Synergistic amelioration between Ligusticum striatum DC and borneol against cerebral ischemia by promoting astrocytes-mediated neurogenesis

ETHNOPHARMACOLOGICAL RELEVANCE

Ligusticum chuanxiong Hort (LCH), with the accepted name of Ligusticum striatum DC in "The Plant List" database, is a widely used ethnomedicine in treating ischemic stroke, and borneol (BO) is usually prescribed with LCH for better therapy. Our previous study confirmed their synergistic effect on neurogenesis against cerebral ischemia. However, the underlying mechanism is still unclear.

AIM OF THE STUDY

More and more evidence indicated that astrocytes (ACs) might be involved in the modulation of neurogenesis via polarization reaction. The study was designed to explore the synergic mechanism between LCH and BO in promoting astrocyte-mediated neurogenesis.

MATERIALS AND METHODS

After primary cultures and identifications of ACs and neural stem cells (NSCs), the oxygen-glucose deprivation (OGD) model and the concentrations of LCH and BO were optimized. After the OGD-injured ACs were treated by LCH, BO, and their combination, the conditioned mediums were used to culture the OGD-injured NSCs. The proliferation, migration, and differentiation of NSCs were assessed, and the secretions of BDNF, CNTF, and VEGF from ACs were measured. Then the expressions of C3 and PTX3 were detected. Moreover, the mice were performed a global cerebral ischemia/reperfusion model and treated with LCH and (or) BO. After the assessments of Nissl staining, the expressions of Nestin, DCX, GFAP, C3, PTX3, p65 and p-p65 were probed.

RESULTS

The most appropriate duration of OGD for the injury of both NSCs and ACs was 6 h, and the optimized concentrations of LCH and BO were 1.30 μg/mL and 0.03 μg/mL, respectively. The moderate OGD environment induced NSCs proliferation, migration, astrogenesis, and neurogenesis, increased the secretions of CNTF and VEGF from ACs, and upregulated the expressions of C3 and PTX3. For the ACs, LCH further increased the secretions of BDNF and CNTF, enhanced PTX3 expression, and reduced C3 expression. Additionally, the conditioned medium from LCH-treated ACs further enhanced NSC proliferation, migration, and neurogenesis. The in vivo study showed that LCH markedly enhanced the Nissl score and neurogenesis, and decreased astrogenesis which was accompanied by downregulations of C3, p-p65, and p-p65/p65 and upregulation of PTX3. BO not only decreased the expression of C3 in ACs both in vitro and in vivo but also downregulated p-p65 and p-p65/p65 in vivo. Additionally, BO promoted the therapeutic effect of LCH for most indices.

CONCLUSION

A certain degree of OGD might induce ACs to stimulate the proliferation, astrogenesis, and neurogenesis of NSCs. LCH and BO exhibited a marked synergy in promoting ACs-mediated neurogenesis and reducing astrogenesis, in which LCH played a dominant role and BO boosted the effect of LCH. The mechanism of LCH might be involved in switching the polarization of ACs from A1 to A2, while BO preferred to inhibit the formation of A1 phenotype via downregulating NF-κB pathway.

Borneol serves as an adjuvant agent to promote the cellular uptake of curcumin for enhancing its photodynamic fungicidal efficacy against Candida albicans

Candida albicans (C. albicans), a major opportunistic pathogenic fungus, is known to cause superficial skin infections. Unfortunately, the misuse of antibiotics has led to the emergence of drug resistance in fungi. Antimicrobial photodynamic therapy (aPDT), a non-antibiotic alternative, has shown potential in treating drug-resistant fungal infections. Curcumin is a photodynamically active phytochemical whose photodynamic fungicidal efficacy is largely dependent on its intracellular accumulation. However, curcumin faces challenges in penetrating the cytoplasm due to its poor water solubility and the fungal cell wall. Borneol, another monoterpenoid phytochemical, is known for its ability to enhance drug absorption. In this study, we showed that borneol improved the cellular uptake of curcumin, thereby enhancing its photodynamic fungicidal efficacy against C. albicans. This effect was attributed to borneol's ability to increase cell permeability. Transcriptomic analysis further confirmed that borneol disrupted the normal structure and function of the C. albicans cell wall and membrane, resulting in dysregulated mRNA expression of related genes and ultimately increased cell permeability. As a result, the excessive accumulation of curcumin in C. albicans triggered the overproduction of intracellular ROS upon exposure to blue light. These excessive intracellular ROS disrupted various cellular structures, interfered with essential cellular processes, inhibited biofilm formation and reduced virulence. Remarkably, borneol was also found to enhance curcumin uptake by C. albicans within biofilms, further enhancing the anti-biofilm efficacy of curcumin-mediated aPDT (Cur-aPDT). In conclusion, the results of this study strongly support the potential of borneol as an adjuvant agent to Cur-aPDT in treating superficial cutaneous fungal infections.

Borneol exerts its antipruritic effects by inhibiting TRPA1 and activating TRPM8

ETHNOPHARMACOLOGICAL RELEVANCE

Borneol is a long-established traditional Chinese medicine that has been found to be effective in treating pain and itchy skin. However, whether borneol has a therapeutic effect on chronic itch and its related mechanisms remain unclear.

AIM OF THE STUDY

To investigate the antipruritic effect of borneol and its molecular mechanism.

MATERIALS AND METHODS

DrugBAN framework and molecular docking were applied to predict the targets of borneol, and the calcium imaging or patch-clamp recording analysis were used to detect the effects of borneol on TRPA1, TRPM8 or TRPV3 channels in HEK293T cells. In addition, various mouse models of acute itch and chronic itch were established to evaluate the antipruritic effects of borneol on C57BL/6J mice. Then, the borneol-induced pruritic relief was further investigated in Trpa1-/-, Trpm8-/-, or Trpa1-/-/Trpm8-/- mice. The effects of borneol on the activation of TRPM8 and the inhibition of TRPA1 were also measured in dorsal root ganglia neurons of wild-type (WT), Trpm8-/- and Trpv1-/- mice. Lastly, a randomized, double-blind study of adult patients was conducted to evaluate the clinical antipruritic effect of borneol.

RESULTS

TRPA1, TRPV3 and TRPM8 are the potential targets of borneol according to the results of DrugBAN algorithm and molecular docking. Calcium imaging and patch-clamp recording analysis demonstrated that borneol activates TRPM8 channel-induced cell excitability and inhibits TRPA1 channel-mediated cell excitability in transfected HEK293T cells. Animal behavior analysis showed that borneol can significantly reduce acute and chronic itch behavior in C57BL/6J mice, but this effect was eliminated in Trpa1-/-, Trpm8-/- mice, or at least in Trpa1-/-/Trpm8-/- mice. Borneol elicits TRPM8 channel induced [Ca2+]i responses but inhibits AITC or SADBE-induced activation of TRPA1 channels in dorsal root ganglia neurons of WT and Trpv1-/- mice, respectively. Furthermore, the clinical results indicated that borneol could reduce itching symptoms in patients and its efficacy is similar to that of menthol.

CONCLUSION

Borneol has therapeutic effects on multiple pruritus models in mice and patients with chronic itch, and the mechanism may be through inhibiting TRPA1 and activating TRPM8.

Health-promoting compounds in Amomum villosum Lour and Amomum tsao-ko: Fruit essential oil exhibiting great potential for human health

The Zingiberaceae family serves as a diverse repository of bioactive phytochemicals, comprising approximately 52 genera and 1300 species of aromatic perennial herbs distinguished by their distinct creeping horizontal or tuberous rhizomes. Amomum villosum Lour. and Amomum tsao-ko Crevost & Lemaire., are the important plants of family Zingiberaceae that have been widely used in traditional medicine for the treatment of many ailments. The Amomum species are employed for their aromatic qualities and are valued as spices and flavorings. In the essential oils (EOs) of Amomum species, notable constituents include, camphor, methyl chavicol, bornyl acetate, trans-p-(1-butenyl) anisole, α-pinene, and β-pinene.

OBJECTIVE

The aim of this review is to present an overview of pharmacological studies pertaining to the extracts and secondary metabolites isolated from both species. The foremost objective of review is not only to increase the popularity of Amomum as a healthy food choice but also to enhance its status as a staple ingredient for the foreseeable future.

RESULT

We endeavored to gather the latest information on antioxidant, antidiabetic, anticancer, antiobesity, antimicrobial, and anti-inflammatory properties of plants as well as their role in neuroprotective diseases. Research conducted through in-vitro studies, animal model, and compounds analysis have revealed that both plants exhibit a diverse array health promoting properties.

CONCLUSION

the comprehensive review paper provides valuable insights into the diverse range of bioactive phytochemicals found in A. villosum and A. tsao-ko, showcasing their potential in preventing diseases and promoting overall human well-being. The compilation of information on their various health-enhancing properties contributes to the broader understanding of these plants and their potential applications in traditional medicine and beyond.

Efficacy of borneol-gypsum in skin regeneration and pain control in toxic epidermal necrolysis: A case report

BACKGROUND

Toxic epidermal necrolysis (TEN) is a life-threatening dermatological emergency mainly induced by drug hypersensitivity reactions. Standard management includes discontinuation of culprit drug and application of immunomodulatory therapy. However, mortality remains high due to complications like septic shock and multiorgan failures. Innovative approaches for skin care are crucial. This report introduces borneol-gypsum, a traditional Chinese drug but a novel dressing serving as an adjuvant of TEN therapy, might significantly improve skin conditions and patient outcomes in TEN.

CASE SUMMARY

A 38-year-old woman diagnosed with eosinophilic granulomatosis with polyangiitis experienced gangrenous complications and motor nerve involvement. After initial treatment of high-dose corticosteroids and cyclophosphamide, symptom of foot drop improved, absolute eosinophil counts decreased, while limb pain sustained. Duloxetine was added to alleviate her symptom. Subsequently, TEN developed. Additional topical application of borneol-gypsum dressing not only protected the skin lesions from infection but also significantly eased localized pain. This approach demonstrated its merit in TEN management by promoting skin healing and potentially reducing infection risks.

CONCLUSION

Borneol-gypsum dressing is a promising adjuvant that could significantly improve TEN management, skin regeneration, and patient comfort.

Borneol-Modified Schisandrin B Micelles Cross the Blood-Brain Barrier To Treat Alzheimer's Disease in Aged Mice

Objective: Schisandrin B (Sch B) is a bioactive dibenzocyclooctadiene derizative that is prevalent in the fruit of Schisandra chinensis. Numerous studies have demonstrated that Sch B has a neuroprotective action by reducing oxidative stress and effectively preventing inflammation. It follows that Sch B is a potential treatment for Alzheimer's disease (AD). However, the drug's solubility, bioavailability, and lower permeability of the blood-brain barrier (BBB) can all reduce its efficacy during the therapy process. Therefore, this study constructed borneol-modified schisandrin B micelles (Bor-Sch B-Ms), which increase brain targeting by accurately delivering medications to the brain, effectively improving bioavailability. High therapeutic efficacy has been achieved at the pathological site. Methods: Bor-Sch B-Ms were prepared using the thin film dispersion approach in this article. On the one hand, to observe the targeting effect of borneol, we constructed a blood-brain barrier (BBB) model in vitro and studied the ability of micelles to cross the BBB. On the other hand, the distribution of micelle drugs and their related pharmacological effects on neuroinflammation, oxidative stress, and neuronal damage were studied through in vivo administration in mice. Results: In vitro studies have demonstrated that the drug uptake of bEnd.3 cells was increased by the borneol alteration on the surface of the nano micelles, implying that Bor-Sch B-Ms can promote the therapeutic effect of N2a cells. This could result in more medicines entering the BBB. In addition, in vivo studies revealed that the distribution and circulation time of medications in the brain tissue were significantly higher than those in other groups, making it more suitable for the treatment of central nervous system diseases. Conclusion: As a novel nanodrug delivery system, borneol modified schisandrin B micelles have promising research prospects in the treatment of Alzheimer's disease.

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.

A Novel Hybrid of Telmisartan and Borneol Ameliorates Neuroinflammation and White Matter Injury in Ischemic Stroke Through ATF3/CH25H Axis

Cerebral ischemic stroke causes substantial white matter injury, which is further aggravated by neuroinflammation mediated by microglia/astrocytes. Given the anti-neuroinflammatory action of telmisartan and the enhancing blood-brain barrier (BBB) permeability potential of resuscitation-inducing aromatic herbs, 13 hybrids (3a-m) of telmisartan (or its simplified analogues) with resuscitation-inducing aromatic agents were designed, synthesized, and biologically evaluated. Among them, the optimal compound 3a (the ester hybrid of telmisartan and (+)-borneol) potently inhibited neuroinflammation mediated by microglia/astrocytes and ameliorated ischemic stroke. Particularly, 3a significantly conferred protection for white matter integrity after cerebral ischemic stroke via decreasing abnormally dephosphorylated neurofilament protein, upregulating myelin basic protein, and attenuating oligodendrocyte damage. Further RNA-sequencing data revealed that 3a upregulated expression of transcriptional regulator ATF3 to reduce the expression of CH25H, prevented proinflammatory state of lipid-droplet-accumulating microglia/astrocytes to limit excessive inflammation, and eventually protected neighboring oligodendrocytes to prevent white matter injury. Taken with the desirable pharmacokinetics behavior and improved brain distribution, 3a may be a feasible therapeutic agent for ischemic stroke and other neurological disorders with white matter injury.

Borneol promotes autophagic degradation of HIF-1α and enhances chemotherapy sensitivity in malignant glioma

Background

Gliomas are characterized by high mortality rates and resistance. Even with conventional chemotherapy the prognosis of glioblastoma remains poor. Many medications are not optimally effective due to limited bioavailability. The bioavailability of medicine can be enhanced by borneol, a monoterpenoid substance. In this study, we investigated the effect of borneol, a commonly used Chinese medicine, on chemosensitivity in C6 glioma and U251 human glioma cell lines and elucidated its therapeutic molecular targets.

Methods

The chemosensitivity-inducing effects of borneol in C6 and U251 cells were examined using CCK8 and clonal formation assays. The mechanism underlying the effect of borneol was evaluated through immunohistochemistry and western blotting assays. Further, the number of autophagosomes was determined via transmission electron microscopy. Finally, the chemical sensitization effect of borneol was evaluated in SD rats after C6 orthotopic tumor transplantation.

Results

Borneol increased cytotoxicity in C6 and U251 cells in response to temozolomide (TMZ). In addition, through transmission electron microscopy, western blotting, and immunohistochemical tests, we found that borneol combined with TMZ significantly increased the level of autophagy and that hypoxia inducible factor-1(HIF-1α) is a candidate target through which borneol enhances the cytotoxic effect of TMZ. Borneol's ability to enhance HIF-1α degradation was counteracted following the administration of autophagy inhibitors. In vivo, borneol treatment was found to enhance the anticancer effect of TMZ and delay tumor progression, and this effect was closely related to its ability to promote the autophagic degradation of HIF-1α.

Conclusions

HIF-1α might be a valid therapeutic target of borneol, which can be potentially applied as a chemosensitizing drug used for glioma treatment.

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.

Anticonvulsant effects of isopimpinellin and its interactions with classic antiseizure medications and borneol in the mouse tonic-clonic seizure model: an isobolographic transformation

BACKGROUND

Overwhelming evidence indicates that some naturally occurring coumarins and terpenes are widely used in folk medicine due to their various therapeutic effects affecting the brain. Antiseizure medications (ASMs) are the principal treatment option for epilepsy patients, although some novel strategies based on naturally occurring substances are intensively investigated. This study was aimed at determining the influence of isopimpinellin (ISOP-a coumarin) when administered either separately or in combination with borneol (BOR-a monoterpenoid), on the antiseizure potencies of four classic ASMs (carbamazepine (CBZ), phenytoin (PHT), phenobarbital (PB), and valproate (VPA)) in the mouse model of maximal electroshock-induced (MES) tonic-clonic seizures.

MATERIALS

Tonic-clonic seizures were evoked experimentally in mice after systemic (ip) administration of the respective doses of ISOP, BOR, and classic ASMs. Interactions for two-drug (ISOP + a classic ASM) and three-drug (ISOP + BOR + a classic ASM) mixtures were assessed isobolographically in the mouse MES model.

RESULTS

ISOP (administered alone) had no impact on the anticonvulsant potencies of four classic ASMs. Due to the isobolographic transformation of data, the combination of ISOP + VPA exerted an antagonistic interaction, whereas the two-drug mixtures of ISOP + CBZ, ISOP + PHT, and ISOP + PB produced additive interactions in the mouse MES model. The three-drug combinations of ISOP + BOR with CBZ and PHT produced additive interactions, while the three-drug combinations of ISOP + BOR with PB and VPA exerted synergistic interactions in the mouse MES model.

CONCLUSIONS

The most intriguing interaction was that for ISOP + VPA, for which the addition of BOR evoked a transition from antagonism to synergy in the mouse MES model.

Research progress on the regulation and mechanism of borneol on the blood-brain barrier in pathological states: a narrative review focused on ischemic stroke and cerebral glioma

Background and Objective

The blood-brain barrier (BBB) serves as a dynamic, selective shield, safeguarding the central nervous system (CNS) by separating the brain from circulating blood, preserving its microenvironment, and ensuring stability. However, in the presence of brain pathology, drug delivery across the BBB and blood-tumor barrier (BTB) becomes challenging, hindering effective treatments. Borneol exhibits promise in bidirectionally modulating the BBB under pathological conditions, suggesting at potential clinical applications for related diseases. Our primary goal in this review is to investigate borneol's potential clinical utility in bidirectionally regulating the BBB under pathological conditions.

Methods

The PubMed database, CNKI (China National Knowledge Infrastructure), Wanfang Data were searched to retrieve articles on animal experiments and cell-based research published from January 1, 2003, to May 1, 2023, using the following medical subject headings (MeSH) terms: borneol, blood-brain barrier, ischemic stroke, cerebral gliomas, anti-inflammatory. The search was limited to articles published in English and Chinese. In total, 86 articles were deemed eligible for inclusion in this study.

Key Content and Findings

The breakdown of the BBB is a key pathological process in ischemic stroke and cerebral glioma. When used alone, the lipophilic properties of borneol can reduce the permeability of the BBB and restore its normal function, thereby repairing brain damage and protecting brain tissue. Its specific protective effects may be related to inflammatory regulation mechanisms. The anti-inflammatory and protective effects of borneol can be used to improve and treat lesions caused by ischemic stroke and cerebral glioma. Furthermore, when combined with other drugs, borneol can accelerate the opening of the BBB, improve permeability through physiological processes, and enhance drug penetration and distribution in the brain without causing pathological damage to the brain.

Conclusions

This review summarizes the mechanisms by which borneol regulates the BBB and BTB in ischemic stroke and cerebral glioma, and discusses the potential clinical applications of borneol in the treatment of these diseases. It is believed that in the future, as research methods are refined, more effective and targeted therapies for cerebral glioma and ischemic stroke will be explored related to the protective mechanism of the BBB under pathological conditions with borneol alone or in combination with other drugs.

Analysis of medication rules and application characteristics of Chinese patent medicine containing borneol based on data mining

Background

In this study, the regularity of drug containing borneol proprietary Chinese medicine was mined, to provide reference for the clinical application and new drug research and development of borneol.

Methods

The database of proprietary Chinese medicines on Pharmaceutical Intelligence Network was searched for internal and external prescriptions that contained borneols and the diseases they treat. Microsoft Office Excel 2019 and SPSS Modeler 18.0 were used to analyze the properties, flavors, meridians tropisms and association rule analysis of the medicines, and Origin 21.0 software was used to draw the association rules diagram.

Results

Among them, 528 prescriptions of internal Chinese patent medicine containing borneol and 387 prescriptions of external Chinese patent medicine were included. The diseases treated by internal prescription were mainly neurological diseases and heart diseases, among which Chinese medicines with higher frequency of compatibility with borneol were bezoar, licorice, cinnabar, musk and scutellaria. The diseases treated by external prescription were mainly physical disabilities, paralysis diseases, sore and ulcer diseases and so on. Among them, menthol, camphor, frankincense, angelica, and carthami flos and so on are the most frequently combined with borneol.

Conclusion

The prescription of Chinese patent medicine containing borneol is composed of cold or warm, pungent or bitter Chinese medicine. Internal prescription primarily targets the meridians of the heart, liver, and lungs, and is often combined with sedative, antipyretic and detoxicating drugs to treat stroke, infantile convulsion and angina pectoris. External prescription mainly acts on liver, heart and spleen meridian, and is often combined with drugs for clearing heat, promoting blood circulation and removing blood stasis to treat rheumatic arthralgia syndrome and sore and ulcer diseases.

Protective effect of borneol on the cutaneous toxicity of gilteritinib

OBJECTIVES

To investigate the effect of borneol on cutaneous toxicity of gilteritinib and to explore possible compounds that can intervene with the cutaneous toxicity.

METHODS

C57BL/6J male mice were given gilteritinib by continuous gavage for 28 d and the damage to keratinocytes in the skin tissues was observed with hematoxylin and eosin (HE) staining, TUNEL assay and immunohistochemistry. Human keratinocytes HaCaT were treated with gilteritinib, and cell death and morphological changes were examined by SRB staining and microscopy; apoptosis of HaCaT cells was examined by Western blotting, flow cytometry with propidium iodide/AnnexinⅤ double staining and immunofluorescence; the accumulation of cellular reactive oxygen species (ROS) was examined by flow cytometry with DCFH-DA. Compounds that can effectively intervene the cutaneous toxicity of gilteritinib were screened from a natural compound library using SRB method, and the intervention effect of borneol on gilteritinib cutaneous toxicity was further investigated in HaCaT cells and C57BL/6J male mice.

RESULTS

In vivo studies showed pathological changes in the skin with apoptosis of keratinocytes in the stratum spinosum and stratum granulosum in the modeling group. Invitro studies showed apoptosis of HaCaT cells, significant up-regulation of cleaved poly (ADP-ribose) polymerase (c-PARP) and gamma-H2A histone family member X (γ-H2AX) levels, and increased accumulation of ROS in gilteritinib-modeled skin keratinocytes compared with controls. Screening of the natural compound library revealed that borneol showed excellent intervention effects on the death of HaCaT cells. In vitro, cell apoptosis was significantly reduced in the borneol+gilteritinib group compared to the gilteritinib control group. The levels of c-PARP, γ-H2AX and ROS in cells were significantly decreased. In vivo, borneol alleviated gilteritinib-induced skin pathological changes and skin cell apoptosis in mice.

CONCLUSIONS

Gilteritinib induces keratinocytes apoptosis by causing intracellular ROS accumulation, resulting in cutaneous toxicity. Borneol can ameliorate the cutaneous toxicity of gilteritinib by reducing the accumulation of ROS and apoptosis of keratinocytes in the skin tissue.

Borneol-modified PEGylated graphene oxide as a nanocarrier for brain-targeted delivery of ginsenoside Rg1 against depression

Depression is a chronic mental disorder which threatens human health and lives. However, the treatment of depression remains challenging largely due to blood brain barrier (BBB), which restricts drugs from entering the brain, resulting in a poor distribution of antidepressants in the brain. In this work, a novel brain-targeted drug delivery system was developed based on borneol-modified PEGylated graphene oxide (GO-PEG-BO). GO-PEG-BO was characterized and proved to possess excellent biocompatibility. By incorporating borneol, GO-PEG-BO could penetrate BBB efficiently by opening tight junctions and inhibiting the efflux system of BBB. The targeted distribution of GO-PEG-BO in the brain was observed by an in vivo biodistribution study. Moreover, GO-PEG-BO exhibited a neuroprotective effect, which is beneficial to the treatment of depression. Ginsenoside Rg1 (GRg1), which can relieve depressive symptoms but difficult to cross BBB, was loaded to GO-PEG-BO for the therapy of depression. In depressive rats, GRg1/GO-PEG-BO improved stress-induced anhedonia, despair and anxiety, and comprehensively relieved the depressive symptoms. In conclusion, GO-PEG-BO could serve as a promising nanocarrier for brain-targeted drug delivery, and provide a new strategy for the therapy of depression.

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.

Microneedle-mediated delivery of Ziconotide-loaded liposomes fused with exosomes for analgesia

Ziconotide (ZIC) is an N-type calcium channel antagonist for treating severe chronic pain that is intolerable, or responds poorly to the administration of other drugs, such as intrathecal morphine and systemic analgesics. As it can only work in the brain and cerebrospinal fluid, intrathecal injection is the only administration route for ZIC. In this study, borneol (BOR)-modified liposomes (LIPs) were fused with exosomes from mesenchymal stem cells (MSCs) and loaded with ZIC to prepare microneedles (MNs) to improve the efficiency of ZIC across the blood-brain barrier. To evaluate local analgesic effects of MNs, the sensitivity of behavioral pain to thermal and mechanical stimuli was tested in animal models of peripheral nerve injury, diabetes-induced neuropathy pain, chemotherapy-induced pain, and ultraviolet-B (UV-B) radiation-induced neurogenic inflammatory pain. BOR-modified LIPs loaded with ZIC were spherical or nearly spherical, with a particle size of about 95 nm and a Zeta potential of -7.8 mV. After fusion with MSC exosomes, the particle sizes of LIPs increased to 175 nm, and their Zeta potential increased to -3.8 mV. The nano-MNs constructed based on BOR-modified LIPs had good mechanical properties and could effectively penetrate the skin to release drugs. The results of analgesic experiments showed that ZIC had a significant analgesic effect in different pain models. In conclusion, the BOR-modified LIP membrane-fused exosome MNs constructed in this study for delivering ZIC provide a safe and effective administration for chronic pain treatment, as well as great potential for clinical application of ZIC.

Genome-wide analyzation and functional characterization on the TPS family provide insight into the biosynthesis of mono-terpenes in the camphor tree

Terpene synthase (TPS) plays an important role in terpenoids biosynthesis. Cinnamomum camphora (camphor tree) contains dozens of terpenoids with medicinal value, especially borneol, which has been widely used since ancient times. However, limited information is available regarding the genome-wide identification and characterization of the TPS family in the C. camphora. In this study, 82 CcTPS genes were identified from the camphor tree genome (CTG). Gene cluster and sequence syntenic analysis suggested that tandem duplication occurred within the TPS family of the CTG, especially for the TPS-b subfamily. The chemotype-specific gene expression analysis showed significantly differential expression patterns among six chemotypes. It is worth noting that three genes (CcTPS26, CcTPS49 and CcTPS72) exhibited relatively high expression in the borneol-type camphor tree, compared to the other five chemotypes. Further functional characterization of them indicated that they were all bornyl diphosphate synthases (BPPSs), which function in catalyzing GPP into BPP and then undergoes dephosphorylation to yield borneol. This is the first report that multiple BPPSs exist within a single species. Intriguingly, CcTPS49 and CcTPS72 lead to the generation of dextral-borneol, while CcTPS26 contributes to the biosynthesis of levo-borneol. In addition, the functional characterization of another six CcTPSs suggested that they are responsible for the biosynthesis of linalool, eucalyptol and several other monoterpenes in camphor tree. In conclusion, these novel results provide a foundation for further exploration of the role of the CcTPS gene family and shed light on a better understanding of the biosynthesis and accumulation of monoterpenes in camphor tree.

and borneol in attenuating BMECs injury and maintaining tight junctions against cerebral ischaemia based on the HIF-1α/VEGF signalling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ligusticum striatum DC., also known as Ligusticum chuanxiong Hort. (LCH), is widely used in China for its excellent effect in ischaemic stroke (IS) patients, and borneol (BO) has been confirmed to maintain the blood‒brain barrier (BBB) after stroke. They are often used as a combination in the prescriptions of IS patients. Although the advantage of their combined treatment in improving brain ischaemia has been verified, their synergistic mechanism on BBB maintenance is still unclear.

AIM OF THE STUDY

This study was designed to evaluate the synergistic effect of maintaining the BBB between LCH and BO against IS and to further explore the potential mechanism.

MATERIALS AND METHODS

After primary mouse brain microvascular endothelial cells (BMECs) were extracted and identified, the duration of oxygen-glucose deprivation (OGD) and the doses of LCH and BO were optimized. Then, the cells were divided into five groups: control, model, LCH, BO, and LCH + BO. Cell viability, injury degree, proliferation and migration were detected by CCK-8, LDH, EdU and wound-healing assays, respectively. Hoechst 33342 staining was adopted to detect the apoptosis rate, and western blotting was employed to observe the expressions of Bax, Bcl-2, caspase-3 and cleaved caspase-3. The TEER value and NaF permeability were measured to assess tight junction (TJ) function, while ZO-1, occludin and claudin-5 were also probed by western blotting. Moreover, the HIF-1α/VEGF pathway was observed to explore the underlying mechanism of BBB maintenance. In vivo, global cerebral ischaemia/reperfusion (GCIR) surgery was performed to establish an IS model. After treatment with LCH (200 mg/kg) and/or BO (160 mg/kg), histopathological structure and BMECs repair were observed by HE staining and immunohistochemistry of vWF. Meanwhile, TJ-associated proteins in vivo were also detected by western blotting.

RESULTS

Basically, LCH and BO had different emphases. LCH significantly attenuated the vacuolar structure, nuclear pyknosis and neuronal loss of GCIR mice, while BO focused on promoting BMECs proliferation and angiogenesis and inhibiting the degradation of TJ-associated proteins in vivo after IS. Interestingly, their combination further enhanced these effects. OGD injury markedly reduced the viability, proliferation and migration of primary BMECs; decreased the ratio of Bcl-2/Bax, TEER value, and the expressions of ZO-1, occludin and claudin-5; induced LDH release and apoptosis; and increased the cleaved caspase-3/caspase-3 ratio and NaF permeability. Meanwhile, BO might be the main contributor to the combinative treatment in ameliorating OGD-induced damage of BMECs and degradation of TJ-related proteins, and the potential mechanism might be involved in upregulating the HIF-1α/VEGF signalling pathway. Although LCH showed no obvious improvement, it could enhance the therapeutic effect of BO. Interestingly, their combination even produced some new improvements, including the reduction of cleaved caspase-3 and increase in TEER value, none of which were exhibited in their monotherapies.

CONCLUSIONS

LCH and BO exhibited complementary therapeutic features in alleviating cerebral ischaemic injury by inhibiting BMECs apoptosis, maintaining the BBB and attenuating the loss of neurons. LCH preferred to protect ischaemic neurons, while BO played a key role in protecting BMECs, maintaining the BBB and TJs by activating the HIF-1α/VEGF signalling pathway.

A mechanistic investigation about hepatoxic effects of borneol using zebrafish

Except for clinical value, borneol is routinely used in food and cosmetics with seldom safety evaluation. To investigate its hepatoxicity, we exposed 3 dpf (days post fertilization) larval zebrafish to borneol at a gradient of concentrations (200-500 μM) for 3 days. Herein, our results revealed that high doses of borneol (300-500 μM) caused liver size decrease or lateral lobe absence. Borneol also seriously disturbed the hepatic protein metabolism presented with the increased activity of alanine aminotransferase (ALT) and lipid metabolism shown with the increased level of triglycerides (TG) and total cholesterol (TC). The lipid accumulation (oil red staining) was detected as well. Additionally, significant upregulation of genes was detected that related to oxidative stress, lipid anabolism, endoplasmic reticulum stress (ERS), and autophagy. Conversely, the lipid metabolism-related genes were markedly downregulated. Moreover, the changes in the superoxide dismutase activity and the level of glutathione and malondialdehyde raised the likelihood of lipid peroxidation. The outcomes indicated the involvement of oxidative stress, ERS, lipid metabolism, and autophagy in borneol-induced lipid metabolic disorder and hepatic injury. This study will provide a more comprehensive understanding of borneol hepatoxicity and the theoretical basis for the safe use of this compound.

Borneol-driven meningeal lymphatic drainage clears amyloid-β peptide to attenuate Alzheimer-like phenotype in mice

Rationale: The accumulation and clearance of amyloid-β (Aβ) peptides play a crucial role in the pathogenesis of Alzheimer's disease (AD). The (re)discovery of meningeal lymphatic vessels in recent years has focused attention on the lymphatic clearance of Aβ and has become a promising therapeutic target for such diseases. However, there is a lack of small molecular compounds that could clearly regulate meningeal lymphatic drainage to remove Aβ from the brain. Methods: We investigated the effect of borneol on meningeal lymphatic clearance of macromolecules with different molecular weights (including Aβ) in the brain. To further investigate the mechanism of borneol regulating meningeal lymphatic drainage, immunofluorescence staining, western blotting, ELISA, RT-qPCR, and Nitric Oxide assay kits were used. The cognitive function of AD mice after borneol treatment was evaluated using two behavioral tests: open field (OF) and Morris water maze (MWM). Results: This study discovered that borneol could accelerate the lymphatic clearance of Aβ from the brain by enhancing meningeal lymphatic drainage. Preliminary mechanism analysis revealed that borneol could improve the permeability and inner diameter of lymphatic vessels, allowing macromolecules to drain into the cervical lymph nodes (CLNS) and then be transported to the lymphatic circulation. To speed up the clearance of macromolecules, borneol also stimulated lymphatic constriction by lowering the level of nitric oxide in the meninges. In addition, borneol stimulated lymphangiogenesis by increasing the levels of FOXC2, VEGFC, and LYVE-1 in the meninges, which promoted the clearance rates of macromolecules. Borneol improved meningeal lymphatic clearance not only for Aβ but also for other macromolecular polymers (molecular weight in the range of 2 KD - 45 KD. Borneol ameliorated cognitive deficits and alleviated brain Aβ burden in Aβ-injected mice. Conclusions: Our findings not only provide a strategy to regulate lymphatic clearance pathways of macromolecules in the brain, but also new targets and ideas for treating neurodegenerative diseases like AD. Furthermore, our findings indicate that borneol is a promising therapeutic drug for AD.

Research progress on mechanism of Chinese Kaiqiao herbs in management of neuropathic pain

The Chinese herbal medicine for Kaiqiao, such as borneol, musk, grassleaf sweetflag rhizome, storax and camphor, have been prescribed in traditional Chinese medicine for thousands of years and now are widely used for neuropathic pain, the main components of which are annular compounds. Studies have shown that their analgesic mechanisms include regulating the expression of γ-aminobutyric acid, N-methyl- D-aspartic acid and other receptors; regulating ion channel function; inhibiting inflammatory response, oxidative stress and apoptosis; regulating neurotransmission and neuronal excitability; and participating in neuroprotection and neurological repair. It is suggested that the mechanisms of action of Kaiqiao herbs in central nervous system analgesia should be further explored; high-quality rapid screening of drug targets may be used, and the targeted agents using the characteristics of Kaiqiao herbs would be developed. This article reviews the research progress on the effect mechanism of traditional Kaiqiao herbs in the treatment of neuropathic pain to provide further research directions.

Enhancing effect of borneol on pharmacokinetics of ginsenoside Rb1 , ginsenoside Rg1 and notoginsenoside R1 in healthy volunteers after oral administration of compound Danshen dropping pills (CDDP)

Borneol (Bingpian), a monoterpenoid pharmaceutical ingredient, is commonly used as a main composition in traditional Chinese medicine (TCM) preparations such as compound Danshen dropping pills (CDDP), and has also been approved by the US FDA as a flavoring substance or adjuvant in food. Borneol plays a regulating and guiding role as messenger drug in CDDP. However, the effect of borneol on the pharmacokinetics of the components of CDDP in human plasma is unclear. In this study, we investigate the effects of borneol on the pharmacokinetics of ginsenoside Rb₁ (Rb₁ ), ginsenoside Rg₁ (Rg₁ ) and notoginsenoside R₁ (NR₁ ) in CDDP. We used a double-cycle crossover-administration model in twelve healthy male volunteers, giving CDDP with borneol (drug T) and without borneol (drug R). The selective response monitoring (SRM) mode was used for mass spectrometry quantification in the positive mode. As a result, we found that borneol could significantly affect the pharmacokinetic parameters of notoginsenosides, and increase the absorption and systemic exposure of Rb₁ , Rg₁ and NR₁ in human plasma by about 1.85 to 3.71 times.

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.

New type of borneol-based fluorine-free superhydrophobic antibacterial polymeric coating

A new type of superhydrophobic borneol-based polymeric coating has been prepared. The chemical composition of the polymer particles was analyzed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, which showed that the polymer did not contain fluorine, which can effectively avoid the cytotoxic risk of fluorine. By dynamic light scattering, scanning electron microscopy, and static contact angle measurement, the contact angle of the prepared coating gradually increased with increasing diameter of the polymer particles, and a superhydrophobic coating surface was finally obtained. Interestingly, after dissolving the superhydrophobic sample with tetrahydrofuran and making it a normal hydrophobic sample, the antiadhesion performance for E. coli was greatly reduced, and it could not effectively prevent E. coli adhesion. In addition, a long-term antiadhesion study of bacteria was performed. The superhydrophobic borneol-based polymer coating showed long-term resistance to E. coli adhesion. Therefore, the excellent antibacterial properties and cell compatibility mean that this series of polymer materials has great potential in the field of biomedicine.

A Structural View on the Stereospecificity of Plant Borneol-Type Dehydrogenases

The development of sustainable processes for the valorization of byproducts and other waste streams remains an ongoing challenge in the field of catalysis. Racemic borneol, isoborneol and camphor are currently produced from α-pinene, a side product from the production of cellulose. The pure enantiomers of these monoterpenoids have numerous applications in cosmetics and act as reagents for asymmetric synthesis, making an enzymatic route for their separation into optically pure enantiomers a desirable goal. Known short-chain borneol-type dehydrogenases (BDHs) from plants and bacteria lack the required specificity, stability or activity for industrial utilization. Prompted by reports on the presence of pure (-)-borneol and (-)-camphor in essential oils from rosemary, we set out to investigate dehydrogenases from the genus Salvia and discovered a dehydrogenase with high specificity (E>120) and high specific activity (>0.02 U mg-1) for borneol and isoborneol. Compared to other specific dehydrogenases, the one reported here shows remarkably higher stability, which was exploited to obtain the first three-dimensional structure of an enantiospecific borneol-type short-chain dehydrogenase. This, together with docking studies, led to the identification of a hydrophobic pocket in the enzyme that plays a crucial role in the stereo discrimination of bornane-type monoterpenoids. The kinetic resolution of borneol and isoborneol can be easily integrated into the existing synthetic route from α-pinene to camphor thereby allowing the facile synthesis of optically pure monoterpenols from an abundant renewable source.

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.

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.

Borneol inhibits CD4 + T cells proliferation by down-regulating miR-26a and miR-142-3p to attenuate asthma

BACKGROUND

Asthma is a chronic airway inflammatory disease caused by a variety of cytokines and signaling pathways closely related to immunoregulation. Corticosteroids are the most widely used drug in the asthma treatment. However, the use of corticosteroids could cause topical side effects. So, it's important to find new drugs for asthma treatment. Our study aims to explore the pharmacological effect of borneol on asthma and its underlying mechanism.

METHODS

We constructed the OVA-induced asthma model to investigate the effect of borneol on asthma in mice. HE and PAS staining was used to detect the effect of borneol on pathological change of mice with asthma. Inflammatory cytokines were measured by ELISA. qRT-PCR was used to explore the effect of borneol on microRNAs expression. Cell proliferation of CD4 + T cells was detected by CCK-8 assay and flow cytometry. Western blot was used to detect pten expression and Akt activation.

RESULTS

We found that borneol significantly alleviated asthma progression in mice. Borneol inhibited CD4 + T cells infiltration in vivo and proliferation in vitro by downregulating miR-26a and miR-142-3p. miR-26a and miR-142-3p promoted CD4 + T cells proliferation in vitro through targeting Pten. Overexpression of miR-26a and miR-142-3p abolished the effect of borneol in vivo.

CONCLUSION

In a word, these findings suggested that borneol attenuated asthma in mice by decreasing the CD4 + T cells infiltration. The molecular mechanism of borneol was dependent on the downregulation of miR-26a and miR-142-3p to upregulate the Pten expression.

Borneol-mediated vardenafil hydrochloride patch for pediatric pulmonary arterial hypertension: Preparation, characterization and in vivo study

BACKGROUND

Pediatric pulmonary arterial hypertension (PPAH) is a malignant progressive rare disease characterized by restricted pulmonary artery blood flow and progressively increasing blood pressure, which has shorter survival time of only about 10 months as compared to adults. Previous studies have shown that low-dose vardenafil hydrochloride (Var) could significantly improve the symptoms of PPAH. However, Var is currently available only in tablet form in the market for erectile dysfunction, and no special preparation is available for PPAH.

METHODS

In this study, borneol-mediated vardenafil hydrochloride patch (BO-VarP) with sodium polyacrylate as the skeleton material was prepared by coating method, which was characterized by temperature resistance, formability, adhesive force, skin irritation and in vitro permeation. Blood concentration of optimized BO-VarP was measured by LC-MS/MS using intragastric administration (i.g.) as a control, and pharmacodynamic studies were conducted using a rat model of pulmonary arterial hypertension induced by monocrotaline.

RESULTS AND DISCUSSION

Optimized BO-VarP showed good appearance, with optimal temperature resistance and formability, appropriate adhesive force and low skin irritation, and its cumulative permeation flux was 14.9 times higher than patch without penetration enhancer. The blood concentration within therapeutic window of BO-VarP lasted longer than i.g., and BO-VarP could improve symptoms of PPAH by reducing pulmonary arterial pressure and right heart hypertrophy index.

CONCLUSION

BO-VarP had good therapeutic effect in PPAH rats and suitable compliance in children, which provided a potential industrial transdermal delivery system for the treatment of PPAH.

Inhibitory actions of borneol on the substantia gelatinosa neurons of the trigeminal subnucleus caudalis in mice

The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) is the first relay site for the orofacial nociceptive inputs via the thin myelinated Aδ and unmyelinated C primary afferent fibers. Borneol, one of the valuable timehonored herbal ingredients in traditional Chinese medicine, is a popular treatment for anxiety, anesthesia, and antinociception. However, to date, little is known as to how borneol acts on the SG neurons of the Vc. To close this gap, the whole-cell patch-clamp technique was applied to elucidate the antinociceptive mechanism responding for the actions of borneol on the SG neurons of the Vc in mice. In the voltage-clamp mode, holding at -60 mV, the borneol-induced non-desensitizing inward currents were not affected by tetrodotoxin, a voltage-gated Na⁺ channel blocker, 6-cyano-7-nitro-quinoxaline-2,3-dione, a non-N-methyl-D-aspartate (NMDA) glutamate receptor antagonist and DL-2-amino-5-phosphonopentanoic acid, an NMDA receptor antagonist. However, borneol-induced inward currents were partially decreased in the presence of picrotoxin, a γ-aminobutyric acid (GABA)_A receptor antagonist, or strychnine, a glycine receptor antagonist, and was almost suppressed in the presence of picrotoxin and strychnine. Though borneol did not show any effect on the glycine-induced inward currents, borneol enhanced GABA-mediated responses. Beside, borneol enhanced the GABA-induced hyperpolarization under the current-clamp mode. Altogether, we suggest that borneol contributes in part toward mediating the inhibitory GABA and glycine transmission on the SG neurons of the Vc and may serve as an herbal therapeutic for orofacial pain ailments.

Monoterpenoid-based inhibitors of filoviruses targeting the glycoprotein-mediated entry process

In this study, we screened a large library of (+)-camphor and (-)-borneol derivatives to assess their filovirus entry inhibition activities using pseudotype systems. Structure-activity relationship studies revealed several compounds exhibiting submicromolar IC₅₀ values. These compounds were evaluated for their effect against natural Ebola virus (EBOV) and Marburg virus. Compound 3b (As-358) exhibited the good antiviral potency (IC₅₀ = 3.7 μM, SI = 118) against Marburg virus, while the hydrochloride salt of this compound 3b·HCl had a strong inhibitory effect against Ebola virus (IC₅₀ = 9.1 μM, SI = 31) and good in vivo safety (LD₅₀ > 1000 mg/kg). The results of molecular docking and in vitro mutagenesis analyses suggest that the synthesized compounds bind to the active binding site of EBOV glycoprotein similar to the known inhibitor toremifene.

TCU-HL1

Borneol is a bicyclic plant monoterpene. It can be degraded by soil microorganisms through the conversion of borneol dehydrogenase (BDH) and a known camphor degradation pathway. Recombinant BDH from Pseudomonas sp. TCU-HL1 was produced in the form of inclusion body. The refolded BDH1 tends to precipitate. Insoluble recombinant BDH1 was converted into a soluble form by adding glycerol in LB medium. The k_cat and k_cat/K_m values of soluble form BDH1 for (+)-borneol turned out to be about 34-fold and 45-fold higher, respectively, than those of the refolded enzyme. On the other hand, a gene knockout mutant, TCU-HL1Δbdh, was constructed to investigate the possible presence of a second copy of the bdh gene in TCU-HL1 genome. A new gene, bdh2, encoding a BDH isozyme, was identified, and the recombinant BDH2 protein was produced in a soluble form. Both bdh1 and bdh2 genes are expressed in the crude extract of wild type TCU-HL1, as shown by RT-qPCR results. Both BDH isozymes prefer to degrade (+)-borneol, rather than (-)-borneol, probably because (+)-camphor is the main form present in nature.

Enhanced dissolution, permeation and oral bioavailability of aripiprazole mixed micelles: In vitro and in vivo evaluation

Aripiprazole (ARP) is an antipsychotic drug approved for the treatment of schizophrenia. It is poorly water-soluble and undergoes extensive hepatic metabolism and P-gp efflux, which lead to poor bioavailability and increased dose-related side effects. This study focuses on the preparation of mixed micelles (MM) to enhance the aqueous solubility, oral bioavailability, and blood-brain barrier permeation of ARP. For this purpose, Soluplus and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) were selected for micelle preparation (ARP-MM). Micelles with borneol as penetration enhancer were also considered (ARP-B-MM). The optimized formulations have sizes of ca 50 nm, defined in distilled water, narrow size distribution (polydispersity index ≤0.1), and high encapsulation efficiency (greater than98%). Both formulations can be freeze-dried without losing their chemical-physical characteristics and are stable during storage for three months. The mixed micelles resulted stable in enzyme free-simulated gastric fluid (SGF, pH 1.2), simulated intestinal fluid (SIF, pH 6.8), and in serum. The in vitro ARP release was evaluated in the same biorelevant media, (SGF and SIF), and it disclosed that both micelles can give prolonged drug release. Furthermore, ARP solubility is greatly increased when loaded into mixed micelles. The absorption and efflux of ARP-loaded micelles were studied in vitro, employing two artificial membranes (Parallel Artificial Membrane Permeability Assay for the intestinal, PAMPA-GI, and the blood-brain barrier, PAMPA-BBB), to simulate the intestinal and brain epithelium, and the brain microvascular endothelial cell line hCMEC/D3. ARP-MM and ARP-B-MM increase the effective permeability of ARP by a factor of about three in the case of PAMPA-GI and about two for PAMPA-BBB. Furthermore, the P-gp mediated efflux was decreased by about six times in the case of ARP-MM and by about four times in the case of ARP-B-MM, compared to unformulated ARP. Finally, both ARP-loaded mixed micelles ameliorate the bioavailability of ARP, as demonstrated by the increase of the pharmacokinetic parameters, such as Cmax, AUC_0-24h, and t1/2.

Analgesic and anti-inflammatory effects and mechanism of action of borneol on photodynamic therapy of acne

This study aims to explore the analgesic and anti-inflammatory effects of borneol, a traditional Chinese medicine, on photodynamic treatment of acne. Here, we found that borneol significantly decreased the auricular swelling rate and pain threshold of rats. We also showed that borneol noticeably reduced macrophage and lymphocyte infiltration. The number of Th cells was significantly higher in the control PDT group than in the PDT plus borneol treatment group (P < 0.05). The expression of IL-6, TNF-α, and IL-8 mRNA and proteins were noticeably lower in the treatment group in comparison to those of the PDT control group, while PDT plus borneol activated the p38-COX-2-PGE2 signaling pathway, increasing expression in the treatment group. Borneol has significant analgesic and anti-inflammatory effects on PDT of acne, and enhances the healing of acne by activating p38-COX-2-PGE2 signaling pathway.

Molecular cloning and functional characterization of a two highly stereoselective borneol dehydrogenases from Salvia officinalis L

Enzymes for selective terpene functionalization are of particular importance for industrial applications. Pure enantiomers of borneol and isoborneol are fragrant constituents of several essential oils and find frequent application in cosmetics and therapy. Racemic borneol can be easily obtained from racemic camphor, which in turn is readily available from industrial side-streams. Enantioselective biocatalysts for the selective conversion of borneol and isoborneol stereoisomers would be therefore highly desirable for their catalytic separation under mild reaction conditions. Although several borneol dehydrogenases from plants and bacteria have been reported, none show sufficient stereoselectivity. Despite Croteau et al. describing sage leaves to specifically oxidize one borneol enantiomer in the late 70s, no specific enzymes have been characterized. We expected that one or several alcohol dehydrogenases encoded in the recently elucidated genome of Salvia officinalis L. would, therefore, be stereoselective. This study thus reports the recombinant expression in E. coli and characterization of two enantiospecific enzymes from the Salvia officinalis L. genome, SoBDH1 and SoBDH2, and their comparison to other known ADHs. Both enzymes produce preferentially (+)-camphor from racemic borneol, but (-)-camphor from racemic isoborneol.

Borneol and poly (ethylene glycol) dual modified BSA nanoparticles as an itraconazole vehicle for brain targeting

Itraconazole (ITZ) can be used for the treatment of cryptococcus neoformans meningitis and aspergillus brain abscess. While, the inherent hydrophobicity of ITZ and the existence of blood brain barrier (BBB) limit its applications as a central nervous system drug. In this study, a novel brain targeting drug delivery system based on bovine serum albumin (BSA) was constructed for enhancing ITZ distribution in brain. Firstly, ITZ was loaded into BSA nanoparticles (ITZ-NPs) with 11.6% of drug loading. Subsequently, the nanoparticles were modified with borneol (BO) and polyethylene glycol (PEG) (PEG/BO-ITZ-NPs). The resulting nanoparticles retained their nanosize (186.3 nm), uniform and spherical morphology, and negative surface charge (-21.03 mV). Cell uptake studies showed that compared with ITZ-NPs, PEG/BO-ITZ-NPs had significantly increased uptake in bEnd.3 cells, and the increase in BO concentration was beneficial for the cellular uptake of NPs. Moreover, PEG/BO-ITZ-NPs displayed an approximately 3.5-fold higher area under the curve in rats and about 2-fold higher brain distribution in mice than that of Sporanox®, i.e. ITZ solubilized by hydroxylpropyl-β-cyclodetrin, after i.v. administration. In a word, BO and PEG dual modified BSA nanoparticles may potentially serve as an ITZ vehicle for brain targeting.

Borneol-modified chitosan: Antimicrobial adhesion properties and application in skin flora protection

Antimicrobial modifications of chitosan usually endow the products with strong bactericidal activities. However, if the products come into direct contact with human skin, the skin flora, which is beneficial to human health, may be damaged. To address this issue, we developed a stereochemical antimicrobial strategy by grafting borneol 4-formylbenzoate to chitosan using a stable Schiff base bond; this process yielded borneol-modified chitosan (BMC) as a novel antimicrobial material. This material was challenged with gram-negative Escherichia coli, gram-positive Bacillus subtilis, and Aspergillus niger. All tests showed excellent antimicrobial adhesive properties. Guinea pig skin experiments further demonstrated that BMC did not damage the skin flora. Owing to the antimicrobial mechanism of borneol stereochemistry, BMC successfully defended against pathogens and protected the skin flora. Thus, this material may have excellent potential applications in multifunctional textiles, healthcare, and flexible skin electronics.

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

Puerarin (PUE) and tetramethylpyrazine (TMP) are central nervous system (CNS) drugs used in cerebrovascular diseases. Poor brain–blood barrier (BBB) permeability limited their clinical application. Borneol and α-asarone have been proposed as an oral brain-targeting enhancer. In this study, we aimed to first evaluate the ‘orifice-opening’ effect of borneol and α-asarone, both aromatic resuscitation drugs, on improvement of brain delivery of PUE and TMP and second to investigate whether the enhancing effects were associated with adenosine receptors (ARs)-mediated trans-BBB pathway. In vitro BBB model was established and borneol and α-asarone significantly increased the cumulative amount of permeated PUE and TMP and the enhancing effects could be counteracted by AR inhibitors. Borneol and α-asarone could decrease expression of ZO-1, an important BBB junction protein, but inversely increase the expression of A₁AR and A_2AAR. In vivo pharmacokinetic study also confirmed that oral co-administration of borneol or α-asarone significantly increased AUC_brain for PUE and TMP. These results suggested that borneol and α-asarone are both effective adjuvant agents for delivery of PUE and TMP to the brain.

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.

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.

Chemotaxis by Pseudomonas putida (ATCC 17453) towards camphor involves cytochrome P450cam (CYP101A1)

The camphor-degrading microorganism, Pseudomonas putida strain ATCC 17453, is an aerobic, gram-negative soil bacterium that uses camphor as its sole carbon and energy source. The genes responsible for the catabolic degradation of camphor are encoded on the extra-chromosomal CAM plasmid. A monooxygenase, cytochrome P450_cam, mediates hydroxylation of camphor to 5-exo-hydroxycamphor as the first and committed step in the camphor degradation pathway, requiring a dioxygen molecule (O₂) from air. Under low O₂ levels, P450_cam catalyzes the production of borneol via an unusual reduction reaction. We have previously shown that borneol downregulates the expression of P450_cam. To understand the function of P450_cam and the consequences of down-regulation by borneol under low O₂ conditions, we have studied chemotaxis of camphor induced and non-induced P. putida strain ATCC 17453. We have tested camphor, borneol, oxidized camphor metabolites and known bacterial attractants (d)-glucose, (d) - and (l)-glutamic acid for their elicitation chemotactic behavior. In addition, we have used 1-phenylimidazole, a P450_cam inhibitor, to investigate if P450_cam plays a role in the chemotactic ability of P. putida in the presence of camphor. We found that camphor, a chemoattractant, became toxic and chemorepellent when P450_cam was inhibited. We have also evaluated the effect of borneol on chemotaxis and found that the bacteria chemotaxed away from camphor in the presence of borneol. This is the first report of the chemotactic behaviour of P. putida ATCC 17453 and the essential role of P450_cam in this process.

Percutaneous absorption and brain distribution facilitation of borneol on tetramethylpyrazine in a microemulsion-based transdermal therapeutic system

In this study, we show that the percutaneous absorption and brain distribution of tetramethylpyrazine (TMP) is enhanced when combined with borneol (BN) in a microemulsion-based transdermal therapeutic system (ME-TTS). The formulation of the TMP and BN microemulsion (TEM-BN-ME) was optimized in skin permeation studies in vitro following a uniform experimental design. Male Sprague-Dawley rats were used for the in vivo pharmacokinetic and tissue distribution studies of TMP-BN-ME-TTS. In the pharmacokinetic study, the TMP-BN-ME-TTS treated rats had significantly higher (P < 0.05) C_max and AUC of TMP than the TMP-ME-TTS treated rats, indicating that BN improves the rate and extent of TMP percutaneous absorption. In the tissue distribution study, the AUC of TMP in brain was significantly higher in the TMP-BN-ME-TTS group (P < 0.05), indicating that BN facilitates the distribution of TMP in brain. In summary, BN enhanced the percutaneous absorption and brain distribution of TMP in a microemulsion-based transdermal therapeutic system.

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.

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

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

Sulfate turpentine: a resource of tick repellent compounds

Compounds with tick (Ixodes ricinus) repellent properties were isolated from sulfate turpentine consisting of Norway spruce (80%) and Scots pine (20%) from southern Sweden. The turpentine was divided into two fractions by distillation under reduced pressure resulting in one monoterpene hydrocarbon fraction and a residual containing higher boiling terpenoids. The monoterpene fraction was further oxidized with SeO2 to obtain oxygenated monoterpenes with potential tick repellent properties. The oxidized fraction and the high boiling distillation residual were each separated by medium pressure liquid chromatography. The fractions were tested for tick repellency and the compounds in those with highest tick repellency were identified by GC-MS. The fractions with highest repellency contained, mainly (-)-borneol, and mixtures of (+)- and (-)-1-terpineol and terpinen-4-ol. The enantiomers of borneol showed similar tick repellent properties.

Essential Oil of Thymus munbyanus subsp. coloratus from Algeria: Chemotypification and in vitro Biological Activities

Thymus munbyanus subsp. coloratus (Lamiaceae) is a small shrub endemic to Algeria and Morocco where is found in lawns, rockeries and mountainous regions. From a phytochemical point of view this taxon has never been characterized. In this work we have analysed the chemical compositions of the essential oils obtained from inflorescences and vegetative parts by GC/MS. A new chemotype, i.e. borneol-chemotype, was characterized for the first time in the species. Furthermore, we assessed the biological activities of essential oils, namely the antioxidant, antimicrobial and cytotoxicity on tumor cells that were evaluated by the DPPH, ABTS, and FRAP, disc diffusion, and MTT methods, respectively. Biological assays highlighted a moderate inhibitory effect on Staphylococcus aureus, Escherichia coli and Candida albicans (inhibition zone diameter in the range 9 - 10 mm), and noteworthy cytotoxicity on A375 human melanoma cells (IC₅₀ of 46.95 μg/ml).

Improvement of wound tissue repair by chitosan films containing (-)-borneol, a bicyclic monoterpene alcohol, in rats

The aim of this study was to investigate the wound-healing activity of (-)-borneol (BOR) incorporated in chitosan film on healing protocol in rodents. To assess the BOR wound-healing potential, male Wistar rats were subjected to a full-thickness excisional wound. The animals were divided into three groups: dressed with chitosan-based film (QUIN); dressed with chitosan-based film containing 0·5% BOR (QUIBO05); or dressed with chitosan-based film containing 1% BOR (QUIBO1). Dressing the wound areas and histological analysis were performed on the 3rd, 7th, 14th, and 21st days. The myeloperoxidase (MPO) activity was assessed on the third and seventh days after surgical procedures. Wounds dressed with chitosan-based film containing BOR reduced significantly the MPO activity (P < 0·001), showed significantly larger wound retraction rates (7 days, P < 0·05), improved the granulation reaction, and also provided better collagenisation density and arrangement during wound healing. It is suggested that BOR modulates the wound-healing process and is a promising compound to be used in wound care. This product may be quite useful in improving wound healing and could be a new biotechnological product with healing properties and clinical application. Further ongoing studies will enable us to understand the precise mechanisms whereby BOR improves the wound-healing process.

Effect of borneol on the transdermal permeation of drugs with differing lipophilicity and molecular organization of stratum corneum lipids

The aim of the present paper was to investigate the promoting activity of borneol on the transdermal permeation of drugs with differing lipophilicity, and probe its alterations in molecular organization of stratum corneum (SC) lipids. The toxicity of borneol was evaluated in epidermal keratinocyte HaCaT and dermal fibroblast CCC-HSF-1 cell cultures and compared to known enhancers, and its irritant profile was also assessed by transepidermal water loss (TEWL) evaluation. The promoting effect of borneol on the transdermal permeation of five model drugs, namely 5-fluorouracil, antipyrine, aspirin, salicylic acid and ibuprofen, which were selected based on their lipophilicity denoted by logp value, were performed using in vitro skin permeation studies. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) was employed to monitor the borneol-induced alteration in molecular organization of SC lipids. The enhancer borneol displayed lower cytotoxicity or irritation in comparison to the well-established and standard enhancer Azone. Borneol could effectively promote the transdermal permeation of five model drugs, and its enhancement ratios were found to be parabolic curve with the logp values of drugs, which exhibited the optimum permeation activity for relatively hydrophilic drugs (an estimated logp value of -0.5 ∼0.5). The molecular mechanism studies suggested that borneol could perturb the structure of SC lipid alkyl chains, and extract part of SC lipids, resulting in the alteration in the skin permeability barrier.

Xingnaojing mPEG2000-PLA modified microemulsion for transnasal delivery: pharmacokinetic and brain-targeting evaluation

Xingnaojing microemulsion (XNJ-M) administered intranasally is used for stroke treatment. In order to decrease the XNJ-M-induced mucosal irritation, XNJ-M modified by mPEG2000-PLA (XNJ-MM) were prepared in a previous work. The present work aimed to assess the impact of mPEG2000-PLA on pharmacokinetic features and brain-targeting ability of XNJ-M. The bioavailability and brain-target effects of borneol and geniposide in XNJ-M and XNJ-MM were compared in mice after intravenous (i.v.) and intranasal (i.n.) administrations. Gas chromatography, high-performance liquid chromatography, and ultra-performance liquid chromatography/tandem mass spectrometry methods were developed for the quantification of borneol and geniposide. Blood and brain samples were collected from mice at different time points after i.v. and i.n. treatments with borneol at 8.0 mg/kg, geniposide at 4.12 mg/kg. In addition, near-infrared fluorescence dye, 1,1'-dioctadecyl-3,3,3',3'-tetramethyl indotricarbocyanine iodide was loaded into microemulsions to evaluate the brain-targeting ability of XNJ-M and XNJ-MM by near-infrared fluorescence imaging in vivo and ex vivo. For XNJ-M and XNJ-MM, the relative brain targeted coefficients (Re) were 134.59% and 198.09% (borneol), 89.70% and 188.33% (geniposide), respectively. Besides, significant near-infrared fluorescent signal was detected in the brain after i.n. administration of microemulsions, compared with that of groups for i.v. administration. These findings indicated that mPEG2000-PLA modified microemulsion improved drug entry into blood and brain compared with normal microemulsion: the introduction of mPEG2000-PLA in microemulsion resulted in brain-targeting enhancement of both fat-soluble and water-soluble drugs. These findings provide a basis for the significance of mPEG2000-PLA addition in microemulsion, defining its effects on the drugs in microemulsion.