Borneol and Α-asarone as adjuvant agents for improving blood-brain barrier permeability of puerarin and tetramethylpyrazine by activating adenosine receptors

Volatile oil of Acori tatarinowii rhizoma: potential candidate drugs for mitigating dementia

Objective

This study aims to elucidate the mitigating effects of the volatile oil of Acori tatarinowii rhizoma (ATR) on dementia, in order to provide a reference for future research and applications of the volatile oil of ATR in the field of dementia.

Materials and methods

A search strategy was developed using terms such as "Acori tatarinowii rhizoma," "Acorus tatarinowii Schott," "Asarone," and "Dementia." The literature search was conducted in PubMed, Web of Science, and Google Scholar, and studies not meeting the inclusion criteria were excluded. This study summarizes the main metabolites, active ingredients, toxicological properties, and pharmacokinetic characteristics of the volatile oil from ATR in mitigating dementia, with a particular focus on its potential mechanisms of action. Furthermore, the study highlights the limitations of existing research and offers insights into future research directions.

Results

The volatile oil of ATR mitigates dementia through multiple pathways, including reducing abnormal protein aggregation, promoting neurogenesis, inhibiting neuronal apoptosis, regulating neurotransmitters, improving synaptic function, modulating autophagy, countering cellular stress, reducing neuroinflammation, and alleviating vascular risk factors.

Conclusion

The multi-pathway pharmacological effects of the volatile oil of ATR are well-aligned with the complex mechanisms of dementia progression, highlighting its significant therapeutic potential for anti-dementia applications. This provides new perspectives for the development of more effective anti-dementia drugs. Nonetheless, further rigorous and high-quality preclinical and clinical investigations are required to address key issues, including the chemical characterization of the volatile oil of ATR, potential synergistic effects among active ingredients, toxicity profiles, and definitive clinical efficacy.

Acori Tatarinowii Rhizoma regulates OCT3/OATP2 and P-gp/MRP1 to "guide medicines upwards" in Kai-Xin-San to treat Alzheimer's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Kai-Xin-San (KXS) has a significant effect therapeutic on Alzheimer's disease (AD) in clinical practice. According to the compatibility theory of traditional Chinese medicine, Acori Tatarinowii Rhizoma (ATR) serves as the guiding drug in the KXS formulation and is believed to enhance the bioavailability and brain tissue distribution of the other drugs. However, the mechanism underlying the "guiding medicine upwards" effect of ATR in KXS remains unexplored.

AIM OF THE STUDY

The aim of this study is to investigate the role of ATR in the efficacy of KXS on amyloid precursor protein/presenilin 1 (APP/PS1) mice, as well as its impact on the brain tissue distribution of other active ingredients in the KXS formula, and to elucidate the mechanism of ATR's "guiding medicine upwards" effect in KXS.

MATERIALS AND METHODS

The pharmacodynamic effects of ATR in KXS were assessed through behavioral tests, immunohistochemical staining, and Nissl staining. Additionally, the levels of inflammatory factors, as well as the activities of malondialdehyde, superoxide dismutase, and acetylcholinesterase, were measured using enzyme-linked immunosorbent assay kits. Subsequently, the effect of ATR on the ultrastructure of the blood-brain barrier (BBB) in APP/PS1 mice was observed using transmission electron microscopy (TEM), and the pharmacodynamic components of KXS in cerebrospinal fluid were quantified by ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS). Furthermore, Western blot (WB) analysis was used to quantitatively assess the expression of tight junction proteins (Claudin-5, Occludin, and ZO-1) and transporters (OCT3, OATP2, P-gp, and MRP1) in the BBB. Finally, bEND.3 cells and astrocyte cells were co-cultured to validate the effect of ATR on KXS. The expressions of OCT3/OATP2 and P-gp/MRP1 in BBB cell model were determined by WB and the content of pharmacodynamic components in the lower chamber of the transwell were also analyzed by UPLC-MS/MS.

RESULTS

Behavioral test results suggest that KXS significantly improved the learning and memory capacities of APP/PS1 mice compared to the ATR-free KXS group. Furthermore, KXS was more effective in reducing amyloid-β protein deposition in the brain and repairing damaged neurons in the CA1 and CA3 regions than ATR-free KXS. Notably, KXS significantly reversed the pathological biochemical indices compared to the ATR-free KXS group. These results indicate that ATR has a positive effect on the pharmacodynamics of KXS in treating AD. Most importantly, TEM results revealed that KXS repaired the damaged BBB in AD mice, and ATR contributed to the improvement of BBB integrity. Furthermore, KXS and ATR increased the expression levels of Claudin-5, Occludin, and ZO-1 proteins in AD mice. Meanwhile, the levels of ginsenoside Rg1, ginsenoside Rb1, and polygalaxanthone III in the cerebrospinal fluid of the KXS group were 1.47, 1.39, and 2.02 times higher than those in the ATR-free KXS group, respectively. WB results showed that ATR and KXS significantly upregulated the expression of OCT3/OATP2 uptake transporters and downregulated the expression of P-gp/MRP1 efflux transporters compared to ATR-free KXS. Concurrently, in vitro BBB cell experimental results suggest that ATR promoted the transport of ginsenoside Rg1, ginsenoside Rb1, and polygalaxanthone III across BBB cells in KXS, and the regulation of OCT3/OATP2 and P-gp/MRP1 expression was consistent with the in vivo trends observed in AD mice.

CONCLUSIONS

ATR plays a critical role in enhancing the efficacy of KXS in treating AD and facilitates the entry of other pharmacodynamic components into the brain. The mechanism underlying the "guiding medicine upwards" effect of ATR may involve the regulation of OCT3/OATP2 and P-gp/MRP1 transporters.

Much More than Nutrients: The Protective Effects of Nutraceuticals on the Blood-Brain Barrier in Diseases

The dysfunction of the blood-brain barrier (BBB) is well described in several diseases, and is considered a pathological factor in many neurological disorders. This review summarizes the most important groups of natural compounds, including alkaloids, flavonoids, anthocyanidines, carotenoids, lipids, and vitamins that were investigated for their potential protective effects on brain endothelium. The brain penetration of these compounds and their interaction with BBB efflux transporters and solute carriers are discussed. The cerebrovascular endothelium is considered a therapeutic target for natural compounds in diseases. In preclinical studies modeling systemic and central nervous system diseases, nutraceuticals exerted beneficial effects on the BBB. In vivo, they decreased BBB permeability, brain edema, astrocyte swelling, and morphological changes in the vessel structure and basal lamina. At the level of brain endothelial cells, nutraceuticals increased cell survival and decreased apoptosis. From the general endothelial functions, decreased angiogenesis and increased levels of vasodilating agents were demonstrated. From the BBB functions, elevated barrier integrity by tightened intercellular junctions, and increased expression and activity of BBB transporters, such as efflux pumps, solute carriers, and metabolic enzymes, were shown. Nutraceuticals enhanced the antioxidative defense and exerted anti-inflammatory effects at the BBB. The most important signaling changes mediating the increased cell survival and BBB stability were the activation of the WNT, PI3K-AKT, and NRF2 pathways, and inhibition of the MAPK, JNK, ERK, and NF-κB pathways. Nutraceuticals represent a valuable source of new potentially therapeutic molecules to treat brain diseases by protecting the BBB.

A comprehensive review on pharmacokinetic mechanism of herb-herb/drug interactions in Chinese herbal formula

Oral administration of Chinese Herbal Medicine (CHM) faces various challenges in reaching the target organs including absorption and conversion in the gastrointestinal tract, hepatic metabolism via the portal vein, and eventual systemic circulation. During this process, factors such as gut microbes, physical or chemical barriers, metabolic enzymes, and transporters play crucial roles. Particularly, interactions between different herbs in CHM have been observed both in vitro and in vivo. In vitro, interactions typically manifest as detectable physical or chemical changes, such as facilitating solubilization or producing precipitates when decoctions of multiple herbs are administered. In vivo, such interactions cause alterations in the ADME (absorption, distribution, metabolism, and excretion) profile on metabolic enzymes or transporters in the body, leading to competition, antagonism, inhibition, or activation. These interactions ultimately contribute to differences in the therapeutic and pharmacological effects of multi-herb formulas in CHM. Over the past two thousand years, China has cultivated profound expertise and solid theoretical frameworks over the scientific use of herbs. The combination of multiple herbs in one decoction has been frequently employed to synergistically enhance therapeutic efficacy or mitigate toxic and side effects in clinical settings. Additionally combining herbs with increased toxicity or decreased effect is also regarded as a remedy, a practice that should be approached with caution according to Traditional Chinese Medicine (TCM) physicians. Such historical records and practices serve as a foundation for predicting favorable multi-herb combinations and their potential risks. However, systematic data that are available to support the clinical practice and the exploration of novel herbal formulas remain limited. Therefore, this review aims to summarize the pharmacokinetic interactions and mechanisms of herb-herb or herb-drug combinations from existing works, and to offer guidance as well as evidence for optimizing CHM and developing new medicines with CHM characteristics.

Borneol acts as an adjuvant agent to enhance the oral absorption of Panax notoginseng saponins in rats: Effect of optical configuration and compatibility ratios

ETHNOPHARMACOLOGICAL RELEVANCE

Panax notoginseng saponins (PNS), as the main active component of Panax notoginseng, shows broad pharmacological effects but with low oral bioavailability. Borneol (BO) is commonly used as an adjuvant drug in the field of traditional Chinese medicine, which has been proven to facilitate the absorption of ginsenosides such as Rg1 and Rb1 in vivo. The presence of chiral carbons has resulted in three optical isomers of BO commercially available in the market, all of which are documented by national standards.

AIM OF THE STUDY

This study aimed to investigate the role of BO in promoting the oral absorption of PNS from the perspective of optical configuration and compatibility ratios.

MATERIALS AND METHODS

In this study, an ultra-performance liquid chromatography coupled with triple quadrupole-linear ion trap tandem mass spectrometry (UPLC-QTRAP-MS/MS) method was validated and applied to determine the concentrations of five main saponins in PNS in rat plasma. The kinetic characteristics of PNS were compared when co-administered with BO based on optical isomerism and different compatibility ratios.

RESULTS

The results showed that BO promoted the exposure of PNS in rats. Three forms of BO, namely d-borneol (DB), l-borneol (LB), and synthetic borneol (SB), exhibited different promotion strengths. SB elevated PNS exposure in rats more than DB or LB. It is also interesting to note that under different compatibility ratios, SB can exert a strong promoting effect only when PNS and BO were combined in a 1:1 ratio (PNS 75 mg/kg; BO 75 mg/kg). As a pharmacokinetic booster, the dosage of BO is worthy of consideration and should follow the traditional medication principles of Chinese medicine.

CONCLUSIONS

This study shed new light on the compatible use of PNS and BO from the perspective of "configuration-dose-influence" of BO. The results provide important basis for the clinical application and selection of BO.

Advances and perspectives on pharmacological activities and mechanisms of the monoterpene borneol

BACKGROUND

Borneol, a highly lipid-soluble bicyclic terpene mainly extracted from plants, is representative of monoterpenoids. Modern medicine has established that borneol exhibits a range of pharmacological activities and used in the treatment of many diseases, particularly Cardio-cerebrovascular diseases (CVDs). The crucial role in enhancing drug delivery and improving bioavailability has attracted much attention. In addition, borneol is also widely utilized in food, daily chemicals, fragrances, and flavors industries.

PURPOSE

This review systematically summarized the sources, pharmacological activities and mechanisms, clinical trial, pharmacokinetics, toxicity, and application of borneol. In addition, this review describes the pharmacological effects of borneol ester and the combination of borneol with nanomaterial. This review will provide a valuable resource for those pursuing researches on borneol inspiring the pharmacological applications in the medicine, food and daily chemical products, and developing of new drugs containing borneol or its derivatives.

METHODS

This review searched the keywords ("borneol" or "bornyl esters") and ("pharmacology" or "Traditional Chinese medicine" or "Cardio-cerebrovascular diseases" or "blood-brain barrier" or "ischemic stroke" or "nanomaterials" or "neurodegenerative diseases" or "diabetes" or "toxicity") in Web of Science, PubMed, Google Scholar and China National Knowledge Infrastructure (CNKI) from January 1990 to May 2024. The search was limited to articles published in English and Chinese.

RESULTS

Borneol exhibits extensive pharmacological activities including anti-inflammatory effects, analgesia, antioxidation, and has the property of crossing biological barriers and treating CVDs. The intrinsic molecular mechanisms are involved in multiple components, such as regulation of various key factors (including Tumor necrosis factor-α, Nuclear factor kappa-B, Interleukin-1β, Malondialdehyde), inhibiting transporter protein function, regulating biochemical levels, and altering physical structural changes. In addition, this review describes the pharmacological effects of borneol ester and the combination of borneol with nanomaterial.

CONCLUSION

The pharmacological properties and applications of borneol are promising, including anti-inflammatory, analgesic, antimicrobial, and antioxidant properties, as well as enhancing drug delivery and treating CVDs. However, its clinical application is hindered by the limited research on safety, efficacy, and pharmacokinetics. Therefore, this review systemically summarized the advances on pharmacological activities and mechanisms of the borneol. Standardized clinical trials and exploration of synergistic effects with other drugs were also are outlined.

Microneedle-mediated drug delivery for neurological diseases

Neurological disorders, including brain injury, brain tumors, and neurodegenerative diseases, rank as the second leading cause of death worldwide. Exploring effective new treatments for neurological disorders has long been a hot research issue in clinical practice. Recently, microneedles (MNs) have attracted much attention due to their designation as a "painless and non-invasive" novel transdermal delivery method, characterized by their biocompatibility and sustainability. The advantages of MNs open an avenue for potential therapeutic interventions targeting neurological disorders. This review presents a concise overview of progress in the field of MNs, with highlights on the application in the treatment of neurological disorders. Notably, trends in the development of MNs and future challenges are also discussed.

Complementary therapy with Chinese aromatic herbs to promote awakening in a comatose patient: A case report

RATIONALE

Traumatic brain injury frequently leads to prolonged coma, posing significant medical management challenges. Complementary therapies, including traditional Chinese herbal medicine, have been investigated as potential interventions in comatose patients. Chinese aromatic herbs, such as Borneolum (Bingpian), Moschus (Shexiang), and Acori tatarinowii rhizoma (Shichangpu), have long been believed to be "resuscitation with aromatics" based on traditional Chinese medicines theory.

PATIENT CONCERNS

A 16-year-old male was admitted to the intensive rehabilitation unit for further treatment due to prolonged coma and frequent seizures following traumatic brain injury.

DIAGNOSES

Western medicine diagnosed the patient as coma, diffuse axonal injury, and epilepsy. According to traditional Chinese medicine theory, the syndrome differentiation indicates a Yin-closed disease.

INTERVENTIONS

According to the patient's condition, we use the Chinese aromatic herbs as a complementary therapy.

OUTCOMES

Following a month-long administration, the patient's consciousness and electroencephalogram (EEG) background progressively improved. A 6-month follow-up demonstrated full arousal, though with ambulatory EEG revealing mild to moderate abnormality in the background.

LESSONS

The addition of Chinese aromatic herbs appears to have a beneficial effect on the patient's consciousness and EEG background. This could be attributed to the herbs' inherent pharmacological properties, as well as their potential to enhance the permeability of the blood-brain barrier to other drugs. This makes them a promising option for complementary therapy.

Dual fluorescence images, transport pathway, and blood-brain barrier penetration of B-Met-W/O/W SE

Borneol is an aromatic traditional Chinese medicine that can improve the permeability of the blood-brain barrier (BBB), enter the brain, and promote the brain tissue distribution of many other drugs. In our previous study, borneol-metformin hydrochloride water/oil/water composite submicron emulsion (B-Met-W/O/W SE) was prepared using borneol and SE to promote BBB penetration, which significantly increased the brain distribution of Met. However, the dynamic images, transport pathway (uptake and efflux), promotion of BBB permeability, and mechanisms of B-Met-W/O/W SE before and after entering cells have not been clarified. In this study, rhodamine B and coumarin-6 were selected as water-soluble and oil-soluble fluorescent probes to prepare B-Met-W/O/W dual-fluorescent SE (B-Met-W/O/W DFSE) with concentric circle imaging. B-Met-W/O/W SE can be well taken up by brain microvascular endothelial cells (BMECs). The addition of three inhibitors (chlorpromazine hydrochloride, methyl-β-cyclodextrin, and amiloride hydrochloride) indicated that its main pathway may be clathrin-mediated and fossa protein-mediated endocytosis. Meanwhile, B-Met-W/O/W SE was obviously shown to inhibit the efflux of BMECs. Next, BMECs were cultured in the Transwell chamber to establish a BBB model, and Western blot was employed to detect the protein expressions of Occludin, Zona Occludens 1 (ZO-1), and p-glycoprotein (P-gp) after B-Met-W/O/W SE treatment. The results showed that B-Met-W/O/W SE significantly down-regulated the expression of Occludin, ZO-1, and P-gp, which increased the permeability of BBB, promoted drug entry into the brain through BBB, and inhibited BBB efflux. Furthermore, 11 differentially expressed genes (DEGs) and 7 related signaling pathways in BMECs treated with B-W/O/W SE were detected by transcriptome sequencing and verified by quantitative real-time polymerase chain reaction (qRT-PCR). These results provide a scientific experimental basis for the dynamic monitoring, transmembrane transport mode, and permeation-promoting mechanism of B-Met-W/O/W SE as a new brain-targeting drug delivery system.

Borneol-modified docetaxel plus tetrandrine micelles for treatment of drug-resistant brain glioma

OBJECTIVE

Glioma is the most common and deadly primary malignant tumor in adults. Treatment outcomes are ungratified due to the presence of blood-brain barrier (BBB), glioma stem cells (GSCs) and multidrug resistance (MDR). Docetaxel (DTX) is considered as a potential drug for the treatment of brain tumor, but its effectiveness is limited by its low bioavailability and drug resistance. Tetrandrine (TET) reverses the resistance of tumor cells to chemotherapy drugs. Borneol (BO) modified in micelles has been shown to promote DTX plus TET to cross the BBB, allowing the drug to better act on tumors. Therefore, we constructed BO-modified DTX plus TET micelles to inhibit chemotherapeutic drug resistance.

SIGNIFICANCE

Provide a new treatment method for drug-resistant brain gliomas.

METHODS

In this study, BO-modified DTX plus TET micelles were prepared by thin film dispersion method, their physicochemical properties were characterized. Its targeting ability was investigated. The therapeutic effect on GSCs was investigated by in vivo and in vitro experiments.

RESULTS

The BO-modified DTX plus TET micelles were successfully constructed by thin film dispersion method, and the micelles showed good stability. The results showed that targeting micelles increased bEnd.3 uptake and helped drugs cross the BBB in vitro. And we also found that targeting micelles could inhibit cell proliferation, promote cell apoptosis and inhibit the expression of drug-resistant protein, thus provide a new treatment method for GSCs in vitro and in vivo.

CONCLUSIONS

BO-modified DTX plus TET micelles may provide a new treatment method for drug-resistant brain gliomas.

Comparison of pharmacological activity and safety of different stereochemical configurations of borneol: L-borneol, D-borneol, and synthetic borneol

BACKGROUND

Chiral drugs generally exhibit differences in activity because they bind differently to their target receptor. The Chinese medicine borneol ('Bing Pian' in Chinese) is a bicyclic monoterpenoid with a wide range of biological activities. Three kinds of Chinese medicines comprising borneol are used clinically, namely, L-Borneolum ('Ai Pian' in Chinese), Borneolum ('Tian Ran Bing Pian' in Chinese), and synthetic borneol ('He Cheng Bing Pian' in Chinese). The three kinds of borneol have different stereochemical configurations, but their clinical uses are nearly identical, and their prices vary widely. However, there is no clear rational basis for the selection of these kinds of borneol in clinical applications.

PURPOSE

The purpose of this study was to clarify differences in the biological activity, safety, and structure-activity relationship of the three kinds of borneol.

METHODS

'borneol', 'Bing Pian', 'Ai Pian', 'Tian Ran Bing Pian', and 'He Cheng Bing Pian' were selected as keywords to search for and extract relevant literature in the CNKI, PubMed, and Google Scholar databases up to November 2022.

RESULTS

L-borneol has better potential in cerebrovascular diseases. The three kinds of borneol have stronger penetration-promoting effects on hydrophilic drugs. L-borneol and isoborneol promote intestinal mucosal absorption of drugs via bidirectional regulation of P-glycoprotein. D-borneol exhibits better antitumour sensitizing effects than L-borneol. L-borneol exhibits better inhibition of bacterial adhesion because of its C² chiral centre. Synthetic borneol is less safe.

CONCLUSION

L-borneol has excellent potential in many aspects, has various sources, and can effectively replace expensive D-borneol in some applications.

Therapeutic potential of puerarin against cerebral diseases: From bench to bedside

The incidence of cerebral diseases is rapidly increasing worldwide, and they have become an important challenge for modern medicine. Most of the available chemical drugs used in the treatment of cerebral diseases are highly toxic and single-targeted. Therefore, novel drugs from natural resources have attracted much attention for their potential to manage cerebral diseases. Puerarin is a natural isoflavone isolated from the roots of Pueraria species such as P. lobata (Willd) Ohwi, P. thomsonii, and P. mirifica. Several authors have reported the beneficial effects of puerarin in cerebral ischemic disease, intracerebral hemorrhage, vascular dementia, Alzheimer's disease, Parkinson's disease, depression, anxiety, and traumatic brain injury. This review summarizes the brain pharmacokinetics, brain drug delivery system, clinical use (in cerebral diseases), toxicity, and the adverse clinical reactions of puerarin. We have systematically presented the pharmacological actions and the molecular mechanisms of puerarin in various cerebral diseases to provide a direction for future research on the therapeutic use of puerarin in cerebral diseases.

The history, stereochemistry, ethnopharmacology and quality assessment of borneol

ETHNOPHARMACOLOGICAL RELEVANCE

Borneol (BO) represents a global trade-driven spreading of ethnic medicine traceable to the classical age, and won its name specific to its original habitat "Borneo". BO shows broad spectral pharmacological effects, such as anti-inflammatory, analgesic, antipyretic, inducing resuscitation, and widely applied in the protection and treatment of cardiovascular and cerebrovascular diseases, used singly or mostly in compound formulae.

AIM OF THE STUDY

Three stereoscopic configuration forms of BO, l-borneol (LB), d-borneol (DB), and dl-borneol (synthetic, SB), are formulated in broad spectral application, yet their diverse pharmacodynamic and pharmacokinetic properties caused by configurations, and accurate assay and quality assessment are often overlooked. A systematic review and analysis of lumped studies and applications is necessary to clarify the relationship between configuration and its original plant, analysis method, activity and side effect BO in order to guarantee the efficacy and safety during their application.

MATERIALS AND METHODS

The public databases including PubMed, Web of Science, Google Scholar, China National Knowledge Infrastructure were referenced to summarize a comprehensive research and application data of BO published up to date.

RESULTS

This review includes following sections: History and current status, Stereochemistry, Ethnopharmacology, and Quality assessment. In the section of history, the changes of the plant origins of the two isomeric forms of natural BO were described respectively, and the methods for synthetic racemate SB were also included. The section of stereochemistry deals with the stereoscopic structures, physical/chemical property, optical rotation of the three forms of BO, as well as the main related substances like isoborneol, obtained in SB via chemical transformation of camphor and turpentine oil. In the section of Ethnopharmacology, pharmacological activities and pharmacokinetics of different forms of BO were discussed. BO is usually used as an "adjuvant", by enhancing the permeability of the blood-brain barrier and intervene the ADME/T pathways of the other ingredients in the same formulation. In the section of quality assessment, the analytical methods, including chromatography, especially GC, and spectroscopy were addressed on the chiral separation of the coexisting enantiomers.

CONCLUSIONS

This overview systematically summarized three forms of BO in terms of history, stereochemistry, ethnopharmacology, and quality assessment, which, hopefully, can provide valuable information and strategy for more reasonable application and development of the globally reputed ethnic medicine borneol with characteristics in stereochemistry.

Bidirectional effects and mechanisms of traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

The bidirectional property of traditional Chinese medicines (TCMs) was recorded in the classic work Medicine Origin (Yi Xue Qi Yuan) as early as the Jin and Yuan dynasties of ancient China. Since then, this imperative theory has been applied to guide the clinical application of TCMs. Studies have been performed to investigate this phenomenon only over the last three decades. A limited number of reviews on the bidirectional role of TCMs have been published, and almost all current studies are published in the Chinese language.

AIM OF THE REVIEW

The aim of this review is to provide the first comprehensive evidence regarding the bidirectional effects and the underlying mechanisms of TCMs and their active compounds.

MATERIALS AND METHODS

Information relevant to opposing pharmacological activities or opposing properties exerted by TCM prescriptions, herbal medicines, and their active compound, as well as their mechanisms was summarized by searching Chinese and English databases, including the Chinese National Knowledge Infrastructure (CNKI), Wan Fang Data, Chinese Scientific Journal Database (VIP), Google Scholar, PubMed, Web of Science, Science Direct, and Wiley Online Library.

RESULTS

Although the bidirectional regulation of TCMs has been applied in the clinic since ancient times in China, only limited reviews have been published in Chinese. The existing data showed that bidirectional effects can be found in TCM prescriptions, herbal medicines, and pure active compounds. Additionally, the bidirectional role of TCMs was primarily reported in the modulation of immune function, blood circulation and hemostasis, gastrointestinal motility, the central nervous system and blood pressure. This may because the therapeutic outcomes of these disorders are more obvious than those of other complicated diseases. Intriguingly, some herbal medicines have multiple bidirectional activities; for instance, Panax ginseng C. A. Meyer showed bidirectional regulation of immune function and the central nervous system; Astragalus membranaceus can bidirectionally regulate blood pressure and immune function; and Rheum officinale Baill exerts bidirectional effects on blood circulation and hemostasis, gastrointestinal motility and immune function. The mechanisms underlying the bidirectional effects of TCMs are largely attributed to the complexity of herbal constituents, dosage differences, the processing of herbal medicine, and compatibility of medicines, the physiological conditions of patients and adaptogenic effects.

CONCLUSION

Uncovering the bidirectional effects and mechanisms of TCMs is of great importance for both scientific research and clinical applications. This review may help to facilitate the recognition of the bidirectional role of TCMs, to explain some seemingly-opposite phenomena in the pharmacological study of herbal medicines and to provide guidance for TCM practitioners.

Pharmacological Activity, Pharmacokinetics, and Clinical Research Progress of Puerarin

As a kind of medicine and food homologous plant, kudzu root (Pueraria lobata (Willd.) Ohwi) is called an "official medicine" in Chinese folk medicine. Puerarin is the main active component extracted from kudzu root, and its structural formula is 8-β-D-grapes pyranose-4, 7-dihydroxy isoflavone, with a white needle crystal; it is slightly soluble in water, and its aqueous solution is colorless or light yellow. Puerarin is a natural antioxidant with high health value and has a series of biological activities such as antioxidation, anti-inflammation, anti-tumor effects, immunity improvement, and cardio-cerebrovascular and nerve cell protection. In particular, for the past few years, it has also been extensively used in clinical study. This review focuses on the antioxidant activity of puerarin, the therapy of diverse types of inflammatory diseases, various new drug delivery systems of puerarin, the "structure-activity relationship" of puerarin and its derivatives, and pharmacokinetic and clinical studies, which can provide a new perspective for the puerarin-related drug research and development, clinical application, and further development and utilization.

The barrier and interface mechanisms of the brain barrier, and brain drug delivery

Three different barriers are formed between the cerebrovascular and the brain parenchyma: the blood-brain barrier (BBB), the blood-cerebrospinal fluid barrier (BCSFB), and the cerebrospinal fluid-brain barrier (CBB). The BBB is the main regulator of blood and central nervous system (CNS) material exchange. The semipermeable nature of the BBB limits the passage of larger molecules and hydrophilic small molecules, Food and Drug Administration (FDA)-approved drugs for the CNS have been generally limited to lipid-soluble small molecules. Although the complexity of the BBB affects CNS drug delivery, understanding the composition and function of the BBB can provide a platform for the development of new methods for CNS drug delivery. This review summarizes the classification of the brain barrier, the composition and role of the basic structures of the BBB, and the transport, barrier, and destruction mechanisms of the BBB; discusses the advantages and disadvantages of different drug delivery methods and prospects for future drug delivery strategies.

Comprehensive chemical profiling of volatile constituents of Angong Niuhuang Pill in vitro and in vivo based on gas chromatography coupled with mass spectrometry

Background

Angong Niuhuang Pill (ANP), a renowned precious traditional Chinese medicine prescription, is extensively utilized for the clinical treatment of stroke, meningitis and encephalorrhagia in China. As a classic resuscitation-inducing aromatic prescription, ANP has been investigated for its pharmacological effects in recent years, while the volatile composition in ANP still lacks comprehensive elucidation.

Method

To better explore the volatile constituents in ANP, a qualitative analysis method was developed based on gas chromatography coupled with mass spectrometry. Furthermore, a validated quantitative method was established to determine 21 main compounds in 8 batches of commercially available ANP samples by gas chromatography-tandem mass spectrometry. The quantitative data were successively subjected to Pearson correlation coefficient analysis. Additionally, the absorbed volatile constituents in rat plasma after single oral administration of ANP have also been characterized.

Results

A total of 93 volatile constituents including 29 sesquiterpenoids, 28 monoterpenoids, 13 fatty acids and their esters, 7 alkanes, 6 ketones, 3 phenols, 3 aldehydes, 2 benzoate esters, and 2 other types, were preliminarily characterized, which primarily originated from Borneolum, Moschus, Curcumae Radix, and Gardeniae Fructus. d-Borneol, isoborneol and muscone were the top three abundant ingredients (> 600 μg/g) in 8 batches of ANP samples. Subsequently, the average Pearson correlation coefficient of the contents of 21 analytes was 0.993, inferring the high batch-to-batch similarity among 8 batches. After oral administration of ANP, d-borneol, isoborneol, muscone and camphor were the main volatile constituents absorbed in the rat plasma.

Conclusion

This research may be helpful for the comprehensive quality control study of ANP, and provide for guarantee the clinical efficacy of ANP.

Regulatory mechanisms of tetramethylpyrazine on central nervous system diseases: A review

Central nervous system (CNS) diseases can lead to motor, sensory, speech, cognitive dysfunction, and sometimes even death. These diseases are recognized to cause a substantial socio-economic impact on a global scale. Tetramethylpyrazine (TMP) is one of the main active ingredients extracted from the Chinese herbal medicine Ligusticum striatum DC. (Chuan Xiong). Many in vivo and in vitro studies have demonstrated that TMP has a certain role in the treatment of CNS diseases through inhibiting calcium ion overload and glutamate excitotoxicity, anti-oxidative/nitrification stress, mitigating inflammatory response, anti-apoptosis, protecting the integrity of the blood-brain barrier (BBB) and facilitating synaptic plasticity. In this review, we summarize the roles and mechanisms of action of TMP on ischemic cerebrovascular disease, spinal cord injury, Parkinson’s disease, Alzheimer’s disease, cognitive impairments, migraine, and depression. Our review will provide new insights into the clinical applications of TMP and the development of novel therapeutics.

Therapeutics for Chemotherapy-Induced Peripheral Neuropathy: Approaches with Natural Compounds from Traditional Eastern Medicine

Chemotherapy-induced peripheral neuropathy (CIPN) often develops in patients with cancer treated with commonly used anti-cancer drugs. The symptoms of CIPN can occur acutely during chemotherapy or emerge after cessation, and often accompany long-lasting intractable pain. This adverse side effect not only affects the quality of life but also limits the use of chemotherapy, leading to a reduction in the survival rate of patients with cancer. Currently, effective treatments for CIPN are limited, and various interventions are being applied by clinicians and patients because of the unmet clinical need. Potential approaches to ameliorate CIPN include traditional Eastern medicine-based methods. Medicinal substances from traditional Eastern medicine have well-established analgesic effects and are generally safe. Furthermore, many substances can also improve other comorbid symptoms in patients. This article aims to provide information regarding traditional Eastern medicine-based plant extracts and natural compounds for CIPN. In this regard, we briefly summarized the development, mechanisms, and changes in the nervous system related to CIPN, and reviewed the substances of traditional Eastern medicine that have been exploited to treat CIPN in preclinical and clinical settings.

Molecular Mechanisms and Therapeutic Potential of α- and β-Asarone in the Treatment of Neurological Disorders

Neurological disorders are important causes of morbidity and mortality around the world. The increasing prevalence of neurological disorders, associated with an aging population, has intensified the societal burden associated with these diseases, for which no effective treatment strategies currently exist. Therefore, the identification and development of novel therapeutic approaches, able to halt or reverse neuronal loss by targeting the underlying causal factors that lead to neurodegeneration and neuronal cell death, are urgently necessary. Plants and other natural products have been explored as sources of safe, naturally occurring secondary metabolites with potential neuroprotective properties. The secondary metabolites α- and β-asarone can be found in high levels in the rhizomes of the medicinal plant Acorus calamus (L.). α- and β-asarone exhibit multiple pharmacological properties including antioxidant, anti-inflammatory, antiapoptotic, anticancer, and neuroprotective effects. This paper aims to provide an overview of the current research on the therapeutic potential of α- and β-asarone in the treatment of neurological disorders, particularly neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), as well as cerebral ischemic disease, and epilepsy. Current research indicates that α- and β-asarone exert neuroprotective effects by mitigating oxidative stress, abnormal protein accumulation, neuroinflammation, neurotrophic factor deficit, and promoting neuronal cell survival, as well as activating various neuroprotective signalling pathways. Although the beneficial effects exerted by α- and β-asarone have been demonstrated through in vitro and in vivo animal studies, additional research is required to translate laboratory results into safe and effective therapies for patients with AD, PD, and other neurological and neurodegenerative diseases.

Traditional herbal medicine and nanomedicine: Converging disciplines to improve therapeutic efficacy and human health

Traditional herbal medicine (THM), an ancient science, is a gift from nature. For thousands of years, it has helped humans fight diseases and protect life, health, and reproduction. Nanomedicine, a newer discipline has evolved from exploitation of the unique nanoscale morphology and is widely used in diagnosis, imaging, drug delivery, and other biomedical fields. Although THM and nanomedicine differ greatly in time span and discipline dimensions, they are closely related and are even evolving toward integration and convergence. This review begins with the history and latest research progress of THM and nanomedicine, expounding their respective developmental trajectory. It then discusses the overlapping connectivity and relevance of the two fields, including nanoaggregates generated in herbal medicine decoctions, the application of nanotechnology in the delivery and treatment of natural active ingredients, and the influence of physiological regulatory capability of THM on the in vivo fate of nanoparticles. Finally, future development trends, challenges, and research directions are discussed.

Multiple regulation and targeting effects of borneol in the neurovascular unit in neurodegenerative diseases

Efficient delivery of brain-targeted drugs is highly important for the success of therapies in neurodegenerative diseases. Borneol has several biological activities, such as anti-inflammatory and cell penetration enhancing effect, and can regulate processes in the neurovascular unit (NVU), such as protein toxic stress, autophagosome/lysosomal system, oxidative stress, programmed cell death and neuroinflammation. However, the influence of borneol on NVU in neurodegenerative diseases has not been fully explained. This study searched the keywords 'borneol', 'neurovascular unit', 'endothelial cell', 'astrocyte', 'neuron', 'blood-brain barrier', 'neurodegenerative diseases' and 'brain disease', in PubMed, BioMed Central, China National Knowledge Infrastructure (CNKI), and Bing search engines to explore the influence of borneol on NVU. In addition to the principle and mechanism of penetration of borneol in the brain, this study also showed its multiple regulation effects on NVU. Borneol was able to penetrate the blood-brain barrier (BBB), affecting the signal transmission between BBB and the microenvironment of the brain, down-regulating the expression of inflammatory and oxidative stress proteins in NVU, especially in microglia and astrocytes. In summary, borneol is a potential drug delivery agent for drugs against neurodegenerative diseases.

Exosomes and biomimetic nanovesicles-mediated anti-glioblastoma therapy: A head-to-head comparison

Exosomes (Exos) are promising vehicles for brain drug delivery due to nanosize and the ability to breach the blood-brain barrier (BBB). But the low yield of natural exosomes limits its application for nanomedicine. The generation of bioinspired nanovesicles (BNVs) that mimicking Exos is attractive, but there is a lack of comparative evaluation of Exos and BNVs. Here, we perform the first head-to-head comparison study of Exos and BNVs for brain tumor drug delivery. We show that BNVs derived from brain-derived endothelial cells are competent alternative nanocarrier to natural exosomes. The drug-loading capacity of Exos and BNVs are similar, but the yield of BNVs is substantially higher (500-fold) than Exos. Doxorubicin (DOX)-loaded BNVs (BNV/DOX) and DOX-loaded Exos (Exo/DOX) showed similar pharmacokinetic profiles and prolonged circulation od DOX. Despite inconsistent mechanisms, BNV/DOX can across the BBB, and exhibit suppression effects similar to Exo/DOX on the progress of glioblastoma (GBM) in zebrafish and in vivo subcutaneous and orthotopic xenografts mice models, with minimal systemic toxicity. Findings from this head-to-head comparison study indicate that autologous BNVs is a effective alternative of Exos for brain tumor nanomedicine.

Borneol: a Promising Monoterpenoid in Enhancing Drug Delivery Across Various Physiological Barriers

Incorporation of permeation enhancers is one of the most widely employed approaches for delivering drugs across biological membranes. Permeation enhancers aid in delivering drugs across various physiological barriers such as brain capillary endothelium, stratum corneum, corneal epithelium, and mucosal membranes that pose resistance to the entry of a majority of drugs. Borneol is a natural, plant-derived, lipophilic, volatile, bicyclic monoterpenoid belonging to the class of camphene. It has been used under the names "Bing Pian" or "Long Nao" in Traditional Chinese Medicine for more than 1000 years. Borneol has been incorporated predominantly as an adjuvant in the traditional Chinese formulations of centrally acting drugs to improve drug delivery to the brain. This background knowledge and anecdotal evidence have led to extensive research in establishing borneol as a permeation enhancer across the blood-brain barrier. Alteration in cell membrane lipid structures and modulation of multiple ATP binding cassette transporters as well as tight junction proteins are the major contributing factors to blood-brain barrier opening functions of borneol. Owing to these mechanisms of altering membrane properties, borneol has also shown promising potential to improve drug delivery across other physiological barriers as well. The current review focuses on the role of borneol as a permeation enhancer across the blood-brain barrier, mucosal barriers including nasal and gastrointestinal linings, transdermal, transcorneal, and blood optic nerve barrier.

Protein Nanoparticle-Related Osmotic Pressure Modifies Nonselective Permeability of the Blood-Brain Barrier by Increasing Membrane Fluidity

BACKGROUND

Intracellular tension plays a crucial role in the destruction of the blood-brain barrier (BBB) in response to lesion stimuli. Tight junction structure could be primarily affected by tension activity. In this study, we aimed to determine the effects of extracellular BBB damage on intracellular tension activity, and elucidate the mechanism underlying the effects of intracellular protein nanoparticle-related osmotic pressure on BBB permeability.

METHODS

The intracellular tension for tight junction proteins occludin and ZO1 was evaluated using the fluorescence resonance energy transfer (FRET)-based tension probes and cpstFRET analysis. The changes in mobility ratios of occludin were evaluated via the fluorescence recovery after photobleaching (FRAP) test. The cytoplasmic osmotic pressure (OP) was measured using Osmometer. The count rate of cytoplasmic nanoparticles was detected by Nanosight NS300. The activation of cofilin and stathmin was examined by Western blot analysis. The BBB permeability in vivo was determined via the changes of Evans Blue (EB) injected into SD rats. The tight junction formation was assessed by the measurement of transendothelial electrical resistance (TEER). Intracellular calcium or chloride ions were measured using Fluo-4 AM or MQAE dyes.

RESULTS

BBB lesions were accompanied by changes in occludin/ZO1 tension. Increases in intracellular osmotic pressure were involved in alteration of BBB permeability, possibly through the depolymerization of microfilaments or microtubules and mass production of protein nanoparticles according to the Donnan effect. Recovery of protein nanoparticle-related osmotic pressure could effectively reverse the effects of changes in occludin/ZO1 tension under BBB lesions. Outward tension of intracellular osmotic potential also caused upregulation of membrane fluidity, which promoted nonselective drug influx.

CONCLUSION

Our results suggest a crucial mechanical mechanism underlying BBB lesions, and protein nanoparticle-related osmotic pressure could be a novel therapeutic target for BBB lesion-related brain diseases.

Puerarin Inhibits Ferroptosis and Inflammation of Lung Injury Caused by Sepsis in LPS Induced Lung Epithelial Cells

Background: Ferroptosis is a new type of programmed cell death, which plays an important role in lung injury caused by sepsis. Studies have reported that Puerarin (Pue) can treat lung injury caused by sepsis in children, but whether it plays a role by regulating iron death has not been reported. Methods: LPS induced human alveolar epithelial cell A549 to form a model of lung injury caused by sepsis. MTT detected the effect of Pue on A549 cell viability and the effect of Pue on LPS-induced A549 cell viability. The effects of Pue on LPS-induced inflammatory cytokines TNF-α, IL-8, IL-1β in A549 cells were determined by ELISA assay. The expression level of MDA was detected by TBARS colorimetric quantitative detection kit. GSH kit was used to detect the expression of GSH in cells. The iron kit detected the total iron level and the expression level of ferric divalent ions in the cells. DCFH-DA fluorescent probe was used to detect ROS levels. Western blot was used to detect the expression of ferroptosis-related proteins in cells. Results: Pue alleviated LPS-induced injury and inflammatory response in A549 cells, and Pue reduced the expression of ROS, MDA and GSH in LPS-induced A549 cells. In addition, Pue reduced total iron levels and ferrous ion levels in LPS-induced A549 cells, and decreased the expression of iron ferroptosis-related proteins. Conclusion: Puerarin inhibited ferroptosis and inflammation of lung injury caused by sepsis in children in LPS induced lung epithelial cells.

Effects of Borneol on the Release of Compound Danshen Colon-Specific Osmotic Pump Capsule In Vitro and Pharmacokinetics Study in Beagle Dogs

Borneol can enhance the bioavailability of several other drugs by opening the blood-brain barrier and inhibiting P-glycoprotein (P-gp) efflux. However, whether borneol will impact the bioavailability and the mechanism of compound Danshen colon-specific osmotic pump capsule (CDCOPC) remains unclear. This study aimed to determine the effects of borneol on the in vitro release and in vivo pharmacokinetic characteristics of CDCOPC. Besides, the in vitro release behavior of CDCOPC was further assessed by chromatographic fingerprints. The in vitro release studies showed that borneol followed the zero-order release and hardly impacted the in vitro release of Salvia miltiorrhiza and Panax notoginseng in CDCOPC. Moreover, as revealed from the similarity results of fingerprints, the in vitro release of different components of CDCOPC was almost simultaneous. Compared with the commercially available tablets, the pharmacokinetics studies suggested that both CDCOPCs containing and lacking borneol could significantly prolong the retention time of these effective components; their average relative bioavailability values increased to 448.70% and 350.97%, respectively. Notably, borneol significantly improved the relative bioavailability of some components of CDCOPC, such as salvianolic acid B (SAB), tanshinone IIA (Tan IIA), notoginsenoside R₁ (R₁), ginsenoside Rg₁ (Rg₁), and ginsenoside Re (Re) from CDCOPC, while it slightly impacted ginsenoside Rb₁ (Rb₁) and ginsenoside Rd (Rd). Summarily, borneol is capable of improving the bioavailability of some effective components in CDCOPC, which is critical to design with CDCOPC for enhanced bioavailability. This study could also help reveal the composition principle of the compound Danshen formula (CDF).

Engineering EHD1-Targeted Natural Borneol Nanoemulsion Potentiates Therapeutic Efficacy of Gefitinib against Nonsmall Lung Cancer

Despite the effective targeting of the epidermal growth factor receptor (EGFR), the use of gefitinib (GFT) for nonsmall cell lung cancer (NSCLC) treatment meets a failure because of the insufficient drug accumulation in the tumor region. Therefore, developing chemosensitizers of GFT with synergistic therapeutic effects is urgently needed for advanced cancer therapy. Herein, a natural chemosensitizer, natural borneol (NB), is reformulated as an oil-in-water nanoemulsion to enhance its solubility, distribution, and to ultimately increase the therapeutic index with GFT. The nanolization of NB (NBNPs) displays stronger targeted delivery and cytotoxicity than NB by selectively identifying eight specific protein targets in A549 NSCLC cells as revealed by the proteomic studies. Consistently, NBNPs realize stronger chemosensitization effects than NB with GFT by effectively regulating EGFR/EHD1-mediated apoptosis in A549 NSCLC cells. Owing to the satisfying synergistic effect between NBNPs and GFT, the combined therapy not only enhances the anticancer ability of GFT against NSCLC proliferation but also avoids heavy double toxicity in vivo. This finding demonstrates the effective synergism between NBNPs and GFT with clear mechanistic investigation and is expected to extend the application of NBNPs as a novel chemosensitizer for advanced cancer chemotherapy.

A Novel Co-Crystal of Bexarotene and Ligustrazine Improves Pharmacokinetics and Tissue Distribution of Bexarotene in SD Rats

Bexarotene (BEX), a specific retinoic acid X receptor (RXR) agonist granted by Food and Drug Administration (FDA) approval for the clinical treatment of T cell lymphoma, has now been found to exert pharmacological effects in the nervous system, with low bioavailability and poor cerebral distribution limiting its application in treatment on neurological disorders. Pharmaceutical co-crystal was a helpful method to improve the bioavailability and tissue distribution of active pharmaceutical ingredients (APIs). Here, 2bexarotene-ligustrazine (2BEX-LIG), a novel co-crystal system of BEX and ligustrazine (LIG) of which with BEX is an API, was constructed with satisfactory stability and enhanced solubility. The pharmacokinetics characteristics of BEX were detected, and the results showed that the absolute bioavailability and the cerebral concentration of BEX in rats administrated with 2BEX-LIG were enhanced from 22.89% to 42.86% and increased by 3.4-fold, respectively, compared with those in rats administrated an equivalent of BEX. Hence, our present study indicated that the novel co-crystal of 2BEX-LIG contributed to improving BEX oral bioavailability and cerebral distribution, thereby providing significant advantages for clinical application of brain tumors and other neurological diseases.

Preparation, Characterization and in vivo Study of Borneol-Baicalin-Liposomes for Treatment of Cerebral Ischemia-Reperfusion Injury

Purpose

Baicalin (BA) has a good neuroprotective effect, but it is eliminated quickly in the body and does not easily reach the brain. In this experiment, borneol (BO) was used as an auxiliary drug to prepare borneol-baicalin-liposomes (BO-BA-LP) to prolong the efficacy time of BA, synergistically synergize, introduce drugs into the brain, and better exert the therapeutic effect on cerebral ischemia-reperfusion (I/R) injury.

Methods

Through single-factor inspection and response surface optimization analysis, obtained the best preparation process of BO-BA-LP and characterized by various analytical techniques. Validated the long-term effectiveness of BA-BO-LP through pharmacokinetic studies and conducted pharmacodynamic studies on the middle cerebral artery occlusion (MCAO) rat model to verify the therapeutic effect of BO-BA-LP on cerebral I/R injury.

Results

The optimum preparation conditions of BO-BA-LP were as follows: the dosage of BO was 9.55 mg, the ratio of phospholipid to drug was 4.02:1, the ratio of phospholipid to cholesterol was 7.25:1, the entrapment efficiency (EE) was 41.49%, and the drug loading (DL) was 4.29%. The particle size range of the liposomes was 167.1 nm, and the polydispersity index (PDI) range was 0.113. The results of pharmacokinetic experiments showed that the combination of BA and BO liposomes effectively improved the pharmacokinetic parameters of BA and prolonged the half-life of BA. Pharmacodynamic studies have found that, compared with BA-LP, BO-BA-LP can significantly improve neurological deficits, cerebral infarction volume, and brain pathological states on MCAO rats.

Conclusion

These results demonstrated that BO-BA-LP can improve the circulation of drugs in the blood, and the addition of BO can enhance the therapeutic effect of BA and effectively improve cerebral I/R.

Nanoparticle Drug Delivery System for Glioma and Its Efficacy Improvement Strategies: A Comprehensive Review

Gliomas are the most common tumor of the central nervous system. However, the presence of the brain barrier blocks the effective delivery of drugs and leads to the treatment failure of various drugs. The development of a nanoparticle drug delivery system (NDDS) can solve this problem. In this review, we summarized the brain barrier (including blood-brain barrier (BBB), blood-brain tumor barriers (BBTB), brain-cerebrospinal fluid barrier (BCB), and nose-to-brain barrier), NDDS of glioma (such as passive targeting systems, active targeting systems, and environmental responsive targeting systems), and NDDS efficacy improvement strategies and deficiencies. The research prospect of drug-targeted delivery systems for glioma is also discussed.

Ginkgo biloba extract improves brain uptake of ginsenosides by increasing blood-brain barrier permeability via activating A1 adenosine receptor signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba leaves and Panax ginseng are Chinese medicine commonly used in combination for cerebral disease.

AIM OF THE STUDY

To investigate the effect of standard extract of Ginkgo biloba leaves (EGb) on facilitating brain uptake of ginsenoside and its underlying mechanisms.

MATERIALS AND METHODS

The increasing uptake of ginsenosides in the brain of rats by EGb were detected by LC-MS/MS analysis. Evans blue and FITC-dextran leakage were determined to evaluate blood-brain barrier (BBB) permeability in vivo. Transendothelial electrical resistance (TEER) and Na-F penetration rate were measured with a co-culture of the human cerebral microvascular endothelial cell line (hCMEC/D3) and human normal glial cell line (HEB) in vitro BBB model. WB were used to analyzed the expression of BBB tight junctions (TJs) related protein (ZO-1, Occludin, Claudin-3, p-ERM, and p-MLC), ultrastructure of TJs was determined by transmission electron microscope.

RESULTS

LC-MS/MS analysis demonstrated that EGb could improve brain uptake of ginsenoside Rg1, Re, Rd and Rb1. In vivo study showed that, BBB permeability was significantly increased after EGb administration, evidenced by the markedly increased penetration of FITC-dextran and Evans Blue into the mice brain parenchyma. In the in vitro BBB model, reduced TEER and increased Na-F penetration rate was observed in EGb group, which was associated with alteration of TJs ultrastructure. Furthermore, the expression of p-ERM and p-MLC in hCMEC/D3 as well as mice brain microvessels were significantly upregulated, but no significant change on the expression of TJs proteins (ZO-1, Occludin and Claudin-3). Moreover, the effect of EGb on in vitro BBB permeability and ERM, MLC phosphorylation was counteracted by DPCPX, an A1 adenosine receptor (A1R) antagonist.

CONCLUSIONS

EGb might induce ERM/MLC phosphorylation and increase the cell-cell junction gaps to cause a reversible increase of the BBB permeability via A1R signaling pathway. Our results may contribute to better use of EGb in the treatment of brain diseases.

Increased microneedle-mediated transdermal delivery of tetramethylpyrazine to the brain, combined with borneol and iontophoresis, for MCAO prevention

The aim of this research was to improve transdermal delivery and distribution of tetramethylpyrazine (TMP) in the brain, by adding borneol (BN) and iontophoresis (ITP), and using microneedles (MN), to prevent middle cerebral artery occlusion (MCAO). BN was encapsulated into sulfobutylated-β-cyclodextrin (BN-SBE-β-CD), and then dispersed together with TMP. Four delivery groups were tested: passive (with no ITP and MN), ITP, MN, and MN combined with ITP (MN-ITP). In vitro transdermal fluxes of the drugs in those groups and in that corresponding order were 79.12 ± 14.5, 395.43 ± 12.37, 319.16 ± 29.99, and 1018.07 ± 108.92 μg/cm² (for TMP), and 39.34 ± 1.31, 202.81 ± 53.56, 715.47 ± 75.52, and 1088.60 ± 53.90 μg/cm² (for BN), respectively, which indicated that the use of MN-ITP greatly enhanced transdermal TMP and BN delivery compared to the other groups. The AUC_0-t for the combined use of TMP and BN drugs was measured using two in vivo studies, cutaneous microdialysis and pharmacodynamic, yielding increased folds of 3.69 and 1.98 in ITP, 6.05 and 2.73 in MN, and 12.43 and 7.47 in MN-ITP groups, respectively, as compared to those in the passive group. In addition, the combined use of TMP and BN increased TMP distribution in the heart and the brain, indicated by TMP C_max of 1.76- and 1.59-fold higher (p < 0.05), and TMP AUC_0-t of 1.50 times and 1.19-fold higher (p < 0.01), than with administration of TMP in absence of BN, respectively. The brain infarction area and IL-β expression in the MCAO rat were significantly decreased in the MN-ITP group, compared with the control group (p < 0.05). In conclusion, combination of MN and ITP resulted in a synergistic enhancement of transdermal delivery and distribution of TMP in the brain, when in combination with BN, thereby significantly decreasing the infarct volumes and improving the neurological scores of MCAO.

Pharmacokinetics and drug delivery systems for puerarin, a bioactive flavone from traditional Chinese medicine

Pueraria lobata (Willd.) Ohwi is a medicinal and edible homologous plant with a long history in China. Puerarin, the main component isolated from the root of Pueraria lobata, possesses a wide range of pharmacological properties. Daidzein and glucuronides are the main metabolites of puerarin and are excreted in the urine and feces. As active substrates of P-gp, multidrug resistance-associated protein and multiple metabolic enzymes, the pharmacokinetics of puerarin can be influenced by different pathological conditions and drug-drug interactions. Due to the poor water-solubility and liposolubility, the applications of puerarin are limited. So far, only puerarin injections and eye drops are on the market. Recent years, researches on improving the bioavailability of puerarin are developing rapidly, various nanotechnologies and preparation technologies including microemulsions and SMEDDS, dendrimers, nanoparticles and nanocrystals have been researched to improve the bioavailability of puerarin. In order to achieve biocompatibility and desired activity, more effective quality evaluations of nanocarriers are required. In this review, we summarize the pharmacokinetics and drug delivery systems of puerarin up to date.

Synergistic protection of tetramethylpyrazine phosphate and borneol on brain microvascular endothelium cells injured by hypoxia

The combination of tetramethylpyrazine phosphate (TMPP) and borneol (BO) protects against cerebral ischemia. However, the mechanism for their synergistic effect is unclear. In this study, an oxygen-glucose deprivation (OGD) injured brain model was induced in microvascular endothelium cells (BMECs). TMPP and BO concentrations were optimized according to an MTT assay. Cells were divided into five groups: control, model, TMPP, BO, and TMPP+BO. Subsequently, oxidative stress was evaluated based on the levels of superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GSH-Px), and reactive oxygen species (ROS). Intracellular calcium ([Ca2+]i) was detected using a laser confocal microscope. Cellular apoptosis was examined via Hoechst 33342 staining, flow cytometry, and expression of p53, B-cell lymphoma 2 (BCL-2), BCL-2-like protein 4 (BAX), and caspase-3 mRNA. Angiogenesis was evaluated based on expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), fibroblast growth factor receptor 1 (FGFR1), Vascular endothelial growth factor receptor 1 (VEGFR1), and VEGFR2. Results showed that 5.0 μM TMPP and 0.5 μM BO were optimal. Monotherapy significantly enhanced CAT, BCL-2, and VEGF, and also reduced [Ca2+]i, apoptosis, and BAX. TMPP increased SOD, GSH-Px, and bFGF, and reduced MDA, ROS, p53, and caspase-3 levels. BO reduced VEGFR1 expression. TMPP+BO combination exhibited synergistic effects in decreasing apoptosis, and modulating expression of BCL-2, BAX, and VEGFR1. These results indicate that protection of OGD-injured BMECs by TMPP+BO combination involves anti-oxidation, apoptosis inhibition, and angiogenesis. Moreover, their synergistic mechanism was mainly related to the regulation of apoptosis and angiogenesis.