Safety evaluations of the processed lateral root of Aconitum carmichaelii Debx. And its hepatotoxicity mechanisms in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The processed lateral root of Aconitum carmichaelii Debx. is known as Fuzi, an extensively used Traditional Chinese Medicine to treat cardiovascular diseases, rheumatism arthritis, bronchitis, pains, and hypothyroidism, etc. Although Chinese Pharmacopeia regulates the safe clinical dosage of Fuzi at 3-15 g/person/day, such recommendation not only lacks bench evidence but also does not differentiate Fuzi with different processing types, such as Heishunpian and Paofupian. AIM OF THE STUDY: The current study aimed to 1) determine No-Observed-Adverse-Effect-Levels of Heishunpian and Paofupian in rats and 2) investigate the related toxicity mechanisms for their safe clinical use. MATERIALS AND METHODS: After giving clinically relevant dosing regimen of Heishunpian/Paofupian to rats, we conducted toxicity assessments including ECG monitoring, histopathological changes and serum biomarkers to detect organ injury. Metabolomic study in the liver revealed changes in endogenous metabolite levels after two-week treatment of Fuzi preparations or its corresponding six toxic alkaloids mixtures. RESULTS: The NOAEL for both bolus and two-week treatments of Heishunpian and Paofupian in rats was designated to be 7.5 g/kg and 15 g/kg, respectively. Corresponding recommended doses in humans were 7.5-25 g/person/day for Heishunpian and 15-50 g/person/day for Paofupian. Metabolic profiles revealed more significant alterations in endogenous substances from rats receiving the two Fuzi preparations than their corresponding toxic alkaloids mixtures. Upregulation of bile acid pathway could be responsible for Fuzi induced liver injury. CONCLUSIONS: Compared to the current maximum recommended dose, our suggested upper limit of guided dose for Heishunpian was comparable, whereas that for Paofupian could be further elevated. Both C19-diterpenoid alkaloids and co-occurring components in Fuzi preparations contributed to their hepatotoxicity via upregulation of bile acid pathway.

Protective effect of Glechoma hederacea extract against gallstone formation in rodent models.

BACKGROUND: Our current study aimed to evaluate the effect of an Glechoma hederacea extract (Hitrechol®) in normal rats and gallstone diseased mice to explore its underlying mechanisms. Normal rats and C57BL/6 mice with/without cholesterol gallstone were used in this study. METHODS: To monitor the effect of Hitrechol® on bile secretion, bile flow rates at 15 min interval until 2 h post-dosing in normal rats treated with vehicle and Hitrechol® were compared using multiple t-test with a p < 0.05 considered as statistically significant different. To further evaluate the effect of Hitrechol® against the development of gallstone in lithogenic diet treated mice, mice were treated with vehicle or Hitrechol® (QD-once daily or TID-three times daily) for 3 weeks followed by comparing the levels of bile composition among the treatment groups. In addition, the anti-oxidative biomarkers in liver and anti-inflammatory biomarkers in serum were detected and compared among all the treatment groups to evaluate the hepato-protective effect of Hitrechol®. The obtained levels of biomarkers and bile composition were compared among different treatment groups using one-way ANOVA tests followed by Tukey's multiple comparisons with p < 0.05 considered as statistically significant. RESULTS: Despite no significant impact on the bile flow rate, Hitrechol® TID treatment dramatically decreased size and amount of gallstone crystals and total cholesterol level (p < 0.05), as well as total bile acid (p < 0.05) and several types of bile acid (p < 0.05) levels in gallstone disease model mice. Hitrechol® TID treatment could significantly decrease the frequencies of hepatocyte necrosis and lipid aggregation notably as well as increase the antioxidant enzyme level (p < 0.05) in the liver. CONCLUSIONS: Our findings for the first time demonstrated the beneficial effect of Hitrechol® against gallstone via its litholytic, liver-protective and antioxidant activities.

Overview of Pharmacokinetics and Liver Toxicities of Radix Polygoni Multiflori.

Radix Polygoni Multiflori (RPM), a traditional Chinese medicine, has been used as a tonic and an anti-aging remedy for centuries. However, its safe and effective application in clinical practice could be hindered by its liver injury potential and lack of investigations on its hepatotoxicity mechanism. Our current review aims to provide a comprehensive overview and a critical assessment of the absorption, distribution, metabolism, excretion of RPM, and their relationships with its induced liver injury. Based on the well-reported intrinsic liver toxicity of emodin, one of the major components in RPM, it is concluded that its plasma and liver concentrations could attribute to RPM induced liver injury via metabolic enzymes alteration, hepatocyte apoptosis, bile acids homeostasis disruption, and inflammatory damage. Co-administered 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucopyranoside in RPM and other drugs/herbs could further aggravate the hepatotoxicity of emodin via enhancing its absorption and inhibiting its metabolism. To ensure the safe clinical use of RPM, a better understanding of the toxicokinetics and effect of its co-occurring components or other co-administered drugs/herbs on the pharmacokinetics of emodin is warranted.

Is it safe to take Radix Salvia Miltiorrhiza - Radix Pueraria Lobate product with warfarin and aspirin? A pilot study in healthy human subjects.

ETHNOPHARMACOLOGICAL RELEVANCE: Radix Salvia Miltiorrhiza (Danshen) and Radix Pueraria Lobate (Gegen) are officially listed in the Chinese Pharmacopoeia and have long been used together as a Compound Chinese Traditional Medicine (CCTM) for treatment of coronary heart diseases, which are often co-administered with aspirin or warfarin to patients suffering from cardiovascular diseases. AIM OF STUDY: Since significant pharmacokinetic and pharmacodynamic interactions between Danshen-Gegen (DG) formula and aspirin/warfarin have been observed in our previous rat studies, the current study was proposed aiming to further verify such pharmacokinetic and pharmacodynamic interactions in healthy human subjects and explore related mechanisms. MATERIALS AND METHODS: A 5-day, multiple dose, five-session clinical trial has been carried out (n = 14) with 2-week washout periods between sessions, during which the subjects would receive different combinations of the medications. Plasma samples were collected for pharmacokinetic evaluation, and whole blood samples were collected for pharmacodynamic evaluation. In addition, an in-vitro mechanistic study is conducted to investigate the role of danshensu on the anti-thrombotic and anti-platelet aggregation effects of warfarin and aspirin respectively. RESULTS: Significant pharmacokinetic and pharmacodynamic herb-drug interactions were observed in healthy human subjects. pharmacokinetically, co-administration of DG with aspirin or warfarin could lead to a moderately increased AUC0→t of aspirin and a decreased AUC0→t of 7-hydroxyl warfarin respectively. The systemic exposure of danshensu (DSS, the marker component of DG) would be significantly increased after co-administration with warfarin. Pharmacodynamically, a reduction in systemic thromboxane B2 concentration was noticed after administration of DG with aspirin, which could be associated with the increased systemic exposure of aspirin and the synergistic effect of danshensu, aspirin and salicylic acid on cyclooxygenase (COX) inhibition. An offset on the warfarin induced soluble thrombomodulin induction was observed after its co-administration with DG, which could be partially attributed to the COX-2 inhibition effect of danshensu. CONCLUSION: Our results indicated that co-administration of DG with aspirin/warfarin would lead to significant pharmacokinetic and pharmacodynamic herb-drug interactions in healthy human subjects.

Absorption difference between hepatotoxic pyrrolizidine alkaloids and their N-oxides - Mechanism and its potential toxic impact.

ETHNOPHARMACOLOGICAL RELEVANCE: Pyrrolizidine alkaloids (PAs) are a group of phytotoxins widely present in about 3% of flowering plants. Many PA-containing herbal plants can cause liver injury. Our previous studies demonstrated that PA N-oxides are also hepatotoxic, with toxic potency much lower than the corresponding PAs, due to significant differences in their toxicokinetic fates. AIM OF STUDY: This study aimed to investigate the oral absorption of PAs and PA N-oxides for better understanding of their significant differences in toxicokinetics and toxic potency. MATERIALS AND METHODS: The oral absorption of PAs and PA N-oxides in rats and in rat in situ single pass intestine perfusion model was investigated. The intestinal permeability and absorption mechanisms of five pairs of PAs and PA N-oxides were evaluated by using Caco-2 monolayer model. RESULTS: The plasma concentrations of total PAs and PA N-oxides within 0-60 min were significantly lower in rats orally treated with a PA N-oxide-containing herbal alkaloid extract than with a PA-containing herbal alkaloid extract at the same dose, indicating that the absorption of PA N-oxides was lower than that of PAs. Using the rat in situ single pass intestine perfusion model, less cumulative amounts of retrorsine N-oxide in mesenteric blood were observed compared to that of retrorsine. In Caco-2 monolayer model, all five PAs showed absorption with Papp AtoB values [(1.43-16.26) × 10-6 cm/s] higher than those of corresponding N-oxides with Papp AtoB values lower than 1.35 × 10-6 cm/s. A further mechanistic study demonstrated that except for senecionine N-oxide, retrorsine N-oxide, and lycopsamine N-oxide, all PAs and PA N-oxides investigated were absorbed via passive diffusion. While, for these 3 PA N-oxides, in addition to passive diffusion as their primary transportation, efflux transporter-mediated active transportation was also involved but to a less extent with the efflux ratio of 2.31-3.41. Furthermore, a good correlation between lipophilicity and permeability of retronecine-type PAs and their N-oxides with absorption via passive diffusion was observed, demonstrating that PAs have a better oral absorbability than that of the corresponding PA N-oxides. CONCLUSION: We discovered that among many contributors, the lower intestinal absorption of PA N-oxides was the initiating contributor that caused differences in toxicokinetics and toxic potency between PAs and PA N-oxides.

Tissue Accumulations of Toxic Aconitum Alkaloids after Short-Term and Long-Term Oral Administrations of Clinically Used Radix Aconiti Lateralis Preparations in Rats.

Although Radix Aconiti Lateralis (Fuzi) is an extensively used traditional Chinese medicine with promising therapeutic effects and relatively well-reported toxicities, the related toxic aconitum alkaloid concentrations in major organs after its short-term and long-term intake during clinical practice are still not known. To give a comprehensive understanding of Fuzi-induced toxicities, current study is proposed aiming to investigate the biodistribution of the six toxic alkaloids in Fuzi, namely Aconitine (AC), Hypaconitine (HA), Mesaconitine (MA), Benzoylaconine (BAC), Benzoylhypaconine (BHA) and Benzoylmesaconine (BMA), after its oral administrations at clinically relevant dosing regimen. A ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for simultaneous quantification of six toxic alkaloids in plasma, urine and major organs of Sprague Dawley rats after oral administrations of two commonly used Fuzi preparations, namely Heishunpian and Paofupian, at their clinically relevant dose for single and 15-days. Among the studied toxic alkaloids and organs, BMA demonstrated the highest concentrations in all studied organs with liver containing the highest amount of the studied alkaloids, indicating their potential hepatotoxicity. Moreover, tissue accumulation of toxic alkaloids after multiple dose was observed, suggesting the needs for dose adjustment and more attention to the toxicities induced by chronic use of Fuzi in patients.

Impact of the Chinese herbal medicines on dual antiplatelet therapy with clopidogrel and aspirin: Pharmacokinetics and pharmacodynamics outcomes and related mechanisms in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Dual antiplatelet therapy (DAPT) with aspirin (ASA) and clopidogrel (CLP) has been consistently shown clinical effectiveness in patients with coronary artery disease. According to the literature, four traditional Chinese medicine (TCM) herbs effective for prevention cardiovascular diseases, namely Radix Salvia Miltiorrhiza (Red sage root, Danshen), Radix Pueraria Lobata (Kudzu root, Gegen), Radix Angelica Sinensis (Angelica root, Danggui), and Rhizoma Ligusticum chuanxiong (Szehuan lovage rhizome, Chuanxiong), are of high potential to be co-administered during DAPT. Since all these herbs are blood vitalizing medicines and can promote blood circulation and eliminate blood stasis, it was hypothesized that they may potentially alter the clinical outcomes of DAPT with clopidogrel and aspirin. AIM OF STUDY: The current study is proposed aiming to preliminarily evaluate the impact of these four commonly used Chinese medicinal herbs on the pharmacokinetics and pharmacodynamics of the combination therapy with clopidogrel and aspirin and its relevant outcomes and mechanisms. MATERIALS AND METHODS: In order to mimic the standard dosing regimen for DAPT in human, various Sprague-Dawley rats treatment groups were received a bolus oral dose of DAPT on day 1 followed by DAPT for consecutive 13 days in absence and presence of orally co-administered four TCM herbs (Danshen, Gegen, Danggui and Chuanxiong) at their low and high doses. On day 14, serial blood samples were collected after dosing to obtain the plasma concentrations of ASA, CLP and their corresponding metabolites by LC/MS/MS. At the end of last blood sampling point of each rat, about 4.5 ml of whole blood were collected to estimate the prothrombin time from each treatment groups. After all the blood sampling, the rats were sacrificed followed by collecting their livers for evaluations of enzyme activities and expressions in the related liver microsome preparations and stomach tissues for evaluations of their potential ulcer index. In addition, gene expression and protein levels of related biomarkers (COX-1, COX-2, P2Y12) in rat livers were measured by RT-PCR and Western blot, respectively, and compared among different treatment groups. RESULTS: Co-administration of Gegen and Danggui significantly altered the pharmacokinetics of ASA and CLP in DAPT with increased systemic exposure of ASA and CLP respectively. Although minimal impact on aspirin esterase activity for all co-administered herbs, significant inhibition on rCyp2c11 and carboxylesterase activities were observed for DAPT with Danshen, Gegen and Danggui co-treatment. In addition, significantly longer PT were found in all DAPT treatment groups. However, a trend of decrease in PT of DAPT in presence of Gegen, Danggui and Chuanxiong was noticed. Nevertheless, all the treatments did not cause detectable changes in COX and P2Y12 mRNA and protein expressions. CONCLUSION: Among the four studied TCMs, it was demonstrated that co-administration of Gegen and Danggui could lead to altered pharmacokinetics of DAPT with significant inhibition on rCyp2c11 and carboxylesterase activities. Although Gegen, Danggui and Chuanxiong might potentially offset the anticoagulant activity of DAPT, the overall pharmacodynamics outcome was not considered to be harmful due to lack of risk in bleeding, which warrant further verification for its clinical impact.

Brain-Targeting Delivery of Two Peptidylic Inhibitors for Their Combination Therapy in Transgenic Polyglutamine Disease Mice via Intranasal Administration.

Polyglutamine diseases are a set of progressive neurodegenerative disorders caused by misfolding and aggregation of mutant CAG RNA and polyglutamin protein. To date, there is a lack of effective therapeutics that can counteract the polyglutamine neurotoxicity. Two peptidylic inhibitors, QBP1 and P3, targeting the protein and RNA toxicities, respectively, have been previously demonstrated by us with combinational therapeutic effects on the Drosophila polyglutamine disease model. However, their therapeutic efficacy has never been investigated in vivo in mammals. The current study aims to (a) develop a brain-targeting delivery system for both QBP1 and L1P3V8 (a lipidated variant of P3 with improved stability) and (b) evaluate their therapeutic effects on the R6/2 transgenic mouse model of polyglutamine disease. Compared with intravenous administration, intranasal administration of QBP1 significantly increased its brain-to-plasma ratio. In addition, employment of a chitosan-containing in situ gel for the intranasal administration of QBP1 notably improved its brain concentration for up to 10-fold. Further study on intranasal cotreatment with the optimized formulation of QBP1 and L1P3V8 in mice found no interference on the brain uptake of each other. Subsequent efficacy evaluation of 4-week daily QBP1 (16 µmol/kg) and L1P3V8 (6 µmol/kg) intranasal cotreatment in the R6/2 mice demonstrated a significant improvement on the motor coordination and explorative behavior of the disease mice, together with a full suppression on the RNA- and protein-toxicity markers in their brains. In summary, the current study developed an efficient intranasal cotreatment of the two peptidylic inhibitors, QBP1 and L1P3V8, for their brain-targeting, and such a novel therapeutic strategy was found to be effective on a transgenic polyglutamine disease mouse model.

Relationships between the Toxicities of Radix Aconiti Lateralis Preparata (Fuzi) and the Toxicokinetics of Its Main Diester-Diterpenoid Alkaloids.

The processed lateral root of Aconitum carmichaelii Deb (Aconiti Radix lateralis praeparata or Fuzi) is a potent traditional herbal medicine extensively used in treatment of cardiovascular diseases, rheumatism arthritis, and bronchitis in many Asian countries. Although Fuzi has promising therapeutic effects, its toxicities are frequently observed. Three main C19-diester-diterpenoid alkaloids (DDAs) are believed to be the principal toxins of the herb. Although toxicokinetic profiles of the toxic DDAs have already been examined in several studies, they have seldom been correlated with the toxicities of Fuzi. The current article aimed to investigate the relationship between the up-to-date toxicokinetic data of the toxic DDAs and the existing evidence of the toxic effects of Fuzi. Relationships between the cardiac toxicity and the plasma and heart concentration of DDAs in mice and rats were established. Based on our findings, clinical monitoring of the plasma concentrations of DDAs of Fuzi is recommended to prevent potential cardiac toxicities. Additionally, caution with respect to potential hepatic and renal toxicity induced by Fuzi should be exercised. In addition, further analyses focusing on the preclinical tissue distribution profile of DDAs and on the long-term toxicokinetic-toxicity correlation of DDAs are warranted for a better understanding of the toxic mechanisms and safer use of Fuzi.

Overview of the anti-inflammatory effects, pharmacokinetic properties and clinical efficacies of arctigenin and arctiin from Arctium lappa L.

Arctigenin (AR) and its glycoside, arctiin, are two major active ingredients of Arctium lappa L (A lappa), a popular medicinal herb and health supplement frequently used in Asia. In the past several decades, bioactive components from A lappa have attracted the attention of researchers due to their promising therapeutic effects. In the current article, we aimed to provide an overview of the pharmacology of AR and arctiin, focusing on their anti-inflammatory effects, pharmacokinetics properties and clinical efficacies. Compared to acrtiin, AR was reported as the most potent bioactive component of A lappa in the majority of studies. AR exhibits potent anti-inflammatory activities by inhibiting inducible nitric oxide synthase (iNOS) via modulation of several cytokines. Due to its potent anti-inflammatory effects, AR may serve as a potential therapeutic compound against both acute inflammation and various chronic diseases. However, pharmacokinetic studies demonstrated the extensive glucuronidation and hydrolysis of AR in liver, intestine and plasma, which might hinder its in vivo and clinical efficacy after oral administration. Based on the reviewed pharmacological and pharmacokinetic characteristics of AR, further pharmacokinetic and pharmacodynamic studies of AR via alternative administration routes are suggested to promote its ability to serve as a therapeutic agent as well as an ideal bioactive marker for A lappa.

First evidence of pyrrolizidine alkaloid N-oxide-induced hepatic sinusoidal obstruction syndrome in humans.

Pyrrolizidine alkaloids (PAs) are among the most potent phytotoxins widely distributed in plant species around the world. PA is one of the major causes responsible for the development of hepatic sinusoidal obstruction syndrome (HSOS) and exerts hepatotoxicity via metabolic activation to form the reactive metabolites, which bind with cellular proteins to generate pyrrole-protein adducts, leading to hepatotoxicity. PA N-oxides coexist with their corresponding PAs in plants with varied quantities, sometimes even higher than that of PAs, but the toxicity of PA N-oxides remains unclear. The current study unequivocally identified PA N-oxides as the sole or predominant form of PAs in 18 Gynura segetum herbal samples ingested by patients with liver damage. For the first time, PA N-oxides were recorded to induce HSOS in human. PA N-oxide-induced hepatotoxicity was further confirmed on mice orally dosed of herbal extract containing 170 µmol PA N-oxides/kg/day, with its hepatotoxicity similar to but potency much lower than the corresponding PAs. Furthermore, toxicokinetic study after a single oral dose of senecionine N-oxide (55 µmol/kg) on rats revealed the toxic mechanism that PA N-oxides induced hepatotoxicity via their biotransformation to the corresponding PAs followed by the metabolic activation to form pyrrole-protein adducts. The remarkable differences in toxicokinetic profiles of PAs and PA N-oxides were found and attributed to their significantly different hepatotoxic potency. The findings of PA N-oxide-induced hepatotoxicity in humans and rodents suggested that the contents of both PAs and PA N-oxides present in herbs and foods should be regulated and controlled in use.