Improved blood-brain barrier distribution: effect of borneol on the brain pharmacokinetics of kaempferol in rats by in vivo microdialysis sampling

Kaempferol efficacy in metabolic diseases: Molecular mechanisms of action in diabetes mellitus, obesity, non-alcoholic fatty liver disease, steatohepatitis, and atherosclerosis

The incidence of metabolic diseases has progressively increased, which has a negative impact on human health and life safety globally. Due to the good efficacy and limited side effects, there is growing interest in developing effective drugs to treat metabolic diseases from natural compounds. Kaempferol (KMP), an important flavonoid, exists in many vegetables, fruits, and traditional medicinal plants. Recently, KMP has received widespread attention worldwide due to its good potential in the treatment of metabolic diseases. To promote the basic research and clinical application of KMP, this review provides a timely and comprehensive summary of the pharmacological advances of KMP in the treatment of four metabolic diseases and its potential molecular mechanisms of action, including diabetes mellitus, obesity, non-alcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH), and atherosclerosis. According to the research, KMP shows remarkable therapeutic effects on metabolic diseases by regulating multiple signaling transduction pathways such as NF-κB, Nrf2, AMPK, PI3K/AKT, TLR4, and ER stress. In addition, the most recent literature on KMP's natural source, pharmacokinetics studies, as well as toxicity and safety are also discussed in this review, thus providing a foundation and evidence for further studies to develop novel and effective drugs from natural compounds. Collectively, our manuscript strongly suggested that KMP could be a promising candidate for the treatment of metabolic diseases.

Comprehensive evaluation of Dragon's Blood in combination with borneol in ameliorating ischemic/reperfusion brain injury using RNA sequencing, metabolomics, and 16S rRNA sequencing

Ischemia/reperfusion (IR) can induce deleterious responses such as apoptosis, inflammation, and oxidative stress; however, there are currently no efficient therapeutics to treat IR brain injury. Dragon's blood (DB) plays a significant role in treating ischemic stroke in China. Borneol (B) is an upper ushering drug that guides drugs to the target organs, including the brain. Therefore, we hypothesized that the combination of DB and B (DB + B) would provide cooperative therapeutic benefits for IR brain injury. To confirm this, we first investigated the protective effect of DB + B in an IR brain injury rat model using the modified neurological severity score (mNSS), infarction size measure, HE staining, and laser speckle contrast imaging. Then, we comprehensively evaluated the mechanism of DB + B in ameliorating IR brain injury based on RNA sequencing, serum untargeted metabolomics, and 16S rRNA sequencing. We have confirmed that DB + B enhanced the efficacy of the ischemic stroke treatment compared to DB or B alone for the first time. Our study provisionally confirms that the mechanism by which DB + B prevents IR brain injury is related to the maintenance of intestinal microecological balance and regulation of metabolic dysfunction, thereby suppressing inflammation and regulating immunity. DB + B may effectively regulate intestinal flora including o_Pseudomonadales, s_Bacteroides_caecimuris, o_unidentified_Bacilli, f-Pseudomonadaceae, and g-Pseudomonas, mainly regulate serum metabolites including improve the protective benefit of IR brain injury lysoPCs and lysoPEs, thus inhibiting TLR4/MyD88/NF-κB and IL-17 signing pathway to reduce inflammatory reactions. hat this mechanism is associated with the maintenance of intestinal flora balance and the regulation of metabolic dysfunction, thereby suppressing inflammation and regulating immunity. This provides scientific support for the clinical translation of DB + B in the prevention and treatment of ischemic stroke and establishes a basis for further investigation of its therapeutic mechanism.

An Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) Method for Qualifying DAPB in Rat Plasma and Application to Pharmacokinetic Studies

DAPB, a new molecule including danshensu, borneol, and a mother nucleus of ACEI (Angiotensin-converting enzyme inhibitors), is being developed as an antihypertensive candidate compound. A rapid, accurate, and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established and validated for the determination of DAPB in rat plasma. Chromatographic separation was performed on an Agilent SB-C18 column after protein precipitation by acetonitrile with a mobile phase consisting of acetonitrile and deionized water with 0.02% formic acid and 5 mM NH4F (v/v) at a flow rate of 0.2 mL/min. Quantification was performed using electrospray positive ionization mass spectrometry in the multiple reaction monitoring (MRM) mode. The method was linear over the range of 2-1000 ng/mL. The intra- and inter-day precision was within 12%, with accuracies less than 7%. Stability was within the acceptable limits under various storage and processing conditions. No apparent matrix effect was detected. The validated method was applied to the pre-clinical pharmacokinetic study of DAPB after oral administration of 30 mg/kg and intravenous administration of 6 mg/kg in rats.

Enhanced Brain Targeting Delivery of Salvianic Acid Using Borneol as a Promoter of Blood/Brain Transport and Regulator of P-gp

BACKGROUND

Borneol can enhance the blood-brain barrier (BBB) permeability of some drugs and suppress the efflux transport of P-glycoprotein (P-gp), which will contribute to the brain delivery of salvianic acid A (SAA).

OBJECTIVE

The study aimed to develop an approach to improve the brain targeting delivery of SAA with the aid of borneol.

MATERIALS AND METHODS

"Borneol" was involved in SAA via esterified prodrug SAA borneol ester (SBE) and combined administration (SAA-borneol, SAA-B). Subsequently, the blood-brain transport of SAA through brain/blood distribution and P-gp regulation via expression and function assay were investigated in rats.

RESULTS

The SBE and SAA-B-treated group received a three-fold brain concentration and longer t1/2 and retention period of active SAA than that of SAA alone (20.18/13.82 min vs. 6.48 min; 18.30/17.42 min vs. 11.46 min). In addition, blood to brain transport of active SAA in SBE was altered in comparison to that of SAA-B, ultimately resulting in a better drug targeting index (9.93 vs. 3.63). Further studies revealed that SBE-induced downregulation of P-gp expression occurred at the later stage of administration (60 min, P < 0.01), but SBE always showed a more powerful drug transport activity across BBB represented by Kp value of rhodamine 123 than SAA-B (30, 60 min, P < 0.05).

CONCLUSION

The comparative results indicate that SBE exhibits prominent efficiency on SAA's targeting delivery through improved blood/brain metabolic properties and sustained inhibitory effect of "borneol" on P-gp efflux. Therefore, prodrug modification can be applied as a more effective approach for brain delivery of SAA.

Therapeutic considerations of bioactive compounds in Alzheimer's disease and Parkinson's disease: Dissecting the molecular pathways

Leading neurodegenerative diseases Alzheimer's disease (AD) and Parkinson's disease (PD) are characterized by the impairment of memory and motor functions, respectively. Despite several breakthroughs, there exists a lack of disease-modifying treatment strategies for these diseases, as the available drugs provide symptomatic relief and bring along side effects. Bioactive compounds are reported to bear neuroprotective properties with minimal toxicity, however, a detailed elucidation of their modes of neuroprotection is lacking. The review elucidates the neuroprotective mechanism(s) of some of the major phyto-compounds in pre-clinical and clinical studies of AD and PD to understand their potential in combating these diseases. Curcumin, eugenol, resveratrol, baicalein, sesamol and so on have proved efficient in countering the pathological hallmarks of AD and PD. Curcumin, resveratrol, caffeine and so on have reached the clinical phases of these diseases, while aromadendrin, delphinidin, cyanidin and xanthohumol are yet to be extensively explored in pre-clinical phases. The review highlights the need for extensive investigation of these compounds in the clinical stages of these diseases so as to utilize their disease-modifying abilities in the real field of treatment. Moreover, poor pharmacokinetic properties of natural compounds are constraints to their therapeutic yields and this review suggests a plausible contribution of nanotechnology in overcoming these limitations.

Transporter modulation of molnupiravir and its metabolite β-D-N4-hydroxycytidine across the blood-brain barrier in a rat

BACKGROUND

The antiviral drug molnupiravir is an orally bioavailable prodrug of the nucleoside analog β-D-N4-hydroxycytidine (NHC), which is used to treat coronavirus disease 2019 (COVID-19). However, there is very little information on the barrier distribution of molnupiravir. Our hypothesis is that molnupiravir and NHC can penetrate the blood‒brain barrier (BBB) into brain tissue and that nucleoside transporters (equilibrative nucleoside transporters; ENT and concentrative nucleoside transporters; CNT) can modulate this process.

METHODS

To investigate the mechanism of molnupiravir transport through the BBB, multiple microdialyses coupled to a validated ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC‒MS/MS) was developed to monitor dialysates, and nitrobenzylthioinosine (NBMPR; an inhibitor of ENT) was administered concomitantly with molnupiravir (100 mg/kg, i.v.) in the male rat.

RESULTS

Here, we show that molnupiravir is rapidly metabolized to NHC in the blood and crossed the BBB in 20 min. Furthermore, when NBMPR is concomitantly administered to inhibit efflux, the concentrations of molnupiravir and NHC in the brain increased significantly.

CONCLUSIONS

In summary, molnupiravir rapidly transforms into NHC and crosses the BBB and reaches the brain at approximately 0.3-0.8% of the blood‒brain ratio. The maximum concentration of NHC in the blood and brain is above the average half maximal inhibitory concentration (IC50) of the drug required to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, suggesting a therapeutic effect. The penetration of NHC is modulated by NBMPR. These findings provide constructive information on brain disorders in clinical patients with COVID-19.

Phase Inversion-Based Doxycycline Hyclate-Incorporated Borneol In Situ Gel for Periodontitis Treatment

Borneol has been successfully employed as a gelling agent for in situ forming gel (ISG). While 40% borneol can regulate drug release, there is interest in novel approaches to achieve extended drug release, particularly through the incorporation of hydrophobic substances. Herein, triacetin was selected as a hydrophobic additive solvent for doxycycline hyclate (Dox)-loaded 40% borneol-based ISGs in N-methyl-2-pyrrolidone (NMP) or dimethyl sulfoxide (DMSO), which were subsequently evaluated in terms of their physicochemical properties, gel formation morphology, water sensitivity, drug release, and antimicrobial activities. ISG density and viscosity gradually decreased with the triacetin proportion to a viscosity of <12 cPs and slightly influenced the surface tension (33.14-44.33 mN/m). The low expelled force values (1.59-2.39 N) indicated the convenience of injection. All of the prepared ISGs exhibited favorable wettability and plastic deformation. Higher gel firmness from ISG prepared using NMP as a solvent contributed to the ability of more efficient controlled drug release. High triacetin (25%)-loaded ISG retarded solvent diffusion and gel formation, but diminished gel firmness and water sensitivity. ISG containing 5% triacetin efficiently prolonged Dox release up to 10 days with Fickian diffusion and presented effective antimicrobial activities against periodontitis pathogens such as Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Therefore, the Dox-loaded 40% borneol-based ISG with 5% triacetin is a potential effective local ISG for periodontitis treatment.

Chemical Synthesis, Safety and Efficacy of Antihypertensive Candidate Drug 221s (2,9)

Hypertension is the main risk factor of cardiovascular and cerebrovascular diseases. In this paper, a novel compound known as 221s (2,9), which includes tanshinol, borneol and a mother nucleus of ACEI, was synthesized by condensation esterification, deprotection, amidation, deprotection, and amidation, with borneol as the initial raw material, using the strategy of combinatorial molecular chemistry. The structure of the compound was confirmed by ¹H NMR, ¹³C NMR, and high-resolution mass spectrometry, with a purity of more than 99.5%. The compound 221s (2,9) can significantly reduce the systolic and diastolic blood pressure of SHR rats by about 50 mmHg and 35 mmHg after 4 weeks of administration. The antihypertensive effect of 221s (2,9) is equivalent to that of captopril. The use of 221s (2,9) can reduce the content of Ren, Ang II and ACE in the serum of SHR rats, inhibit the RAAS and enhance the vascular endothelial function by upregulating the level of NO. Pathological studies in this area have shown that high dosage of 221s (2,9) can notably protect myocardial fibrosis in rats and reduce the degeneration and necrosis of myocardial fibers, inflammatory cell infiltration, and proliferation of fibrous tissue in the heart of rat. Therefore, the existing work provided a foundation for preclinical research and follow-up clinical research of 221s (2,9) as a new drug.

Lincomycin HCl-Loaded Borneol-Based In Situ Gel for Periodontitis Treatment

Solvent exchange-induced in situ forming gel (ISG) has emerged as a versatile drug delivery system, particularly for periodontal pocket applications. In this study, we developed lincomycin HCl-loaded ISGs using a 40% borneol-based matrix and N-methyl pyrrolidone (NMP) as a solvent. The physicochemical properties and antimicrobial activities of the ISGs were evaluated. The prepared ISGs exhibited low viscosity and reduced surface tension, allowing for easy injection and spreadability. Gel formation increased the contact angle on agarose gel, while higher lincomycin HCl content decreased water tolerance and facilitated phase separation. The drug-loading influenced solvent exchange and matrix formation, resulting in thinner and inhomogeneous borneol matrices with slower gel formation and lower gel hardness. The lincomycin HCl-loaded borneol-based ISGs demonstrated sustained drug release above the minimum inhibitory concentration (MIC) for 8 days, following Fickian diffusion and fitting well with Higuchi's equation. These formulations exhibited dose-dependent inhibition of Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 8739, and Prophyromonas gingivalis ATCC 33277, and the release of NMP effectively inhibited Candida albicans ATCC 10231. Overall, the 7.5% lincomycin HCl-loaded 40% borneol-based ISGs hold promise as localized drug delivery systems for periodontitis treatment.

A Multilevel Study of Eupatorin and Scutellarein as Anti-Amyloid Agents in Alzheimer's Disease

Today, Alzheimer's disease (AD)-the most common neurodegenerative disorder, which affects 50 million people-remains incurable. Several studies suggest that one of the main pathological hallmarks of AD is the accumulation of abnormal amyloid beta (Aβ) aggregates; therefore, many therapeutic approaches focus on anti-Aβ aggregation inhibitors. Taking into consideration that plant-derived secondary metabolites seem to have neuroprotective effects, we attempted to assess the effects of two flavones-eupatorin and scutellarein-on the amyloidogenesis of Aβ peptides. Biophysical experimental methods were employed to inspect the aggregation process of Aβ after its incubation with each natural product, while we monitored their interactions with the oligomerized Aβ through molecular dynamics simulations. More importantly, we validated our in vitro and in silico results in a multicellular organismal model-namely, Caenorhabditis elegans-and we concluded that eupatorin is indeed able to delay the amyloidogenesis of Aβ peptides in a concentration-dependent manner. Finally, we propose that further investigation could lead to the exploitation of eupatorin or its analogues as potential drug candidates.

Natural borneol serves as an adjuvant agent to promote the cellular uptake of piperlongumine for improving its antiglioma efficacy

Piperlongumine (PL) can selectively inhibit the proliferation of various cancer cells by increasing reactive oxygen species (ROS) level to cause a redox imbalance in cancer cells rather than in normal cells. However, the clinical application of PL is limited by its poor cellular uptake. Natural borneol (NB) is extracted from the fresh branches and leaves of Cinnamomum camphora (L.) Presl. with the purity of (+)-borneol no less than 96.0%. NB has been often used as an adjuvant agent to promote the cellular uptake of other drugs. This study aims to investigate the effect of NB on the cellular uptake of PL for improving its antiglioma efficacy and underlying mechanism. NB obviously promoted the cellular uptake of PL with a 1.3-fold increase in the maximum peak concentration and an earlier peak time of 30 min in C6 glioma cells. The cellular uptake of PL was enhanced by NB through down-regulating the expression levels of P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2). The combination of NB and PL significantly induced higher levels of ROS, which increased apoptosis and enhanced G2/M cycle arrest of C6 glioma cells, compared to PL alone administration. NB-enhanced antiglioma efficacy of PL without side effects was confirmed in tumor-bearing mice, which was attributed to the improved cellular uptake of PL. The distribution of PL in the tumor tissue of combined group increased 2.39 times than that of PL-treated group. We firstly report NB as an adjuvant agent to improve the antiglioma efficacy of PL in a ROS-dependent manner, which is due to the enhanced cellular uptake of PL by NB though down-regulating the expression levels of ABCB1 and ABCG2. This work provides a new strategy to promote the cellular uptake of PL with great potential for the treatment of glioma.

Chemical Variation and Environmental Influence on Essential Oil of Cinnamomum camphora

Cinnamomum camphora is a traditional aromatic plant used to produce linalool and borneol flavors in southern China; however, its leaves also contain many other unutilized essential oils. Herein, we report geographic relationships for the yield and compositional diversity of C. camphora essential oils. The essential oils of 974 individual trees from 35 populations in 13 provinces were extracted by hydrodistillation and analyzed qualitatively and quantitatively by gas chromatography-mass spectrometry and gas chromatography-flame ionization detection, respectively. Oil yields ranged from 0.01% to 3.46%, with a significantly positive correlation with latitude and a significantly negative correlation with longitude. In total, 41 compounds were identified, including 15 monoterpenoids, 24 sesquiterpenoids, and two phenylpropanoids. Essential oil compositions varied significantly among individuals and could be categorized into various chemotypes. The six main chemotypes were eucalyptol, nerolidol, camphor, linalool, selina, and mixed types. The other 17 individual plants were chemotypically rare and exhibited high levels of methyl isoeugenol, methyl eugenol, δ-selinene, or borneol. Eucalyptol-type plants had the highest average oil yield of 1.64%, followed in decreasing order by linalool-, camphor-, mixed-, selina-, and nerolidol-type plants. In addition, the five main compounds exhibited a clear geographic gradient. Eucalyptol and linalool showed a significantly positive correlation with latitude, while selina-6-en-4-ol was significantly and negatively correlated with latitude. trans-Nerolidol and selina-6-en-4-ol showed significantly positive correlations with longitude, whereas camphor was significantly and negatively correlated with longitude. Canonical correspondence analysis indicated that environmental factors could strong effect the oil yield and essential oil profile of C. camphora.

TRP channels and monoterpenes: Past and current leads on analgesic properties

The activation of the transient receptor potential (TRP) channels expressed by sensory neurons is essential to the transduction of thermal and mechanical sensory information. In the setting of chronic inflammatory conditions, the activation of the melastatin family member 8 (TRPM8), the TRP vanilloid 1 (TRPV1), and the TRP ankyrin 1 (TRPA1) is correlated with pain hypersensitivity reactions. Monoterpenes, among which pulegone and menthol, a major class of phytocompounds present in essential oils of medicinal plants, are known modulators of those TRP channels activity. In the present review, we correlate the monoterpene content of plants with their historical therapeutic properties. We then describe how monoterpenes exert their anti-inflammatory and antihyperalgesia effects through modulation of TRP channels activity. Finally, we discuss the importance and the potential of characterizing new plant extracts and reassessing studied plant extracts for the development of ethnopharmacology-based innovative treatments for chronic pain. This review suggests that monoterpene solutions, based on composition from traditional healing herbs, offer an interesting avenue for the development of new phytotherapeutic treatments to alleviate chronic inflammatory pain conditions.

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.

Improvement of pneumonia by curcumin-loaded bionanosystems based on platycodon grandiflorum polysaccharides via calming cytokine storm

Pneumonia can lead to high morbidity and mortality secondary to uncontrolled inflammation of the lung tissue. Blocking cytokine storm storms may be the key to saving the life of patients with severe pneumonia. According to the medicinal guide theory of Traditional Chinese Medicine (TCM) and the inherent affinity with macrophages for the site of inflammation, we constructed the drug delivery platform (MNPs) derived from macrophage-membrane encapsulated reaction oxygen species (ROS)-responsive Platycodon grandiflorum polysaccharides (PGP) nanoparticles (PNPs) to calm the cytokine storm and improve lung inflammation. By loading the anti-inflammatory agent Curcumin (Cur), we demonstrated that MNPs@Cur significantly attenuated inflammation and cytokine storm syndrome in acute lung injury (ALI) mice by suppressing pro-inflammatory factor production and inflammatory cell infiltration. Interestingly, we observed that the PNPs also have potent pulmonary targeting ability compared to other polysaccharide carriers, which is in line with the medicinal guide theory of TCM. Our study revealed the rational design of drug delivery platforms to improve the treatment of lung injury, which inherits and develops the important theories of TCM through the perfect combination of guide theory and biomimetic nanotechnology and provides the experimental scientific basis for the clinical application of channel ushering drugs.

Comparative Review on Effects of Pien Tze Huang and AnGong NiuHuang Pill and their Potential on Treatment of Central Nervous System Diseases

Abstract:

The ancient composite formulae Angong Niuhuang pill and Pien Tze Huang that were used a few hundred years ago to treat febrile disease and inflammation respectively are found to exert effects benefiting other neurological diseases and conditions. This short review introduces the main constituents of the two formulae, looking into both the cumulative synergetic and possible individual effects of each herb or animal apcoien. In essence, the main effects of Angong Niuhuang pill include antiinflammation, antioxidation, anti-cell death, anticonvulsion, antiedema, antipyretic, antithrombotic, antimicrobial (bacteria, viruses, fungi), neuroprotective effects, and cardiovascular protection. The main effects of Pien Tze Huang include antiinflammation, antioxidation, anti-cell death, antithrombotic, antimicrobial, neuroprotective effects, and cardiovascular protection. Comparing both composites, similarities of the effects and part of the components are found, showing some pharmacological evidence. This review casts light on research on the effects of neuroprotective and cardiovascular protective mechanisms as well as treatment mechanisms for cerebral accidents in the integrative medicine perspective.

Amelioration of Alzheimer's disease pathology by mitophagy inducers identified via machine learning and a cross-species workflow

A reduced removal of dysfunctional mitochondria is common to aging and age-related neurodegenerative pathologies such as Alzheimer’s disease (AD). Strategies for treating such impaired mitophagy would benefit from the identification of mitophagy modulators. Here we report the combined use of unsupervised machine learning (involving vector representations of molecular structures, pharmacophore fingerprinting and conformer fingerprinting) and a cross-species approach for the screening and experimental validation of new mitophagy-inducing compounds. From a library of naturally occurring compounds, the workflow allowed us to identify 18 small molecules, and among them two potent mitophagy inducers (Kaempferol and Rhapontigenin). In nematode and rodent models of AD, we show that both mitophagy inducers increased the survival and functionality of glutamatergic and cholinergic neurons, abrogated amyloid-β and tau pathologies, and improved the animals’ memory. Our findings suggest the existence of a conserved mechanism of memory loss across the AD models, this mechanism being mediated by defective mitophagy. The computational–experimental screening and validation workflow might help uncover potent mitophagy modulators that stimulate neuronal health and brain homeostasis.

Two potent mitophagy inducers, identified and characterized via unsupervised machine learning and a cross-species screening approach, ameliorated the pathology of Alzheimer’s disease in worms and mice.

Borneol enhances the protective effect against cerebral ischemia/reperfusion injury by promoting the access of astragaloside IV and the components of Panax notoginseng saponins into the brain

BACKGROUND

Astragalus and Panax notoginseng are significant traditional Chinese medicines for treating ischemic stroke, with astragaloside IV (AST IV) and Panax notoginseng saponins (PNS) being the major effective compounds, respectively. These compounds can also be used in combination. We have previously shown that AST IV and PNS have an antagonistic effect on cerebral ischemia/reperfusion (I/R) injury, and the combination of these two drugs can elevate this effect; unfortunately, AST IV and PNS cannot easily enter the brain tissues through the blood brain barrier (BBB). Previous studies have confirmed that the combination of borneol with other agents could promote the penetration of the drug components through the BBB. However, it remains unclear whether borneol can promote entry of the active components of AST IV and PNS into the brain tissues and enhance their effect against cerebral ischemia.

OBJECTIVE

This study aimed to investigate the effects of a combination of borneol with AST IV and PNS against I/R injury and explore the mechanisms of borneol-promoting penetration of drug components into the BBB based on the drug transport of brain tissues.

METHODS

A rat model of focal cerebral I/R injury was established, and drugs, including borneol, AST IV, and PNS, as well as their combinations were intragastrically administered. Subsequently, drug efficacy was assessed, and the condition of AST IV and PNS active components (Rg1, Rb1, R1) delivered into the brain was analyzed. Moreover, BBB permeability was determined, and the expression of related drug transporters and their genes were evaluated.

RESULTS

After treatment with borneol, AST IV, PNS, AST Ⅳ+PNS, and borneol+AST Ⅳ+PNS after cerebral I/R, the neurological function deficit scores, cerebral infarct rate, and brain water content markedly decreased. The effects of the three-drug-combination were better than those of the drugs used alone and those of AST Ⅳ+PNS. Moreover, after I/R in rats, AST IV and the components of PNS (Rg1, Rb1, R1) were mainly found in the cerebral cortex and in the cerebellum, respectively, when used alone. Borneol combined with AST IV and PNS increased the contents of AST IV, Rb1, Rg1, and R1 in the cerebral cortex and in the cerebellum, thus, promoting the enrichment of active components to the cerebral cortex, especially to the affected side. In addition, following I/R, diffuse distribution of lanthanum particles in the basement membrane, intercellular and intracellular locations of rat brain tissues indicated BBB destruction and increase in permeability, which were alleviated in each drug group. The effects of borneol combined with AST IV and PNS were stronger than those of the drug single-used and those of the AST IV+PNS group. Finally, the expression of effluent transporters (ET) and their genes, including P-glycoprotein (P-gp), multidrug resistance protein (MRP)-1, MRP-2, MRP-4, and MRP-5 in brain tissues, strikingly increased after I/R. Borneol remarkedly down-regulated the protein expression of P-gp, MRP-2, and MRP-4 in the brain, whereas PNS down-regulated MRP-4 and MRP-5 protein expression. AST IV, AST IV+PNS, and bornoel+AST IV+PNS effectively decreased the expression of P-gp, MRP-2, MRP-4, and MRP-5 proteins. The effects of the three-drug combination were significantly greater than those of the drug single-used and AST IV+PNS groups. The expression of each ET gene manifested corresponding results. Meanwhile, PNS, AST IV+PNS, and bornoel+AST IV+PNS significantly inhibited the down-regulation of the uptake transporter organic anion transporting polypeptide (OATP)-2 expression, and the effect of bornoel+AST IV+PNS was stronger than that of other groups.

CONCLUSION

After I/R, the brain tissues were injured, BBB permeability increased, expression of critical ET and their genes were markedly up-regulated, and the main uptake transporters were down-regulated. We propose that the combination of borneol, AST IV and PNS could enhance the effect against cerebral I/R injury and protect BBB integrity. The potential mechanism might be the delivery of AST IV and active components of PNS to the brain tissues after treatment in combination with borneol, which could be effectively promoted by down-regulating the expression of ETs and up-regulating the expression of uptake transporters in the brain tissues. This study was the first to demonstrate that borneol combined with AST IV+PNS enhanced the effect against cerebral I/R injury through promoting the entry of AST and PNS active components to the brain tissues. Thus, this study proposes an instructive role in developing effective active ingredients combination of Chinese medicine with clear ingredients and synergistic effects in terms of the characteristic of borneol.

Anti-Hyperalgesic Properties of Menthol and Pulegone

Context: Menthol, the main monoterpene found in Mentha piperita L. (M. piperita) is known to modulate nociceptive threshold and is present in different curative preparations that reduce sensory hypersensitivities in pain conditions. While for pulegone, a menthol-like monoterpene, only a limited number of studies focus on its putative analgesic effects, pulegone is the most abundant monoterpene present in Calamintha nepeta (L.) Savi (C. nepeta), a plant of the Lamiaceae family used in traditional medicine to alleviate rheumatic disorders, which counts amongst chronic inflammatory diseases.

Objectives: Here, we analyzed the monoterpenes composition of C. nepeta and M. piperita. We then compared the putative anti-hyperalgesic effects of the main monoterpenes found, menthol and pulegone, in acute inflammatory pain conditions.

Methods:C. nepeta and M. piperita extracts were obtained through pressurized liquid extraction and analyzed by gas chromatography-mass spectrometry. The in vitro anti-inflammatory activity of menthol or pulegone was evaluated by measuring the secretion of the tumour necrosis factor alpha (TNF α) from LPS-stimulated THP-1 cells. The in vivo anti-hyperalgesic effects of menthol and pulegone were tested on a rat inflammatory pain model.

Results: Pulegone and menthol are the most abundant monoterpene found in C. nepeta (49.41%) and M. piperita (42.85%) extracts, respectively. In vitro, both pulegone and menthol act as strong anti-inflammatory molecules, with EC50 values of 1.2 ± 0.2 and 1.5 ± 0.1 mM, respectively, and exert cytotoxicity with EC50 values of 6.6 ± 0.3 and 3.5 ± 0.2 mM, respectively. In vivo, 100 mg/kg pulegone exerts a transient anti-hyperalgesic effect on both mechanical (pulegone: 274.25 ± 68.89 g, n = 8; vehicle: 160.88 ± 35.17 g, n = 8, p < 0.0001), thermal heat (pulegone: 4.09 ± 0.62 s, n = 8; vehicle: 2.25 ± 0.34 s, n = 8, p < 0.0001), and cold (pulegone: 2.25 ± 1.28 score, n = 8; vehicle: 4.75 ± 1.04 score, n = 8, p = 0.0003). In a similar way, 100 mg/kg menthol exerts a transient anti-hyperalgesic effect on both mechanical (mechanical: menthol: 281.63 ± 45.52 g, n = 8; vehicle: 166.25 ± 35.4 g, n = 8, p < 0.0001) and thermal heat (menthol: 3.65 ± 0.88 s, n = 8; vehicle: 2.19 ± 0.26 s, n = 8, <0.0001).

Conclusion: Here, we show that both pulegone and menthol are anti-inflammatory and anti-hyperalgesic monoterpenes. These results might open the path towards new compound mixes to alleviate the pain sensation.

Progress in Borneol Intervention for Ischemic Stroke: A Systematic Review

Background: Borneol is a terpene and bicyclic organic compound that can be extracted from plants or chemically synthesized. As an important component of proprietary Chinese medicine for the treatment of stroke, its neuroprotective effects have been confirmed in many experiments. Unfortunately, there is no systematic review of these studies. This study aimed to systematically examine the neuroprotective effects of borneol in the cascade reaction of experimental ischemic stroke at different periods. Methods: Articles on animal experiments and cell-based research on the actions of borneol against ischemic stroke in the past 20°years were collected from Google Scholar, Web of Science, PubMed, ScienceDirect, China National Knowledge Infrastructure (CNKI), and other biomedical databases. Meta-analysis was performed on key indicators in vivo experiments. After sorting the articles, we focused on the neuroprotective effects and mechanism of action of borneol at different stages of cerebral ischemia. Results: Borneol is effective in the prevention and treatment of nerve injury in ischemic stroke. Its mechanisms of action include improvement of cerebral blood flow, inhibition of neuronal excitotoxicity, blocking of Ca²⁺ overload, and resistance to reactive oxygen species injury in the acute ischemic stage. In the subacute ischemic stage, borneol may antagonize blood-brain barrier injury, intervene in inflammatory reactions, and prevent neuron excessive death. In the late stage, borneol promotes neurogenesis and angiogenesis in the treatment of ischemic stroke. Conclusion: Borneol prevents neuronal injury after cerebral ischemia via multiple action mechanisms, and it can mobilize endogenous nutritional factors to hasten repair and regeneration of brain tissue. Because the neuroprotective effects of borneol are mediated by various therapeutic factors, deficiency caused by a single-target drug is avoided. Besides, borneol promotes other drugs to pass through the blood-brain barrier to exert synergistic therapeutic effects.

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.

Borneol in cardio-cerebrovascular diseases: Pharmacological actions, mechanisms, and therapeutics

With the coming acceleration of global population aging, the incidence rate of cardio-cerebrovascular diseases (CVDs) is increasing. It has become the leading cause of human mortality. As a natural drug, borneol (BO) not only has anti-inflammatory, anti-oxidant, anti-apoptotic, anti-coagulant activities and improves energy metabolism but can also promote drugs to enter the target organs or tissues through various physiological barriers, such as the blood-brain barrier (BBB), mucous membrane, skin. Thus, it has a significant therapeutic effect on various CVDs, which has been confirmed in a large number of studies. However, the pharmacological actions and mechanisms of BO on CVDs have not been fully investigated. Hence, this review summarizes the pharmacological actions and possible mechanisms of BO, which provides novel ideas for the treatment of CVDs.

Role of natural plant products against Alzheimer's disease

Alzheimer's disease (AD) is one of the major neurodegenerative disorder. Deposition of amyloid fibrils and tau protein are associated with various pathological symptoms. Currently limited medication is available for AD treatment. Most of the drugs are basically cholinesterase inhibitors and associated with various side effects. Natural plant products have shown potential as a therapeutic agent for the treatment of AD symptoms. Variety of secondary metabolites like flavonoids, tannins, terpenoids, alkaloids and phenols are used to reduce the progression of the disease. Plant products have less or no side effect and are easily available. The present review gives a detailed account of the potential of natural plant products against the AD symptoms.

The effects of borneol on the pharmacokinetics and brain distribution of tanshinone IIA, salvianolic acid B and ginsenoside Rg1 in Fufang Danshen preparation in rats

Fufang Danshen preparation (FDP) is consisted of Salviae Miltiorrhizar Radix et Rhizoma (Danshen), Notoginseng Radix et Rhizoma (Sanqi) and Borneolum Syntheticum (borneol). FDP is usually used to treat myocardial ischemia hypoxia, cerebral ischemia and alzheimer's disease, etc. In the treatment of cerebrovascular diseases, borneol is usually used to promote the absorption and distribution of the bioactive components to proper organs, especially to the brain. The purpose of this study is investigating the effects of borneol on the pharmacokinetics and brain distribution of tanshinone IIA (TS IIA), salvianolic acid B (SAB) and ginsenoside Rg1 in FDP. Male healthy Sprague-Dawley (SD) rats were given Danshen extracts, Sanqi extracts (Panax notoginsengsaponins) or simultaneously administered Danshenextracts, Sanqi extracts and borneol. Plasma and brain samples were collected at different points in time. The concentration of TS IIA, SAB and Rg1 was determined by UPLC-MS/MS method. The main pharmacokinetics parameters of plasma and brain tissue were calculated by using Phoenix WinNolin 6.1 software. In comparison with Danshen and Sanqi alone, there were significant differences in pharmacokinetic parameters of TS IIA, SAB and Rg1, and the brain distribution of SAB and TS IIA when Danshen, Sanqi and borneol were administrated together. Borneol statistically significant shortened t_max of TS IIA, SAB and Rg1 in plasma and brain, increased the bioavaiability of Rg1, inhibited metabolism of Rg1 and enhanced the transport of TS IIA and SAB to brain. These results indicated that borneol could affect the multiple targets components and produce synergistic effects. Through accelerating the intestinal absorption and brain distribution, borneol caused the effective ingredients of Danshen and Sanqi to play a quicker therapeutic role and improved the therapeutic effect.

Simultaneous blood and brain microdialysis in a free-moving mouse to test blood-brain barrier permeability of chemicals

Neurotoxic chemicals that pass through the blood-brain barrier (BBB) can influence brain function. Efficient methods to test the permeability of the BBB to specific chemicals would facilitate identification of potentially neurotoxic agents. We report here a simultaneous blood and brain microdialysis in a free-moving mouse to test BBB permeability of different chemicals. Microdialysis sampling was conducted in mice at 3-5 days after implantation of a brain microdialysis probe and 1 day after implantation of a blood microdialysis probe. Therefore, mice were under almost physiological conditions. Results of an intravenous injection of lucifer yellow or uranine showed that the BBB was functioning in the mice under the experimental conditions. Mice were given phenyl arsenic compounds orally, and concentration-time profiles for phenyl arsenic compounds such as diphenylarsinic acid, phenylarsonic acid, and phenylmethylarsinic acid in the blood and brain dialysate samples were obtained using simultaneous blood and brain microdialysis coupled with liquid chromatography-tandem mass spectrometry. Peak area-time profiles for linalool and 2-phenethyl alcohol (fragrance compounds or plant-derived volatile organic chemicals) were obtained using simultaneous blood and brain microdialysis coupled with gas chromatography-mass spectrometry in mice given lavender or rose essential oils intraperitoneally. BBB function was confirmed using lucifer yellow in these mice, and results indicated that the phenyl arsenic compounds, linalool and 2-phenethyl alcohol, passed through the BBB. The present study demonstrates that simultaneous blood and brain microdialysis in a free-moving mouse makes it possible to test the BBB permeability of chemicals when coupled with appropriate chemical analysis methods.

Compound Danshen Dripping Pill Promotes Adaptation to Acute High-Altitude Exposure

Li, Zongbin, Jun Guo, Chunwei Liu, Yajun Shi, Yang Li, Jinli Wang, Dandan Li, Jing Wang, and Yundai Chen. Compound Danshen Dripping Pill promotes adaptation to acute high-altitude exposure. High Alt Med Biol. 21:258-264, 2020. Background: In this study, we aimed to investigate whether the traditional Chinese medicine, Compound Danshen Dripping Pill (CDDP), can prevent acute mountain sickness (AMS). We allocated CDDP and matching placebos to 160 volunteers before they ascended to a high altitude. Treadmill exercise tests, echocardiography, blood routine examinations, biochemical analysis, and blood gas analysis were performed upon arrival at high altitude. The primary outcome included incidence of AMS, exercise times, and metabolic equivalents (METs) of treadmill exercise tests. Second endpoints included the heart rates and rate-pressure product (RPP) before and after treadmill exercise tests. Results: After high-altitude exposure, the incidence of AMS in the CDDP group was lower than that in the placebo group (48.6% vs. 67.6%, p = 0.022). The exercise time of the treadmill exercise test was significantly longer (507 ± 77.9 seconds vs. 457 ± 90.8 seconds, p = 0.004), the heart rate was lower (pre-exercise: 91.8 ± 11.7 beats/min vs. 97.2 ± 12.7 beats/min, p = 0.016; postexercise: 114 ± 22.2 beats/min vs. 121 ± 22.6 beats/min, p = 0.019), the pre-exercise and postexercise RPP were lower (pre-exercise: 1.13 × 10⁴ ± 1.68 × 10³ mmHg·beats/min vs. 1.23 × 10⁴ ± 1.84 × 10³ mmHg·beats/min, p = 0.027; postexercise: 1.19 × 10⁴ ± 1.75 × 10³ mmHg·beats/min vs. 1.31 × 10⁴ ± 2.00 × 10³ mmHg·beats/min, p = 0.002), and the MET value of the treadmill exercise test was significantly higher (9.93 ± 1.18 METs vs. 9.31 ± 1.52 METs, p = 0.037) in the CDDP group. Discussion: CDDP decreases the incidence of AMS and enhances exercise tolerance greater than placebo after high-altitude exposure. CDDP decreases the heart rate and myocardial oxygen consumption, increases the levels of hemoglobin, hematocrit, and antioxidant factors, and decreases the levels of inflammatory factors, which may explain the roles of CDDP in improving the adaptation to high-altitude exposure.

Therapeutic Potential of Volatile Terpenes and Terpenoids from Forests for Inflammatory Diseases

Forest trees are a major source of biogenic volatile organic compounds (BVOCs). Terpenes and terpenoids are known as the main BVOCs of forest aerosols. These compounds have been shown to display a broad range of biological activities in various human disease models, thus implying that forest aerosols containing these compounds may be related to beneficial effects of forest bathing. In this review, we surveyed studies analyzing BVOCs and selected the most abundant 23 terpenes and terpenoids emitted in forested areas of the Northern Hemisphere, which were reported to display anti-inflammatory activities. We categorized anti-inflammatory processes related to the functions of these compounds into six groups and summarized their molecular mechanisms of action. Finally, among the major 23 compounds, we examined the therapeutic potentials of 12 compounds known to be effective against respiratory inflammation, atopic dermatitis, arthritis, and neuroinflammation among various inflammatory diseases. In conclusion, the updated studies support the beneficial effects of forest aerosols and propose their potential use as chemopreventive and therapeutic agents for treating various inflammatory diseases.

Studies of blood-brain barrier permeability of gastrodigenin in vitro and in vivo

According to the basic theories of traditional Chinese medicine, Gastrodia elata (GE) is clinically utilized for the treatment of cephalalgia and migraine. The gastrodigenin (p-hydroxybenzyl alcohol, HBA), one of the effective components of GE, may pass through the blood-brain barrier (BBB) to exert its pharmacological effects. This study aimed to investigate BBB permeability of HBA via in vitro hCMEC/D3 BBB model and in vivo microdialysis in rats. For the establishment of in vitro BBB model, hCMEC/D3 cells were used to construct the monolayer. The integrity of the monolayer was evaluated by TEER measurements, expression analysis of tight junction proteins (claudin-5, zo-1 and occludin) and apparent permeability coefficients (P_app) of fluorescein disodium. During the 6-day incubation of hCMEC/D3 cells, the values of TEER gradually increased and maintained above 100 Ω·cm². Besides, the expression levels of claudin-5 and zo-1 in hCMEC/D3 cells increased over time, and tended to be stable, suggesting that integrity of the monolayer has been completely established. Moreover, the P_app of fluorescein disodium was 3.94 × 10^-7 cm·s^-1 after administration for 180 min, indicating that the monolayer retains the characteristics of BBB and can restrict the diffusion of hydrophilic small-molecule compounds. A sensitive HPLC method was established for HBA detection, and the transport rate of HBA was assessed by a transwell system. HBA crossed the hCMEC/D3 BBB model rapidly, but a plateau was observed when HBA concentrations were relatively similar between the two sides of transwell. Permeability assay revealed that 32.91% of HBA could penetrate the in vitro BBB model after 240 min of administration. In vivo BBB permeability was evaluated by determining the concentrations of HBA in blood and brain simultaneously. Following HBA administration, the samples of microdialysis were collected at 20, 40 and 60 min, and then every 30 min until the procedure ended. Pharmacokinetic parameters of HBA showed that HBA could pass through BBB and reach its maximum concentration at 40 min in blood and brain tissue. Furthermore, AUC_0-t and AUC_0-inf for the brain-to-blood distribution ratio of HBA were 0.1925 and 0.2083, respectively, indicating that approximately 20% of HBA in blood could pass through the BBB and subsequently transported into the brain. Both in vitro and in vivo experiments confirmed that HBA could penetrate the BBB. In summary, the findings of this study highlight that a promising amount of HBA in blood can pass through the BBB and exerts its pharmacological effects on central nervous system (CNS) diseases.

A Nasal Temperature and pH Dual-Responsive In Situ Gel Delivery System Based on Microemulsion of Huperzine A: Formulation, Evaluation, and In Vivo Pharmacokinetic Study

Huperzine A (hup A), extracted from the Chinese medicinal plant Huperzia serrata, is a reversible and highly selective second-generation acetylcholine esterase (AchE) inhibitor for treating Alzheimer's disease (AD), but it suffers from low bioavailability in the brain. This study aimed to develop a nasal temperature and pH dual-responsive in situ gel delivery system based on microemulsion of hup A (hup A-M-TPISG). The optimal formulation was obtained by central composite design and response surface methodology. The optimized mucoadhesive formulation, hup A-M-TPISG, was composed of pluronic F127 (20.80%), pluronic F68 (2.8%), and chitosan (0.88%) as the gel matrix, which could gelatinize under physiological conditions (29-34°C, pH 6.5) because of its temperature and pH responsiveness. The optimized hup A-M-TPISG formulation was further evaluated by in vitro release and in vivo pharmacokinetic studies via microdialysis. The in vitro release study showed continuous and steady drug release from hup A-M-TPISG, which was in accordance with the first-order model. Moreover, the pharmacokinetic results revealed that the optimized formulation for nasal administration, with convenient administration and improved patient compliance, could achieve similar brain-targeting properties as intravenous administration. In conclusion, the hup A-M-TPISG for intranasal administration, as an effective and safe vehicle, could enhance the absorption of hup A in vivo and would be a promising noninvasive alternative for partially improving brain-targeting therapy.

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.

Borneol, a messenger agent, improves central nervous system drug delivery through enhancing blood-brain barrier permeability: a preclinical systematic review and meta-analysis

To achieve sufficient blood–brain barrier (BBB), penetration is one of the biggest challenges in the development of diagnostic and therapeutic for central nervous system (CNS) disorders. Here, we conducted a systematic review and meta-analysis to assess the preclinical evidence and possible mechanisms of borneol for improving co-administration of CNS drug delivery in animal models. The electronic literature search was conducted in six databases. Fifty-eight studies with 63 comparisons involved 1137 animals were included. Among 47 studies reporting the assessments of CNS drug concentration, 45 studies showed the significant effects of borneol for improving CNS drug delivery (p<.05), whereas 2 studies showed no difference (p>.05). Nineteen comparisons showed borneol up-regulated BBB permeability (p<.05) using brain EB content (n = 8), Rh 123 content (n = 4), brain imaging agent content (n = 2), brain water content (n = 1) and observing ultrastructure of BBB (n = 4), whereas three studies showed no difference or unclear results. Seven studies reported the safety, in which one study showed borneol was reversible changes in the BBB penetration; six studies showed borneol did not increase co-administration of blood drugs concentration of peripheral tissues (p > .05). Effects of borneol are closely associated with inhibition of efflux protein function, releasement of tight junction protein, increasement of vasodilatory neurotransmitters, and inhibition of active transport by ion channels. In conclusion, borneol is a promising candidate for CNS drug delivery, mainly through mediating a multi-targeted BBB permeability.

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.

Improving glioblastoma therapeutic outcomes via doxorubicin-loaded nanomicelles modified with borneol

Glioblastoma is a grade IV malignant glioma with high recurrence and metastasis and faces a therapeutic obstacle that the blood-brain barrier (BBB) severely hinders the brain entry and efficacy of therapeutic drugs. Previous studies suggest that borneol (BO) has been used to enhance interested drugs to penetrate the BBB. In this study, a borneol-modified nanomicelle delivery system was established to facilitate the brain entry of doxorubicin for glioblastoma therapy. Herein, we firstly conjugated borneol molecules with DSPE-PEG₂₀₀₀-COOH to synthesize a novel carrier DSPE-PEG₂₀₀₀-BO and also characterized its structure. Doxorubicin-loaded nanomicelles (DOX BO-PMs) were prepared using DSPE-PEG₂₀₀₀-BO via electrostatic interaction and the physicochemical properties were investigated. The average particle size and zeta potential of DOX BO-PMs were respectively (14.95 ± 0.17)nm and (-1.27 ± 0.06)mV, and the drug encapsulation efficiency and loading capacity in DOX BO-PMs were (95.69 ± 0.49)% and (14.62 ± 0.39)%, respectively. The drug release of the DOX BO-PMs exhibited a both time- and pH-dependent pattern. The results demonstrated that DOX BO-PMs significantly enhanced the transport efficiency of DOX across the BBB and also exhibited a quick accumulation in the brain tissues. The in vitro anti-proliferation assay results suggested that DOX BO-PMs exerted a strong inhibitory effect on proliferation of glioblastoma cells. Importantly, in vivo antitumor results demonstrated that DOX BO-PMs significantly inhibited the tumor growth and metastasis of glioblastoma. In conclusion, DOX BO-PMs can improve the glioblastoma therapeutic outcomes and become a promising nanodrug candidate for the application of doxorubicin in the field of glioblastoma therapy.

A critical review on grape polyphenols for neuroprotection: Strategies to enhance bioefficacy

The aging of populations worldwide is driving greater demands for dietary polyphenols which have been recognized as promising prophylactic and/or therapeutic agents in the context of neurodegeneration, and are ubiquitously present in plant-based diets. In particular, grape-derived products encompass a wide array of phenolic compounds purported with multiple health benefits including neuroprotective efficacy. Despite the increasing preclinical and clinical evidence demonstrating high potential of grape polyphenol (GPP)-rich botanicals in preventing and attenuating diverse neurodegenerative disorders, the limited bioavailability of GPPs, especially in the brain, generates questions as to their applications and effectiveness in neuroprotection. To address this issue, significant research efforts have been made to enhance oral bioavailability of GPPs via application of novel strategies. This review highlights some critical issues related to the bioavailability and neuroprotective efficacy of GPPs and GPP-rich botanicals. The representative bioavailability-enhancing strategies are critically reviewed to provide practical solutions for augmenting the bioefficacy of GPP-rich botanicals. Synergistic applications of encapsulation techniques (for physiochemical protection and bypassing xenobiotic metabolism) and dietary intervention strategies involving modulation of gut microbiota (for generating more bioavailable phenolic metabolites) appear promising, and may substantially enhance the bioefficacy, especially the neuroprotective efficacy, of orally consumed GPPs.

Metabolomics Study on the Effects of Salvianolic Acid B and Borneol for Treating Cerebral Ischemia in Rats by Ultra-Performance Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry

Salviae miltiorrliza-borneol Jun-Shi coupled-herbs have been widely used for treatment of ischemia stroke. Salvianolic acid B was the most abundant and bioactive compound of Salviae miltiorrliza and used for prevention and treatment of cerebrovascular diseases. However, the scientific intension and compatible mechanism of Salvianolic acid B - borneol combination were still unknown. A metabolomics study approach based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) combined with a pathological study has been applied to study the metabolic disturbances of cerebral ischemia and evaluate the efficacies of Sal B and Sal B/borneol against cerebral ischemia in middle cerebral artery occlusion (MCAO) rats. The neuroprotection of Sal B and Sal B/borneol was reversed through the evaluation of neurological deficits, infarct volume, and neuronal apoptosis in MCAO model. The metabonomic analysis revealed that the MCAO-induced cerebral ischemia could be ameliorated by Sal B through improving the energy metabolism, lipids metabolism, inflammatory responses, and oxidant stress. Borneol could enhance the neuroprotective effects, was associated with the increased concentration of Sal B, and attenuate the function of sphingolipid metabolism pathway in cerebral ischemia rats. These findings perhaps clarify the mechanism of neuroprotective effects of treating ischemia stroke by Sal B or Sal B/borneol preliminarily through metabolomics and push the quality promotion and the composition of borneol/Sal B in secondary development of prescription.

Metabolite identification of tanshinol borneol ester in rats by high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight mass spectrometry

Tanshinol borneol ester (DBZ) is a potential drug candidate composed of danshensu and borneol. It shows anti-ischemic and anti-atherosclerosis activity. However, little is known about its metabolism in vivo. This research aimed to elucidate the metabolic profile of DBZ through analyzing its metabolites using high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight mass spectrometry. Chromatographic separation was performed on an Agilent TC-C₁₈ column (150 × 4.6 mm, 5.0 μm) with gradient elution using methanol and water containing 0.2% (v/v) formic acid as the mobile phase. Metabolite identification involved analyzing the retention behaviors, changes in molecular weights and MS/MS fragment patterns of DBZ and its metabolites. As a result, 20 potential metabolites were detected and tentatively identified in rat plasma, urine and feces after administration of DBZ. DBZ could be metabolized to O-methylated DBZ, DBZ-O-glucuronide, O-methylated DBZ-O-glucuronide, hydroxylated DBZ and danshensu. Danshensu, a hydrolysis product of DBZ, could further be transformed into 12 metabolites. The proposed method was confirmed to be a reliable and sensitive alternative for characterizing metabolic pathways of DBZ and providing valuable information on its druggability.

Effect of borneol as a penetration enhancer on brain targeting of nanoliposomes: facilitate direct delivery to neurons

Aim: This study is aimed to evaluate borneol as a penetration enhancer to improve brain target of nanoliposome. Materials & methods: Effects of borneol on pharmacokinetics, targeting efficiency, brain subareas distribution and neuron-targeting level and pathway were studied by fluorescence spectrophotometry and immunofluorescence. Results: Borneol did not influence physicochemical property of doxorubicin hydrochloride nanoliposome (Dox-nanoLips). Co-administration of Dox-nanoLips with borneol elevated brain-target efficiency due to selective distribution increase in the cerebral cortex and hippocampus without difference in contralateral hemisphere. Borneol improved neuronal-targeting level of Dox-nanoLips in the cortex, CA3 and dentate gyrus regions via opening tight junctions of blood–brain barrier and then bypassing astrocyte. Conclusion: Borneol is potential to be a promising penetration enhancer for nanocarrier to target neurons.

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.

Suppression of MIF-induced neuronal apoptosis may underlie the therapeutic effects of effective components of Fufang Danshen in the treatment of Alzheimer's disease

Fufang Danshen (FFDS or Compound Danshen) consists of three Chinese herbs Danshen (Salviae miltiorrhizae radix et rhizome), Sanqi (Notoginseng radix et rhizome) and Tianranbingpian (Borneolum, or D-borneol), which has been show to significantly improve the function of the nervous system and brain metabolism. In this study we explored the possible mechanisms underlying the therapeutic effects of the combination of the effective components of FFDS (Tan IIA, NG-R1 and Borneol) in the treatment of Alzheimer's disease (AD) based on network pharmacology. We firstly constructed AD-related FFDS component protein interaction networks, and revealed that macrophage migration inhibitory factor (MIF) might regulate neuronal apoptosis through Bad in the progression of AD. Then we investigated the apoptosis-inducing effects of MIF and the impact of the effective components of FFDS in human neuroblastoma SH-SY5Y cells. We observed the characteristics of a "Pendular state" of MIF, where MIF (8 ng/mL) increased the ratio of p-Bad/Bad by activating Akt and the IKKα/β signaling pathway to assure cell survival, whereas MIF (50 ng/mL) up-regulated the expression of Bad to trigger apoptosis of SH-SY5Y cells. MIF displayed neurotoxicity similar to Aβ_1-42, which was associated with the MIF-induced increased expression of Bad. Application of the FFDS composite solution significantly decreased the expression levels of Bad, suppressed MIF-induced apoptosis in SH-SY5Y cells. In a D-galactose- and AlCl₃-induced AD mouse model, administration of the FFDS composite solution significantly improved the learning and memory, as well as neuronal morphology, and decreased the serum levels of INF-γ. Therefore, the FFDS composite solution exerts neuroprotective effects through down-regulating the level of Bad stimulated by MIF.

Borneol and Luteolin from Chrysanthemum morifolium Regulate Ubiquitin Signal Degradation

Targeting the two degradation systems, ubiquitin proteasome pathway and ubiquitin signal autophagy lysosome system, plays an important function in cancer prevention. Borneol is called an "upper guiding drug". Luteolin has demonstrated anticancer activity. The fact that borneol regulates luteolin can be sufficient to serve as an alternative strategy. Borneol activates luteolin to inhibit E1 and 20S activity (IC₅₀ = 118.8 ± 15.7 μM) and perturb the 26S proteasome structure in vitro. Borneol regulates luteolin to inhibit 26S activity (IC₅₀ = 157 ± 19 μM), induces apoptosis (LC₅₀ = 134 ± 4 μM), and causes pre-G1 and G0/G1 arrest in HepG2 cells. Borneol regulates luteolin to induce ubiquitin signal autophagic degradation, resulting in induction of E1, reduction of USP47, and accumulation of p62 in HepG2 reporter cells. Interestingly, luteolin decreased Ub conjugates, while borneol increased the accumulation of Ub conjugates in HepG2 reporter cells. E1, p62, and ubiquitin levels were downregulated in borneol-treated HepG2 reporter cells at 24 h. These observations suggest a potential autophagic inhibitor of borneol that may guide luteolin in the ubiquitin proteasome pathway and the ubiquitin signal autophagic degradation.

The Role and Mechanism of Borneol to Open the Blood-Brain Barrier

Background: The blood-brain barrier (BBB) is the greatest challenge in the treatment of intracranial malignant tumors. Objective: The aim of this study is to determine the role of borneol in opening the BBB and elucidate the underlying mechanisms. Materials and Methods: Twenty Sprague-Dawley (SD) rats were randomized into borneol group intragastrically administered with 10% borneol corn oil (2 mL/kg) and control group. After 30 minutes, 2% Evans blue (4 mL/kg) was injected. Thirty minutes later, brain tissue was analyzed using the Evans blue standard curve. Another 40 SD rats were randomized into high-, medium-, and low-dose borneol groups and a control group. Each rat in the experimental groups was intragastrically administered with 10% borneol corn oil (2 mL/kg, 1.25 mL/kg, and 0.5 mL/kg, respectively). The control group was injected with corn oil of 1.25 mL/kg. After 30 minutes, the rats were killed, and the brain tissues were collected. The expression of occludin, occludens-1, nitric oxide synthase, P-glycoprotein, and intercellular cell adhesion molecule-1 (ICAM-1) was detected by immunohistochemy. Results: The concentration of Evans blue in the borneol group was higher than in the control group (P < .05). The mean density of ICAM-1 expression was higher in the experimental group than in the control group (P < .05). In contrast, significant differences of positive area and total density of ICAM-1 were shown only between the high-dose group and the control group (P < .05). Conclusion: Borneol can open the BBB, which might be related with the increased expression of ICAM-1.

The protective roles of L-borneolum, D-borneolum and synthetic borneol in cerebral ischaemia via modulation of the neurovascular unit

OBJECTIVE

Borneol has been used to treat stroke in China since ancient times. In our previous research, we demonstrated the effect of borneol on cerebral ischaemia injury via meta-analysis. The neurovascular unit (NVU) is the structural basis of the preservation of the brain microenvironment and is believed to be a promising target in treating stroke. In this research, we explored the roles of three kinds of borneol, namely, L-borneolum (B1), D-borneolum (B2) and synthetic borneol (B3), in the NVU with permanent middle cerebral artery occluded (pMCAO) rats.

METHODS

The Longa scoring method was used to evaluate nerve function deficits in the pMCAO rats. Awakening time, brain water content, brain index and brain edema rate were also measured. TTC staining was used to calculate the cerebral infarction rate. The morphology of the ischaemia penumbra brain tissue was observed via HE staining, and the neuronal denatured cell index (DCI) was calculated. An enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of vascular endothelial growth factor VEGF and TNF-α in the serum. Moreover, the ultrastructures of the neurons and of the blood-brain barrier (BBB) were observed using transmission electron microscopy. The expression levels of Claudin-5, Bcl-2 and Bax in the ischaemia penumbra of pMCAO rats were detected using real-time PCR and immunohistochemistry.

RESULTS

Pretreatment with B1, B2 and B3 delayed the recovery time (P < 0.01). B1 remarkably ameliorated neurological deficits 24 h after cerebral ischaemia (P < 0.05). Moreover, B1 and B3 were both able to ameliorate brain edema and the area of cerebral infarction. In addition, B1, B2 and B3 all increased serum VEGF levels and decreased serum TNF-α levels (P < 0.01). For the ultrastructure determination, the BBB and the nerve centre were significantly improved by B1, B2 and B3. The mechanistic exploration revealed that B2 and B3 protected the brain by reducing the Bax/Bcl-2 ratio (P < 0.05, P < 0.01, respectively). Immunohistochemistry suggested that B1, B2 and B3 could also enhance the expression of Claudin-5 (P < 0.01).

CONCLUSION

The three kinds of borneol demonstrated different protective effects on cerebral ischaemia injury. L-Borneolum displayed the most prominent anti-cerebral ischaemia effect among them. The mechanism was most likely executed via anti-apoptosis and anti-inflammation effects and maintenance of the stability of the BBB and TJs to comprehensively improve NVU function.

Enhanced permeability of blood-brain barrier and targeting function of brain via borneol-modified chemically solid lipid nanoparticle

Introduction

The incidence of central nervous system disease has increased in recent years. However, the transportation of drug is restricted by the blood-brain barrier, contributing to the poor therapeutic effect in the brain. Therefore, the development of a new brain-targeting drug delivery system has become the hotspot of pharmacy.

Materials and methods

Borneol, a simple bicyclic monoterpene extracted from Dryobalanops aromatica, can direct drugs to the upper body parts according to the theory of traditional Chinese medicine. Dioleoyl phosphoethanolamine (DOPE) was chemically modified by borneol as one of the lipid materials of solid lipid nanoparticle (SLN) in the present study.

Results

The borneol-modified chemically solid lipid nanoparticle (BO-SLN/CM), borneol-modified physically solid lipid nanoparticle (BO-SLN/PM), and SLN have similar diameter (of about 87 nm) and morphological characteristics. However, BO-SLN/CM has a lower cytotoxicity, higher cell uptake, and better blood-brain barrier permeability compared with BO-SLN/PM and SLN. BO-SLN/CM has a remarkable targeting function to the brain, while BO-SLN/ PM and SLNs are concentrated at the lung.

Conclusion

The present study provides an excellent drug delivery carrier, BO-SLN/CM, having the application potential of targeting to the brain and permeating to the blood-brain barrier.

In vivo microdialysis with ultra performance liquid chromatography-mass spectrometry for analysis of tetramethylpyrazine and its interaction with borneol in rat brain and blood

Tetramethylpyrazine (TMP) has been widely used in the treatment of ischemic cerebrovascular disease. However, the mechanism of TMP and how to increase its bioavailability need to be further explored. In our study, an in vivo microdialysis sampling technique coupled with ultra-performance liquid chromatography-mass spectrometry method was developed to investigate the pharmacokinetic properties of TMP and its interaction with different doses of borneol (BO) in rats. Linearity of TMP in brain and blood dialysates exhibited good linear relationships over the concentration range of 0.991-555.14 ng/mL. The specificity, linearity, accuracy, precision, matrix effect and stability were within acceptable ranges. The results demonstrated that BO had a marked impact on the pharmacokinetic properties of TMP. After co-administration, the areas under the concentration-time curve (AUC) of TMP in brain and blood were significantly increased. Meanwhile, the peak concentration of TMP in brain was also enhanced. The AUC_Brain /AUC_Blood of TMP, increased from 44% to 56 and 60.8% after co-administration with BO (15 and 30 mg/kg). The pharmacodynamic results showed that TMP co-administration with BO enhanced the cerebral blood flow during the period of ischemia and reduced the infarct volume. Overall, it might be an effective way to treat stroke to use TMP co-administered with BO.