Natural-Origin Hypocrellin-HSA Assembly for Highly Efficient NIR Light-Responsive Phototheranostics against Hypoxic Tumors.

Tumor hypoxia severely limits the therapeutic efficacy of solid tumors in photodynamic therapy. One strategy is to develop photosensitizers with simultaneously high efficiency in photodynamic (PDT) and photothermal therapies (PTT) in a single natural-origin phototheranostic agent to overcome this problem. However, less attention has been paid to the natural-origin phototheranostic agent with high PDT and PTT efficiencies even though they have negligible side effects and are environmentally sustainable in comparison with many reported phototheranostic agents. In addition, almost all clinical applied photosensitizers are of natural origin so far. Herein, we synthesized a natural product-based hypocrellin derivative (AETHB), with a high singlet oxygen quantum yield of 0.64 as an efficient photosensitizer different from commercially available porphyrin-based photosensitizers. AETHB is further assembled with human serum albumin to construct nanoparticles (HSA-AETHB NPs) with a high photothermal conversion efficiency (more than 50%). As-prepared HSA-AETHB NPs have shown good water solubility and biocompatibility, pH and light stability, wide absorption (400-750 nm), and NIR emission centered at 710 nm. More importantly, HSA-AETHB NPs can be applied for fluorescent/photoacoustic dual-mode imaging and simultaneously highly efficient PDT/PTT in hypoxic solid tumors. Therefore, this natural-origin multifunctional phototheranostic agent is showing very promising for effective, precise, and safe cancer therapy in clinical applications.

Solid lipid nanoparticles as carriers for oral delivery of hydroxysafflor yellow A.

Hydroxysafflor yellow A (HSYA) is the main bioactive flavonoid extracted from the flower of Carthamus tinctorius L., which is widely used in traditional Chinese medicine for the treatment of myocardial ischemia and cerebral ischemia. HSYA has high water solubility but poor intestinal membrane permeability, resulting in low oral bioavailability. Currently, only HSYA sodium chloride injection has been approved for clinical use and oral formulations are urgently needed. In this study, HSYA solid lipid nanoparticles (SLNs) with the structure of w/o/w were prepared by a warm microemulsion process using approved drug excipients for oral delivery to increase the oral absorption of HSYA. The optimized HSYA SLNs are spherical with an average size of 214nm and the encapsulation efficiency is 55%. HSYA SLNs exhibited little cytotoxicity in Caco-2 and Hela cells, but increased the oral absorption of HSYA about 3.97-fold in rats, compared to HSYA water solution. In addition, cycloheximide pretreatment significantly decreased the oral absorption of HSYA delivered by SLNs. Importantly, the pharmacodynamics evaluation demonstrated that SLNs further decreased the infarct areas in rats. In conclude, SLNs could be a promising delivery system to enhance the oral absorption and pharmacological activities of HSYA.

Synergistic cardioprotective effects of Danshensu and hydroxysafflor yellow A against myocardial ischemia-reperfusion injury are mediated through the Akt/Nrf2/HO-1 pathway.

In clinical practice, the traditional Chinese medicinal herbs, Radix Salvia Miltiorrhiza and Carthamus tinctorius L., are usually prescribed in combination due to their significant cardioprotective effects. However, the mechanisms responsible for these combined effects remain unknown. Thus, in this study, we investigated the mechanisms responsible for the combined effects of Danshensu (DSS) and hydroxysafflor yellow A (HSYA) by establishing a rat model of myocardial ischemia/reperfusion (MI/R), as well as a model of hypoxia/reoxygenation (H/R) using H9c2 cells. The combination index (CI) was calculated using the median-effect method. DSS and HSYA in combination led to a CI value of <1 as regards infarct size in vivo and cell viability in vitro. The rats with MI/R injury that were treated with DSS and/or HSYA were found to have significantly lower levels of creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) and malondialdehyde (MDA), and a lower expressoin of 8-hydroxydeoxyguanosine (8-OHdG), and markedly enhanced superoxide dismutase (SOD) activity. Our in vitro experiments revealed that the cells treated with DSS and/or HSYA had a reduced lactate dehydrogenase (LDH) activity and a decreased percentage of cell apoptosis (increased Bcl-2/Bax ratio, decreased expression of cleaved caspase-3). DSS and HSYA increased the expression of heme oxygenase-1 (HO-1), the phosphorylation of Akt and the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2). Furthermore, the Akt inhibitor, LY294002, partially hampered the expression of Nrf2 and HO-1. The HO-1 inhibitor, zinc protoporphyrin IX (ZnPP­IX), did not decrease the expression of p-Akt and Nrf2, although it abolished the anti-apoptotic and antioxidant effects of DSS and HSYA. The findings of our study thus demonstrate that DSS and HSYA confer synergistic cardioprotective effects through the Akt/Nrf2/HO-1 signaling pathway, to certain extent, by enhancing the antioxidant defense system and exerting anti-apoptotic effects.

Low dose triterpene-quinone fraction from Ardisia crispa root precludes chemical-induced mouse skin tumor promotion.

BACKGROUND: Drastic increment of skin cancer incidence has driven natural product-based chemoprevention as a promising approach in anticancer drug development. Apart from its traditional usages against various ailments, Ardisia crispa (Family: Myrsinaceae) specifically its triterpene-quinone fraction (TQF) which was isolated from the root hexane extract (ACRH) was recently reported to exert antitumor promoting activity in vitro. This study aimed at determining chemopreventive effect of TQF against chemically-induced mouse skin tumorigenesis as well as elucidating its possible pathway(s). METHODS: Mice (n = 10) were initiated with single dose of 7,12-dimethylbenz[α]anthracene (DMBA) (390 nmol/100 µl) followed by, a week later, repeated promotion (twice weekly; 20 weeks) with 12-O-tetradecanoylphorbol-13-acetate (TPA) (1.7 nmol/100 µl). TQF (10, 30 and 100 mg/kg) and curcumin (10 mg/kg; reference) were, respectively, applied topically to DMBA/TPA-induced mice 30 min before each TPA application. Upon termination, histopathological and biochemical analysis, as well as Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and transcription factor enzyme-linked immunosorbent assay (ELISA) assays were performed to elucidate the potential mechanism of TQF. RESULTS: With comparison to the carcinogen control, results revealed that lower dose of TQF (10 mg/kg) conferred antitumor promoting effect via significant (P < 0.05) suppression against lipid peroxidation (LPO), apoptotic index (cell death) and nuclear factor-kappa B (NF-κB), along with reduction of keratinocyte proliferation; whilst its higher dose (100 mg/kg) was found to promote tumorigenesis by significantly (P < 0.05) increasing LPO and apoptotic index, in addition to aggravating keratinocyte proliferation. CONCLUSIONS: This study evidenced that TQF, particularly at its lower dosage (10 mg/kg), ameliorated DMBA/TPA-induced mouse skin tumorigenesis. Though, future investigations are warranted to determine the lowest possible therapeutic dose of TQF in subsequent in vivo chemopreventive studies.

Liposomal hypocrellin B as a potential photosensitizer for age-related macular degeneration: pharmacokinetics, photodynamic efficacy, and skin phototoxicity in vivo.

Photodynamic therapy (PDT) has been successfully implemented as a treatment for wet age-related macular degeneration (AMD), but very few photosensitizers have been developed for clinical use. Herein, we describe a novel formulation of liposomal hypocrellin B (LHB) that was prepared by high-pressure homogenization. The encapsulation efficiency and PDT efficacy in vitro of this new preparation were found to remain nearly constant over 1 year. Moreover, LHB is rapidly cleared from the blood, with a half-life of 2.319 ± 0.462 h and a very low serum concentration at 24 h after injection. Testing in a rat model of choroidal neovascularization (CNV) showed that leakage of blood vessels in CNV lesions was significantly reduced when LHB PDT was given at a dose of 1 mg kg(-1) along with yellow laser irradiation; the damage to the collateral retina and the retinal pigment epithelium was minimal. Skin phototoxicity assays showed that only two of the 200 mice given a 4 mg per kg dose of LHB experienced an inflammatory reaction in the auricle irradiated at 24 h after dosing. These data collectively indicate that LHB may be a safe and effective photosensitizer for vascular-targeted PDT of AMD.

Pharmacokinetic profiles of hydroxysafflor yellow A following intravenous administration of its pure preparations in healthy Chinese volunteers.

ETHNOPHARMACOLOGICAL RELEVANCE: Hydroxysafflor yellow A (HSYA), the major active marker compound isolated from Carthamus tinctorius L., has been demonstrated to possess various attractive pharmacological activities. However, there is a lack of information about the complete clinical pharmacokinetic profiles of HSYA following the administration of its pure preparations. The purpose of this study was to fully characterize the pharmacokinetic (PK) properties of HSYA in healthy Chinese volunteers following drip intravenous infusion of injectable powder of pure HSYA (IPPH), a new drug recently approved for the phase I clinical study by China Food and Drug Administration. MATERIALS AND METHODS: 36 healthy subjects of either sex were recruited in this single-center, and open-label, single doses (25, 50, and 75 mg) and multiple doses (50 mg, once daily, 7 consecutive days) study. Plasma samples were analyzed with a validated LC-MS/MS method. Various PK parameters were estimated from the plasma concentration versus time data using non-compartmental methods. RESULTS: After single dose administration of IPPH, the values of AUC(0-t), AUC(0-∞) and C(max) for HSYA were statistically proportional over the dose range of 25-75 mg. After 7 repeated doses of 50 mg IPPH, both C(max) and AUC(0-∞) were significantly decreased, from 3207 to 2959 µg L(-1), and from 12,811 to 12,135 µg h L(-1) respectively, while t(1/2) was significantly prolonged from 3.912 to 4.414 h. The minimum plasma concentrations on day 5, 6 and 7 showed good stability with no significant difference. Both Cmax and AUC of HSYA in male volunteers were generally lower than that in females. IPPH was generally well tolerated in healthy volunteers by either single or multiple dosing. CONCLUSION: HSYA displayed moderately linear PK properties over the doses ranging from 25 to 75 mg of IPPH. Repeated administration of IPPH once daily could not lead to the in-vivo drug accumulation, but significantly affect PK behavior of HSYA. Gender difference should be considered for dosage recommendation in the clinic.

Hydroxysafflor yellow A ameliorates lipopolysaccharide-induced acute lung injury in mice via modulating toll-like receptor 4 signaling pathways.

Hydroxysafflor yellow A (HSYA) is a main bio-active compound important of a traditional Chinese medicine named Carthamus tinctorius L. and has been shown to possess various effects, especially anti-inflammatory benefits and potential protections against acute lung injury (ALI) in previous studies. Therefore, in this present study, we aimed to evaluating effects of HSYA on lipopolysaccharide (LPS)-induced ALI in mice. ALI was induced by intratracheal instillation of LPS into lung, and dexamethasone was used as a positive control. Results demonstrated that HSYA abated LPS-induced pathological change and attenuated lung vascular permeability and edema. HSYA down-regulated both the ability of myeloperoxidase (MPO) in lung tissues and levels of inflammatory mediators including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6 and IFN(interferon)-ß in serum. Moreover, HSYA prevented toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and TIR-domain-containing adapter-inducing interferon-ß (TRIF) protein up-expressions. In addition, the activations of mitogen-activated protein kinases including p38, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) were blocked by HSYA. And also, the phosphorylations of interferon regulatory factor 3 (IRF3), translocation of nuclear factor kappa B (NF-κB)/p65 and inhibitory kappa B (IκB)-α were inhibited by HSYA. In conclusion, HSYA attenuated inflammatory response in ALI mice through inhibition of TLR 4-dependent signaling pathways.

Hydroxysafflor yellow A attenuates left ventricular remodeling after pressure overload-induced cardiac hypertrophy in rats.

CONTEXT: Hydroxysafflor yellow A (HSYA), the main chemical component of the safflower yellow pigments, is used extensively in traditional Chinese medicine for the treatment of cerebrovascular and cardiovascular diseases. OBJECTIVE: The present study determined the effects of HSYA on left ventricular hypertrophy after pressure overload and investigated the underlying mechanisms. MATERIALS AND METHODS: Cardiac hypertrophy was induced by the ligation of abdominal aorta in male Wistar rats. The rats were then divided into five groups and treated with captopril (100 mg/kg) or HSYA at different doses (0, 10, 20 and 40 mg/kg). Six weeks after treatment, the weight of left ventricle, LVMI (left ventricular mass index) and pathological changes were measured. MMP-2 (metalloproteinase 2) and MMP-9 (metalloproteinase 9) levels were determined by ELISA. Protein expressions of Bcl-2 and Bax were evaluated by immunohistochemistry. RESULTS: HSYA (20, 40 mg/kg) significantly attenuated the increase of LVMI (ventricular weight/body weight) by 13.04 and 30.43% respectively, when compared with the model group. This was associated with the amelioration of pathological lesion, such as cardiac muscle fibers were smaller and the nuclei of cardiomyocytes were lightly stained in animals treated with HSYA (20, 40 mg/kg). In addition, the administration of HSYA at doses of 20 and 40 mg/kg increased the Bcl-2/Bax ratio (1.17 ± 0.08 and 1.39 ± 0.07 versus 0.71 ± 0.06). In addition, the serum MMP-2 and MMP-9 levels were blocked by the treatment at doses of 20 and 40 mg/kg HSYA (MMP-2, 76.1 ± 9.2 and 65.6 ± 6.8 versus 82.9 ± 6.2, ng/ml; MMP-9, 66.6 ± 4.8 and 57.5 ± 5.0 versus 83.5 ± 6.0, ng/ml). CONCLUSION: These findings indicated that HSYA has beneficial effects on hypertensive ventricular remodeling, which may involve mechanisms of inhibiting cell apoptosis and suppressing metalloproteinases expression.

[Pharmacokinetic effect of Sappan Lignum on hydroxysafflor yellow A in Carthami Flos].

OBJECTIVE: To investigate the pharmacokinetic effect of Sappan Lignum on hydroxysafflor yellow A (HSYA) in Carthami Flos. METHOD: Concentration of HSYA in rat plasma was detected by RP-HPLC after rats were orally administered with extracts of Carthami Flos or Carthami Flos combined with Sappan Lignum. Pharmacokinetic parameters were calculated by DAS 2.0 pharmacokinetic software. RESULT: In vivo pharmacokinetic models of HSYA were two-compartment open models in both of the Carthami Flos group and the Carthami Flos combined with Sappan Lignum group. After compatibility, HSYA showed a significant lower in apparent volumes of distribution of t(1/2Ka), t(1/2alpha) and V1/F, with slight advance in T(max). CONCLUSION: Sappan Lignum can accelerate absorption, distribution and metabolic process of HSYA in vivo and reduce its accumulation in vivo.

A strategy for detecting optimal ratio of cardioprotection-dependent three compounds as quality control of guan-xin-er-hao formula.

AIMS: We aimed to detect optimal ratio of cardioprotection-dependent absorbed bioactive compounds (ABCs) as quality control of guan-xin-er-hao (GXEH) formula extracted by various processings. METHODS: Ferulic acid (F), tanshinol (T), hydroxysafflor yellow A (A), protocatechualdehyde (P) and paeoniflorin (E) in GXEH formula and FTA in blood from rat with acute myocardial infarction (AMI) were first identified by HPLC-MS/MS, and FTAPE in GXEH formulae with various herbs, extraction times and extraction water volumes were then quantitated only by HPLC. RESULTS: FTAPE in various GXEH were determined. FTA were selected as GXEH's ABCs. Ratios of FTA were determined, suggesting the high (1:6.1:15.6), medium (1:1.7:15.2) and low (1:0.2:15.3) ratios. Three FTA ratios and their parent formulae ratio-dependently reduced infarct size, myocardial apoptosis and caspase-3 activity. CONCLUSION: There is the optimal ratio of F:T:A among various formulae, contributing to the best cardioprotection. This FTA ratio was developed as quality control of GXEH formula.

The mechanisms for enhanced oral absorption of hydroxysafflor yellow A by chuanxiong volatile oil.

The aims of this study were to investigate the effect of ligusticum chuanxiong volatile oil (CVO) on the oral absorption of hydroxysafflor yellow A (HSYA). The effects were studied both IN VITRO and IN VIVO. The contents of CVO were measured by GC-MS. The Caco-2 cell model was used to evaluate HSYA permeation with or without the presence of CVO. Transepithelial electrical resistance (TEER) of the Caco-2 cell monolayers was monitored and the alteration in the subcellular localization of claudin-1, the tight junction protein, was observed by immunofluorescence. The irritation of CVO on rat intestine was studied by paraffin slice technology. Our results demonstrated that CVO mainly contained ligustilide (47.82 %). The Papp of HSYA was improved by 5.34-fold and 4.62-fold in the presence of 0.02 mg/mL and 0.01 mg/mL of CVO, respectively. After opening of the tight junctions of the Caco-2 cell monolayer, TEER decreased, the position of claudin-1 changed, and its expression increased. CVO at different concentrations (10, 25, 100 and 200 mg/kg) caused no significant irritation on rat intestine. The bioavailability of HSYA in rats was increased by 6.48-fold and 4.91-fold when 100 and 25 mg/kg of CVO were co-administrated, respectively. CVO was an effective absorption enhancer for oral delivery of BCS III drugs. It can cause redistribution of claudin-1 proteins and open the tight junctions.

Pharmacokinetic properties of hydroxysafflor yellow A in healthy Chinese female volunteers.

ETHNOPHARMACOLOGICAL RELEVANCE: Hydroxysafflor yellow A (HSYA) was isolated from the dried flower of Carthamus tinctorius L. which was extensively used in traditional Chinese medicine to treat diseases due to blood stasis. However, there have been few detailed pharmacokinetic studies about HSYA on human beings. AIM OF THE STUDY: The aim was to investigate the pharmacokinetic characteristics of HSYA in healthy Chinese female volunteers. MATERIALS AND METHODS: The volunteers were given intravenous infusion of single doses of safflor yellow injection (containing HSYA 35, 70 and 140 mg) in separate trial periods with 1 week washout period. The concentration levels of HSYA in plasma were determined with HPLC. Various pharmacokinetic parameters were estimated from the plasma concentration versus time data using non-compartmental methods. RESULTS: The C(max) values were 2.02+/-0.18, 7.47+/-0.67 and 14.48+/-4.71 microg/mL after the administration of single doses of 35, 70, and 140 mg of HSYA, respectively. The corresponding values of AUC(0-15 h) were 6.57+/-1.20, 25.90+/-4.62 and 48.47+/-12.11 microg/(mL h(-1)), and the values of t(1/2) were 3.21+/-1.26, 3.33+/-0.68 and 2.98+/-0.09 h. The Student-Newman-Keuls test results showed that C(max) and AUC(0-15 h) were both linearly related to dose. CONCLUSIONS: In this study, the pharmacokinetic properties of HSYA are based on first-order kinetics over the dose range tested.

[Effects of hydroxy safflor yellow A on blood vessel and mRNA expression with VEGF and bFGF of transplantation tumor with gastric adenocarcinoma cell line BGC-823 in nude mice].

OBJECTIVE: To investigate the effects of Hydroxy Safflor yellow A (HSYA) on the growth of blood vessel of transplantation tumor of gastric adenocarcinoma cell line BGC-823 in nude mice and its underlying mechanism of antagonizing tumor angiogenesis. METHOD: The BGC-823 cells was subcutaneouly injected into the right anterior armpit of BALB/C nu/nu nude mice and established the animal model of transplantation tumor. Then nude mice were divided into 4 groups at random: model group, control group, high or low dosage of HSYA group. The model group were treated with normal sodium by intraperitoneal injection, HSYA groups were treated with HSYA at concentration of 0.056 g x L(-1) and 0.028 g x L(-1) by intraperitoneal injection, and in these groups each mouse was injected 2 times everyday with 0.2 mL by 4-6 hours interval. The control group were injected in enterocoelia 1 times every 2 days starting from the third day with cytoxan at 2 g x L(-1). 20 days later, the volume and weight of nude mice were observed. The pathological change of tumor tissue was observed under optical microscope. The mRNA expression of VEGF and bFGF of transplantation tumor were detected by real time quantitative PCR. RESULT: The volume (607.42 +/- 252.96) mm3, weight (0.88 +/- 0.14) g of transplantation tumor, the mRNA expression level of VEGF 0.49 +/- 0.13 and bFGF 0.60 +/- 0.48 are reduced significantly after treatment with HSYA at the concentration of 0.028 g x L(-1) compared with physiologic saline-treated group (P < 0.05 or P < 0.01). The tumor pathological angiogenesis of HSYA group is also less obvious than the normal sodium-treated group. CONCLUSION: HSYA in given concentration can inhibit the growth of BGC-823 transplantation tumor, and decreasing the mRNA expression of VEGF and bFGF, which suggests that inhibiting tumor angiogenesis may be one of the mechanisms of HSYA antagonizing tumor.

Nutritional benefit of olive oil: the biological effects of hydroxytyrosol and its arylating quinone adducts.

Olive oil is the essential component of the Mediterranean diet, a nutritional regimen gaining ever-increasing renown for its beneficial effects on inflammation, cardiovascular disease, and cancer. A unique characteristic of olive oil is its enrichment in oleuropein, a member of the secoiridoid family, which hydrolyzes to the catechol hydroxytyrosol and functions as a hydrophilic phenolic antioxidant that is oxidized to its catechol quinone during redox cycling. Little effort has been spent on exploring the biological properties of the catechol hydroxytyrosol quinone, a strong arylating electrophile that forms Michael adducts with thiol nucleophiles in glutathione and proteins. This study compares the chemical and biological characteristics of hydroxytyrosol with those of the tocopherol family in which Michael adducts of arylating desmethyltocopherol quinones have been identified and correlated with biologic properties including cytotoxicity and induction of endoplasmic reticulum stress. It is noted that hydroxytyrosol and desmethyltocopherols share many similarities, suggesting that Michael adduct formation by an arylating quinone electrophile may contribute to the biological properties of both families, including the unique nutritional benefit of olive oil.

Hydroxysafflor yellow A inhibits rat brain mitochondrial permeability transition pores by a free radical scavenging action.

Hydroxysafflor yellow A (HSYA), the major and most active antioxidant from Carthamus tinctorius L., has been clinically prescribed in China to treat patients with cerebral ischemia, but the detailed mechanism is not known. This study examines the effect of HSYA on mitochondrial permeability transition pores (mtPTP) in the rat brain. HSYA at 10-80 micromol.l(-1) inhibited Ca(2+)- and H(2)O(2)-induced swelling of mitochondria isolated from rat brains. The addition of Ca(2+) generated reactive oxygen species (ROS) in isolated mitochondria. HSYA (10-80 micromol.l(-1)) inhibited Ca(2+)-induced generation of ROS. At the same time, HSYA significantly improved mitochondrial energy metabolism, enhanced ATP levels and the respiratory control ratio. These results suggest that HSYA inhibits the opening of mtPTP by a free radical scavenging action in the brain, and this may contribute to the neuroprotective effect of HSYA.

Renierol from marine sponge Haliclona.SP.: a natural inhibitor of xanthine oxidase with hypouricemic effects.

The purpose of this study was to evaluate the inhibitory effect of renierol, extracted from marine sponge Halicdona.SP., on xanthine oxidase (XO) and its hypouricemic effect in vivo. Renierol and a positive control, allopurinol, were tested for their effects on XO activity by measuring the formation of uric acid and superoxide radical from xanthine. Renierol inhibited XO in a concentration-dependent and competitive manner. IC(50) value was 1.85 microg.ml(-1) through the measuring of uric acid and was 1.36 microg.ml(- 1) through the measuring of superoxide radical. Renierol was found to have an in vivo hypouricemic activity against potassium oxonate-induced hyperuricaemia in mice. After oral administration of renierol at doses of 10, 20 and 30 mg.kg(- 1), there was a significant decrease in the serum urate level (4.08 +/- 0.09 mg.dl(- 1), P < 0.01), (3.47 +/- 0.11 mg.dl(- 1), P < 0.01) and (3.12 +/- 0.08 mg.dl(- 1), P < 0.01), when compared to the hyperuricaemic control (6.74 +/- 0.23 mg.dl(- 1)). Renierol was a potent XO inhibitor with hypouricemic activity in mice.

Inhibition of 5-lipoxygenase product synthesis by natural compounds of plant origin.

The biosynthesis of leukotrienes (LTs) is initiated by the transformation of free arachidonic acid to LTA (4) by 5-lipoxygenase (5-LO). Subsequent enzymatic conversion of LTA (4) yields LTB (4) and the cysteinyl-LTs C (4), D (4) and E (4). LTs have prominent functions in pathophysiology and are connected to numerous disorders including bronchial asthma, allergic rhinitis, inflammatory bowel and skin diseases, rheumatoid arthritis, cancer, osteoporosis and cardiovascular diseases. Pharmacological and genetic interruption of the 5-LO pathway or blockade of LT receptors, serving as means for intervention with LTs, may be of therapeutic value for certain related disorders. Natural or plant-derived substances were among the first 5-LO inhibitors identified in the early 1980 s. To date, a huge number of diverse plant-derived compounds have been reported to interfere with 5-LO product synthesis. However, many investigations have addressed the efficacy of a given compound solely in cellular test systems and analysis of direct interference with 5-LO has been neglected. In the first part of this review, the biology and molecular pharmacology of the 5-LO pathway is summarized in order to understand its overall regulation and complexity as well as to comprehend the possible points of attack of compounds that eventually lead to inhibition of 5-LO product formation in intact cells. In the second part, natural compounds that interfere with 5-LO product formation are compiled and grouped into structural classes, and the underlying molecular mechanisms and structure-activity relationships are discussed.

Identification of a novel intestinal first pass metabolic pathway: NQO1 mediated quinone reduction and subsequent glucuronidation.

Quinones represent a very important class of compounds found in nature and for the chemically synthesized drugs. The present study was designed to elucidate the intestinal first pass metabolic pathways in vivo and in vitro, of tanshinone IIA (TS), a derivative of phenanthrene-quinone isolated from Salvia miltiorrhiza. Five metabolites, proposed to be TS catechol glucuronides (two position isomers), dehydrotanshinone IIA and its two catechol glucuronides, were identified from the rat intestinal homogenates after oral administration of TS. TS metabolism was further conducted in the subcellular system including cytosol, microsomes, mitochondrial and S9 under both phase I and phase II metabolic conditions. TS underwent negligible metabolism in all of the subcellular systems under phase I metabolic condition using NADPH as the cofactor. However, significant and substantial metabolic elimination of TS was observed in the cytosol and S9 fractions, while not in the microsomes fractions, when both NADPH and UDPGA were added. Two TS catechol glucuronides were identified from such an in vitro metabolic medium. Dicoumarol, a specific inhibitor of the NAD(P)H dependent quinone oxidoreductase (NQO1), significantly inhibited the metabolic elimination of TS in a noncompetitive way, suggesting that NQO1 was responsible for the quinone reduction of TS to form the catechol intermediate. The catechol intermediate failed to be detected directly was proved to be highly unstable and autoxidized back to TS accompanied with hydrogen peroxide generation. Dicoumarol exhibited a significant inhibitory effect on the hydrogen peroxide generation, further supporting that the reduction of TS was catalyzed by NQO1. The absolute bioavailability of TS was significantly enhanced by oral dicoumarol pretreatment. In conclusion, a novel intestinal metabolic pathway for quinones, NQO1 mediated reduction and subsequent glucuronidation, was determined using TS as a model compound. This study should be helpful for the general understanding of quinones absorption and intestinal first pass metabolism.

[Preparation of Shuxiong micropellets by centrifugal granulation technology].

OBJECTIVE: To prepare shuxiong micropellets. METHOD: Shuxiong micropellets were prepared by using a centrifugal granulator. The formulation composition and process factors were optimized investigated by adopting several indices such as size distribution, repose angle, bulk density and friability as indexes. RESULT: The optimal process parameters were as follows. The ratio of fine intermediate product and MCC was 3:1 (w/w), the adhesive agent was 3% HMPC solution, the rotating rate of plate was 200 r x min(-1), the blower rate was 15 x 20 L x min(-1), the rate of air flow was 15 L x min(-1), the spray air pressure was 0.5 MPa, the rotating of spray solution pump was 5-25 r x min(-1) and the rotating rate of powder feed machine was 5-25 r x min(-1). CONCLUSION: Under the optimal conditions, micropellets prepared by using centrifugal granulator hadpossessed prefect shape and surface characteristics and the yield of shuxiong pellets was 90.5%.

Pharmacokinetics and excretion of hydroxysafflor yellow A, a potent neuroprotective agent from safflower, in rats and dogs.

Studies were conducted to characterize the pharmacokinetics and excretion of hydroxysafflor yellow A (HSYA) in rats and dogs after administration by intravenous injection or infusion. Plasma, urine, feces and bile concentrations of HSYA were measured using five validated mild HPLC methods. Linear pharmacokinetics of HSYA after the intravenous administrations were found at doses ranging from 3 to 24 mg/kg in rats and from 6 to 24 mg/kg in dogs. At a dose of 3 mg/kg, HSYA in urine, feces and bile was determined. For 48 h after dosing, the amount of urinary excretion accounted for 52.6 +/- 17.9 % (range: 31.1 - 78.7%, n = 6) of the dose, and the amount of fecal amount accounted for 8.4 +/- 5.3% (range 1.7 - 16.4%, n = 6) of the dose. Biliary excretion amount accounted for 1.4 +/- 1.0% (range 0.4-2.9%; n = 6) of the dose for 24 h after dosing. Percent plasma protein binding of HSYA ranged from 48.0 to 54.6% at 72 h. In summary, five mild HPLC methods for the determinations of HSYA in rat plasma, urine, feces, bile and dog plasma have been developed and successfully applied to preclinical pharmacokinetics and excretion of HSYA in rats and dogs. The results of excretion studies indicated that HSYA was rapidly excreted as unchanged drug in the urine. In view of previous pharmacological work, the concentration-dependent neuroprotective effect of HSYA in rats was defined.