Simultaneous determination of three sesquiterpene lactones from Herba Inula extract in rat plasma by LC/MS/MS and its application to pharmacokinetic study

Targeting Keap1 with Inulae Herba activated the Nrf2 receptor to alleviate LPS-mediated acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Inulae Herba (IH) is known as Jinfeicao recorded in Chinese Pharmacopoeia with effects of lowering qi and eliminating phlegm, and used for the treatment of pulmonary diseases. However, its protective mechanism on pulmonary diseases, especially acute lung injury (ALI), is still undefined.

AIM OF THE STUDY

This study aimed to explore anti-inflammatory and anti-oxidation effects of IH and its underlying mechanism for treating ALI.

MATERIALS AND METHODS

We constructed a lipopolysaccharide (LPS)-ALI mouse model to reveal the therapeutical effect of IH. Western blot, real-time quantitative PCR, flow cytometry, small RNA interference, immunohistochemical staining, and the dual-luciferase experiment were performed to study the mechanism of IH for treating ALI.

RESULTS

IH attenuated LPS-mediated pathological changes (e.g. pneumonedema and pulmonary congestion) through inactivation of macrophages in an ALI mouse model. The result of flow cytometry demonstrated that IH regulated the homeostasis of M1 (CD80+CD206-) and M2 (CD80+CD206+) phenotype macrophages. Furthermore, IH suppressed mRNA expressions of M1 phenotype markers, such as iNOS and IL-6, whereas promoted mRNA expressions of M2 phenotype markers, such as ARG1 and RETNLA in LPS-mediated mice. Notably, IH targeted Keap1 to activate the Nrf2 receptor, exerting its anti-inflammatory and anti-oxidation effects proved by using immunohistochemical staining, dual-luciferase, and Keap1 knockdown technologies.

CONCLUSION

These findings suggested that targeting Keap1 with IH alleviated LPS-mediated ALI, and it could serve as a herbal agent for developing anti-ALI drugs.

What dominates the changeable pharmacokinetics of natural sesquiterpene lactones and diterpene lactones: a review focusing on absorption and metabolism

Sesquiterpene lactones (STLs) and diterpene lactones (DTLs) are two groups of common phytochemicals with similar structures. It's frequently reported that both exhibit changeable pharmacokinetics (PK) in vivo, especially the unstable absorption and extensive metabolism. However, the recognition of their PK characteristics is still scattered. In this review, representative STLs (atractylenolides, alantolactone, costunolide, artemisinin, etc.) and DTLs (ginkgolides, andrographolide, diosbulbins, triptolide, etc.) as typical cases are discussed in detail. We show how the differences of treatment regimens and subjects alter the PK of STLs and DTLs, with emphasis on the effects from absorption and metabolism. These compounds tend to be quite permeable in intestinal epithelium, but gastrointestinal pH and efflux transporters (represented by P-glycoprotein) have great impact and result in the unstable absorption. As the only characteristic functional moiety, the metabolic behavior of lactone ring is not dominant. The α, β-unsaturated lactone moiety has the strongest metabolic activity. While with the increase of low-activity saturated lactone moieties, the metabolism is led by other groups more easily. The phase I (oxidation, reduction and hydrolysis reaction) and II metabolism (conjugation reaction) are both extensive. CYP450s, mainly CYP3A4, are largely involved in biotransformation. However, only UGTs (UGT1A3, UGT1A4, UGT2B4 and UGT2B7) has been mentioned in studies about phase II metabolic enzymes. Our work offers a beneficial reference for promoting the safety evaluation and maximizing the utilization of STLs and DTLs.

Pharmacokinetics and Tissue Distribution Study of Modified Xiaochaihu Granules Against Gastric Ulcer Induced by Ethanol in Rats by UPLC-MS/MS

Gastric ulcer (GU) is one of the major gastrointestinal disorder diseases, with increasing incidence and prevalence globally. Modified Xiaochaihu granules (MXCHG) have been used effectively for treating chronic gastritis and GU clinically. To investigate the pharmacokinetics and tissue distribution of MXCHG, an ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method was established for the simultaneous determination of 8 bioactive ingredients (baicalin, wogonoside, baicalein, liquiritin, glycyrrhizic acid, berberine hydrochloride, saikosaponin a, and saikosaponin d) in rat plasma and various tissues using puerarin as an internal standard (IS). The biological samples were pretreated by protein precipitation with acetonitrile. The chromatographic separation was carried out on a C18 column with a gradient mobile phase consisting of acetonitrile and 0.1% formic acid in water. All analytes and IS were quantitated through ESI in the positive/negative ion multiple reaction monitoring mode. The mass transitions were as follows: m/z 445.0 → 268.5 for baicalin, m/z 458.7 → 282.8 for wogonoside, m/z 269.2 → 222.6 for baicalein, m/z 417.0 → 254.8 for liquiritin, m/z 822.1 → 350.8 for glycyrrhizic acid, m/ z 336.0 → 319.9 for berberine hydrochloride, m/z 780.3 → 618.5 for saikosaponin, and m/z 415.0 → 294.6 for the IS. The validated method was successfully applied to the pharmacokinetics and tissue distribution study of 8 compounds in rat plasma and tissues after the intragastric administration of MXCHG. The results demonstrated that 8 components were distributed widely and rapidly in various rat tissues after intravenous administration. Tissue deposition of the compounds in the rats was mainly in the small intestine and stomach. The present study can provide more useful information to guide the clinical use of MXCHG and the developed analytical method can also be applied for further clinical pharmacokinetic studies.

beta-caryophyllene oxide and trans-nerolidol affect enzyme activity of CYP3A4 - in vitro and in silico studies

Evaluation of possible interactions with enzymes of drug metabolism is an important part of studies on safety and, in general, on the properties of any drug or biologically active compound. Here, focus is given on interactions of three sesquiterpenes (beta-caryophyllene oxide (CAO), trans-nerolidol (tNER) and farnesol (FAR)) with CYP3A4. To determine the CYP3A4 activity, specific substrates testosterone (TES) and midazolam (MDZ) were used. In human liver microsomes, the CAO inhibited the MDZ 1´-hydroxylation by mixed type inhibition and K(i) 46.6 microM; TES 6beta-hydroxylation was inhibited more strongly by tNER by the same mechanism and with K(i) of 32.5 microM. Results indicated a possibility of different mode of interaction of both compounds within the active site of CYP3A4 and this was why the molecular docking study was done. The docking experiments showed that the studied sesquiterpenes (CAO and tNER) bound to the CYP3A4 active site cause a significant decrease of binding affinity of substrates tested which corresponded well to the inhibition studies. The inhibition observed, however, most probably does not pose a real harm to microsomal drug metabolism as the levels of sesquiterpenes in plasma (assuming the use of these compounds as spices or flavoring additives) does not usually exceed micromolar range. Hence, the interaction of drugs metabolized by CYP3A4 with sesquiterpenes is less probable.

Characterization by liquid chromatography-mass spectrometry and antioxidant activity of an ethanolic extract of Inula viscosa leaves

Inula viscosa (I. viscosa) is a common Mediterranean plant, well known for its content on bioactive molecules. The chemical composition of an ethanolic extract from I. viscosa leaves, growing in Algeria, was analysed by liquid chromatography coupled to photodiode array detection and electrospray ionization mass spectrometry (LC-DAD-ESI-MS/MS) operating in negative and positive mode. The methodology used revealed the presence of 51 compounds from which 47 were putatively identified, including 11 phenolic acids, 23flavonoids, one lignan and 12 terpenoids. Twenty-six of these compounds are described for the first time in I. viscosa. Antioxidant activity was measured using three different and complementary chemical assays: DPPH radical scavenging activity, oxygen radical absorbance capacity (ORAC) and hydroxyl radical scavenging capacity (HOSC). Results demonstrate that ethanolic leaf extract exhibit a high scavenging ability against DPPH (157.72 ± 6.45 μM TE/g DW), peroxyl (4471.42 ± 113.16 μM TE/g DW) and hydroxyl (630.10 ± 17.81 μM TE/g DW) radicals, indicating that I. viscosa can be a promising source of bioactive compounds.

Pharmacokinetics, tissue distribution and excretion of isoalantolactone and alantolactone in rats after oral administration of Radix Inulae extract

Radix Inulae is endemic to China and has been used in traditional medicine to treat upper body pain, emesis and diarrhoea, and to eliminate parasites. Here, an UPLC-MS/MS method was developed and applied to study the pharmacokinetics, distribution and excretion of isoalantolactone and alantolactone, which are two main active sesquiterpene lactones in Radix Inulae, in Sprague-Dawley rats following oral administration of total Radix Inulae extract. Isoalantolactone, alantolactone and osthole (internal standard) were prepared using acetonitrile precipitation, and the separation of isoalantolactone and alantolactone was achieved by isocratic elution using water (containing 0.1% formic acid) and acetonitrile as the mobile phase using a ZORBAX Eclipse Plus C18 column. The total run time was 6.4 min. The present study showed poor absorption of isoalantolactone and alantolactone in vivo. The apparent Cmax, Tmax, T1/2 and total exposure (AUC0-12h) in rat plasma were 37.8 ng/mL, 120 min, 351.7 min and 6112.3 ng-min/mL for isoalantolactone and 25.9 ng/mL, 90 min, 321.0 min and 4918.9 ng-min/mL for alantolactone, respectively. It was shown that the highest concentration was achieved in the small intestine and feces clearance was shown to be the dominant elimination pathway of the lactones.

The metabolism of YiGan San and subsequent pharmacokinetic evaluation of four metabolites in rat based on liquid chromatography with tandem mass spectrometry

A new method based on liquid chromatography-tandem time-of-flight mass spectrometry was developed to identify the metabolites in rat urine after oral administration of YiGan San (YGS). Eighteen prototype compounds and four metabolites named 11-hydroxyhirsuteine, 19-carbonylhirsutine, 19-carbonyl-dihydrocorynantheine, and 18-hydroxy-geissoschizine methyl ether were identified. Subsequently, a method of high-performance liquid chromatography coupled with triple-quadrupole mass spectrometry was established for pharmacokinetic study of YGS in rat plasma. The concentration-time curves of four prototype compounds, senkyunolide I, ajmalicine, isocorynoxeine and rhynchophylline were constructed after an oral (9.1g YGS per kilogram of body weight) administration in rats. Method validation revealed excellent linearity over the range 220.00-0.55, 220.00-0.55, 21.40-0.05, and 19.80-0.05ng/mL for the four prototype compounds respectively. The stabilities results indicate that all of the analytes were stable in rat plasma in the autosampler for 24h, under freeze/thaw cycles (4 times in 24h), and at -20°C for one week. Residual analysis, heteroskedasticity test, and goodness-of-fit test were also performed to determine the accuracy of the linear regression method. The pharmacokinetic parameters were obtained. Four hours after administration, compound 11-hydroxyhirsuteine can be detected in rat plasma. Compared with purified ligustilide, YGS required a slightly longer period to reach maximum concentration (Cmax) in rat plasma.

Pharmacokinetic study of multiple active constituents from Kushen-Gancao Decoction after oral administration in rat by HPLC-MS/MS

Kushen-Gancao Decoction (KGD) is a classic traditional Chinese herb combination in treating viral hepatitis and chronic liver diseases. This study aims to investigate the pharmacokinetic (PK) study of matrine (MT), oxymatrine (OMT), glycyrrhizic acid (GL) and glycyrrhetinic acid (GA) following oral administration of KGD in rats. A rapid, sensitive and reliable HPLC-MS/MS method was successfully developed for the simultaneous determination of MT, OMT, GL and GA in rat plasma. A Inertsil C18 analytical column was used with a gradient mobile phase system of methanol-ammonium acetate (5mM) with a flow rate of 0.5 mL/min. The analysis was performed on a positive and negative ionization electrospray mass spectrometer via multi reaction monitoring (MRM). Linear calibration curves were obtained for the following concentration range: 10-5000 ng/mL for MT, OMT and GL, 50-15,000 ng/mL for GA in rat plasma (R(2)>0.99). The lower limit of quantification (LLOQ) was 5 ng/mL (MT, OMT and GL) and 20 ng/mL (GA). The intra- and inter-day accuracies ranged from -7.91 to 9.10% and precisions (RSD) were within 15%. The analytes were found to be stable under short-term temperature conditions, post-preparative temperature conditions, and after three freeze-thaw cycles conditions. The validated method was successfully applied to a pharmacokinetic study in rats after oral administration of KGD.

Pharmacokinetic comparisons of different combinations of Shaoyao-Gancao-Decoction in rats: simultaneous determination of ten active constituents by HPLC-MS/MS

A specific HPLC-MS/MS method was developed and validated for simultaneous determination of ten constituents including albiflorin, oxypaeoniflorin, paeoniflorin, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, ononin, glycyrrhizin and glycyrrhetinic acid in rat plasma using genistein as an internal standard (IS). The rat plasma samples were prepared by a one-step direct protein precipitation procedure with methanol. HPLC separation was achieved on a Zorbax XDB-C18 column (2.1mm×50mm i.d., 3.5μm) with gradient elution (A: 0.1% aqueous formic acid; B: methanol with 0.1% formic acid) at a flow rate of 0.5mL/min in a run time of 7min. All analytes and IS were detected by multiple reaction monitoring scanning with electrospray ionization in the negative ion mode. Calibration curves showed good linearity (r>0.998) over a wide concentration range for all analytes. The intra- and inter-day precisions were all within 15% and the accuracies were in the range of -6.2% to 10.1%. The validated method was successfully applied to determination and comparative pharmacokinetics investigation of the ten constituents in rat plasma after oral administration of different combinations (Radix Paeoniae Alba:Glycyrrhiza uralensis=1:1 or 4:1) of Shaoyao-Gancao-Decoction (SGD) extracts. Pharmacokinetic parameters were evaluated by a compartment model. There were perceptible differences in pharmacokinetic parameters (Cmax, AUC0-t, CL) of the analytes except for liquiritin between the two groups of SGD.

Pharmacokinetics of 8-O-acetylharpagide and harpagide after oral administration of Ajuga decumbens Thunb extract in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ajuga decumbens Thunb is a medicinal plant native to China popularly used to treat chronic pelvic inflammation and hysteromyoma. Its main bioactive components are iridoid glycosides, such as 8-O-acetylharpagide and harpagide that had presented antibacterial, anti-inflammatory, and antiviral activities.

AIM OF THE STUDY

To establish a sensitive LC-MS/MS method and compare the pharmacokinetics of 8-O-acetylharpagide and harpagide in rats after oral administration of their pure forms and from compounds obtained from Ajuga decumbens extract.

MATERIALS AND METHODS

Rats received orally 15 mg/kg (equivalent of 6 mg/kg 8-O-acetylharpagide and 1.5mg/kg harpagide), 30 mg/kg and 60 mg/kg of Ajuga decumbens Thunb extract and were compared to animals that received 12 mg/kg of 8-O-acetylharpagide or 3mg/kg of harpagide p.o. Concentrations of 8-O-acetylharpagide and harpagide in plasma were determined by LC-MS/MS method at different time points and all pharmacokinetic parameters were estimated by non-compartmental analysis.

RESULTS

Results showed that the iridoid glycosides were quickly absorbed by oral route and showed a dose-dependence profile. Pharmacokinetic parameters of both glycosides were essentially the same except Tmax when dosed as the extract or pure forms.

CONCLUSION

8-O-acetylharpagide was metabolized to harpagide, which affected the pharmacokinetic profiles of harpagide when dosed as the extract. This pharmacokinetic study seems to be useful for a further clinical study of Ajuga decumbens Thunb extract.

Pharmacokinetics and tissue distribution of a bioactive sesquiterpenoid from Polygonum jucundum following oral and intravenous administrations to rats

Polygonum jucundum is a traditional Chinese medicine used for the treatment of diseases. The major bioactive compound in the ethanol extract of P. jucundum is 2α-hydroxyl-3β-angeloylcinnamolide (HAC), a drimane-type sesquiterpenoid, which possesses anti-inflammatory activities. The purpose of this study was to investigate in vivo pharmacokinetics and tissue distribution of HAC after oral and intravenous administrations to rats by using a reversed-phase high performance liquid chromatography in conjunction with mass spectrometry (LC-MS). Chromatographic separation was achieved on a C18 column within 8 min. Quality control samples for both tissues and plasma demonstrated accuracy and precision within 94.59-107.74% of the nominal values and 1.65-10.77% relative standard derivative (RSD), respectively. The pharmacokinetic profiles, estimated by using non-compartment models, revealed that HAC was rapidly absorbed into the systemic circulation and was widely distributed throughout the body, followed by a rapid elimination phase. The highest amount of HAC was found in kidney, followed in order by lung, heart, spleen and liver. The current paper was the first report on the pharmacokinetic profiles of HAC in rat plasma and tissues after oral and intravenous administrations. It could provide a meaningful insight for the clinical applications of this bioactive compound extracted from the traditional Chinese medicine.

Inuloxins A-D, phytotoxic bi-and tri-cyclic sesquiterpene lactones produced by Inula viscosa: potential for broomrapes and field dodder management

Four phytotoxic bi- and tri-cyclic sesquiterpene lactones, named inuloxins A-D, were isolated together with the known α-costic acid, from the aerial parts of Inula viscosa (family Asteraceae), a widespread Mediterranean plant well known for its content of pharmacologically active metabolites. The structures of inuloxins A-D were established by spectroscopic and chemical methods and determined to be: (4E,7R*,8R*,10S*)-3-oxo-germacra-4,11(13)-dien-8β-12-olide (A), its 11,13-dihydro analogue (B), (5R*,7R*,8R*,10R*)-1,15-methylene-5β-hydroxy-eudesm-1(15),11(13)-dien-8β-12-olide (C), and (7R*,8R*)-1,4-dimethyl-4-hydroxy-secoeudesm-5(10),11(13)-dien-8β-12-olide (D). The S absolute stereochemistry at C-5 of 5-hydroxyhexan-2-yl side chain of inuloxin D was assigned by applying an advanced Mosher's method. The phytotoxic activity of inuloxins A-D, that of the diazo and monoacetyl derivatives (of inuloxin A and C, resply), as well as that of α-costic acid was evaluated against two parasitic plant species, i.e. crenate broomrape (Orobanche crenata) and field dodder (Cuscuta campestris). Inuloxins A, C and D were the most active on both parasites and caused up to 100% inhibition of the seed germination. Inuloxin B was less active on Cuscuta and completely inactive against Orobanche. The main metabolite α-costic acid had a suppressive effect on the dodder seed germination but had a stimulating action on the broomrape seed germination. These preliminary results allowed to suppose some structure-activity relationships.