Fabrication of phosphoric-crosslinked chitosan@g-C3N4 gel beads for uranium(VI) separation from aqueous solution.

In this work, a novel g-C3N4 filled, phosphoric-crosslinked chitosan gel bead (P-CS@CN) was successfully prepared to adsorb U(VI) from water. The separation performance of chitosan was improved by introducing more functional groups. At pH 5 and 298 K, the adsorption efficiency and adsorption capacity could reach 98.0 % and 416.7 mg g-1, respectively. After adsorption, the morphological structure of P-CS@CN did not change and adsorption efficiency remained above 90 % after 5 cycles. P-CS@CN exhibited an excellent applicability in water environment based on dynamic adsorption experiments. Thermodynamic analyses demonstrated the value of ΔG, manifesting the spontaneity of U(VI) adsorption process on P-CS@CN. The positive values of ΔH and ΔS showed that the U(VI) removal behavior of P-CS@CN was an endothermic reaction, indicating that the increase of temperature was great benefit to the removal. The adsorption mechanism of P-CS@CN gel bead could be summarized as the complexation reaction with the surface functional groups. This study not only developed an efficient adsorbent for the treatment of radioactive pollutants, but also provided a simple and feasible strategy for the modification of chitosan-based adsorption materials.

Muyocoxanthones O-S: Undescribed xanthones with antioxidative damage bioactivity to cardiomyocytes from the endophytic fungus Muyocopron laterale.

The metabolites from the endophytic fungus Muyocopron laterale hosted in the medicinal plant Tylophora ovata were investigated, and five undescribed xanthones, muyocoxanthones O-S, along with seven known compounds were isolated. Their structures were elucidated by HR-ESI-MS, NMR, and ECD calculations. Compounds were evaluated for their anti-cardiomyocyte oxidative damage activity using a model of oxidative damage induced by cell hypoxia incubation. Muyocoxanthones O-Q and blennolide L exhibited moderate activity against oxidative damage to cardiomyocytes with relative viabilities of 62.4, 54.8, 60.3 and 54.9%, respectively.

Undescribed meleagrin alkaloids from the endophytic fungus Penicillium commune.

Six undescribed meleagrin analogues, isomeleagrin, meleagrin F, meleagrin G, methylmeleagrin G, isomethylmeleagrin G and meleagrin H, were isolated from the endophytic fungus Penicillium commune, which was obtained from the fresh leaves of a toxic medicinal plant, Tylophora ovata. The structures of these analogues were elucidated through extensive spectroscopic data analysis, and their absolute configurations were characterized by calculated electronic circular dichroism (ECD). Structurally, meleagrin F features an undescribed skeleton with an aniline moiety, which is linked to meleagrin through a C-C bond at C8-C26. Connecting N19-C3' through the C-N bond in meleagrin G, methylmeleagrin G, isomethylmeleagrin G and meleagrin H was rare for amino acid condensation. The cytotoxicity activity of these undescribed compounds was evaluated, and isomeleagrin exhibited a selective cytotoxicity activity against HGC27 cells with an IC50 value of 2.01 µM.

Secondary metabolites with diversified structures from an endophytic fungus Colletotrichum gloeosporioides associated with a toxic medicinal plant Tylophora ovata.

Six new secondary metabolites, including two new nor-triterpenes (1 and 2), one new sesquiterpene (4), two new α-pyrone derivatives (6 and 7), and one new natural product (5) along with two known compounds (3 and 8) were isolated from an endophytic fungus Colletotrichum gloeosporioides obtained from a toxic medicinal plant Tylophora ovata. Their structures were elucidated by spectroscopic data analyses, while their absolute configurations were determined by CD and X-ray diffraction analyses. The in vitro anti-inflammatory activities of these compounds were evaluated.

[Investigation on secondary metabolites of endophytic fungus Talaromyces purpurogenus hosted in Tylophora ovate].

Eight compounds,(R)-2-[5-(methoxycarbonyl)-4-methyl-6-oxo-3,6-dihydro-2H-pyran-2-yl]acetic acid(1),(3S,4R)-3,4-dihydro-3,4-epoxy-5-hydroxynaphthalen-1(2H)-one(2),(-)-mitorubrinol(3),(-)-mitorubrin(4),(±)-asperlone A(5), terreusinone(6), verrucisidinol(7) and cerebroside C(8) were isolated from the endophytic fungus Talaromyces purpurogenus by using various column chromatographic techniques. Their structures were identified by NMR, MS, CD and optical rotation. Compounds 1 and 2 were new compounds. Their anti-diabetic activities in vitro were evaluated, and compound 1 showed moderate inhibitory activity toward XOD at 10 µmol·L~(-1) with the inhibition rate of 69.9%.

Nonadride and Spirocyclic Anhydride Derivatives from the Plant Endophytic Fungus Talaromyces purpurogenus.

Six new nonadride derivatives (1-6) and three new spirocyclic anhydride derivatives (7-9) were isolated from the endophytic fungus Talaromyces purpurogenus obtained from fresh leaves of the toxic medicinal plant Tylophora ovata. The structures of these compounds were determined by spectroscopic analyses including 1D and 2D NMR, HRESIMS, and ECD techniques. Maleic anhydride derivatives 1-9 were evaluated for their in vitro anti-inflammatory activities. Compound 1 showed significant inhibitory activity against NO production in LPS-induced RAW264.7 cells with an IC50 value of 1.9 µM. Compounds 2 and 6 showed moderate inhibitory activities toward XOD and PTP1b, respectively, at 10 µM with inhibition rates of 67% and 76%.

Sesquiterpenes from an Endophytic Aspergillus flavus.

Eight new cadinene-sesquiterpenes (1-8), one eudesmane-sesquiterpene (9), and three known compounds (10-13) were isolated from an endophytic fungus, Aspergillus flavus, which was isolated from a toxic medicinal plant, Tylophora ovata. Their structures were elucidated by interpretation of spectroscopic data, and absolute configurations determined according to the specific rotation and electron circular dichroism methods. Compounds 4-8, 11, and 12 exhibited latent hepatic protection effects at 10 µM, and compound 12 selectively inhibited the proliferation of MCF-7 breast cancer cells with an IC50 values of 2.6 µM.

Development and Application of an UHPLC-MS/MS Method for Comparative Pharmacokinetic Study of Eight Major Bioactive Components from Yin Chen Hao Tang in Normal and Acute Liver Injured Rats.

Yin Chen Hao Tang (YCHT) is one of the most famous hepatoprotective herbal formulas in China, but its pharmacokinetic investigation in model rats has been rarely conducted. In this study, the hepatic injury model was caused by intraperitoneal injections of carbon tetrachloride (CCl4), and YCHT was orally administered to the model and normal rats. An ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was established to analyze the plasma pharmacokinetics of eight major bioactive ingredients from YCHT in both the normal and liver injured rats. The calibration curves presented good linearity (r > 0.9981) in the concentration range. The relative standard deviation (RSD%) of inter- and intraday precision was within 9.55%, and the accuracy (RE%) ranged from -10.72% to 2.46%. The extraction recovery, matrix effect, and stability were demonstrated to be within acceptable ranges. The lower limit of detection (LLOD) and lower limit of quantitation (LLOQ) were around 0.1 ng/mL and 0.5 ng/mL, respectively, which were much lower than those in other related researches. Results reveal that there are significant differences in the pharmacokinetics of scoparone, geniposide, rhein, aloe-emodin, physcion, and chrysophanol in hepatic injured rats as compared to those in control except for scopoletin and emodin. Our experimental results provide a meaningful reference for the clinical dosage of YCHT in treating liver disorders, and the improvement of LLOD and LLOQ can also broaden the range of our method's application, which is very suitable for quantitating these eight compounds with low levels.

Effects of Danshen tablets on pharmacokinetics of atorvastatin calcium in rats and its potential mechanism.

CONTEXT: Danshen tablets (DST), an effective traditional Chinese multi-herbal formula, are often combined with atorvastatin calcium (AC) for treating coronary heart disease in the clinic. OBJECTIVE: This study investigated the effects of DST on the pharmacokinetics of AC and the potential mechanism. MATERIALS AND METHODS: The pharmacokinetics of AC (1 mg/kg) with or without pretreatment of DST (100 mg/kg) were investigated using LC-MS/MS. The effects of DST (50 µg/mL) on the metabolic stability of AC were also investigated using rat liver microsome incubation systems. RESULTS: The results indicated that Cmax (23.87 ± 4.27 vs. 38.94 ± 5.32 ng/mL), AUC(0-t) (41.01 ± 11.32 vs. 77.28 ± 12.92 ng h/mL), and t1/2 (1.91 ± 0.18 vs. 2.74 ± 0.23 h) decreased significantly (p < 0.05) when DST and AC were co-administered, which suggested that DST might influence the pharmacokinetic behavior of AC when they are co-administered. The metabolic stability (t1/2) of AC was also decreased (25.7 ± 5.2 vs. 42.5 ± 6.1) with the pretreatment of DST. DISCUSSION AND CONCLUSIONS: This study indicated that the main components in DST could accelerate the metabolism of AC in rat liver microsomes and change the pharmacokinetic behaviors of AC. So these results showed that the herb-drug interaction between DST and AC might occur when they were co-administered. Therefore, the clinical dose of AC should be adjusted when DST and AC are co-administered.

Pharmacokinetic interaction of aconitine, liquiritin and 6-gingerol in a traditional Chinese herbal formula, Sini Decoction.

1. This study aimed to investigate the pharmacokinetic interaction of the three ingredients in a traditional Chinese herbal formulation, Sini Decoction, and provide evidence for its compatibility mechanism. 2. First, the effect of liquiritin and 6-gingerol on the pharmacokinetic parameters of aconitine was investigated in rats by using a sensitive and reliable LC-MS/MS method. Then the Caco-2 cell monolayer model and Rhodamine-123 uptake assay were used to investigate the effect of liquiritin and 6-gingerol on the absorption of aconitine and the activity of P-gp. 3. The Cmax of aconitine increased significantly (p < 0.05) from 10.34 ± 1.99 to 17.68 ± 2.65 ng/mL with the pretreatment of liquiritin (20 mg/kg), and to 17.43 ± 0.96 ng/mL with 6-gingerol (20 mg/kg). When aconitine was co-administered with liquiritin and 6-gingerol, the Cmax and AUC(0-t) of aconitine increased approximately twofold, and while t1/2 only increased 1.2-fold. The Caco-2 cell monolayer model and Rhodamine-123 uptake assay indicated that both liquiritin and 6-gingerol could increase the absorption of aconitine by inhibiting the activity of P-gp. 4. These results indicated that both liquiritin and 6-gingerol could promote the absorption of aconitine and increase its drug concentration in blood by inhibiting the activity of P-gp, and it could also provide evidence for compatibility mechanism of the traditional Chinese herbal formula, Sini Decoction.

Corrigendum to "Development and Application of an UHPLC-MS/MS Method for Comparative Pharmacokinetic Study of Eight Major Bioactive Components from Yin Chen Hao Tang in Normal and Acute Liver Injured Rats".

[This corrects the article DOI: 10.1155/2018/3239785.].

Schisandra Lignan Extract Protects against Carbon Tetrachloride-Induced Liver Injury in Mice by Inhibiting Oxidative Stress and Regulating the NF-κB and JNK Signaling Pathways.

Schisandra chinensis (S. chinensis) is a traditional Chinese herbal medicine widely used for the treatment of liver disease, whose main active components are lignans. However, the action mechanisms of the lignans in S. chinensis remain unclear. This study aimed to investigate the protective effect and related molecular mechanism of Schisandra lignan extract (SLE) against carbon tetrachloride- (CCl4-) induced acute liver injury in mice. Different doses of SLE at 50, 100, and 200 mg/kg were administered daily by gavage for 5 days before CCl4 treatment. The results showed that SLE significantly decreased the activities of serum ALT/AST and reduced liver pathologic changes induced by CCl4. Pretreatment with SLE not only decreased the content of MDA but increased SOD, GSH, and GSH-Px activities in the liver, suggesting that SLE attenuated CCl4-induced oxidative stress. The expression levels of inflammatory cytokines TNF-a, IL-1ß, and IL-6 were decreased after oral administration of SLE, probably because lignans inhibited the NF-κB activity. Additionally, SLE also inhibited hepatocyte apoptosis by suppressing JNK activation and regulating Bcl-2/Bax signaling pathways. In conclusion, these results suggested that SLE prevented CCl4-induced liver injury through a combination of antioxidative stress, anti-inflammation, and antihepatocyte apoptosis and alleviated inflammation and apoptosis by regulating the NF-κB, JNK, and Bcl-2/Bax signaling pathways.

Effect of Ginkgo Leaf Tablets on the Pharmacokinetics of Amlodipine in Rats.

BACKGROUND AND OBJECTIVE: Ginkgo leaf tablet (GLT) is an effective traditional Chinese multi-herbal formula, which is often combined with amlodipine for treating senile hypertension in clinic. The aim of this study was to study the pharmacokinetics of amlodipine after oral administration of amlodipine and GLT and to investigate the potential for pharmacokinetic herb-drug interactions between GLT and amlodipine in rats. METHODS: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method was developed for quantification of amlodipine in rat plasma. The accuracy, precision, linearity, selectivity and recovery were all within an acceptable range. Male Sprague-Dawley rats were randomly assigned to two groups: amlodipine group and amlodipine + GLT group. Plasma concentrations of amlodipine were determined at the designated time points after oral administration by using the developed LC-MS/MS method, and the main pharmacokinetic parameters were calculated and compared. As ginkgolides A, ginkgolides B, bilobalide, quercetin and kaempferol were the main components of GLT, the effects of these ingredients in GLT on metabolism of amlodipine were further investigated in rat liver microsomes. RESULTS: The pharmacokinetic parameters, maximum plasma concentration (C max), time to reach C max (T max), area under the concentration-time curve (AUC), area under the first moment plasma concentration-time curve (AUMC) and elimination half-life (t 1/2), of amlodipine were significantly increased in amlodipine + GLT group, which suggested that GLT may influence the pharmacokinetic behavior after oral co-administration with amlodipine. Amlodipine is metabolized by cytochrome P450 (CYP) 3A4, so it was speculated that GLT may change the pharmacokinetic parameters of amlodipine through modulating the metabolism of CYP3A4 enzymes. When ginkgolides B, bilobalide, or quercetin and amlodipine were co-incubated in the rat liver microsomes, the metabolic rate of amlodipine was prolonged to 533.1, 216.1 and 407.6 min, respectively, from 73.7 min. CONCLUSIONS: These results suggested that these components in GLT inhibit the metabolism of amlodipine. So it can be speculated that the herb-drug interactions between GLT and amlodipine resulted from inhibiting the metabolism of amlodipine by GLT when they were co-administered.

Comparative pharmacokinetics of hypaconitine after oral administration of pure hypaconitine, Aconitum carmichaelii extract and Sini Decoction to rats.

Hypaconitine (HC) is one of the main aconitum alkaloids in Aconitum carmichaelii (AC), which is considered to be effective on cardiovascular disease, although it also has high toxicity. Sini Decoction (SND), composed of Aconitum carmichaelii, Glycyrrhiza uralensis and Zingiber officinale, is a traditional Chinese multi-herbal formula for recuperating the depleted yang. The aim of this study was to compare the pharmacokinetics of HC in rat plasma after oral administration of HC, AC extract and SND, and investigate the effect of other two herbal ingredients on absorption, metabolism and elimination of HC. A sensitive and specific LC-MS/MS method was developed to determine HC in rat plasma. Eighteen male Sprague-Dawley rats were randomly assigned to three groups: HC, AC and SND group. Plasma concentrations of HC were determined at designated points after oral administration, and main pharmacokinetic parameters were estimated. It was found that there was obvious difference (p < 0.05) on the pharmacokinetic parameters among three groups. Compared with AC group, Tmax, Cmax, k, AUC(0-24) and AUC(0-∞) decreased in SND group, while t1/2 and MRT had been lengthened, which indicated that the ingredients in other two herbs could influence the pharmacokinetic behavior of HC.

Biopharmaceutical and pharmacokinetic characterization of asiatic acid in Centella asiatica as determined by a sensitive and robust HPLC-MS method.

ETHNOPHARMACOLOGICAL RELEVANCE: Asiatic acid is one of the main components in the herb Centella asiatica, which is a well-known herbal medicine for its excellent pharmacological effects. To enhance the development potentials of asiatic acid as a chemopreventative agent, there is a great need to further understand its biopharmaceutical and pharmacokinetic properties. The aim of this research is to clarify the mechanisms of absorption and metabolism of asiatic acid, and explore its biopharmaceutical and pharmacokinetic properties in rats by using a sensitive and robust HPLC-MS method. MATERIALS AND METHODS: Male Sprague-Dawley rats were randomly assigned to 2 groups and administered with asiatic acid by oral and intravenous administration. Plasma concentrations of asiatic acid were determined at designated points and main pharmacokinetic parameters were estimated. The absorption of asiatic acid was investigated by using Caco-2 cell line absorption model in vitro and rat intestinal perfusion model in situ. The metabolic rate of asiatic acid was investigated by incubating it in rat liver microsome system in vitro. In addition, the solubility of asiatic acid in aqueous solution was also determined by using HPLC-MS method. RESULTS: The absolute oral bioavailability of asiatic acid is 16.25%. It was found that the permeability of asiatic acid is more than 10(-5) in the Caco-2 cell monolayer and rat intestinal perfusion model, and its main absorption region is the jejunum in rats. The metabolic rate of asiatic acid in rat liver microsomes, t1/2, is 9.493min, which shows that asiatic acid can be metabolized rapidly. The solubility of aisiatic acid was 0.1583mgmL(-1), and its poor solubility will result in low bioavailability. CONCLUSIONS: The asiatic acid in a variety of matrixes was analyzed by using a sensitive and specific HPLC-MS method, and its absolute oral bioavailability in rats was very low. Asiatic acid can be metabolized rapidly in rat liver microsomes, and has good permeability across Caco-2 monolayer cell and rat intestine perfusion. It can be deduced that the low bioavailability of asiatic acid results from poor solubility and rapid metabolism.

Absorption and metabolism of three monoester-diterpenoid alkaloids in Aconitum carmichaeli after oral administration to rats by HPLC-MS.

ETHNOPHARMACOLOGICAL RELEVANCE: Aconitum carmichaelii (AC) is a well-known herbal medicine for its excellent pharmacological effects and toxicity. The monoester-diterpenoid alkaloids (MDAs), including benzoylmesaconine (BMC), benzoylaconine (BAC) and benzoylhyaconine (BHC), are the main active components in AC. It was found that the diester alkaloids could be transformed into monoester-diterpenoid alkaloids after being decocted. In Chinese pharmacopoeia, the MDAs are also used as phytochemical markers for the quality control of AC. Benzoylmesaconine, benzoylaconine and benzoylhyaconine are representatives of monoester-diterpenoid alkaloids. It was reported that the absolute bioavailability of MDAs was very low but there was toxicity often occurred in AC. Because most of DDAs are transformed into MDAs after decoction, we speculate that some other components may promote the bioavailability of MDAs but result in toxicity by enhancing their absorption. To demonstrate the dynamic changes of MDAs in vivo and reveal the causes of low bioavailability and toxicity, this study will explore the mechanisms of absorption and metabolism of 3 MDAs. MATERIALS AND METHODS: A sensitive, accurate and specific LC-MS method was developed to determine the three MDAs in rat plasma. The pharmacokinetic parameters were estimated after orally administered 3 MDAs to the Male Sprague-Dawley rats, and the metabolism stability was calculated after incubating with rat liver microsomes, finally, the absorption characteristics of the 3 MDAs were investigated using Caco-2 transwell model. RESULTS: It was found that the pharmacokinetic parameters of 3 MDAs were similar, Cmax and Tmax were very small, and t1/2 was large, which indicated 3 MDAs can be absorbed rapidly and is difficult to be metabolized or excreted. However, the low Cmax indicated that the bioavailability of 3 MDAs will be very low and their absorption may be inhibited by some transport proteins. By incubating three MDAs in rat liver microsomes, it was proved that they almost can't be metabolized in vivo. The Caco-2 transwell experiments reveal that the P-gp inhibits the absorption of MDAs. CONCLUSIONS: LC-MS combined with a direct precipitation method for the simultaneous quantification of 3 MDAs in rat plasma has been developed and validated and successfully used in pharmacokinetic study of 3 MDAs. It was proved that the three components almost can't be metabolized in vivo, and P-gp inhibits the absorption of MDAs.

Influence of compound danshen tablet on the pharmacokinetics of losartan and its metabolite EXP3174 by liquid chromatography coupled with mass spectrometry.

Losartan is an effective anti-hypotension drug frequently used in clinic. Compound danshen tablet (CDST) is an important traditional Chinese multiherbal formula composed of Danshen, Sanqi and Bingpian, which is widely used for the treatment of cardiovascular and cerebrovascular diseases in China. More often, losartan and CDST are simultaneously used for the treatment of anti-hypertension in the clinic. The aim of this study was to compare the pharmacokinetics of losartan and EXP3174 after oral administration of single losartan and both losartan and CDST, and to investigate the influence of CDST on the pharmacokinetics of losartan and its metabolite EXP3174. Male Sprague-Dawley rats were randomly assigned to two groups: a losartan-only group and a losartan and CDST group. Plasma concentrations of losartan and EXP3174 were determined by LC-MS at designated points after drug administration, and the main pharmacokinetic parameters were estimated. It was found that there were significant differences (p < 0.05) between the pharmacokinetic parameters of losartan and EXP3174, which showed that CDST influenced the metabolism and excretion of losartan in vivo. The result could be used for clinical medication guidance of losartan and CDST to avoid the occurrence of adverse reactions.