrical methylenedioxy biphenyl structure, regioselective deuterium-substituted DDB-S (d(5)-DDB-S) was used to assign the metabolic modification. The major metabolic pathways of DDB-S were identified as demethylenation of the methylenedioxy moiety, O-demethylation of the methoxy moiety and glucuronidation. In addition, N-demethylation of the methylaminoethyl group was also detected as a minor reaction.

Garlic oil and DDB, comprised in a pharmaceutical composition for the treatment of patients with viral hepatitis, prevents acute liver injuries potentiated by glutathione deficiency in rats

A pharmaceutical composition PENNEL comprising garlic oil (GO) and dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDB) as ingredients active for phase II enzyme induction and liver protection, respectively, has been used as a curative preparation for patients with acute or chronic viral hepatitis. In spite of the wide clinical use of PENNEL in Asian and Middle Eastern countries, whether GO+DDB treatment synergistically protects the liver from injuries potentiated by GSH deficiency compared to the individual treatment has not been determined. This study investigated the effects of GO+DDB in comparison with each ingredient alone on chemical-induced liver injury potentiated by a GSH depleting agent. Rats that had been daily pretreated with GO+DDB, GO, DDB, ursodesoxycholic acid or silymarin for 6 days were exposed to buthionine sulfoximine (BSO) and then injected with a single dose of CCl4. The effects of the agents on acute liver toxicities induced by BSO, CCl4 or BSO+CCl4 were assessed by blood biochemistry and histopathology. GO+DDB pretreatment effectively prevented increases in plasma aminotransferases or lactate dehydrogenase activities in rats exposed to BSO+CCl4, compared to GO or DDB treatment alone. Whereas BSO potentiated CCl4-induced liver injuries as evidenced by elevations in central necrosis, hepatocyte degeneration and inflammation, pretreatment with GO+DDB abrogated BSO+CCl4-induced liver injuries more efficaciously than did that with GO or DDB. The hepatoprotective effect of GO+DDB was superior to that of ursodesoxycholic acid or silymarin. Also, blood biochemistry indicated that GO+DDB pretreatment prevented increases in plasma triglyceride contents in rats insulted with CCl4 or BSO+CCl4. The present study demonstrated that GO+DDB, when daily pretreated for six consecutive days, exerted synergistic protection of the liver from chemical-induced injury potentiated by the condition of GSH deficiency, and has additional advantages in lowering the plasma lipids.

Effect of diphenyl dimethyl bicarboxylate on concanavalin A-induced liver injury in mice

Diphenyl dimethyl bicarboxylate (DDB) is a hepatoprotectant and used in the treatment of chronic viral hepatitis patients in China. The aim of the present paper was to investigate the effect of DDB on liver injury mediated by immune response in concanavalin A (Con A)-treated mice. A dose of Con A 30 mg/kg was injected via the tailvein to induce liver injury in mice. Serum alanine transaminase (ALT), aspartate aminotransferase (AST), total bile acid (TBA), total bilirubin (TBIL) and tumor necrosis factor alpha (TNF-alpha) level as well as liver TNF-alpha mRNA expression were determined. The following results were obtained: (1) Prior oral administration of DDB 150 mg/kg markedly reduced the elevated serum ALT, TBA and TBIL levels, and the liver lesions in Con A-treated mice; (2) DDB significantly inhibited the elevation of serum TNF-alpha and liver TNF-alpha mRNA expression 2 h after Con A injection; (3) DDB significantly inhibited hepatocyte nuclear DNA fragmentation 12 h after Con A injection; (4) DDB dose-dependently prevented the direct DNA damage induced by CuSO(4)-Phen-Vit C-H(2)O(2) system in vitro, and the ex vivo experiment also showed that the administration of DDB reduced the susceptibility of mouse liver nuclei DNA to CuSO(4)-Phen-Vit C-H(2)O(2) system. These results suggest that DDB could directly protect hepatocyte DNA from oxidative damage, and inhibit TNF-alpha mRNA expression in liver tissue, which resulted in prevention of liver damage induced by Con A in mice.

DDB treatment of patients with chronic hepatitis

We report 13 patients (10 with chronic hepatitis C, 1 with chronic hepatitis B, 2 with nonalcoholic steatohepatitis) with persistently elevated alanine aminotransferase (ALT) levels who were treated with dimethyl-4,4'-dimethoxy-5,6,5',6-dimethylenedioxybiphenyl-2,2' dicarboxylate (DDB). ALT rapidly normalized in 12/13 patients and remained normal during treatment. Unlike ALT levels, aspartate aminotransferase, gamma-glutamyl transferase and glutamate dehydrogenase levels were not affected. Furthermore, there was no beneficial effect on the histological grade and stage of liver disease. In vitro experiments with hepatocytes resulted in a significant decrease of hepatocellular ALT levels in the DDB treated cells, suggesting, that DDB affects the synthesis and/or degradation of ALT in liver cells. In conclusion, the normalization of ALT during DDB treatment does not indicate therapeutic efficacy. In view of the wide use of DDB in patients with chronic liver diseases who participate in clinical studies DDB use should be excluded.