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.

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.

(+)-Borneol enantiomer ameliorates epileptic seizure via decreasing the excitability of glutamatergic transmission.

Epilepsy is one common brain disorder, which is not well controlled by current pharmacotherapy. In this study we characterized the therapeutic potential of borneol, a plant-derived bicyclic monoterpene compound, in the treatment of epilepsy and elucidated the underlying mechanisms. The anti-seizure potency and properties of borneol were assessed in both acute and chronic mouse epilepsy models. Administration of (+)-borneol (10, 30, 100 mg/kg, i.p.) dose-dependently attenuated acute epileptic seizure in maximal-electroshock seizure (MES) and pentylenetetrazol (PTZ)-induced seizure models without obvious side-effect on motor function. Meanwhile, (+)-borneol administration retarded kindling-induced epileptogenesis and relieved fully kindled seizures. Importantly, (+)-borneol administration also showed therapeutic potential in kainic acid-induced chronic spontaneous seizure model, which was considered as a drug-resistant model. We compared the anti-seizure efficacy of 3 borneol enantiomers in the acute seizure models, and found (+)-borneol being the most satisfying one with long-term anti-seizure effect. In electrophysiological study conducted in mouse brain slices containing the subiculum region, we revealed that borneol enantiomers displayed different anti-seizure mechanisms, (+)-borneol (10 µM) markedly suppressed the high frequency burst firing of subicular neurons and decreased glutamatergic synaptic transmission. In vivo calcium fiber photometry analysis further verified that administration of (+)-borneol (100 mg/kg) inhibited the enhanced glutamatergic synaptic transmission in epilepsy mice. We conclude that (+)-borneol displays broad-spectrum anti-seizure potential in different experimental models via decreasing the glutamatergic synaptic transmission without obvious side-effect, suggesting (+)-borneol as a promising anti-seizure compound for pharmacotherapy in epilepsy.

Natural borneol enhances the anti-cerebral ischaemia efficacy of formononetin in MCAO/R rats by promoting its delivery in the brain.

Objectives Due to its high morbidity, high mortality, and high disability, stroke has been the first cause of death and the major cause of adult disability in China. Natural borneol has been widely utilized in Traditional Chinese Medicine to promote drug absorption. Formononetin is a natural isoflavonoid with potent neuroprotective activity but poor brain delivery. Methods This study aimed to screen the optimum proportion that natural borneol promotes formononetin entry into the brain, evaluate the anti-cerebral ischaemia efficacy of formononetin/natural borneol combination in middle cerebral artery occlusion/reperfusion model rats, and clarify the possible mechanism for natural borneol's promoting formononetin delivery in the brain. Key findings Our studies exhibited that natural borneol remarkably promoted formononetin entry into the brain when combined with formononetin in a 1 : 1 molar ratio and notably improved neuro-behavioural scores and reduced the infarct of middle cerebral artery occlusion/reperfusion model rats. This study further discovered that the enhanced anti-cerebral ischaemia effect resulted from natural borneol increasing the permeability of the blood-brain barrier to elevate formononetin concentration in the brain rather than the pharmacodynamic synergy or addition between formononetin and natural borneol. Conclusions The study provides a good strategy to screen drug combinations for the treatment of brain disease by combining natural borneol with other drugs.

In Silico and Ex Vivo Studies on the Spasmolytic Activities of Fenchone Using Isolated Guinea Pig Trachea.

Fenchone is a bicyclic monoterpene found in a variety of aromatic plants, including Foeniculum vulgare and Peumus boldus, and is used in the management of airways disorders. This study aimed to explore the bronchodilator effect of fenchone using guinea pig tracheal muscles as an ex vivo model and in silico studies. A concentration-mediated tracheal relaxant effect of fenchone was evaluated using isolated guinea pig trachea mounted in an organ bath provided with physiological conditions. Sustained contractions were achieved using low K+ (25 mM), high K+ (80 mM), and carbamylcholine (CCh; 1 µM), and fenchone inhibitory concentration-response curves (CRCs) were obtained against these contractions. Fenchone selectively inhibited with higher potency contractions evoked by low K+ compared to high K+ with resultant EC50 values of 0.62 mg/mL (0.58-0.72; n = 5) and 6.44 mg/mL (5.86-7.32; n = 5), respectively. Verapamil (VRP) inhibited both low and high K+ contractions at similar concentrations. Pre-incubation of the tracheal tissues with K+ channel blockers such as glibenclamide (Gb), 4-aminopyridine (4-AP), and tetraethylammonium (TEA) significantly shifted the inhibitory CRCs of fenchone to the right towards higher doses. Fenchone also inhibited CCh-mediated contractions at comparable potency to its effect against high K+ [6.28 mg/mL (5.88-6.42, n = 4); CCh] and [6.44 mg/mL (5.86-7.32; n = 5); high K+]. A similar pattern was obtained with papaverine (PPV), a phosphodiesterase (PDE), and Ca2+ inhibitor which inhibited both CCh and high K+ at similar concentrations [10.46 µM (9.82-11.22, n = 4); CCh] and [10.28 µM (9.18-11.36; n = 5); high K+]. However, verapamil, a standard Ca2+ channel blocker, showed selectively higher potency against high K+ compared to CCh-mediated contractions with respective EC50 values of 0.84 mg/mL (0.82-0.96; n = 5) 14.46 mg/mL (12.24-16.38, n = 4). The PDE-inhibitory action of fenchone was further confirmed when its pre-incubation at 3 and 5 mg/mL potentiated and shifted the isoprenaline inhibitory CRCs towards the left, similar to papaverine, whereas the Ca2+ inhibitory-like action of fenchone pretreated tracheal tissues were authenticated by the rightward shift of Ca2+ CRCs with suppression of maximum response, similar to verapamil, a standard Ca2+ channel blocker. Fenchone showed a spasmolytic effect in isolated trachea mediated predominantly by K+ channel activation followed by dual inhibition of PDE and Ca2+ channels. Further in silico molecular docking studies provided the insight for binding of fenchone with Ca2+ channel (-5.3 kcal/mol) and K+ channel (-5.7), which also endorsed the idea of dual inhibition.

Fenchone Derivatives as a Novel Class of CB2 Selective Ligands: Design, Synthesis, X-ray Structure and Therapeutic Potential.

A series of novel cannabinoid-type derivatives were synthesized by the coupling of (1S,4R)-(+) and (1R,4S)-(-)-fenchones with various resorcinols/phenols. The fenchone-resorcinol derivatives were fluorinated using Selectfluor and demethylated using sodium ethanethiolate in dimethylformamide (DMF). The absolute configurations of four compounds were determined by X-ray single crystal diffraction. The fenchone-resorcinol analogs possessed high affinity and selectivity for the CB2 cannabinoid receptor. One of the analogues synthesized, 2-(2',6'-dimethoxy-4'-(2″-methyloctan-2″-yl)phenyl)-1,3,3-trimethylbicyclo[2.2.1]heptan-2-ol (1d), had a high affinity (Ki = 3.51 nM) and selectivity for the human CB2 receptor (hCB2). In the [35S]GTPγS binding assay, our lead compound was found to be a highly potent and efficacious hCB2 receptor agonist (EC50 = 2.59 nM, E(max) = 89.6%). Two of the fenchone derivatives were found to possess anti-inflammatory and analgesic properties. Molecular-modeling studies elucidated the binding interactions of 1d within the CB2 binding site.

Molecular and functional characterization of a conserved odorant receptor from Aedes albopictus.

BACKGROUND: The Asian tiger mosquito Aedes albopictus is a competent vector of several viral arboviruses including yellow fever, dengue fever, and chikungunya. Several vital mosquito behaviors (e.g., feeding, host-seeking, mating, and oviposition) are primarily dependent on the olfactory system for semiochemicals detection and discrimination. However, the limited number of studies hampers our understanding of the relationships between the Ae. albopictus olfactory system and the complex chemical world. METHODS: We performed RT-qPCR assay on antennae of Ae. albopictus mosquitoes of different sexes, ages and physiological states, and found odorant receptor 11 (AalbOr11) enriched in non-blood-fed female mosquitoes. Then, we examined the odorant preference with a panel of physiologically and behaviorally relevant odorants in Xenopus oocytes. RESULTS: The results indicated that AalbOr11 could be activated by ten aromatics, seven terpenes, six heterocyclics, and three alcohols. Furthermore, using post-RNA interference (RNAi) hand-in-cage assay, we found that reducing the transcript level of AalbOr11 affected the repellency activity mediated by (+)-fenchone at a lower concentration (0.01% v/v). CONCLUSIONS: Using in vitro functional characterization, we found that AalbOr11 was a broadly tuned receptor. Moreover, we found that AalbOr11 shared a conserved odorant reception profile with homologous Anopheles gambiae Or11. In addition, RNAi and bioassay suggested that AablOr11 might be one of the receptors mediating (+)-fenchone repellency activity. Our study attempted to link odor-induced behaviors to odorant reception and may lay the foundation for identifying active semiochemicals for monitoring or controlling mosquito populations.

Borneol reduces sympathetic vasomotor hyperactivity and restores depressed baroreflex sensitivity in rats with renovascular hypertension.

Borneol is a bicyclic monoterpene that has long been used in traditional Chinese medicine to increase blood-brain barrier permeability and has shown promising cardiovascular effects. The present study aimed to evaluate the effect of borneol on vascular tone, blood pressure, autonomic function, and baroreflex sensitivity in normotensive and hypertensive rats. A combination of in vitro and in vivo assays was performed in 2-kidneys-1-clip hypertensive rats (2K1C) and their controls (sham). We assessed the in vivo effect of oral treatment with borneol on blood pressure, heart rate, autonomic function, and baroreflex sensitivity in sham and 2K1C rats. Additionally, the vasorelaxant effect of borneol in the superior mesenteric artery isolated from rats and its mechanism of action were evaluated. Oral administration of borneol (125 mg/kg/day) reduced blood pressure, sympathetic vasomotor hyperactivity, and serum oxidative stress and improved baroreflex sensitivity in 2K1C rats. In vessel preparations, borneol induced endothelium-independent vasodilatation after precontraction with phenylephrine or KCl (60 mM). There was no difference in the vascular effect induced by borneol in either the 2K1C or the sham group. In addition, borneol antagonized the contractions induced by CaCl2 and reversed (S)-(-)-Bay K 8644-induced contraction. These data suggest that borneol presents antihypertensive effects in 2K1C rats, which is associated with its ability to improve autonomic impairment and baroreflex dysfunction. The borneol-induced relaxation in the superior mesenteric artery involves L-type Ca2+ channel blockade. This vascular action associated with the antioxidant effect induced by borneol may be responsible, at least in part, for the in vivo effects induced by this monoterpene.

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

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

Neuroprotective effects of synthetic borneol and natural borneol based on the neurovascular unit against cerebral ischaemic injury.

OBJECTIVES: Natural borneol and synthetic borneol were commonly used to treat ischaemic stroke in clinical practice. This study evaluated their different neuroprotective effects on the remodelling and repair of the neurovascular unit (NVU) after cerebral ischaemia. METHODS: We evaluated the different effects of borneol through neurological test and staining methods in cerebral ischaemia injury. Western blot, immunohistochemistry and transmission electron microscopy were used to evaluate the reparative effects of borneol on NVU. KEY FINDINGS: The prevention and treatment of borneol could prolong recovery time, reduce body temperature and cerebral infarction rate and improve pathological conditions. Further investigations revealed that borneol could inhibit the expression of DII4, Hes1, Hes5 and p65 and increase the Nissl body number and microvessel density. They also inhibited the activation of the microglia. It was also observed through an ultramicroelectron microscope that the structural stability of the NVU has also been repaired. Moreover, natural borneol shows better results in most indicators when compared with synthetic borneol. CONCLUSIONS: Natural borneol showed a stronger effectiveness and had better regulation and neuroprotection on the NVU when compared with synthetic borneol, indicating that it may be better to use natural borneol in the prescription of Chinese patent medicine in clinical practice.

Effect and mechanism of "Danggui-kushen" herb pair on ischemic heart disease.

AIMS: The purpose of this study was to investigate the mechanism and effects of "Danggui-kushen" herb pair (DKHP) better than single drug in ischemic heart disease (IHD). METHODS: IHD model was established by left anterior descending branch of coronary artery in rats. Rats were randomized into six groups and oral administration for 7 days: control, model, Danshen dripping pills (DS) (5.103 g/kg), Danggui (DG) (2.7 g/kg), Kushen (KS) (2.7 g/kg) and DKHP (2.7 g/kg). Electrocardiogram (ECG), myocardial infarction and damage assessment, histological inspection analysis, and various biochemical indexes of myocardial tissue were measured to evaluate the myocardial damage and the protective effects of drugs. The inflammatory levels were identified by HE staining and serum cytokine, and the expression of hypoxia-inducible factor 1α (HIF-1α), inhibitor kappa B kinaseß (IKKß) and nuclear transcription factor kappa B (NF-κB) were measured by immunohistochemistry. KEY FINDINGS: The results suggested that: compared with the control group, model group showed significantly myocardial tissue abnormalities, and increased levels of inflammatory cytokine. Treatment with drugs inhibited the increase of α-hydroxybutyrate dehydrogenase (α-HBDH), creatine kinase (CK), creatinekinase isoenzyme (CK-MB), interleukin 1 (IL-1) and interleukin 6 (IL-6). The results of immunohistochemical showed that drugs-treatment inhibited the expression of IKKß and the P-p65, increased the expression of HIF-1α, which demonstrated that the anti-inflammatory effects of DKHP was achieved by suppressing of NF-κB signaling. CONCLUSION: These observations indicated that DKHP can ameliorate myocardial injury better than single. And these are related to the inhibition of NF-κB and actives HIF-1α signaling.

Compound Danshen Dripping Pill inhibits high altitude-induced hypoxic damage by suppressing oxidative stress and inflammatory responses.

CONTEXT: Previous studies indicate that compound Danshen Dripping Pill (CDDP) improves the adaptation to high-altitude exposure. However, its mechanism of action is not clear. OBJECTIVE: To explore the protective effect of CDDP on hypobaric hypoxia (HH) and its possible mechanism. MATERIALS AND METHODS: A meta-analysis of 1051 human volunteers was performed to evaluate the effectiveness of CDDP at high altitudes. Male Sprague-Dawley rats were randomized into 5 groups (n = 6): control at normal pressure, model, CDDP-170 mg/kg, CDDP-340 mg/kg and acetazolamide groups. HH was simulated at an altitude of 5500 m for 24 h. Animal blood was collected for arterial blood-gas analysis and cytokines detection and their organs were harvested for pathological examination. Expression levels of AQP1, NF-κB and Nrf2 were determined by immunohistochemical staining. RESULTS: The meta-analysis data indicated that the ratio between the combined RR of the total effective rate and the 95% CI was 0.23 (0.06, 0.91), the SMD and 95% CI of SO2 was 0.37 (0.12, 0.62). Pre-treatment of CDDP protected rats from HH-induced pulmonary edoema and heart injury, left-shifted oxygen-dissociation curve and decreased P50 (30.25 ± 3.72 vs. 37.23 ± 4.30). Mechanistically, CDDP alleviated HH-reinforced ROS by improving SOD and GPX1 while inhibiting pro-inflammatory cytokines and NF-κB expression. CDDP also decreased HH-evoked D-dimer, erythrocyte aggregation and blood hemorheology, promoting AQP1 and Nrf2 expression. DISCUSSION AND CONCLUSIONS: Pre-treatment with CDDP could prevent HH-induced tissue damage, oxidative stress and inflammatory response. Suppressed NF-κB and up-regulated Nrf2 might play significant roles in the mechanism of CDDP.

Evaluation of the analgesic potential and safety of Cinnamomum camphora chvar. Borneol essential oil.

Cinnamomum camphora chvar. Borneol essential oil (BEO, 18.2% v/v borneol) is a by-product of steam distillation to produce natural crystalline borneol (NCB, 98.4% v/v borneol). Given the known medicinal properties of borneol, the analgesic function and safety were studied. Horn's method and the Draize test revealed a gender difference in mice regarding acute oral LD50, i.e., low-toxicity to female mice (2749 mg/kg), but practically nontoxic to male mice (5081 mg/kg). There was no acute and skin or eye irritation when BEO was applied directly, if the BEO concentration was less than 50%. The analgesic effect of BEO was evaluated by the glacial acetic acid-induced writhing pain model. Continuous topical application of BEO to the abdomen of mice for 6 d, significantly reduced observed writhing in mice (p < 0.001) with a strong dose-response relationship (r = -0.9006). Concomitantly, the levels of the serum pain-related mediators, prostaglandin E2 (PGE2) and transient receptor potential melastatin-8 (TRPM8) were significantly reduced (p < 0.001), and the latter showed a strong dose-response relationship (r = -0.9427). Therefore, BEO had similar analgesic functions to borneol and was demonstrated to be safe for medicinal use.

Y-2 reduces oxidative stress and inflammation and improves neurological function of collagenase-induced intracerebral hemorrhage rats.

Intracerebral hemorrhage (ICH) is a devastating disease, and there is currently no specific pharmacological treatment that can improve clinical outcomes. Y-2 sublingual tablets, each containing 30 mg edaravone and 6 mg (+)-borneol, is undergoing a phase III clinical trial for treatment of ischemic stroke in China. The purpose of the present study is to investigate the efficacy and potential mechanism of Y-2 in a rat model of collagenase IV injection induced ICH. Sublingual administration of Y-2 at the dose of 1, 3 and 6 mg/kg improved ICH-induced sensorimotor dysfunction, alleviated cell death and histopathological change, restored the hippocampal long-term potentiation (LTP), reduced brain edema and maintained blood-brain barrier (BBB) integrality in ICH rats. Further study demonstrated that Y-2 could reduce inflammatory response and oxidative stress by decreasing the levels of myeloperoxidase (MPO), ionized calcium-binding adaptor protein-1 (Iba-1), inflammatory cytokines and oxidative products, inhibit transcription factor nuclear factor-κB (NF-κB) activation, cyclooxygenase-2 (COX-2) and matrix metallopeptidase 9 (MMP-9) expression in brain tissue around in the core regions of hematoma. Importantly, the protective efficacy of Y-2 from ICH-induced injury was superior to edaravone. In conclusion, Y-2 sublingual tablets might be a promising therapeutic agent for the treatment of ICH.

Bioinspired Durable Antibacterial and Antifouling Coatings Based on Borneol Fluorinated Polymers: Demonstrating Direct Evidence of Antiadhesion.

Substituting natural products for traditional poison-killing antifouling agents is an efficient and promising method to alleviate the increasingly serious ecological crisis and aggravate the loss due to marine biofouling. Herein, the successful synthesis of poly(methyl methacrylate-co-ethyl acrylate-co-hexafluorobutyl methacrylate-co-isobornyl methacrylate) copolymer (PBAF) with borneol monomers and fluorine by a free radical polymerization method is reported. The PBA0.09F coating exhibits outstanding antibacterial and antifouling activity, achieving 98.2% and 92.3% resistance to Escherichia coli and Staphylococcus aureus, respectively, and the number of Halamphora sp. adhesion is only 26 (0.1645 mm2) in 24 h. This remarkable antibacterial and antifouling performance is attributed to the incorporation of fluorine components into the copolymer, which induces a low surface energy and hydrophobicity and the complex molecular structure of the natural nontoxic antifouling agent borneol. In addition, the results showed that the contents of the adhesion-related proteins mfp-3, mfp-5, and mfp-6 were significantly reduced, which proved that natural substances affect the secretion of biological proteins. Importantly, the PBAF coating exhibits excellent environmental friendliness and long-term stability. The antifouling mechanism is clarified, and an effective guide for an environmentally friendly antifouling coating design is proposed.

Appraisal of hypotensive effect of natural monoterpene: Bornyl acetate and in-silico molecular docking analysis.

The modern trend of research is highly focused on finding new bioactive molecules from medicinal plants. As a functional bicyclic monoterpene, Bornyl acetate (BA) has displayed antioxidant and anti-inflammatory properties in different types of cells and tissues. The purpose of this research was to evaluate the probable hypotensive effect of BA, an underlying mechanism(s) backboned by in-silico studies. Mean arterial pressure and heart rate were recorded via invasive blood pressure measuring technique in normotensive Sprague-Dawley rats following the administration of BA (1-80mg/kg). Docking studies were carried out with various targets involved in the pathophysiology of hypertension.RO5 and ADMET properties were also evaluated. In the current study dose-dependent reduction in systolic, diastolic and mean arterial pressure was observed. Pretreatment with atropine and captopril significantly (p<0.001) reduced the hypotensive effect produced by BA. On the other hand docking studies showed pronounced interactions with M2 mAch receptor in an agonistic way and ACE protein in an antagonistic way. BA justified all cut-off limits of RO5 and had an acceptable predicted computational toxicity profile. Results postulate that dose-dependent hypotensive effect of BA is mediated through the muscarinic pathway and ACE inhibitory activity corresponding well with findings of in-silico studies.

Neuroprotection with the Cannabidiol Quinone Derivative VCE-004.8 (EHP-101) against 6-Hydroxydopamine in Cell and Murine Models of Parkinson's Disease.

The 3-hydroxyquinone derivative of the non-psychotrophic phytocannabinoid cannabigerol, so-called VCE-003.2, and some other derivatives have been recently investigated for neuroprotective properties in experimental models of Parkinson's disease (PD) in mice. The pharmacological effects in those models were related to the activity on the peroxisome proliferator-activated receptor-γ (PPAR-γ) and possibly other pathways. In the present study, we investigated VCE-004.8 (formulated as EHP-101 for oral administration), the 3-hydroxyquinone derivative of cannabidiol (CBD), with agonist activity at the cannabinoid receptor type-2 (CB2) receptor in addition to its activity at the PPAR-γ receptor. Studies were conducted in both in vivo (lesioned-mice) and in vitro (SH-SY5Y cells) models using the classic parkinsonian neurotoxin 6-hydroxydopamine (6-OHDA). Our data confirmed that the treatment with VCE-004.8 partially reduced the loss of tyrosine hydroxylase (TH)-positive neurons measured in the substantia nigra of 6-OHDA-lesioned mice, in parallel with an almost complete reversal of the astroglial (GFAP) and microglial (CD68) reactivity occurring in this structure. Such neuroprotective effects attenuated the motor deficiencies shown by 6-OHDA-lesioned mice in the cylinder rearing test, but not in the pole test. Next, we explored the mechanism involved in the beneficial effect of VCE-004.8 in vivo, by analyzing cell survival in cultured SH-SY5Y cells exposed to 6-OHDA. We found an important cytoprotective effect of VCE-004.8 at a concentration of 10 µM, which was completely reversed by the addition of antagonists, T0070907 and SR144528, aimed at blocking PPAR-γ and CB2 receptors, respectively. The treatment with T0070907 alone only caused a partial reversal, whereas SR144528 alone had no effect, indicating a major contribution of PPAR-γ receptors in the cytoprotective effect of VCE-004.8 at 10 µM. In summary, our data confirmed the neuroprotective potential of VCE-004.8 in 6-OHDA-lesioned mice, and in vitro studies confirmed a greater relevance for PPAR-γ receptors rather than CB2 receptors in these effects.

Quaternary ammonium salts based on (-)-borneol as effective inhibitors of influenza virus.

A series of compounds containing a 1,7,7-trimethylbicyclo[2.2.1]heptane fragment were evaluated for their antiviral activity against influenza A virus strain A/Puerto Rico/8/34 (H1N1) in vitro. The most potent antiviral compound proved to be a quaternary ammonium salt based on (-)-borneol, 10a. In in vitro experiments, compound 10a inhibited influenza A viruses (H1, H1pdm09, and H3 subtypes), with an IC50 value of 2.4-16.8 µM (depending on the virus), and demonstrated low toxicity (CC50 = 1311 µM). Mechanism-of-action studies for compound 10a revealed it to be most effective when added at the early stages of the viral life cycle. In direct haemolysis inhibition tests, compound 10a was shown to decrease the membrane-disrupting activity of influenza A virus strain A/Puerto Rico/8/34. According to molecular modelling results, the lead compound 10a can bind to different sites in the stem region of the viral hemagglutinin.

Site-selective labeling and electron paramagnetic resonance studies of human cannabinoid receptor CB2.

Integral membrane G protein-coupled receptors (GPCR) regulate multiple physiological processes by transmitting signals from extracellular milieu to intracellular proteins and are major targets of pharmaceutical drug development. Since GPCR are inherently flexible proteins, their conformational dynamics can be studied by spectroscopic techniques such as electron paramagnetic resonance (EPR) which requires selective chemical labeling of the protein. Here, we developed protocols for selective chemical labeling of the recombinant human cannabinoid receptor CB2 by judiciously replacing naturally occurring reactive cysteine residues and introducing a new single cysteine residue in selected positions. The majority of the 47 newly generated single cysteine constructs expressed well in E. coli cells, and more than half of them retained high functional activity. The reactivity of newly introduced cysteine residues was assessed by incorporating nitroxide spin label and EPR measurement. The conformational transition of the receptor between the inactive and activated form were studied by EPR of selectively labeled constructs in the presence of either a full agonist CP-55,940 or an inverse agonist SR-144,528. We observed evidence for higher mobility of labels in the center of internal loop 3 and a structural change between agonist vs. inverse agonist-bound CB2 in the extracellular tip of transmembrane helix 6. Our results demonstrate the utility of EPR for studies of conformational dynamics of CB2.

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.