Bioavailability and brain-targeting of geniposide in gardenia-borneol co-compound by different administration routes in mice

Geniposide and Harpagoside Functionalized Cerium Oxide Nanoparticles as a Potential Neuroprotective

Alzheimer's disease is associated with protein aggregation, oxidative stress, and the role of acetylcholinesterase in the pathology of the disease. Previous investigations have demonstrated that geniposide and harpagoside protect the brain neurons, and cerium nanoparticles (CeO2 NPs) have potent redox and antioxidant properties. Thus, the effect of nanoparticles of Ce NPs and geniposide and harpagoside (GH/CeO2 NPs) on ameliorating AD pathogenesis was established on AlCl3-induced AD in mice and an aggregation proteins test in vitro. Findings of spectroscopy analysis have revealed that GH/CeO2 NPs are highly stable, nano-size, spherical in shape, amorphous nature, and a total encapsulation of GH in cerium. Treatments with CeO2 NPs, GH/CeO2 NPs, and donepezil used as positive control inhibit fibril formation and protein aggregation, protect structural modifications in the BSA-ribose system, have the ability to counteract Tau protein aggregation and amyloid-β1-42 aggregation under fibrillation condition, and are able to inhibit AChE and BuChE. While the GH/CeO2 NPs, treatment in AD induced by AlCl3 inhibited amyloid-β1-42, substantially enhanced the memory, the cognition coordination of movement in part AD pathogenesis may be alleviated through reducing amyloidogenic pathway and AChE and BuChE activities. The findings of this work provide important comprehension of the chemoprotective activities of iridoids combined with nanoparticles. This could be useful in the development of new therapeutic methods for the treatment of neurodegenerative diseases.

Terpenes-Modified Lipid Nanosystems for Temozolomide, Improving Cytotoxicity against Glioblastoma Human Cancer Cells In Vitro

Currently, increasing the efficiency of glioblastoma treatment is still an unsolved problem. In this study, a combination of promising approaches was proposed: (i) an application of nanotechnology approach to create a new terpene-modified lipid system (7% w/w), using soybean L-α-phosphatidylcholine, N-carbonyl-methoxypolyethylene glycol-2000)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine for delivery of the chemotherapy drug, temozolomide (TMZ, 1 mg/mL); (ii) use of TMZ associated with natural compounds-terpenes (1% w/w) abietic acid and Abies sibirica Ledeb. resin (A. sibirica). Different concentrations and combinations of terpene-lipid systems were employed to treat human cancer cell lines T 98G (glioblastoma), M-Hela (carcinoma of the cervix) and human liver cell lines (Chang liver). The terpene-lipid systems appeared to be unilamellar and of spherical shape under transmission electron microscopy (TEM). The creation of a TMZ-loaded terpene-lipid nanosystem was about 100 nm in diameter with a negative surface charge found by dynamic light scattering. The 74% encapsulation efficiency allowed the release time of TMZ to be prolonged. The modification by terpenes of TMZ-loaded lipid nanoparticles improved by four times the cytotoxicity against human cancer T 98G cells and decreased the cytotoxicity against human normal liver cells. Terpene-modified delivery lipid systems are of potential interest as a combination therapy.

Therapeutic potential of plant iridoids in depression: a review

CONTEXT

Depression is a mental disorder characterized by low mood, reduced interest, impaired cognitive function, and vegetative symptoms such as sleep disturbances or poor appetite. Iridoids are the active constituents in several Chinese classical antidepressant formulae such as Yueju Pill, Zhi-Zi-Hou-Po Decoction, Zhi-Zi-Chi Decoction, and Baihe Dihuang Decoction. Parallel to their wide usages, iridoids are considered potential lead compounds for the treatment of neurological diseases.

OBJECTIVE

The review summarizes the therapeutic potential and molecular mechanisms of iridoids in the prevention or treatment of depression and contributes to identifying research gaps in iridoids as potential antidepressant medication.

METHODS

The following key phrases were sought in PubMed, Google Scholar, Web of Science, and China National Knowledge Internet (CNKI) without time limitation to search all relevant articles with in vivo or in vitro experimental studies as comprehensively as possible: ('iridoid' or 'seciridoid' or 'depression'). This review extracted the experimental data on the therapeutic potential and molecular mechanism of plant-derived iridoids for depression.

RESULTS

Plant iridoids (i.e., catalpol, geniposide, loganin), and secoiridoids (i.e., morroniside, gentiopicroside, oleuropein, swertiamarin), all showed significant improvement effects on depression.

DISCUSSION AND CONCLUSIONS

Iridoids exert antidepressant effects by elevating monoamine neurotransmitters, reducing pro-inflammatory factors, inhibiting hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, increasing brain-derived neurotrophic factor (BDNF) and its receptors, and elevating intestinal microbial abundance. Further detailed studies on the pharmacokinetics, bioavailability, and key molecular targets of iridoids are also required in future research, ultimately to provide improvements to current antidepressant medications.

Geniposide-Loaded Liposomes for Brain Targeting: Development, Evaluation, and In Vivo Studies

Geniposide (GE) possesses excellent neuroprotective effects but with poor brain targeting and short half-life. Liposome was considered to have great potential for brain diseases. Therefore, this research aimed to develop a geniposide liposome (GE-LP) as a brain delivery system for cerebral ischemia reperfusion injury (CIRI) therapy and evaluate its characterization, pharmacokinetics, brain targeting, and neuroprotective effects in vivo. Then, a reverse-phase evaporation method was applied to develop the GE-LP and optimize the formulation. Notably, the GE-LP had suitable size, which was 223.8 nm. Subsequently, the pharmacokinetic behavior of GE solution and GE-LP in mice plasma was investigated, and the brain targeting was also researched. The results showed that GE in plasma of GE-LP displayed three folds longer distribution half-life and a higher bioavailability and brain targeting compared to GE solution. In vivo neuroprotective effects was evaluated through the middle cerebral artery occlusion (MCAO) rat model, and GE-LP exhibited a stronger tendency in preventing the injury of CIRI, which can significantly improve neurological deficits. Overall, this study demonstrates GE-LP as a new formulation with ease of preparation, sustained release, and high brain targeting, which has significant development prospects on CIRI; this is expected to improve the efficacy of GE and reduce the frequency of administration.

Nose-to-brain Delivery of Natural Compounds for the Treatment of Central Nervous System Disorders

BACKGROUND

Several natural compounds have demonstrated potential for the treatment of central nervous system disorders such as ischemic cerebrovascular disease, glioblastoma, neuropathic pain, neurodegenerative diseases, multiple sclerosis and migraine. This is due to their well-known antioxidant, anti-inflammatory, neuroprotective, anti-tumor, anti-ischemic and analgesic properties. Nevertheless, many of these molecules have poor aqueous solubility, low bioavailability and extensive gastrointestinal and/or hepatic first-pass metabolism, leading to a quick elimination as well as low serum and tissue concentrations. Thus, the intranasal route emerged as a viable alternative to oral or parenteral administration, by enabling a direct transport into the brain through the olfactory and trigeminal nerves. With this approach, the blood-brain barrier is circumvented and peripheral exposure is reduced, thereby minimizing possible adverse effects.

OBJECTIVE

Herein, brain-targeting strategies for nose-to-brain delivery of natural compounds, including flavonoids, cannabinoids, essential oils and terpenes, will be reviewed and discussed. Brain and plasma pharmacokinetics of these molecules will be analyzed and related to their physicochemical characteristics and formulation properties.

CONCLUSION

Natural compounds constitute relevant alternatives for the treatment of brain diseases but often require loading into nanocarrier systems to reach the central nervous system in sufficient concentrations. Future challenges lie in a deeper characterization of their therapeutic mechanisms and in the development of effective, safe and brain-targeted delivery systems for their intranasal administration.

Traditional Chinese Medicine in Emergency Treatment Mechanism and Application

Traditional Chinese medicine has usually been recognized to be efficacious to treat chronic diseases from the western point-of-view. However, there is a long history in China of applying traditional Chinese medicine in many acute and urgent medical conditions. In this review, selected methods documented in traditional Chinese medicine including blowing air to ear, nose insufflating therapy, acupuncture and moxibustion were presented as the common practices to promote consciousness recovery from coma. We aimed to explore the mechanism of these four methods with current scientific evidence, further discuss the potential of traditional Chinese medicine to be applied in emergency medicine and provide a path forward to more rigorously validate these procedures. The development of the integrated traditional Chinese medicine and western medicines provides a new therapeutic direction for the new first-aid treatment.

Nose to brain drug delivery - A promising strategy for active components from herbal medicine for treating cerebral ischemia reperfusion

Cerebral ischemia reperfusion injury (CIRI), one of the major causes of death from stroke in the world, not only causes tremendous damage to human health, but also brings heavy economic burden to society. Current available treatments for CIRI, including mechanical therapies and drug therapies, are often accompanied by significant side-effects. Therefore, it is necessary to discovery new strategies for treating CIRI. Many studies have confirmed that the herbal medicine has the advantages of abundant resources, good curative effect and little side effects, which can be used as potential drug for treatment of CIRI through multiple targets. It's known that oral administration commonly has low bioavailability, and injection administration is inconvenient and unsafe. Many drugs can't delivery to brain through routine pathways due to the blood-brain-barrier (BBB). Interestingly, increasing evidences have suggested the nasal administration is a potential direct route to transport drug into brain avoiding the BBB and has the characteristics of high bioavailability for treating brain diseases. Therefore, intranasal administration can be treated as an alternative way to treat brain diseases. In the present review, effective methods to treat CIRI by using active ingredients derived from herbal medicine through nose to brain drug delivery (NBDD) are updated and discussed, and some related pharmacological mechanisms have also been emphasized. Our present study would be beneficial for the further drug development of natural agents from herbal medicines via NBDD.

Gardenia jasminoides Enhances CDDP-Induced Apoptosis of Glioblastoma Cells via AKT/mTOR Pathway While Protecting Death of Astrocytes

Gliomas are the most observed primary brain tumor, of which glioblastoma multiform (GBM) shows the highest incidence. Radiotherapy with temozolomide is the standard therapeutic method, but because of side effects, search for alternative therapies is required. Gardenia jasminoides (GJ) is flavonoid abundant with beneficial effects on inflammation, metabolic diseases, and cancers. In this study, we investigated the synergistic combination of GJ and cisplatin (CDDP) in U87MG and U373MG GBM cells. GJ and CDDP both showed cytotoxicity in U87MG cells, however GJ did not affect viability of normal astrocytes while CDDP displayed high toxicity. Cytotoxic effect of GJ and CDDP was related in apoptosis when confirmed by Western blot assays on cleaved caspase-3, caspase-9, and PARP. Moreover, GJ and CDDP showed synergistic combination in cell death of GBM cells, which was further confirmed by Western blot assays of apoptosis factors and also flow cytometry of Annexin V. Analysis on autophagy factors showed that GJ/CDDP combination induced autophagy, and through inhibition of autophagy, we could confirm autophagy is crucial to cytotoxicity of GJ/CDDP in GBM cell lines. The autophagy-mediated apoptosis of GJ/CDDP was dependent on the AKT/mTOR pathway. Overall, our results suggest GJ/CDDP combination as an effective yet safe therapeutic approach to GBMs.

Effect of different doses of borneol on the pharmacokinetics of vinpocetine in rat plasma and brain after intraocular administration

The effect of different doses of borneol on the pharmacokinetics of vinpocetine after intraocular administration in the rat plasma and the brain was investigated.Intraocular administration of vinpocetine (3 mg/kg) was performed, in combination with different doses (0, 5, 10, and 20 mg/kg) of borneol. Intravenous administration of vinpocetine was used as a control (1 mg/kg). The concentrations of vinpocetine in the rat plasma and the brain were determined using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Using the non-compartmental models with the DSA 2.0 software, the main pharmacokinetics parameters and the brain-targeting effect evaluated.In comparison with intravenous administration, after intraocular administration of vinpocetine alone, the absolute bioavailability (F) of vinpocetine was 43.82% for the plasma, and the drug target index (DTI) was 1.05 for the brain. After intraocular administration of vinpocetine combined with different doses of borneol, the relative bioavailability (Fr) of vinpocetine in the plasma was increased by 130.46-182.90%. The relative bioavailability (Fr) of vinpocetine in the brain was improved (147.19-225.36%). The DTI was 1.12, 1.18, and 1.21 for 5, 10, and 20 mg/kg of borneol, respectively.Compared with the intraocular administration of vinpocetine alone, the co-administration of different doses of borneol resulted in an obvious brain targeting effect.

Improved brain delivery of pueraria flavones via intranasal administration of borneol-modified solid lipid nanoparticles

Aim: To improve the drug delivery to the brain with borneol (Bo)-modified solid lipid nanoparticles (SLNs) of pueraria flavones (PTF) via intranasal administration. Materials & methods: PTF-loaded SLNs were modified with Bo by physical and chemical methods to synthesize PTF-Bo-SA-SLNs and PTF-Bo-SLNs. The prepared SLNs were characterized and their brain delivery effects were evaluated in vitro and in vivo. Results: There was a more pronounced accumulation of PTF-Bo-SA-SLNs in Caco-2 cells. Following intranasal administration, more coumarin-6 was found in the rat brain carried by Bo-SA-SLNs. Brain area under the curve and C_max of PTF-Bo-SA-SLN were 7.31- and 7.29-times higher than those of PTF-SLN, respectively. Conclusion: PTF-Bo-SA-SLNs are a promising therapeutic carrier for brain disease after intranasal administration.

Evaluation of intranasal delivery route of drug administration for brain targeting

The acute or chronic drug treatments for different neurodegenerative and psychiatric disorders are challenging from several aspects. The low bioavailability and limited brain exposure of oral drugs, the rapid metabolism, elimination, the unwanted side effects and also the high dose to be added mean both inconvenience for the patients and high costs for the patients, their family and the society. The reason of low brain penetration of the compounds is that they have to overcome the blood-brain barrier which protects the brain against xenobiotics. Intranasal drug administration is one of the promising options to bypass blood-brain barrier, to reduce the systemic adverse effects of the drugs and to lower the doses to be administered. Furthermore, the drugs administered using nasal route have usually higher bioavailability, less side effects and result in higher brain exposure at similar dosage than the oral drugs. In this review the focus is on giving an overview on the anatomical and cellular structure of nasal cavity and absorption surface. It presents some possibilities to enhance the drug penetration through the nasal barrier and summarizes some in vitro, ex vivo and in vivo technologies to test the drug delivery across the nasal epithelium into the brain. Finally, the authors give a critical evaluation of the nasal route of administration showing its main advantages and limitations of this delivery route for CNS drug targeting.

Improved lymphatic targeting: effect and mechanism of synthetic borneol on lymph node uptake of 7-ethyl-10-hydroxycamptothecin nanoliposomes following subcutaneous administration

Borneol as a penetration enhancer is widely used in guiding other components through the biological barrier into the targeting organs or tissues. This study aimed at studying effect and mechanism of synthetic borneol (S-BO) on improving lymphatic-targeting ability of 7-ethyl-10-hydroxycamptothecin liposomes (SN-38-Lips) via increasing lymph node uptake. At first, SN-38-Lips prepared had appropriate particle distribution, drug loading property and compatible stability with S-BO. Both in vitro cellular uptake and in vivo fluorescence imaging showed that 2 and 5 mg/mL S-BO, especially 2 mg/mL S-BO, enhanced cytoplasmic fluorescence signal of SN-38-Lips in the macrophages based on phagocytosis effect. And high-intensity zone appeared in the paracortex and medulla of popliteal lymph node. SN-38-Lips were subcutaneously (s.c.) injected into the right footpad of KM rats in the dose of 4 mg/kg following s.c. injection of 1, 2 and 5 mg/mL BO suspension. The lymphatic pharmacokinetics were investigated to explore the promotion law of S-BO, and combined with tissue irritation to optimize S-BO concentrations. The results indicated that 2 mg/mL S-BO could reduce injection-site retention, and prolong residence time and increase uptake of lymph nodes, which would not cause inflammatory reaction of injection site. In conclusion, the present study may provide a basic study for improving lymphatic-targeting ability of SN-38-Lips by the S-BO regulation, and to be the helpful guidance for further study in lymphatic targeting of delivery system.

Plant-Derived Anticancer Agents: Lessons from the Pharmacology of Geniposide and Its Aglycone, Genipin

For centuries, plants have been exploited by mankind as sources of numerous cancer chemotherapeutic agents. Good examples of anticancer compounds of clinical significance today include the taxanes (e.g., taxol), vincristine, vinblastine, and the podophyllotoxin analogues that all trace their origin to higher plants. While all these drugs, along with the various other available therapeutic options, brought some relief in cancer management, a real breakthrough or cure has not yet been achieved. This critical review is a reflection on the lessons learnt from decades of research on the iridoid glycoside geniposide and its aglycone, genipin, which are currently used as gold standard reference compounds in cancer studies. Their effects on tumour development (carcinogenesis), cancer cell survival, and death, with particular emphasis on their mechanisms of actions, are discussed. Particular attention is also given to mechanisms related to the dual pro-oxidant and antioxidant effects of these compounds, the mitochondrial mechanism of cancer cell killing through reactive oxygen species (ROS), including that generated through the uncoupling protein-2 (UCP-2), the inflammatory mechanism, and cell cycle regulation. The implications of various studies for the evaluation of glycosidic and aglycone forms of natural products in vitro and in vivo through pharmacokinetic scrutiny are also addressed.

A mucoadhesive, thermoreversible in situ nasal gel of geniposide for neurodegenerative diseases

Neurodegenerative diseases are becoming prevalent as the population ages. Geniposide could inhibit oxidative stress, reduce apoptosis, protect neuron, and has been used for therapy of the neurodegenerative diseases. The bioavailability of geniposide by nasal route is greater than that by oral administration. However, mucociliary clearance is a rate-limiting factor for nasal route administration. The objective of this study was to develop and evaluate a mucoadhesive, thermoreversible in situ nasal gel of geniposide. The poloxamers (P407, P188) and the hydroxypropyl methylcellulose were used as thermoreversible and mucoadhesive polymers, respectively. Borneol was used as a permeation enhancer. The hydrogel was prepared with the cold method and optimized by the response surface methodology-central composite design. Gelation temperature, pH, clarity, gel strength, mucoadhesive strength, in vitro and ex vivo release kinetics of formulations were evaluated. The optimized amounts of poloxamer407 (P407), poloxamer188 (P188) and hydroxypropyl methylcellulose were determined to be 19.4-20.5%, 1.1-4.0% and 0.3-0.6% respectively. The second-order polynomial equation in terms of actual factors indicated a satisfactory correlation between the independent variables and the response (R2 = 0.9760). An ANOVA of the empirical second-order polynomial model indicated the model was significant (P<0.01). P407, P188, P407×P188, P4072 and P1882 were significant model terms. The effects of P407 on gelation temperature were greater than those of other independent variables. The pH values of all the formulations were found to be within 6.3-6.5 which was in the nasal physiological pH range 4.5-6.5. The drug content, gel strength, mucoadhesive strength of the optimized formulations were 97-101%, 25-50 sec and 4000-6000 dyn/cm2 respectively. The in vitro release kinetics of cumulative release of geniposide was fitted to the zero-order model. The ex vivo cumulative release kinetics of geniposide was fitted to the Weibull model. This study concludes that the release of geniposide is controlled by gel corrosion, and that the permeation of geniposide is time-dependent. The more residence time, mucoadhesive, thermoreversible in situ nasal gel of geniposide for neurodegenerative diseases is of compliance and potential application.

Borneol, a novel agent that improves central nervous system drug delivery by enhancing blood-brain barrier permeability

The clinical application of central nervous system (CNS) drugs is limited by their poor bioavailability due to the blood-brain barrier (BBB). Borneol is a naturally occurring compound in a class of 'orifice-opening' agents often used for resuscitative purposes in traditional Chinese medicine. A growing body of evidence confirms that the 'orifice-opening' effect of borneol is principally derived from opening the BBB. Borneol is therefore believed to be an effective adjuvant that can improve drug delivery to the brain. The purpose of this paper is to provide a comprehensive review of information accumulated over the past two decades on borneol's chemical features, sources, toxic and kinetic profiles, enhancing effects on BBB permeability and their putative mechanisms, improvements in CNS drug delivery, and pharmaceutical forms. The BBB-opening effect of borneol is a reversible physiological process characterized by rapid and transient penetration of the BBB and highly specific brain regional distribution. Borneol also protects the structural integrity of the BBB against pathological damage. The enhancement of the BBB permeability is associated with the modulation of multiple ATP-binding cassette transporters, including P-glycoprotein; tight junction proteins; and predominant enhancement of vasodilatory neurotransmitters. Systemic co-administration with borneol improves drug delivery to the brain in a region-, dose- and time-dependent manner. Several pharmaceutical forms of borneol have been developed to improve the kinetic and toxic profiles of co-administered drugs and enhance their delivery to the brain. Borneol is a promising novel agent that deserves further development as a BBB permeation enhancer for CNS drug delivery.

Comparison of Chemical Profiles, Anti-Inflammatory Activity, and UPLC-Q-TOF/MS-Based Metabolomics in Endotoxic Fever Rats between Synthetic Borneol and Natural Borneol

Natural borneol (NB, called “Bingpian”) is an important traditional Chinese medicine to restore consciousness, remove heat and relieve pain, all of which are inflammation-related diseases. Recently, due to the limited source of NB, synthetic borneol (SB) is widely used as a substitute for NB in clinics. However, little is known about the effects of SB instead of NB. Herein, the aim of the present study was to compare NB and SB on chemical profiles by gas chromatography-mass spectrometer (GC-MS) analysis, anti-inflammatory activity in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages, and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) metabolomic approaches in endotoxic fever induced in rats. Results showed that, in total, 13 volatile components could be identified in NB and SB by GC-MS analysis, in which a significant difference between them still existed. The main constituents in SB were iso-borneol and borneol, while borneol contributes to 98.96% of the amount in NB. Additionally, both NB and SB exhibited remarkable anti-inflammatory effects to reduce the level of inflammatory factors including NO, TNF-α and IL-6 in LPS-induced RAW 264.7 macrophages, and lower the high body temperature in rats with endotoxic fever induced by LPS. Moreover, it seems that NB exhibited higher efficacy than SB. The unequal bioactive efficiency between NB and SB was also indicated by means of non-targeting metabolomics. Based on UPLC-Q-TOF/MS technology, 12 biomarkers in the serum of fever rats were identified. Pathway analysis revealed that the anti-fever effect of NB and SB was related to regulating the abnormal glycerophospholipid, linoleic acid and alpha-linoleic acid metabolism pathways in the fever model. Results indicated that there was still a great difference between NB and SB involving chemical constituents, anti-inflammation activity and the ability to regulate the abnormal metabolism pathways of the fever model. Certainly, further studies are warranted to better understand the replacement rationale in medicinal application.

Determination of geniposide in adjuvant arthritis rat plasma by ultra-high performance liquid chromatography tandem mass spectrometry method and its application to oral bioavailability and plasma protein binding ability studies

A specific, sensitive and high throughput ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometric method (UHPLC-ESI-MS/MS) was established and validated to assay geniposide (GE), a promising anti-inflammatory drug, in adjuvant arthritis rat plasma: application to pharmacokinetic and oral bioavailability studies and plasma protein binding ability. Plasma samples were processed by de-proteinised with ice-cold methanol and separated on an ACQUITY UPLC™ HSS C18 column (100 mm × 2.1mm i.d., 1.8 μm particle size) at a gradient flow rate of 0.2 mL/min using acetonitrile-0.1% formic acid in water as mobile phase, and the total run time was 9 min. Mass detection was performed in selected reaction monitoring (SRM) mode with negative electro-spray ionization includes the addition of paeoniflorin (Pae) as an internal standard (IS). The mass transition ion-pair was followed as m/z 387.4 → 122.4 for GE and m/z 479.4 → 449.0 for IS. The calibration curves were linear over the concentration range of 2-50,000 ng/mL with lower limit of quantification of 2 ng/mL. The intra-day and inter-day precisions (RSD, %) of the assay were less than 8.4%, and the accuracy was within ± 6.4% in terms of relative error (RE). Extraction recovery, matrix effect and stability were satisfactory in adjuvant arthritis rat plasma. The UHPLC-ESI-MS/MS method was successfully applied to a pharmacokinetic study of GE after oral administration of depurated GE at 33, 66, 132 mg/kg and intravenous injection at 33, 66, 132 mg/kg in adjuvant arthritis (AA) rats. In addition, it was found that GE has rapid absorption and elimination, low absolute bioavailability, high plasma protein binding ability in AA rats after oral administration within the tested dosage range. It suggested that GE showed slow distribution into the intra- and extracellular space, and the binding rate was not proportionally dependent on plasma concentration of GE when the concentration of GE was below 5.0 μg/mL.

Pre-treatment with a Xingnaojing preparation ameliorates sevoflurane-induced neuroapoptosis in the infant rat striatum

Xingnaojing (XNJ), is a standardized Chinese herbal medicine product derived from An Gong Niu Huang Pill. It may be involved in neuroprotection in a number of neurological disorders. Exposure to anesthetic agents during the brain growth spurt may trigger widespread neuroapoptosis in the developing brain. Thus the present study aimed to identify whether there was a neuroprotective effect of XNJ on anesthesia-induced neuroapoptosis. Seven-day-old rats received treatment with 2.1% sevoflurane for 6 h. Rat pups were injected intraperitoneally with 1 or 10 ml/kg XNJ at 0.2, 24 and 48 h prior to sevoflurane exposure. The striata of neonatal rats were collected following administration of anesthesia. Western blotting and immunohistochemistry were used to analyze the expression of activated caspase 3, Bax and phosphorylated protein kinase B (p-AKT) in the striatum. It was found that activated caspase 3 and Bax expression were upregulated in the striatum following sevoflurane treatment. Preconditioning with XNJ attenuated the neuronal apoptosis induced by sevoflurane in a dose-dependent manner. Anesthesia reduced the expression of p-AKT (phosphorylated at sites Thr308 and Ser473) and phosphorylated extracellular-regulated protein kinase (p-ERK) in the striatum. Pre-treatment with XNJ reversed the reduction in p-AKT, but not p-ERK expression. These data suggest that XNJ has an antiapoptotic effect against sevoflurane-induced cell loss in the striatum. It thus holds promise as a safe and effective neuroprotective agent. The action of XNJ on p-AKT may make a significant contribution to its neuroprotective effect.

Comparative pharmacokinetics of borneol in cerebral ischemia-reperfusion and sham-operated rats

OBJECTIVE

This study was designed to investigate the pharmacokinetics of borneol in the pathological conditions of stroke and evaluate the pharmacokinetic differences of borneol caused by stroke after oral administration of borneol and Xingnaojing (XNJ).

METHODS

The rats were divided into two groups, ischemia-reperfusion (IR) and sham-operated (SO) rats. Each group contained two subgroups: pure borneol and XNJ subgroups. After administration with the same dosages of borneol 162.0 mg/kg, plasma samples were collected. The cerebral ischemia-reperfusion model was created by reversible middle cerebral artery occlusion (MCAO). The blood samples were collected punctually after oral administration and a specific gas chromatographic system-flame ionization detector (GC-FID) method was developed and employed to determine the level of borneol in the plasma. The pharmacokinetic parameters were analyzed using non-compartmental methods with Kinetica.

RESULTS

After administration of borneol, the maximum plasma concentration (Cmax) and area under the curve (AUC) values in stroke rats significantly increased by 302% and 275%, respectively, compared with the SO rats, and the same phenomenon appeared after administration of XNJ. In the rats with the same physiological conditions, the Cmax and AUC had higher values in the borneol subgroup (P<0.05).

CONCLUSIONS

These results suggest that the pathological damages of ischemia-reperfusion have a significant impact on the pharmacokinetic traits of borneol and that there are some components in XNJ inhibiting the absorption of borneol.

Enhancing effect of borneol and muscone on geniposide transport across the human nasal epithelial cell monolayer

Geniposide is widely used in the treatment of cerebral ischemic stroke and cerebrovascular diseases for its anti-thrombotic and anti-inflammatory effects. Recent studies demonstrated that geniposide could be absorbed promptly and thoroughly by intranasal administration in mice and basically transported into the brain. Here, we explored its transport mechanism and the effect of borneol and muscone on its transport by human nasal epithelial cell (HNEC) monolayer. The cytotoxicity of geniposide, borneol, muscone and their combinations on HNECs was evaluated by the MTT assay. Transcellular transport of geniposide and the influence of borneol and muscone were studied using the HNEC monolayer. Immunostaining and transepithelial electrical resistance were measured to assess the integrity of the monolayer. The membrane fluidity of HNEC was evaluated by fluorescence recovery after photobleaching. Geniposide showed relatively poor absorption in the HNEC monolayer and it was not a P-gp substrate. Geniposide transport in both directions significantly increased when co-administrated with increasing concentrations of borneol and muscone. The enhancing effect of borneol and muscone on geniposide transport across the HNEC may be attributed to the significant enhancement on cell membrane fluidity, disassembly effect on tight junction integrity and the process was reversible. These results indicated that intranasal administration has good potential to treat cerebrovascular diseases.

Influence of borneol and muscone on geniposide transport through MDCK and MDCK-MDR1 cells as blood-brain barrier in vitro model

The objective of this study was (1) to characterize geniposide transport through MDCK and MDCK-MDR1 cell lines to confirm its transport mechanism and (2) to evaluate the effect of borneol and muscone as enhancers of geniposide transport in the BBB models so as to explore the enhancement mechanism. Transport studies of geniposide were performed in both directions, from apical to basolateral and from basolateral to apical sides. Drug concentrations were analyzed by HPLC. Geniposide showed relatively poor absorption in MDCK and MDCK-MDR1 cells, apparent permeability coefficients ranging from 0.323×10(-6) to 0.422×10(-6) cm/s. The in vitro experiments showed that geniposide transport in both directions was not concentration dependent and saturable, indicating purely passive diffusion. The efflux ratio of geniposide was less than 2 in the two cell models, which suggested that geniposide was not P-gp substrates. Geniposide transport in both directions significantly increased when co-administrated with increasing concentrations of borneol and muscone. Actin staining results indicated that borneol and muscone increased geniposide transport in the BBB models may attribute to disassembly effect on tight junction integrity.