Hepatotoxicity of geniposide in rats

PACAP/VIP in the prefrontal cortex mediates the rapid antidepressant effects of zhizichi decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Zhizichi decoction (ZZCD) is a traditional Chinese medicine formula that consists of Gardenia jasminoides J.Ellis (GJ) and Semen Sojae Praeparatum. It is used to treat insomnia and emotion-related disorders, such as irritability. Previous studies have found that GJ has a rapid antidepressant effect. The study found that ZZCD is safer than GJ at the same dosage. Consequently, ZZCD is a superior drug with quicker antidepressant effects than GJ. The rapid antidepressant effects of ZZCD were examined in this study, along with the components that make up this effect. It was determined that the activation of prefrontal Pituitary Adenylate Cyclase Activating Polypeptide (PACAP)/Vasoactive Intestinal Polypeptide (VIP) is essential for ZZCD's rapid antidepressant effects.

AIM

This study identified and discussed the rapid antidepressant effects and biological mechanisms of ZZCD.

MATERIALS AND METHODS

The tail suspension test (TST) and the forced swimming test (FST) were used to screen the effective dosage of ZZCD (0.67 g/kg, 1 g/kg, 4 g/kg). The effective dosage of ZZCD (1 g/kg) was tested in the TST conducted on Institute of Cancer Research (ICR) mice that were treated with lipopolysaccharide (LPS) at a concentration of 0.1 mg/mL. To confirm the expression of c-Fos, PACAP, and VIP in the prefrontal cortex (PFC), immunohistochemistry tests were conducted on mice following intragastric injection of ZZCD. Chemical characterization analysis and HPLC quality control analysis were conducted using UHPLC-Q-Obitrap-HRMS and chromatographic analysis.

RESULTS

The results showed that an acute administration of ZZCD (1 g/kg) decreased the immobility time of Kunming (KM) mice in TST and FST. Depressive behaviors in TST-induced ICR mice treated with LPS (0.1 mg/mL) were reversed by ZZCD (1 g/kg). The results of immunohistochemical experiments showed that ZZCD (1 g/kg) activated neurons in the PFC and PACAP/VIP in the PFC. In this study, 22 substances in ZZCD were identified. Five primary distinctive fingerprint peaks-geniposide, genistin, genipin-1-β-D-gentiobioside, glycitin, and daidzin-were found among the ten common peaks.

CONCLUSION

ZZCD (1 g/kg) had significant rapid antidepressant effects. PACAP/VIP in the PFC was found to mediate the rapid antidepressant effects of ZZCD.

Advanced quality assessment of Sanshishi (Gardenia jasminoides Ellis) and Kampo medicines using a monoclonal antibody against geniposide

Gardenia jasminoides Ellis, a plant widely used in traditional medicine, is known for its array of biological activities. A key bioactive compound, geniposide (GE), an iridoid glycoside, significantly contributes to the medicinal properties of the plant, with potential side effects. Thus, a reliable and efficient method for GE detection is required to ensure the quality of medicinal-grade G. jasminoides Ellis. This study developed such a method by first synthesizing GE-bovine serum albumin conjugates to function as immunizing agents in mice. This led to the production of a monoclonal antibody (mAb 3A6) against GE from the fusion of splenocytes from immunized mice with myeloma cells (P3U1), resulting in a hybridoma that produces mAb 3A6. Thereafter, we developed a mAb 3A6-based indirect competitive enzyme-linked immunosorbent assay (icELISA). The icELISA exhibited satisfactory sensitivity (0.391-12.5 μg/ml) and repeatability (coefficients of variation <10%). The accuracy of this method was validated through a spike-recovery assay (recovery of 101-112%). Furthermore, the icELISA was employed to determine the GE content in plant and Kampo medicine samples. The GE content positively correlated with those determined by high-performance liquid chromatography-ultraviolet. The proposed icELISA is rapid, cost-effective, and reliable for high-throughput GE detection in G. jasminoides Ellis, thereby contributing to the improved quality control and standardization of this valuable medicinal plant.

Gardenia yellow pigment: Extraction methods, biological activities, current trends, and future prospects

Food coloring plays a vital role in influencing consumers' food choices, imparting vibrant and appealing colors to various food and beverage products. Synthetic food colorants have been the most commonly used coloring agents in the food industry. However, concerns about potential health issues related to synthetic colorants, coupled with increasing consumer demands for food safety and health, have led food manufacturers to explore natural alternatives. Natural pigments not only offer a wide range of colors to food products but also exhibit beneficial bioactive properties. Gardenia yellow pigment is a water-soluble natural pigment with various biological activities, widely present in gardenia fruits. Therefore, this paper aims to delve into Gardenia Yellow Pigment, highlighting its significance as a food colorant. Firstly, a thorough understanding and exploration of various methods for obtaining gardenia yellow pigment. Subsequently, the potential functionality of gardenia yellow pigment was elaborated, especially its excellent antioxidant and neuroprotective properties. Finally, the widespread application trend of gardenia yellow pigment in the food industry was explored, as well as the challenges faced by the future development of gardenia yellow pigment in the field of food and health. Some feasible solutions were proposed, providing valuable references and insights for researchers, food industry professionals, and policy makers.

Unraveling a Combined Inactivation Mechanism of Cytochrome P450s by Genipin, the Major Reactive Aglycone Derived from Gardeniae Fructus

Genipin (GP) is the reactive aglycone of geniposide, the main component of traditional Chinese medicine Gardeniae Fructus (GF). The covalent binding of GP to cellular proteins is suspected to be responsible for GF-induced hepatotoxicity and inhibits drug-metabolizing enzyme activity, although the mechanisms remain to be clarified. In this study, the mechanisms of GP-induced human hepatic P450 inactivation were systemically investigated. Results showed that GP inhibited all tested P450 isoforms via distinct mechanisms. CYP2C19 was directly and irreversibly inactivated without time dependency. CYP1A2, CYP2C9, CYP2D6, and CYP3A4 T (testosterone as substrate) showed time-dependent and mixed-type inactivation, while CYP2B6, CYP2C8, and CYP3A4 M (midazolam as substrate) showed time-dependent and irreversible inactivation. For CYP3A4 inactivation, the kinact/KI values in the presence or absence of NADPH were 0.26 or 0.16 min-1 mM-1 for the M site and 0.62 or 0.27 min-1 mM-1 for the T site. Ketoconazole and glutathione (GSH) both attenuated CYP3A4 inactivation, suggesting an active site occupation- and reactive metabolite-mediated inactivation mechanism. Moreover, the in vitro and in vivo formation of a P450-dependent GP-S-GSH conjugate indicated the involvement of metabolic activation and thiol residues binding in GP-induced enzyme inactivation. Lastly, molecular docking analysis simulated potential binding sites and modes of GP association with CYP2C19 and CYP3A4. We propose that direct covalent binding and metabolic activation mediate GP-induced P450 inactivation and alert readers to potential risk factors for GP-related clinical drug-drug interactions.

Iridoid Derivatives as Anticancer Agents: An Updated Review from 1970-2022

The rise of cancer cases has coincided with the urgent need for the development of potent chemical entities and/or modification of existing commodities to improve their efficacy. Increasing evidence suggests that cancer remains one of the leading causes of death globally, with colon cancer cases alone likely to rise exponentially by 2030. The exponential rise in cancer prevalence is largely attributable to the growing change toward a sedentary lifestyle and modern diets, which include genetically modified foods. At present, the prominent treatments for cancer are chemotherapy, surgery, and radiation. Despite slowing cancer progression, these treatments are known to have devastating side effects that may deteriorate the health of the patient, thus, have a low risk-benefit ratio. In addition, many cancer drugs have low bioavailability, thereby limiting their therapeutic effects in cancer patients. Moreover, the drastic rise in the resistance of neoplastic cells to chemotherapeutic agents is rendering the use of some drugs ineffective, thereby signaling the need for more anticancer chemical entities. As a result, the use of natural derivatives as anticancer agents is gaining considerable attention. Iridoids have the potential to form conjugates with other anticancer, antidiabetic, antileishmanial, and antimalarial drugs, which synergistically have the potential to increase their effects. Published studies have identified the role of iridoids, which, if fully explored, may result in cheaper and less toxic alternative/adjuvant cancer drugs. The subject of this article is natural and synthetic iridoid derivatives and their potential therapeutic roles as anticancer agents.

Updated Pharmacological Effects, Molecular Mechanisms, and Therapeutic Potential of Natural Product Geniposide

At present, the potential of natural products in new drug development has attracted more and more scientists' attention, and natural products have become an important source for the treatment of various diseases or important lead compounds. Geniposide, as a novel iridoid glycoside compound, is an active natural product isolated from the herb Gardenia jasminoides Ellis (GJ) for the first time; it is also the main active component of GJ. Recent studies have found that geniposide has multiple pharmacological effects and biological activities, including hepatoprotective activity, an anti-osteoporosis effect, an antitumor effect, an anti-diabetic effect, ananti-myocardial dysfunction effect, a neuroprotective effect, and other protective effects. In this study, the latest research progress of the natural product geniposide is systematically described, and the pharmacological effects, pharmacokinetics, and toxicity of geniposide are also summarized and discussed comprehensively. We also emphasize the major pathways modulated by geniposide, offering new insights into the pharmacological effects of geniposide as a promising drug candidate for multiple disorders.

Compatibility with Semen Sojae Praeparatum attenuates hepatotoxicity of Gardeniae Fructus by regulating the microbiota, promoting butyrate production and activating antioxidant response

BACKGROUND

Herb-induced liver injury is a leading cause of drug-induced liver injury in China and its incidence is also increasing worldwide. Gardeniae Fructus (ZZ) has aroused wide concern for hepatotoxicity in recent decades. But when ZZ is administered in combination with Semen Sojae Praeparatum (DDC) to compose a herbal pair Zhizichi Decoction (ZZCD), lower hepatotoxicity is observed. The mechanism involved in the attenuated effect remains to be investigated.

HYPOTHESIS/PURPOSE

Our previous studies showed that DDC benefited host metabolism by regulating the gut microbiota and it reduced the exposure of major toxic components of ZZ. The present study was aimed to investigate how DDC attenuated hepatotoxicity of ZZ from the perspective of gut microbiota.

METHODS

Rats received ZZ and ZZCD treatment of different dosages and antibiotic treatment was applied to explore the involvement of gut microbiota. Biochemical assays and histopathological analysis were conducted to evaluate liver injury. Gut microbiota in caecal contents was profiled by 16S rRNA sequencing. Short-chain fatty acids (SCFAs) in caecal contents were measured by gas chromatography mass spectrometry (GCMS). To verify the protective effect of butyrate, it was administered with genipin, the major hepatotoxic metabolite of ZZ, to rats and HepG2 cells. Plasma lipopolysaccharide (LPS) level and colon tissue section were used to evaluate gut permeability. Expression level of Nuclear factor erythroid-derived 2-like 2 (Nrf2) was detected by immunohistochemistry in vitro and by western blot in vivo.

RESULTS

Our study showed that ZZCD displayed lower hepatotoxicity than ZZ at the same dosage. ZZ induced gut dysbiosis, significantly reducing Lactobacillus and Enterococcus levels and increasing the Parasutterella level. In combination with DDC, these alterations were reversed and beneficial genus including Akkermansia and Prevotella were significantly increased. Besides, butyrate production was diminished by ZZ but was restored when in combination with DDC. Butyrate showed detoxification on genipin-induced liver injury by promoting colon integrity and promoting Nrf2 activation. Besides, it protected genipin-induced hepatocyte damage by promoting Nrf2 activation.

CONCLUSION

DDC attenuates ZZ-induced liver injury by regulating the microbiota, promoting butyrate production and activating antioxidant response.

Effects of medicine food Fructus Gardeniae on liver and kidney functions after oral administration to rats for 12 weeks

Fructus Gardeniae (FG) is medicine food widely used for the treatment and prevention of various diseases. However, in recent years, research has suggested that high doses of FG can cause hepatotoxicity and nephrotoxicity. To assess this potential toxicity in more depth, this study investigated the effects of decocted FG and two of its bioactive constituents (geniposide and genipin) on liver and kidney function in rats. Rats were intragastrically administered FG (330 mg/kg body weight), geniposide (50 mg/kg body weight), or genipin (50 mg/kg body weight) for 12 weeks. Changes in body weight, liver and kidney indices, biochemical indices, and inflammatory factors were monitored. In addition, pathological sections were assessed and the expression of caspase-3, NF-κBp65, COX-2, and iNOS was detected by immunohistochemistry and Western blot. It was found that the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine, and urea nitrogen increased following administration of FG, geniposide, and genipin. Furthermore, the activities of superoxide dismutase and reduced glutathione decreased following treatment, while malondialdehyde levels increased. Pathological and immunohistochemical evaluations further confirmed that FG and its constituents may cause damage to the liver and kidneys. The mechanism study revealed that the protein level of inflammatory pathway increased and further promoted apoptosis, suggesting that it should not be taken orally for extended periods of time. PRACTICAL APPLICATIONS: Chinese medicine and food safety have always been public health concerns. Fructus Gardeniae (FG) is a plant with a dual-purpose as it is used as both a medicine and food. Medicinally, it has the effects of heat-clearing and detoxification. However, its adverse effects and related mechanisms are not clear, and this has potential safety implications. In this study, rats were treated with FG for 12 weeks and found that the long-term administration of FG or high dosing can lead to damage to liver and kidney function. Therefore, close attention must be paid to the dosage of FG in order to achieve a therapeutic effect and avoid adverse reactions. Thus, this study lays a foundation for the safety evaluation and clinical application of FG.

Metabolomics based comprehensive investigation of Gardeniae Fructus induced hepatotoxicity

Gardeniae Fructus (Zhizi in Chinese, ZZ in brief), a commonly used herbal medicine, has aroused wide concern for hepatotoxicity, but the mechanism remains to be investigated. This study was aimed at investigating the mechanism of ZZ-induced liver injury in vivo and in vitro based on metabolomics and evaluating the hepatotoxicity prediction ability of the in vitro model. SD rats were administered with extracted ZZ and HepG2 cells were treated with genipin, the major hepatotoxic metabolite of ZZ. Liver, plasma, intracellular and extracellular samples were obtained for metabolomics analysis. As a result, ZZ caused plasma biochemical and liver histopathological alterations in rats, and induced purine and amino acid metabolism disorder in the liver and pyrimidine, primary bile acids, amino acid metabolism and pantothenate and CoA biosynthesis disorder in the plasma. Pyrimidine, purine, amino acid metabolism and pantothenate and CoA biosynthesis were also found to be disturbed in the genipin-treated HepG2 cells, which exhibited similarity with the result in vivo. This study comprehensively illustrates the underlying mechanism involved in ZZ-related hepatotoxicity from the aspect of metabolome, and provides evidence that identifying hepatotoxicity can be achieved in cells, representing a non-animal alternative for systemic toxicology.

Disease Status-Dependent Drug-Herb Interactions: NASH Lowered the Risk of Hepatotoxicity in Rats Coadministered With Simvastatin and Gardenia jasminoides J. Ellis

Concurrent use of simvastatin (SV) and Gardenia jasminoides J. Ellis (GJ) was adopted in patients with multi-morbidity, such as stroke rehabilitation patients with NASH. Although hepatotoxicity has been reported in both of them and NASH could alter the pharmacokinetics of drugs/herbs, the interaction between SV and GJ and the related hepatotoxicity remained uninvestigated under neither healthy nor NASH condition. The current study aimed to evaluate the potential hepatotoxicity resulted from the interactions between SV and GJ in both healthy and NASH rats. Both healthy and NASH rats received two-week SV (p. o., 8.66 mg/kg, once daily) and/or GJ (p.o., 325 mg/kg, twice daily). Pharmacokinetic profiles of SV, simvastatin acid (SVA, active metabolite of SV), and geniposide (major component in GJ); hepatic Cyp2c11/Oatp1b2/P-gp expression; and biomarker levels of liver function, lipid levels, and liver histology were compared to demonstrate the interactions in rats. To explore the mechanism of the interaction-mediated hepatotoxicity, hepatic genipin-protein adduct content and iNOS/COX-1/COX-2 expressions from related groups were compared. Moreover, liver histology of healthy/NASH rats at 90 days after discontinuation of two-week GJ in the absence and presence of SV was evaluated to estimate the long-term impact of the interactions. GJ reduced the systemic exposures of SV and SVA by up-regulating the hepatic P-gp expression in healthy but not NASH rats. Meanwhile, SV increased the systemic exposure of geniposide via inhibiting the activity of P-gp in both healthy and NASH rats. Although neither SV nor GJ induced hepatotoxicity in healthy rats, their co-treatment elevated serum ALT and AST levels, which may attribute to the aggravated genipin-protein adduct formation, inflammation infiltration, and iNOS/COX-1 expressions in the liver. In NASH rats, SV and/or GJ reduced serum ALT, AST, LDL/vLDL, and TC levels via alleviating hepatic inflammation infiltration and iNOS/COX-1 expressions. Moreover, in comparison to NASH rats, more severe fibrosis was observed in the livers of healthy rats at 90 days after discontinuation of two-week SV and GJ coadministration. Although interactions between SV and GJ induced short-term and long-term liver injuries in healthy rats, NASH condition in rats could lower such risk.

Genipin induces developmental toxicity through oxidative stress and apoptosis in zebrafish

Genipin, an iridoid substance, is mainly derived from Gardenia jasminoides Ellis of the traditional Chinese medicine and is widely used in raw materials for the food additive gardenia blue and biological materials. The developmental toxicity of genipin has not been investigated, and its underlying mechanism is unclear. Therefore, in this study we attempt to investigate the potential developmental toxicity of genipin in zebrafish embryos/larvae. The results showed zebrafish embryos treated with 50 μg/ml dose of genipin display inhibited hatching rates and body length. The pericardial edema was observed. It was also found that genipin could induce cardio-toxicity, hepatotoxicity and nephrotoxicity in zebrafish larvae. After genipin treatment, the suppression of antioxidant capacity and increase of oxidative stress were showed for the triggered generation of ROS and MDA, and decreased activity of SOD. Compared with the 0.5% DMSO group, a number of apoptotic cells in zebrafish were increased after genipin exposure. By measuring marker gene expression with the using of qRT-PCR, we proposed that developmental toxicity after genipin treatment might be associated with oxidative stress and apoptosis increase. Our research offers a better understanding for developmental toxicity of genipin.

Gardenia jasminoides Ellis: Ethnopharmacology, phytochemistry, and pharmacological and industrial applications of an important traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Gardenia jasminoides Ellis is a popular shrub in the Rubiaceae family. The desiccative ripe fruits of this plant (called Zhizi in China) are well known and frequently used not only as an excellent natural colourant, but also as an important traditional medicine for the treatment of different diseases, such as reducing fire except vexed, clearing away heat evil, and cooling blood and eliminating stasis to activate blood circulation. It has also been declared as the first batch of dual-purpose plants used for food and medical functions in China.

AIM OF THE STUDY

This review aims to provide a critical and systematic summary of the traditional uses, ethnopharmacology, phytochemistry, pharmacology, toxicity and industrial applications of Gardenia jasminoides Ellis and briefly proposes several suggestions for future application prospects.

MATERIALS AND METHODS

The related information on Gardenia jasminoides Ellis was obtained from internationally recognized scientific databases through the Internet (PubMed, CNKI, Google Scholar, Baidu Scholar, Web of Science, Medline Plus, ACS, Elsevier and Flora of China) and libraries.

RESULTS

Approximately 162 chemical compounds have been isolated and identified from this herb. Among them, iridoid glycosides and yellow pigment are generally considered the main bioactive and characteristic ingredients. Various pharmacological properties, such as a beneficial effect on the nervous, cardiovascular and digestive systems, hepatoprotective activity, antidepressant activity, and anti-inflammatory activity, were also validated in vitro and in vivo. Moreover, geniposide and genipin are the most important iridoid compounds isolated from Gardenia jasminoides Ellis, and genipin is the aglycone of geniposide. As the predominant active ingredient with a distinct pharmacological activity, genipin is also an outstanding biological crosslinking agent. Gardenia yellow pigment has also been widely used as an excellent natural dye-stuff. Hence, Gardenia jasminoides Ellis has been applied to many other fields, including the food industry, textile industry and chemical industry, in addition to its predominant medicinal uses.

CONCLUSIONS

According to this review, Gardenia jasminoides Ellis is outstanding traditional medical plant used in medicine and food. Pharmacological investigations support the traditional use of this herb and may validate the folk medicinal use of Gardenia jasminoides Ellis to treat different diseases. Iridoid glycosides are potential medicines. Gardenia yellow pigment has been the most important source of a natural colourant for food, cloth and paint for thousands of years. This herb has made great contributions to human survival and development. Moreover, it has also achieved outstanding progress in human life and even in art. Although Gardenia jasminoides Ellis has extremely high and comprehensive utilization values, it is still far from being completely explored. Therefore, the comprehensive development of Gardenia jasminoides Ellis deserves further analysis.

Effects of Long-Term Administration of Gardeniae Fructus on Intra-Abdominal Organs of Rats

Many recent reports have suggested a possible association between Japanese traditional (Kampo) medicines containing Gardeniae Fructus (GF, the fruit of Gardenia jasminoides J. Ellis) and the mesenteric phlebosclerosis (MP). MP is a chronic orphan disease characterized by venous calcification extending from the colonic wall to the mesentery, usually developing in the proximal colon. In the present study, we administered GF to Wistar/ST female rats as 1% and 2% feed in the diet for 11 months to evaluate any calcification and/or fibrosis of veins in the colonic wall and mesentery. The reversibility of GF's effects was examined by feeding a normal diet for an additional 3 months. A significant decrease in body weight gain and food consumption occurred in the 2% GF group. Pigmentation of the liver, kidney, and spleen in macroscopic or histopathological examination was observed after 11-month administration, which disappeared after the 3-month recovery period. Histopathological findings such as fibrous thickening and calcification of vein walls, characteristic of human MP, were not observed. Fibrosis in the colonic lamina propria was observed in the 2% GF group but not in the 1% GF group during the treatment period, but the incidence as well as grade of this type of fibrosis decreased in the recovery period, suggesting that the effects of GF were reversible. In the present study, chronic GF administration did not result in any venous pathological changes but induced pigmentation in the liver, kidneys, and spleen and moderate fibrosis in the colonic lamina propria, all of which being reversible. Further studies are required to determine the association between GF and MP.

Acute and Subchronic Oral Toxicity Study of Gardenia Yellow E500 in Sprague-Dawley Rats

Objective: This study was conducted to evaluate the acute and subchronic toxicity of gardenia yellow, a natural colorant widely used in China and other Asian countries. An acute toxicity test was performed in S-D rats of both genders and the lethal dose (LD₅₀) of per oral gardenia yellow was estimated to be more than 15.0 g/kg·bw. In the subchronic study, gardenia yellow was orally administered to rats by gavage at doses of 0, 0.50, 1.50 and 4.50 g/kg·bw/day for 90 days followed by a recovery period of 28 days. No appreciable toxic-related changes were observed in the 0.50 g/kg·bw/day group. When the animals received gardenia yellow at 1.50 g/kg·bw/day or more, body weight loss was observed, and pigments began to deposit in several vital organs, resulting in significant changes of several hematological and biochemical indicators related to the nutritional status of the body, liver and kidney function, more severe in the high dose group. In the recovery period, the alterations of the clinical symptoms and parameters were relieved a lot. Based on the results of the current study, the no observed adverse effect level (NOAEL) of gardenia yellow E500 in rats was set to be 0.50 g/kg·bw/day.

Herb-Induced Liver Injury: Phylogenetic Relationship, Structure-Toxicity Relationship, and Herb-Ingredient Network Analysis

Currently, hundreds of herbal products with potential hepatotoxicity were available in the literature. A comprehensive summary and analysis focused on these potential hepatotoxic herbal products may assist in understanding herb-induced liver injury (HILI). In this work, we collected 335 hepatotoxic medicinal plants, 296 hepatotoxic ingredients, and 584 hepatoprotective ingredients through a systematic literature retrieval. Then we analyzed these data from the perspectives of phylogenetic relationship and structure-toxicity relationship. Phylogenetic analysis indicated that hepatotoxic medicinal plants tended to have a closer taxonomic relationship. By investigating the structures of the hepatotoxic ingredients, we found that alkaloids and terpenoids were the two major groups of hepatotoxicity. We also identified eight major skeletons of hepatotoxicity and reviewed their hepatotoxic mechanisms. Additionally, 15 structural alerts (SAs) for hepatotoxicity were identified based on SARpy software. These SAs will help to estimate the hepatotoxic risk of ingredients from herbs. Finally, a herb-ingredient network was constructed by integrating multiple datasets, which will assist to identify the hepatotoxic ingredients of herb/herb-formula quickly. In summary, a systemic analysis focused on HILI was conducted which will not only assist to identify the toxic molecular basis of hepatotoxic herbs but also contribute to decipher the mechanisms of HILI.

Exploration of the hepatoprotective chemical base of an orally administered herbal formulation (YCHT) in normal and CCl4-intoxicated liver injury rats. Part 2: Hepatic disposition in vivo and hepatoprotective activity in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Yin-Chen-Hao Tang (YCHT) has been a very popular, hepatoprotective three-herb formula with an unclear chemical base.

AIM OF THIS STUDY

To reveal the hepatoprotective chemical base of oral-dosed YCHT, we bridged the hepatic disposition of six compounds in vivo and their hepatoprotection in vitro.

MATERIALS AND METHODS

In vivo, following the oral administration of YCHT in normal and CCl₄-induced liver injury rats, the determinations of chlorogenic acid, 4-hydroxyacetophenone, geniposide, genipin, rhein and emodin were conducted in the portal vein plasma, the liver, and the systemic plasma. In vitro, the hepatoprotective activities of these compounds were determined in the CCl₄-induced HepG2 cells.

RESULTS

Consistent with the highest content in YCHT, geniposide had the highest exposure in vivo. Inconsistent with the negligible content, rhein, 4-hydroxyacetophenone, emodin and genipin showed substantial hepatic accumulations. In contrast, chlorogenic acid, an ingredient that has a high content in YCHT, elicited no hepatic exposure. In normal rats, the hepatic disposition prevented the compounds entering into the systemic plasma from the portal vein plasma by 44.9-100%, except for rhein. CCl₄-induced liver injury caused a decreased hepatic exposure of 4-hydroxyacetophenone, rhein and emodin by 50%. In vitro, all six compounds exerted the hepatoprotection by increasing cell viability, decreasing hepatic marker enzymes and inhibiting lipid peroxidation at varying levels.

CONCLUSION

Geniposide, rhein, emodin, 4-hydroxyacetophenone and genipin directly resisted liver injury in oral-dosed YCHT, while chlorogenic acid likely played an indirect role. This study proved that YCHT exerted hepatoprotection through multiple components and multiple actions. However, close attention should be paid to the possible side effects and oral dosage of YCHT in clinics.

Fructus Gardeniae-induced gastrointestinal injury was associated with the inflammatory response mediated by the disturbance of vitamin B6, phenylalanine, arachidonic acid, taurine and hypotaurine metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Fructus Gardenia (FG) is a widely used bitter and cold herb for clearing heat and detoxicating. Currently, toxicity of FG and its relative formula has been reported in many clinical and animal studies. However, no systematic research has been carried out on FG-related gastrointestinal (GI) injury which has been emphasized in China since the Ming Dynasty.

AIM OF THE STUDY

The purpose of this article is to investigate whether FG could damage GI and explore the mechanisms involved.

MATERIAL AND METHODS

FG was given to male mice by 7-day intragastric administration at average doses of 0.90 g (L group), 1.50 g (M group), and 3.00 g (H group) crude drug/kg FG. Comprehensive understanding of changes in weight, diarrhea degree, stool routine, histomorphology and inflammatory factors of stomach, small intestine, and colon for evaluating the effect of different doses of FG on GI injury. Moreover, metabolomics-based mechanisms exploration of FG on GI injury was carried out via HPLC-Q-TOF/MS analysis on mice urine.

RESULTS

High dose FG caused GI injury with serious diarrhea, decreased weight, abnormal stool routine, sever alteration in histomorphology of small intestine and colon (mild change in stomach), and significant change in inflammatory factors. The results of metabolomics suggested that 55 endogenous metabolites dispersed in 21 significantly altered metabolic pathways in 3.00 g/kg crude FG treated mice. The hub metabolites of GI injury were mainly related with vitamin B6 metabolism, phenylalanine metabolism, arachidonic acid metabolism, and taurine and hypotaurine metabolism via correlated network analysis.

CONCLUSION

FG affected the normal functions of GI via the regulating a variety of metabolic pathways to an abnormal state, and our results provided a research paradigm for the GI-injury of the relative bitter and cold traditional Chinese medicines.

Antioxidative Property and Molecular Mechanisms Underlying Geniposide-Mediated Therapeutic Effects in Diabetes Mellitus and Cardiovascular Disease

Geniposide, an iridoid glucoside, is a major component in the fruit of Gardenia jasminoides Ellis (Gardenia fruits). Geniposide has been experimentally proved to possess multiple pharmacological actions involving antioxidative stress, anti-inflammatory, antiapoptosis, antiangiogenesis, antiendoplasmic reticulum stress (ERS), etc. In vitro and in vivo studies have further identified the value of geniposide in a spectrum of preclinical models of diabetes mellitus (DM) and cardiovascular disorders. The antioxidative property of geniposide should be attributed to the result of either the inhibition of numerous pathological processes or the activation of various proteins associated with cell survival or a combination of both. In this review, we will summarize the available knowledge on the antioxidative property and protective effects of geniposide in DM and cardiovascular disease in the literature and discuss antioxidant mechanisms as well as its potential applications in clinic.

Does the intestinal microenvironment have an impact on the choleretic effect of inchinkoto, a hepatoprotective herbal medicine?

AIM

The choleretic effects of inchinkoto (ICKT), a hepatoprotective herbal medicine, are variable among patients. This study sought to investigate the correlation between the choleretic effects of ICKT and the intestinal microenvironment in patients with biliary obstruction.

METHODS

Patients with biliary obstruction who underwent external biliary drainage were enrolled. The concentrations of total bilirubin and bile acid in the bile, and genipin, a major active ingredient of ICKT, in the bloodstream before and after ICKT treatment were measured. Feces were collected from the patients to determine bacterial count and organic acid concentrations.

RESULTS

Samples from 37 patients were collected and analyzed. The serum concentration of genipin increased 3 h after ICKT treatment and showed a positive correlation with the percent changes of biliary concentrations of bile acid, total bilirubin, and direct bilirubin. Serum genipin concentration also showed a positive correlation with the fecal concentrations of representative obligate anaerobes such as the Clostridium leptum subgroup, Bacteroides fragilis group, Bifidobacterium, and the Atopobium cluster. In sharp contrast, so-called harmful bacteria such as Clostridium difficile, Enterobacteriaceae, and Enterococcus showed a negative correlation with the concentration of genipin. Genipin concentration after ICKT administration showed a positive correlation with the fecal concentration of short chain fatty acids such as propionic acid and butyric acid, and a negative correlation with the fecal concentration of lactic acid.

CONCLUSIONS

The absorption of genipin was variable among patients. This variability may be associated with the fecal microenvironment profile and partly explain the variable choleretic effects of ICKT among patients.

In Vitro Selection of DNA Aptamers that Binds Geniposide

Geniposide is a key iridoid glycoside from Gardenia jasminoides fructus widely used in traditional Chinese herbal medicine. However, detection of this small molecule represents a significant challenge mostly due to the lack of specific molecular recognition elements. In this study, we have performed in vitro selection experiments to isolate DNA aptamers that can specifically bind geniposide. Using a stringent selection procedure, we have isolated DNA aptamers that can distinguish geniposide from genipin and glucose, two structural analogs of geniposide. Two top aptamers exhibit low micromolar binding affinity towards geniposide, but show significantly reduced affinity to genipin and glucose. These aptamers have the potential to be further developed into analytical tools for the detection of geniposide.

Simultaneous quantification method for comparative pharmacokinetics studies of two major metabolites from geniposide and genipin by online mircrodialysis-UPLC-MS/MS

Genipin-1-o-glucuronic acid and genipin-monosulfate are two major metabolites from geniposide and genipin. Based on diabetic rat model, we developed a simultaneous quantification method to investigate their comparative pharmacokinetics by online mircrodialysis-ultra performance liquid chromatography-mass spectrometry (MD-UPLC-MS/MS) without their standard compounds. Online microdialysis sampling could avoid unexpected contamination or degradation of the analytes during the storage and transfer steps. Combined with good sensitivity, selectivity and selectivity of UPLC-MS/MS, online MD-UPLC-MS/MS method could real-timely monitor metabolites in rat blood for quantitative analysis. Our research found that AUC_0→t of genipin-1-o-glucuronic acid and genipin-monosulfate in blood of diabetic group were 17.68 and 7.58 times than those in normal group, respectively, and AUC_0→t of genipin-1-o-glucuronic acid was 2.28 times than that of genipin-monosulfate in blood of diabetic group, which revealed the effect of diabetes on the pharmacokinetic properties of the two metabolites. This study not only provides an approach for pharmacokinetic studies for various metabolites from herb medicines, but also can predict druggability of their bioactive metabolites. The insight obtained should facilitate drug development and toxicity research.

Design, synthesis and preliminary evaluation of the anti-inflammatory of the specific selective targeting druggable enzymome cyclooxygenase-2 (COX-2) small molecule

CONTEXT

Development of a reliable and selective anti-inflammatory agent of cyclooxygenase-2 (COX-2), induced or up-regulated by inflammatory/injury stimulus such as IL-1β, TNF-α and LPS in the various types of organs, tissues and cells, with low side effects is a long-standing medicinal chemistry problem with significant social implications.

OBJECTIVE

To target druggable enzymome COX-2 by exploiting NSAIDs and genipin (GEP) in anti-inflammatory infection.

MATERIALS AND METHODS

The compound aspirin GEP ester (AGE) was designed by computer-assisted screening, synthesized in the esterification of the acylate derivative and the methylate derivative with Et₃N, and evaluated with 20, 40 and 60 mg/kg from days 18 to 24 after immunization in collagen-induced arthritis (CIA) rats by the sequential enzymatic experiments, western-blot analysis and pathological observation methods.

RESULTS

AGE exhibited higher binding affinity with COX-1 and displayed the lowest estimated free energy with COX-2 than other ligands built by hanging NSAIDs with GEP, and was characterized by ¹H NMR, ¹³C NMR and HRMS. AGE was competed against COX-2 with molecule-dependent potencies and selectivity (IC₅₀: 0.36 mM; selectivity index: 275) in the sequential enzymatic experiments and decreased the expression of COX-2 in peripheral blood lymphocytes of CIA rats. AGE (40 and 60 mg/kg) could significantly relieve the secondary hind paw swelling and arthritis index, along with observing AGE attenuated histopathological changes of fibroblast like synovial tissue (FLST) and mesenteric lymph node lymphocytes (MLNL) in CIA rats.

DISCUSSION AND CONCLUSION

AGE pharmacophore reported herein may be an effective strategy to develop a novel anti-inflammatory agent and potential inhibitor of COX-2.

Evaluation of the Antidepressant Activity, Hepatotoxicity and Blood Brain Barrier Permeability of Methyl Genipin

Geniposide (GE) is the main bioactive component of Gardeniae Fructus. The hepatotoxicity of geniposide limited clinical application. In order to get a new geniposide derivative that has less hepatotoxicity and still possesses the antidepressant activity, a new C-1 hydroxyl methylation derivative named methyl genipin (MG) was synthesized from geniposide. In the present study, we demonstrated that MG did not increase the liver index, alanine aminotransferase (ALT) and aspirate aminotransferase (AST). Histopathological examination suggested that no toxic damages were observed in rats treated orally with MG (0.72 mmol/kg). More importantly, a 7-day treatment with MG at 0.13, 0.26, and 0.52 mmol/kg/day could reduce the duration of immobility. It showed that the antidepressant-like effects of MG were similar to GE in the tail suspension test and the forced swim test. Furthermore, we found MG could be detected in the brain homogenate of mice treated orally with MG 0.52 mmol/kg/day for 1 day by HPLC. The area under the curve (AUC) of MG in the brain homogenate was enhanced to 21.7 times that of GE. The brain amount and distribution speed of MG were improved significantly after oral administration. This study demonstrated that MG possessed the antidepressant effects and could cross the blood–brain barrier, but had less hepatotoxicity.

Characterization of picroside II metabolites in rats by ultra-high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Picroside II, a bioactive compound isolated from Picrorhiza scrophulariiflora Pennell, has been reported to have hepatoprotective, neuroprotective, and antioxidant effects. However, the detailed in vivo biotransformation of this compound has been rarely reported. This study aimed to investigate the metabolic profiles of picroside II in rats by using ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry. Metabolite structures were elucidated based on accurate mass measurements of deprotonated molecules and their fragmentation patterns. Thirteen metabolites were structurally identified, and the detailed metabolic pathways were proposed. The findings revealed that after oral administration, picroside II mainly undergoes four metabolic pathways. In the first pathway, picroside II is deglycosylated to generate aglycone, which is isomerized to a dialdehyde-type intermediate. A series of metabolic reactions, including glucuronidation, subsequently occurs. In the second pathway, picroside II is subjected to ester bond hydrolysis to form vanillic acid, which is further subjected to sulfate conjugation, glycine conjugation, glucuronidation, and demethylation. In the third pathway, picroside II is directly conjugated with glucuronic acid to yield a predominant metabolite (M01) in plasma. In the fourth pathway, picroside II is directly conjugated with sulfate. These findings provide insights into the in vivo disposition of picroside II and are useful to understand the mechanism of effectiveness and toxicity of this compound as well as P. scrophulariiflora-related preparations.

Comprehensive characterization of the in vitro and in vivo metabolites of geniposide in rats using ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometer

1. Geniposide (genipin 1-O-glucose), one of the major bioactive constituents isolated from Fructus Gardeniae, possesses many biological activities. In this study, an efficient strategy was developed using ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometer (UPLC-LTQ-Orbitrap) to profile the in vitro and in vivo metabolic patterns of geniposide in rat liver microsomes (RLMs), plasma, urine, and various tissues. And post-acquisition data-mining methods including extracted ion chromatogram (EIC), multiple mass defect filters (MMDF), fragment ion searching (FISh), and isotope pattern filtering (IPF) were adopted to characterize the known and unknown metabolites. 2. A total of 33 metabolites were detected and interpreted according to accurate mass measurement, diagnostic fragment ions, relevant drug biotransformation knowledge, and bibliography data. Among them, 17 metabolites were detected in the plasma, 31 metabolites were identified in the urine, six metabolites could be found in rat heart, 12 in liver, three in spleen, six in lung, 12 in kidney, six in brain, and four in RLMs. 3. A series of corresponding reactions such as hydrolysis, hydroxylation, taurine conjugation, hydrogenation, decarboxylation, demethylation, sulfate conjugation, cysteine S-conjugation, glucosylation, and their composite reactions were all discovered. 4. The results could provide comprehensive insights and guidance for elucidation of side effect mechanism and safety monitoring as well as for rational formulation design in drug delivery system. The newly discovered geniposide metabolites could be targets for future metabolism studies on the important chemical constituents from herbal medicines.

Collagen crosslinking of porcine sclera using genipin

PURPOSE

To evaluate the effect of collagen cross-linking induced by genipin in porcine sclera.

METHODS

Porcine cadaver eyes were treated with genipin at concentrations (by w/v) of 0.01%, 0.03%, 0.1%, 0.3%, 1.0% for 15 and 30 min. Riboflavin/ultraviolet A(UVA)-treated and untreated samples were used as controls. After treatment, scleral strips of 4.0 × 10.0 mm were cut. Twenty-four hours later, the stress-strain parameters of the strips were measured using a biomaterial microtester. The stress and Young's modulus at 8% strain were evaluated.

RESULTS

Compared with untreated groups, after treatment with genipin for 15 min, the stress was increased by 66-246%, depending on the concentration of genipin. As for the 30-min groups, the stress was 171-444% higher than that of the control. The difference of the Young's modulus between genipin 15-min groups, except the 0.01% groups (p = 0.095), also had statistical significance (p < 0.05). The Young's modulus had significant difference between the untreated group and the genipin 30-min groups (all p < 0.05). Of 0.3% genipin for 15 min or 0.01% genipin for 30 min had a similar stress-strain curve with those of eyes treated with the riboflavin/UVA group. The sclera exhibited a bluish colour which became deeper with increase concentration and cross-linking time.

CONCLUSIONS

Collagen cross-linking induced by genipin could increase the biomechanical strength in porcine sclera. The effect depends on the concentration and treatment time of genipin.

Identification of metabolites of geniposide in rat urine using ultra-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Geniposide, an iridoid glycoside, is an important and characteristic compound in the fruits of Gardenia jasminoides Ellis, a commonly used medicinal herb in Chinese traditional and folk medicine for the treatment of inflammation and jaundice. However, few studies have been carried out on the metabolism of geniposide. In this study, we have established a rapid and sensitive method using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC/ESI-QTOF-MS) for analysis of the metabolic profile of geniposide in rat urine after oral administration. A total of ten metabolites were detected and identified by comparing their fragmentation patterns with that of geniposide using Metabolynx™ and MassFragment™ software tools. The results revealed that the principal metabolism pathways of geniposide in rat occurred after deglycosylation of the irdoid glycoside take place and this is followed by glucuronidation and the pyran-ring cleavages. The major metabolite, the glucuronic acid conjugate of genipin as observed in vivo, was further confirmed by the in vitro enzymatic study. The results of this work have demonstrated the feasibility of the UPLC/ESI-QTOF-MS approach for rapid and reliable characterization of metabolites from iridoid compounds.

Biomechanical and angiogenic properties of tissue-engineered rat trachea using genipin cross-linked decellularized tissue

In this study, the obtainment and characterization of decellularized rat tracheal grafts are described. The detergent-enzymatic method, already used to develop bioengineered pig and human trachea scaffolds, has been applied to rat tracheae in order to obtain airway grafts suitable to be used to improve our knowledge on the process of tissue-engineered airway transplantation and regeneration. The results demonstrated that, after 9 detergent-enzymatic cycles, almost complete decellularized tracheae, retaining the hierarchical and mechanical properties of the native tissues with strong in vivo angiogenic characteristics, could be obtained. Moreover, to improve the mechanical properties of decellularized tracheae, genipin is here considered as a naturally derived cross-linking agent. The results demonstrated that the treatment increased mechanical properties, in term of secant modulus, without neither altering the pro-angiogenic properties of decellularized airway matrices or eliciting an in vivo inflammatory response.

Transformation of geniposide into genipin by immobilized β-glucosidase in a two-phase aqueous-organic system

Genipin is the bioactive compound of geniposide and a natural cross-linking agent. In order to improve the preparation process of genipin, the hydrolysis of geniposide to genipin by immobilized β-glucosidase in an aqueous-organic two-phase system was studied. β-Glucosidase was immobilized by the crosslinking-embedding method using sodium alginate as the carrier. The optimum reaction temperature, pH value and time were 55 °C, 4.5 and 2.5 h, respectively. To reduce genipin hydrolysis and byproduct production the reaction was carried out in an aqueous-organic two-phase system comprising ethyl acetate and sodium acetate buffer. The product was analyzed by HPLC, UV, IR, and NMR. The yield of genipin was 47.81% and its purity was over 98% (HPLC).

Genipa americana (Rubiaceae) fruit extract affects mitogen-activated protein kinase cell pathways in human trophoblast-derived BeWo cells: implications for placental development

Genipa americana L. (Rubiaceae) is a fruit tree and a traditional medicine used to treat anemia, icterus, asthma, and liver and spleen problems. The aim of the present study was to verify the effect of G. americana fruit ethanolic extract on the mechanism for proliferation and differentiation of trophoblast-like cells. Qualitative analysis of G. americana fruit extract was performed, and BeWo cells, a well-established placental choriocarcinoma cell line that can undergo differentiation, were used to analyze cell viability and proliferation. Methods consisted of cytotoxic and proliferation measurement, detection of release of human chorionic gonadotrophins, cell fusion observation, and evaluation of cell-signaling pathways (production of cyclic adenosine monophosphate and phosphorylation of mitogen-activated protein kinases [MAPKs]). A stock solution of the extract was diluted in Ham's F-12 medium with 10% fetal bovine serum at concentrations ranging from 50 to 1000 μg/mL. Cells treated with dimethylsulfoxide, forskoline, and MAPK inhibitors (PD98059 or SB203580) were used as a control. Forskoline was used to induce the differentiation state in BeWo cells. Phytoanalysis indicated the presence of steroids only. Results showed that the G. americana fruit extract did not cause any cytotoxicity or interference in cell differentiation. However, a significant antiproliferative state related to inhibition and reactivation of ERK1/2 and p38 MAPK in BeWo cells was seen. These results suggest that steroids from G. americana may affect placental cell regulation.

Kinetic Analysis of Genipin Degradation in Aqueous Solution

Degradation of genipin (GP), a low toxicity natural protein crosslinking agent, in aqueous solution was monitored by HPLC at various pH levels. Degradation of GP was consistent with a mechanism consisting of a first order reaction with a reversible first step. Formation of the intermediate was slowest at more neutral pHs while formation of the irreversible product was correlated to increasing alkalinity. Degradation at all pHs was enhanced by the presence of phosphate ions. Degradation of GP most likely proceeds via the reversible opening of the dihydropyran ring by water followed by irreversible polymerization of the intermediate. Degraded solutions containing no detectable GP or intermediate, however, are still capable of crosslinking proteins.

Exogenous crosslinking recovers the functional integrity of intervertebral disc secondary to a stab injury

Exogenous crosslinking was proved to improve the fatigue resistance of anulus fibrosus and the stability of motion segment. The effect of crosslinking on the recovery of stab-injured discs, however, was less studied. The purpose of this study is to find if the exogenous crosslinking can increase the mechanical function of injured discs. Fresh healthy porcine discs (T2/T9) from 6-month-old swine were obtained immediately following death. Anular puncture using 16 and 18 G spinal needle were used to create medium and large disc stab injury models. Three treatments were designed for each injury model. The first one is the injured discs without treatment. The second one is the injured discs soaked with phosphate buffered solution for 2 days. The third one is the injured discs soaked with 0.33% genipin solution for 2 days. The disc integrity was evaluated using quantitative discomanometry (QD) apparatus. Four QD parameters, that is, the leakage pressure and volume, and the saturate pressure and volume, were analyzed to find the efficacy of treatment. We found that soaking of genipin solution recovered the disc leakage pressure from 1.3 to 1.8 MPa in 16 G-injury-model and from 2.3 to 3.2 MPa in 18 G-injury-model, and recovered the saturate pressure from 1.6 to 2.0 MPa in 16 G-injury-model and from 2.7 to 3.7 MPa in 18 G-injury-model. The improvement of disc integrity by soaking with genipin solution indicate that the exogenous crosslinking may help the biomechanical performance of an injured disc.

A 13-week oral dose subchronic toxicity study of gardenia yellow containing geniposide in rats

Gardenia yellow powders A, B and C, containing geniposide at 0.284%, 0.938% and 2.783%, respectively, were administered orally to male and female SD rats as 3% feed admixtures for 13-weeks to evaluate any potential toxicity. Mean geniposide intake values were 5.72, 18.9 and 56.3mg/kg/day in groups receiving these feed admixtures, respectively. All animals survived the duration of the study. The following findings were evident in the gardenia yellow C group: chromatouria, slightly increased plasma total bilirubin, blackish brown discoloration of the kidneys and liver, brown pigments in the proximal tubular epithelium of the kidneys. Slightly increased plasma total bilirubin was considered to be due to interference of metabolite of geniposide with the system of measurement and not to be a toxic effect since there were no related changes in histopathology of the liver or in any blood chemistry parameters. Other findings were limited to pigmentations or discolorations attributable to metabolites of geniposide. No treatment-related effects were evident on body weight, food consumption, ophthalmology, hematology or organ weights in any group. Therefore, it was concluded that 3-month ingestion of the gardenia yellow powder containing geniposide at 2.783% (approximately 60 mg/kg/day as geniposide intake) does not cause any severe toxic effects.

Japanese herbal medicine Inchin-ko-to as a therapeutic drug for liver fibrosis

BACKGROUND/AIMS

Inchin-ko-to (TJ-135) is an herbal medicine used in Japan for treatment of icteric patients with cirrhosis. Its efficacy as an anti-fibrogenic drug was evaluated in relation to stellate cell activation.

METHODS/RESULTS

Liver fibrosis was induced in rats by repeated injections of carbon tetrachloride (CCl4) or pig-serum. Oral administration of TJ-135 improved the mortality of rats given CCl4 with reduced extents of liver necrosis and fibrosis. Similar improvement of liver fibrosis was found in rats given pig-serum showing no liver necrosis. DNA synthesis of stellate cells activated in vitro after isolation from normal rat liver was decreased by culture with TJ-135 in a dose-related manner, accompanied by decreased smooth muscle alpha actin expression and contractility. Such attenuation was not found in the cells cultured with geniposide, an iridoid compound of TJ-135, but genipin, an aglycone of geniposide formed in the gut by action of bacterial flora, markedly decreased stellate cell activation without affecting synthesis of proteins other than collagen.

CONCLUSIONS

TJ-135 may be useful for treatment of liver fibrosis and portal hypertension through suppression of activated hepatic stellate cell function by genipin, an absorbed form of its component.

Genotoxicity of gardenia yellow and its components

Gardenia fruit (Gardenia jasminoides ELLIS) is widely used as a natural food colorant and as a traditional Chinese medicine for treatment of hepatic and inflammatory diseases. "Gardenia yellow" is a natural food colorant which is extracted by ethanol from gardenia fruit. The purpose of this study was to evaluate the genotoxicity of gardenia yellow. Genotoxicity of gardenia yellow and its components, crocetin, gentiobiose (a component of crocin), geniposide and genipin (formed by hydrolysis of geniposide), was studied by Ames test, rec-assay, and sister chromatid exchange (SCE) using V79 cells. Gardenia yellow and its components were found not to be mutagenic in the Salmonella reverse mutation assay. Gardenia yellow and genipin caused damage of DNA in rec-assay. Gardenia yellow induced a significant dose-dependent increase of SCE frequency (8.6 times at 1000 microg/ml as the value for the solvent control). Only genipin induced SCEs significantly among the components of gardenia yellow. Moreover, genipin induced a significant increase of tetraploids at all doses tested (95% at 8 microg/ml). Gardenia yellow preparation was analyzed by capillary electrophoresis (CE), and geniposide was detected. However, genipin was not observed. In conclusion, we have shown that genipin possesses genotoxicity. Furthermore, there were unidentified genotoxicants in gardenia yellow.

Effect of in vitro and in vivo aerosolized treatment with geniposide on tracheal permeability in ovalbumin-induced guinea pigs

The primary objective of this study was to investigate the effect of geniposide, a potent anti-inflammatory, on ovalbumin-antigen-induced tracheal permeability and transepithelial electrical resistance in guinea pigs. Two weeks after sensitization with ovalbumin (100 mg/ml), the permeability of guinea-pig tracheas was evaluated by flux measurements using the transcellular tracer, [(14)C]estradiol, and the paracellular tracer, [(14)C]mannitol. The effect of extracellular Ca(2+) with geniposide was also studied, using deletion of Ca(2+) in the donor chamber. The in vivo treatment effect of aerosolized geniposide on tracheal permeability in the ovalbumin-sensitized guinea pigs was also evaluated. The results indicate that tight junction permeability of ovalbumin-sensitized trachea was significantly dose dependent and decreased by geniposide (1-10 mM), as evidenced by substantial recovery of transepithelial electrical resistance and decreased transepithelial permeability of [(14)C]mannitol at (1.32+/-0.12) x 10(-5) cm/s. The effect of combination of the removal of extracellular Ca(2+) with geniposide had no effect on tight junction permeability of ovalbumin-sensitized trachea and revealed that transepithelial electrical resistance and junction permeability did not recover. In addition, the cAMP levels and phosphodiesterase activity were not significantly influenced in ovalbumin-sensitized tracheal tissues after geniposide treatment. Inhaled geniposide (50 mM, 30 min after ovalbumin sensitization) significantly restored junction permeability induced by ovalbumin (100 mg/ml, 2 min). Junction permeability did not recover on pretreatment with geniposide (50 mM for 30 min over 16 days consecutive before ovalbumin sensitization) after exposure of conscious guinea pigs to aerosol ovalbumin. In conclusion, geniposide has inhibitory effects on ovalbumin-induced junction permeability and recovery of transepithelial electrical resistance in guinea pig trachea, showing its potential as anti-asthma therapy.

In vitro evaluation of the genotoxicity of a naturally occurring crosslinking agent (genipin) for biologic tissue fixation

The objective of the present study was to evaluate in vitro, using Chinese hamster ovary (CHO-K1) cells, the genotoxicity of genipin, a naturally occurring crosslinking agent. Glutaraldehyde, the most commonly used crosslinking agent for biologic tissue fixation, was employed as a reference chemical. The selected procedures for this evaluation were the micronucleus (MN) and sister chromatid exchange (SCE) assays with or without the addition of a metabolic activation system (S9 mix). Before starting the genotoxicity assays, the maximum noncytotoxic amounts of glutaraldehyde and genipin were determined using the MTT assay. The results obtained in the MTT assay revealed that the cytotoxicity of genipin was significantly lower than that of glutaraldehyde with or without S9 mix. The frequencies of MN observed in the cases drugged with varying concentrations of glutaraldehyde or genipin were not statistically different from those seen in the negative controls (blank) in the presence or absence of S9 mix. However, it was noted that glutaraldehyde significantly inhibited the cell-cycle progression while the cells drugged with genipin did not result in cell-cycle delay. In the SCE assay, the numbers of SCE per cell observed in the cases drugged with varying concentrations of glutaraldehyde were significantly greater than those found in the negative controls with or without S9 mix. Nevertheless, these numbers were still low compared to the numbers of SCE induced by the strong mutagens used as our positive control substances. This suggests that glutaraldehyde may produce a weakly clastogenic response in CHO-K1 cells. In contrast, the numbers of SCE per cell obtained in the cases drugged with genipin were comparable to those observed in the negative controls in those that were except drugged with the highest dose (50 ppm). This suggests that genipin does not cause clastogenic response in CHO-K1 cells provided its concentration is lower than 50 ppm. In conclusion, as far as cytotoxicity and genotoxicity are concerned, genipin is a promising crosslinking agent for biologic tissue fixation.

Genipin, a metabolite derived from the herbal medicine Inchin-ko-to, and suppression of Fas-induced lethal liver apoptosis in mice

BACKGROUND & AIMS

We showed previously that a Kampo (Chinese/Japanese herbal) medicine, Inchin-ko-to (ICKT), inhibits hepatocyte apoptosis induced by transforming growth factor beta1 in vitro. The present study investigated whether ICKT or its ingredients inhibit Fas-mediated liver apoptosis in vivo.

METHODS

Acute liver injury was induced by an intravenous injection of anti-Fas antibody, Jo2. The effects of ICKT and its ingredients on lethality, histology, apoptotic index, serum transaminase levels, caspase activation, mitochondrial membrane potential (Deltapsi(m)), and mitochondrial permeability transition (MPT) were analyzed. Apoptosis in mouse hepatocytes in vitro was also evaluated.

RESULTS

Pretreatment with ICKT rescued 75% of Jo2-treated mice and markedly suppressed liver apoptosis/injury. Genipin, an intestinal bacterial metabolite of geniposide that is a major ingredient of ICKT, was found to be an active principle of ICKT. Genipin also suppressed in vitro Fas-mediated apoptosis in primary-cultured murine hepatocytes. Activation of caspase 3 and 8 in the liver homogenate and rapid reduction of triangle uppsi(m) of hepatocytes isolated from Jo2-treated mice were inhibited by genipin preadministration. The resistance to Ca(2+)-induced MPT was enhanced in liver mitochondria of genipin-treated mice.

CONCLUSIONS

These results suggest that the antiapoptotic activity of genipin via the interference with MPT is a possible mechanism for therapeutic effects of ICKT.

Enzymatic activation of oleuropein: a protein crosslinker used as a chemical defense in the privet tree

Leaves of the privet tree, Ligustrum obtusifolium, contain a large amount of oleuropein, a phenolic secoiridoid glycoside, which is stably kept in a compartment separate from activating enzymes. When the leaf tissue is destroyed by herbivores, enzymes localized in organelles start to activate oleuropein into a very strong protein denaturant that has protein-crosslinking and lysine-decreasing activities. These activities are stronger than ever reported from plant systems and have adverse effects against herbivores by decreasing the nutritive value of dietary protein completely. We report here that strong oleuropein-specific beta-glucosidase in organelles activates oleuropein by converting the secoiridoid glucoside moiety of oleuropein into a glutaraldehyde-like structure, which is also an alpha,beta-unsaturated aldehyde. Oleuropein activated by beta-glucosidase had very strong protein-denaturing, protein-crosslinking, and lysine-alkylating activities that are very similar to, but stronger than, those of glutaraldehyde. Aucubin, another iridoid glycoside, had similar activities after beta-glucosidase treatment. We also detected polyphenol oxidase activity in organelles that activate the dihydroxyphenolic moiety to have protein-crosslinking activities. These data suggest that the privet tree has developed an effective defense mechanism with oleuropein, a unique multivalent alkylator ideal as a protein-crosslinker. Our results that iridoid glycosides are precursors of alkylators may elucidate the chemical bases that underlie various bioactivities and ecological roles of iridoid glycosides.