Involvement of the dopamine D1 receptor system in the anxiolytic effect of cedrol in the elevated plus maze and light–dark box tests

Cedrol in ginger (Zingiber officinale) as a promising hair growth drug: The effects of oral and external administration on hair regeneration and its mechanism

Ginger is an important cooking spice and herb worldwide, and scientific research has gradually confirmed the effect of ginger on preventing hair loss. Cedrol (CE) is a small sesquiterpene molecule in ginger and its external administration (EA) has shown hope in promoting hair growth, and alternative administration mode has become a potential treatment scheme to improve the efficacy of CE. The purpose of this study is to evaluate the effects of oral administration (OA) and EA of CE on hair regeneration of C57BL/6 alopecia areata (AA) mice induced by cyclophosphamide (CP) and to clarify the potential hair growth mechanism of CE in AA model in vitro and in vivo. The results showed that CE-OA has a shorter hair-turning black time and faster hair growth rate, and can lessen hair follicle damage induced by CP and promote hair follicle cell proliferation. Its effect is superior to CE-EA. At the same time, CE can increase the cytokines IFN-γ, IL-2, and IL-7 in the serum of mice, and decrease the expression of adhesion factors ICAM-1 and ELAM-1, thus alleviating the immunosuppression induced by CP. Mechanism research shows that CE regulates the JAK3/STAT3 signaling pathway, activates the Wnt3α/β-catenin germinal center, and ameliorates oxidative stress induced by CP, thus promoting the proliferation of hair follicle cells and reversing AA. These results provide a theoretical basis for understanding the anti-AA mechanism of CE-OA, indicating that CE can be used as raw material for developing oral hair growth drugs.

Role of the telomeric factor TRF2 in post-hypoxic brain damages

The neuronal excitotoxicity that follows reoxygenation after a hypoxic period may contribute to epilepsy, Alzheimer's disease, Parkinson's disease and various disorders that are related to inadequate supplement of oxygen in neurons. Therefore, counteracting the deleterious effects of post-hypoxic stress is an interesting strategy to treat a large spectrum of neurodegenerative diseases. Here, we show that the expression of the key telomere protecting protein Trf2 decreases in the brain of mice submitted to a post-hypoxic stress. Moreover, downregulating the expression of Terf2 in hippocampal neural cells of unchallenged mice triggers an excitotoxicity-like phenotype including glutamate overexpression and behavioral alterations while overexpressing Terf2 in hippocampal neural cells of mice subjected to a post-hypoxic treatment prevents brain damages. Moreover, Terf2 overexpression in culture neurons counteracts the oxidative stress triggered by glutamate. Finally, we provide evidence that the effect of Terf2 downregulation on excitotoxicity involves Sirt3 repression leading to mitochondrial dysfunction. We propose that increasing the level of Terf2 expression is a potential strategy to reduce post-hypoxic stress damages.

Dopamine D2-like receptors on conditioned and unconditioned fear: A systematic review of rodent pharmacological studies

Growing evidence supports dopamine's role in aversive states, yet systematic reviews focusing on dopamine receptors in defensive behaviors are lacking. This study presents a systematic review of the literature examining the influence of drugs acting on dopamine D2-like receptors on unconditioned and conditioned fear in rodents. The review reveals a predominant use of adult male rats in the studies, with limited inclusion of female rodents. Commonly employed tests include the elevated plus maze and auditory-cued fear conditioning. The findings indicate that systemic administration of D2-like drugs has a notable impact on both innate and learned aversive states. Generally, antagonists tend to increase unconditioned fear, while agonists decrease it. Moreover, both agonists and antagonists typically reduce conditioned fear. These effects are attributed to the involvement of distinct neural circuits in these states. The observed increase in unconditioned fear induced by D2-like antagonists aligns with dopamine's role in suppressing midbrain-mediated responses. Conversely, the reduction in conditioned fear is likely a result of blocking dopamine activity in the mesolimbic pathway. The study highlights the need for future research to delve into sex differences, explore alternative testing paradigms, and identify specific neural substrates. Such investigations have the potential to advance our understanding of the neurobiology of aversive states and enhance the therapeutic application of dopaminergic agents.

Stimulation of Calcium/NOS/CK1α Signaling by Cedrol Triggers Eryptosis and Hemolysis in Red Blood Cells

Background

Cedrol (CRL) is a sesquiterpene alcohol present in the essential oils of coniferous trees including Cupressus and Juniperus genera. CRL has shown potent anticancer activity by virtue of apoptosis. Red blood cells (RBCs), although devoid of mitochondria and nucleus, can undergo hemolysis and eryptosis which contribute to chemotherapy-induced anemia (CIA). In this work, we explored the hemolytic and eryptotic potential of CRL in human RBCs as a safety assessment of the sesquiterpene as an anticancer agent.

Methods

RBCs from healthy donors were treated with anticancer concentrations of CRL for 24 h at 37°C with varying experimental manipulations. Hemolysis was photometrically assessed by measuring hemoglobin release whereas flow cytometry was employed to detect phosphatidylserine (PS) exposure by annexin-V-FITC, intracellular Ca2+ by Fluo4/AM, cell volume by forward scatter (FSC), and oxidative stress by 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA).

Results

Significant, concentration-responsive hemolysis was noted upon CRL exposure with concomitant K+, LDH, and AST leakage. CRL also significantly increased annexin-V-positive cells and Fluo4 fluorescence and reduced FSC. Moreover, the cytotoxicity of CRL was significantly ameliorated in the presence of L-NAME, D4476, and PEG 8,000 but was aggravated by urea and sucrose.

Conclusion

CRL stimulates hemolysis and eryptosis characterized by PS exposure, Ca2+ overload, and cell shrinkage. The hemolytic activity of CRL was mediated through nitric oxide synthase and casein kinase 1α. Blocking either enzyme may attenuate the toxicity of CRL to RBCs and prevent undesirable side effects associated with its anticancer applications.

Comparative Anti-Cancer and Anti-Inflammatory Activities of Essential Oils from the Bark and Flower of Magnolia officinalis Rehd. et Wils

This study was designed to compare the antioxidant, antitumor and anti-inflammatory effects of essential oils from the bark and flower of Magnolia officinalis Rehd. et Wils. Distillation extraction and steam distillation were used to extract EOs from the bark and flower. The results showed that the contents of EOs of SDE-F and SDE-B were much higher than that of SD-F and SD-B. EOs from the bark were rich in eudesmol (especially α-eudesmol) and exhibited a stronger antioxidant effect than the flower. The anti-tumor effects of SD-B and SD-F on HepG2 and MDA-MB-231 cells were better than that of SDE-B and SDE-F. The inhibitory rates of SD-B and SD-F on MDA-MB-231 cells were 59.21% and 48.27%, exceeding that of positive control 5-fluorouracil (47.04%) at 50 μg/mL. All four EOs exhibited excellent anti-inflammatory activities through the regulation of nitric oxide production and pro-inflammation cytokines in LPS-induced RAW 264.7 cells and they also remarkably suppressed the mRNA expressions of nitric oxide synthase, IL-6 and TNF-α at the concentration higher than that of positive control dexamethasone. These results indicated significant differences in the composition, and anti-inflammatory and anti-tumor activities of EOs extracted by different methods and provided a theoretical basis for their development and utilization.

Essential oil of Pterocarpus santalinus L. alleviates behavioral impairments in social defeat stress-exposed mice by regulating neurotransmission and neuroinflammation

BACKGROUND

Pterocarpus santalinus L. essential oil (PSEO) is traditionally employed for treating fever and mental aberrations. We aim to explore the antidepressant potential of intranasal PSEO in social defeat stress (SDS)-expose mice and identify its mechanisms and components.

METHODS

PSEO components were analyzed using gas chromatography-mass spectrometry (GC-MS). C57BL/6 mice underwent a 10-day SDS with intranasal PSEO (10, 20 mg/kg) for 21 days. Efficacy was evaluated through changes in behaviors and serum corticosterone (CORT), hippocampal neurotransmitter, and inflammatory cytokine levels. In vitro effects were examined using primary hippocampal neurons, PC12 and BV2 cells.

RESULTS

GC-MS identified 22 volatile compounds in PSEO, and (+)-ledene (16.7%), cedrol (13.5%), and isoaromadendrene epoxide (7.0%) as major components. PSEO (20 mg/kg) significantly reversed SDS-induced social withdrawal, increased open-area explorations in the open field test (OFT) and elevated plus maze (EPM) test, and reduced immobility time in the tail suspension test (TST) and forced swimming test (FST). PSEO downregulated serum CORT and hippocampal interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α levels, while increasing hippocampal gamma-aminobutyric acid (GABA), norepinephrine (NE), and serotonin (5-HT) levels. PSEO (0.1, 1, 10 µg/mL) reduced neurotoxicity and neuroinflammation in PC12 and BV2 cells, respectively. PSEO (10 µg/mL) enhanced glutamic acid decarboxylase 6 (GAD6)- and GABA B receptor 1 (GABABR1)-positive puncta in the hippocampal neurons and FM1-43 fluorescence intensity.

CONCLUSION

Intranasal PSEO exhibited antidepressant-like effects on SDS-exposed mice, potentially through modulating stress hormone, neurotransmission, and neuroinflammation. Further investigation into the pharmacokinetics, bioavailability, and mechanisms of (+)-ledene, cedrol, and isoaromadendrene epoxide is needed.

Cedrol-loaded dissolvable microneedles based on flexible backing for promoting hair growth

OBJECTIVES

The dissolvable microneedles loaded with cedrol based on flexible backing were developed to deliver cedrol directly and continuously to the dermis, where the drug concentration in the hair follicle can be increased locally.

METHODS

The tip-layer matrix solution was prepared by mixing cedrol and polyvinylpyrrolidone K25 (PVP K25), and the pedestal matrix solution was prepared with aqueous hyaluronic acid. The cedrol-loaded dissolvable microneedles (cedrol-DMNs) were prepared under vacuum conditions. The mechanical properties, pig skin penetration efficiency, in vitro cutaneous permeation test, and the amount of drug in the skin and receptor chamber were evaluated. Pharmacodynamical studies were performed with C57BL/6 mice.

RESULTS

The mechanical properties of cedrol-DMNs were good. In vitro cutaneous permeation tests and pharmacodynamical studies demonstrated that cedrol-DMN could efficiently deliver the drug to the deep dermis and effectively promote hair growth.

CONCLUSIONS

The cedrol-DMNs offer a promising strategy for treating patients suffering from hair loss.

Cedrol, a Major Component of Cedarwood Oil, Ameliorates High-Fat Diet-Induced Obesity in Mice

SCOPE

Excellent health-promoting effects of cedrol (CED), including anti-inflammatory, anti-arthritic, and antinociceptive effects, have been reported. The present study aims to investigate the preventive effects of CED on high-fat diet (HFD)-induced obesity and the related metabolic syndrome, and to delineate the underlying mechanism.

METHODS AND RESULTS

Ten-week-old C57BL/6J mice are fed chow, HFD, or HFD supplemented with CED (0.2% w/w) for 19 weeks. Results demonstrate that CED effectively reduces HFD-induced body weight gain, decreases visceral fat pad weight, and significantly prevents adipocyte hypertrophy in mice. HFD-induced hepatic steatosis, glucose intolerance, insulin resistance, and gluconeogenesis are ameliorated by CED supplementation. 16S rRNA analysis reveals that CED does not change gut microbiota composition at the phylum and genus levels, indicating that CED may have limited effects on gut microbiota in HFD-fed mice. Further transcriptome analysis of epididymal white adipose tissue reveals reprogrammed RNA profiles by CED.

CONCLUSION

These results demonstrate that incorporating CED in the diet can prevent HFD-induced obesity and related metabolic syndrome, and highlight that CED can be a promising dietary component for obesity therapeutic intervention.

Involvement of GABAergic and Serotonergic Systems in the Antinociceptive Effect of Jegosaponin A Isolated from Styrax japonicus

The antinociceptive activity of the flower extracts of Styrax japonicus was confirmed in our previous study. However, the key compound for analgesia has not been distinguished, and the corresponding mechanism is obscure. In this study, the active compound was isolated from the flower by multiple chromatographic techniques and structurally illustrated using spectroscopic methods and referring to the related literature. The antinociceptive activity of the compound and the underlying mechanisms were investigated using animal tests. The active compound was determined to be jegosaponin A (JA), which showed significant antinociceptive responses. JA was also shown to possess sedative and anxiolytic activities but no anti-inflammatory effect, implying the association of the antinociceptive effects with the sedative and anxiolytic activities. Further antagonists and calcium ionophore tests showed that the antinociceptive effect of JA was blocked by flumazenil (FM, antagonist for GABA-A receptor) and reversed by WAY100635 (WAY, antagonist for 5-HT_1A receptor). Contents of 5-HT and its metabolite (5-HIAA) increased significantly in the hippocampus and striatum tissues after JA administration. The results indicated that the antinociceptive effect of JA was regulated by the neurotransmitter system, especially GABAergic and serotonergic systems.

Cedrol from ginger alleviates rheumatoid arthritis through dynamic regulation of intestinal microenvironment

The imbalance of intestinal flora would induce immune inflammation. Cedrol (CE), found from ginger by our group earlier, has been proven to play an excellent role in ameliorating rheumatoid arthritis (RA) via acting on JAK3, MAPK, and NF-κB. However, there have been no studies on CE ameliorating RA through the regulation of the micro-environment. In this study, the adjuvant arthritis model (AIA) is established to evaluate the weight, arthritis score, paw swelling, bone destruction, immune organ index, inflammatory cell infiltration, cartilage erosion, and metabolic enzymes of kidneys in AIA rats after CE intervention. The results indicated CE could alleviate paw swelling, reduce arthritis score, decrease the secretion of TNF-α, IL-6, and IL-1β in serum in a dose-dependent manner, and inhibit the immune organ index of the spleen while having no significant effect on metabolic enzymes of the kidney. In addition, pathological sections of ankle and knee joints suggested CE might significantly prevent inflammatory cell infiltration, synovial hyperplasia, and joint degeneration and protect articular cartilage. Then, for the first time, 16S rRNA gene was applied to analyze the regulatory effect of CE on intestinal flora. CE could effectively improve the uniformity, diversity, and richness of intestinal flora, reduce the number of pathogenic bacteria, and increase the proportion of beneficial bacteria, and it significantly inhibited the abundance of Prevotella in RA rats, which was 12.43 times smaller than that in methotrexate. The distribution and excretion of CE in vivo were detected by GC-MS. It was found that CE would massively accumulate in the gastrointestinal tract after oral administration, which is then mainly excreted through feces. Interestingly, the research suggested that CE, which plays a role in the dynamic regulation of the intestinal micro-environment, could be used as a potential component to prevent RA.

Mechanism of tonifying-kidney Chinese herbal medicine in the treatment of chronic heart failure

According to traditional Chinese medicine (TCM), chronic heart failure has the basic pathological characteristics of “heart-kidney yang deficiency.” Chronic heart failure with heart- and kidney-Yang deficiency has good overlap with New York Heart Association (NYHA) classes III and IV. Traditional Chinese medicine classical prescriptions for the treatment of chronic heart failure often take “warming and tonifying kidney-Yang” as the core, supplemented by herbal compositions with functions of “promoting blood circulation and dispersing blood stasis.” Nowadays, there are still many classical and folk prescriptions for chronic heart failure treatment, such as Zhenwu decoction, Bushen Huoxue decoction, Shenfu decoction, Sini decoction, as well as Qili Qiangxin capsule. This review focuses on classical formulations and their active constituents that play a key role in preventing chronic heart failure by suppressing inflammation and modulating immune and neurohumoral factors. In addition, given that mitochondrial metabolic reprogramming has intimate relation with inflammation, cardiac hypertrophy, and fibrosis, the regulatory role of classical prescriptions and their active components in metabolic reprogramming, including glycolysis and lipid β-oxidation, is also presented. Although the exact mechanism is unknown, the classical TCM prescriptions still have good clinical effects in treating chronic heart failure. This review will provide a modern pharmacological explanation for its mechanism and offer evidence for clinical medication by combining TCM syndrome differentiation with chronic heart failure clinical stages.

Dopaminergic and nitric oxide systems interact to regulate the electrical activity of neurons in the medial septal nucleus in rats

Research characterizing the neuronal substrate of anxiety has implicated different brain areas, including the medial septal nucleus (m-SEPT). Previous reports indicated a role of dopamine and nitric oxide (NO) in anxiety-related behaviors. In this study, the extracellular single-unit recording was performed from the m-SEPT in adult male albino Wistar rats. Baseline activity was recorded for 5 min, and the post-injection recording was performed for another 5 min after the microinjection of each drug. The results showed that (1) both D1- and D2-like receptor agonists (SKF-38393 and quinpirole) enhanced the firing rate of m-SEPT neurons; (2) both D1- and D2-like antagonists (SCH-23390 and sulpiride) attenuated the firing rate of m-SEPT neurons; (3) L-arginine (NO precursor) increased the firing rate of m-SEPT neurons, but a non-specific NOS inhibitor, L-NAME, elicited no significant alterations; (4) the non-specific NOS inhibitor reversed the enhanced firing rate produced by SKF-38393 and quinpirole; (5) neither of the dopaminergic antagonists changed the enhanced activity resulted from the application of the NO precursor. These results contribute to our understanding of the complex neurotransmitter interactions in the m-SEPT and showed that both dopaminergic and NO neurotransmission are involved in the modulation of the firing rate of neurons in the m-SEPT.

Anxiolytic Effect of Two Tobacco Essential Oils (Nicotiana tabacum Linn.) on Mice

Tobacco (Nicotiana tabacum Linn.) is a famous traditional herb used in folk medicine. The essential oils of tobacco have been demonstrated in modern studies to possess antioxidant, anti-inflammatory, and neuroprotective properties, while its anxiolytic effect has not been reported. The purpose of this study was to evaluate the anxiolytic effect of Yunnan tobacco essential oil (YTO) and Zimbabwe tobacco essential oil (ZTO) on mice. The constituents of YTO and ZTO were analyzed by GC/MS. The anxiolytic effect of YTO and ZTO (0.1%, 1%, and 10%, v/v) on male ICR mice was evaluated in the light-dark box test (LDB) and the elevated plus maze test (EPM) test via inhalation and transdermal administration. After the behavioral tests, salivary corticosterone levels in mice were measured. The behavioral analysis showed that the administration of both YTO and ZTO elevated the time that the mice spent in the light chamber in the LDB test compared to the untreated control. In the EPM test, YTO and ZTO increased the time spent in open arms and the number of entries into the open arms. In addition, both YTO and ZTO significantly decreased salivary corticosterone levels in mice (p ≤ 0.001). In summary, our results demonstrated that inhalation and transdermal administration of both YTO and ZTO showed anxiolytic effect on male ICR mice.

Cedrol from Ginger Ameliorates Rheumatoid Arthritis via Reducing Inflammation and Selectively Inhibiting JAK3 Phosphorylation

Ginger, as a food spice, is widely applied due to its extensive effects. Cedrol (CE) found in ginger is a sesquiterpene with anti-inflammatory activity. The objective of this research is to discuss the efficacy of CE on ameliorating rheumatoid arthritis (RA). CE inhibited chronic inflammation and pain in a dose-dependent manner accompanied by rapid onset and long duration. Besides, CE treatment effectively ameliorated the paw edema volume and arthritis score with no significant effect on body weight. Organ index, T-cell and B-cell proliferation, histopathology, and immunohistochemistry demonstrated that CE had immunological enhancement and attenuated RA effects. Remarkably, inhibition of phosphorylated-JAK3 protein, thereby abating the secretion of pro-inflammatory cytokines and inflammation-related mediators, was involved in the potential mechanism of CE efficiency through forming a hydrogen bond with ARG953 and ILE955 in the JAK3 active pocket. At the same time, the pharmacokinetic results showed that the absolute bioavailability of CE at 20, 40, and 80 mg/kg was 30.30, 23.68, and 16.11%, respectively. The current results offered clues for mastering the ameliorated RA of CE and further perfected the effective substance basis on the anti-inflammatory effect of ginger, which was beneficial for further applications.

The absence of the aryl hydrocarbon receptor in the R6/1 transgenic mouse model of Huntington's disease improves the neurological phenotype

Huntington's disease (HD) is an inherited neurodegenerative disorder caused by an abnormal CAG repeat expansion in the huntingtin gene coding for a protein with an elongated polyglutamine sequence. HD patients present choreiform movements, which are caused by the loss of neurons in the striatum and cerebral cortex. Previous reports indicate that the absence of the aryl hydrocarbon receptor (AhR) protects mice from excitotoxic insults and increases the transcription of neurotrophic factors. Based on these data, we evaluated the effects of the lack of the AhR on a mice model of HD, generating a double transgenic mouse, expressing human mutated huntingtin (R6/1 mice) and knockout for the AhR. Our results show that the body weight of 30-week-old double transgenic mice is similar to that of R6/1 mice; however, feet clasping, an indicative of neuronal damage in the R6/1 animals, was not observed. In addition, motor coordination and ambulatory behavior in double transgenic mice did not deteriorate over time as occur in the R6/1 mice. Moreover, the anxiety behavior of double transgenic mice was similar to wild type mice. Interestingly, astrogliosis is also reduced in the double transgenic mice. The present data demonstrate that the complete loss of the AhR reduces the motor and behavioral deterioration observed in R6/1 mice, suggesting that the pharmacological modulation of the AhR could be a therapeutic target in HD.