Guiming Yan

The therapeutic potential of cannabinoids is increasingly recognized; however, their use is often associated with adverse effects, such as conditioned place aversion (CPA). The molecular mechanisms underlying CPA remain poorly understood, particularly the role of the kynurenine pathway (KP) and its interaction with cannabinoid receptors. This study aimed to elucidate these mechanisms, focusing on the synthetic. We employed a mouse conditioned place preference behavioral model to assess CPA following the administration of CP-55940 at a dosage of 1 mg/kg via intraperitoneal injection. We conducted a comprehensive analysis of key metabolites in the kynurenine pathway, specifically measuring levels of kynurenic acid (KYNA) in the hippocampus, while also monitoring quinolinic acid levels for comparison. Additionally, we utilized pharmacological inhibition of KATII with PF-04859989 to further explore KYNA’s role in mediating CPA. Our findings revealed significant increases in tryptophan, kynurenine, and KYNA levels in the hippocampus following administration of CP-55940, whereas quinolinic acid levels remained unchanged. Notably, pharmacological inhibition of KATII effectively reduced CPA, thereby affirming the critical role of KYNA in the aversive response. Furthermore, we observed that KYNA downregulated CB1 receptor (CB1R) expression, which was restored upon inhibition of KYNA synthesis. Additionally, G protein-coupled receptor 35 (GPR35) expression was significantly reduced in the CPA model, and its levels were positively correlated with KYNA, suggesting intricate molecular interactions. This study elucidates the complex interplay between KYNA, CB1R, and GPR35 in the context of cannabinoid-induced CPA, highlighting the pivotal role of the TRP–KYN pathway in mediating adverse behavioral effects associated with cannabinoids. These findings open avenues for the development of therapeutic targets aimed at mitigating such effects. Future research should focus on validating these results through gene knockout models and further exploring the clinical implications of KYNA modulation in cannabinoid pharmacology and neuropsychiatric disorders. The online version contains supplementary material available at 10.1186/s12993-026-00327-z.

Thyroid dysfunction and diabetes are reported to be associated with depression. However, their role in the suicide risk in patients with major depressive disorder (MDD) is unclear. The purpose of this study was to investigate and compare thyroid dysfunction and diabetes between suicide attempters and non-suicide attempters in a large sample of first-episode drug-naïve (FEND) MDD patients. A descriptive study was conducted on 1279 Chinese outpatients with a diagnosis of first-episode MDD. Their sociodemographic information, blood levels of thyroid hormones, glucose, lipids and body mass index (BMI) parameters were collected. The positive subscales of the positive and negative syndrome scale (PANSS), Hamilton Anxiety Rating Scale (HAMA), Hamilton Depression Rating Scale (HAMD) were measured for psychotic, anxiety and depressive symptoms. Our results showed that compared with non-suicide attempters (P<0.01), suicide attempters had statistically higher scores on HAMD, HAMA and PANSS psychotic symptoms, as well as higher thyroid stimulating hormone (TSH) serum levels, glucose, anti-thyroglobulin (A-TG), anti-thyroid peroxidase (A-TPO), total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), systolic blood pressure and diastolic blood pressure (all with P<0.001). Further logistic regression analysis indicated that suicide attempts were associated with MDD. These results revealed that TSH, A-TG, A-TPO, TC, TG and LDL-C may be promising biomarkers of suicide risk in MDD, implying the importance of regular assessment of blood glucose level and thyroid function parameters for suicide prevention, along with possible treatment for impaired thyroid function and diabetes for the suicide intervention in MDD patients. Such patients with abnormal blood sugar and TSH must undergo thorough screening for suicidal ideation.

Oropharyngeal candidiasis (OPC) is an oral infection mainly caused by Candida albicans, a dimorphic human opportunistic pathogen that can proliferate and invade the superficial oral epithelium using its hyphae. The filamentation of C. albicans is a hallmark of biofilm formation, accompanied by the occurrence of a hypoxic microenvironment. Paeonol (PAE) is a traditional medicine with multiple properties. In a previous study, we demonstrated the synergism of PAE plus Fluconazole (FLU) or Amphotericin B (AmB) against C. albicans in vitro and in vivo. This study aimed to explore the therapeutic mechanisms of drug combinations on OPC. In an established OPC mouse model, the culture of hypoxia was observed by calcofluor white and hypoxyprobe staining. The expression and levels of IL-17 signaling-associated genes and proteins (IL-17A and IL-23) were evaluated in tissue homogenates and EC109 cells. The results show that compared with the single therapy, PAE plus FLU or AmB can decrease fungal burden, restore mucosal integrity, and reduce the hypoxic microenvironment and inflammation in the OPC mice. Relative to infected mice, the drug combinations can also rectify the abnormal expression of hypoxia inducible factor (hif)-1α, il-17a, and il-23 mRNA. Meanwhile, compared with the infected EC109 cells treated with a single drug, PAE plus FLU or AmB significantly inhibited the mRNA and protein expression of HIF-1α, IL-17A, and IL-23. Taken together, the possible mechanism of PAE plus FLU or AmB can be attributed to the regulation of hypoxia-associated IL-17 signaling in OPC treatment.

This study aimed to evaluate the mono- and dual- antifungal activities of paeonol (PAE) and fluconazole (FLZ)/amphotericin B (AmB). To this end, the effects of PAE and FLZ/AmB on cell surface hydrophobicity, hydrolase activity, morphological transition were investigated in vitro and in a Galleria mellonella infection model. The results showed a relatively high minimum inhibitory concentration (MIC) and sessile MIC (SMIC) of PAE alone. However, compared with the single drug, the combined use of PAE and FLZ/AmB had a potent synergistic potential to inhibit the virulence factors for Candida. The concomitant use of two drugs was consistently more effective than either drug alone for increasing survival rate, decreasing the fungal burden, and alleviating the pathological features of G. mellonella infected by the fungus. Taken together, these findings demonstrate the anti-Candida effects of PAE plus FLZ/AmB and their potential to increase the sensitivity of C. albicans to FLZ/AmB of PAE.

Here, we aim to investigate the antifungal effect and mechanism of action of sodium new houttuyfonate (SNH) against Candida albicans. Microdilution analysis results showed that SNH possesses potent inhibitory activity against C. albicans SC5314, with a MIC₈₀ of 256 μg/mL. Furthermore, we found that SNH can effectively inhibit the initial adhesion of C. albicans. Inverted microscopy, crystal violet staining, scanning electron microscopy and confocal laser scanning microscopy results showed that morphological changes during the transition from yeast to hypha and the biofilm formation of C. albicans are repressed by SNH treatment. We also found that SNH can effectively inhibit the biofilm formation of clinical C. albicans strains (Z103, Z3044, Z1402, and Z1407) and SNH in combination with fluconazole, berberine chloride, caspofungin and itraconazole antifungal agents can synergistically inhibit the biofilm formation of C. albicans. Eukaryotic transcriptome sequencing and qRT-PCR results showed that SNH treatment resulted in significantly down-regulated expression in several biofilm formation related genes in the Ras1-cAMP-Efg1 pathway (ALS1, ALA1, ALS3, EAP1, RAS1, EFG1, HWP1, and TEC1) and significantly up-regulated expression in yeast form-associated genes (YWP1 and RHD1). We also found that SNH can effectively reduce the production of key messenger cAMP in the Ras1-cAMP-Efg1 pathway. Furthermore, using Galleria mellonella as an in vivo model we found that SNH can effectively treat C. albicans infection in vivo. Our presented results suggest that SNH exhibits potential antibiofilm effects related to inhibiting the Ras1-cAMP-Efg1 pathway in the biofilm formation of C. albicans.

Inflammatory bowel disease (IBD), which consists of ulcerative colitis (UC) and Crohn's disease (CD), is a chronic inflammatory disorder of the gastrointestinal tract. Occurrence and development of UC have been associated with multiple potential causative factors, which include fungal dysbiosis. Growing evidence reveals that Candida albicans-associated dysbiosis is correlated with clinical deterioration in UC. Paeonol (PAE) is a commonly used traditional medicine with multiple reported properties including effective alleviation of UC. In this study, a murine UC model was established by colonizing mice with additional C. albicans via gavage prior to dextran sodium sulfate (DSS) administration. Effects of PAE treatment were also assessed at initiation and in preestablished C. albicans-associated colitis. The results showed that C. albicans supplementation could aggravate disease activity index (DAI), compromise mucosal integrity, exacerbate fecal and tissue fungal burdens, increase serum β-glucan and anti-Saccharomyces cerevisiae antibody (ASCA) levels, promote serum and colonic tissue pro-inflammatory cytokine secretion (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8) and decrease the anti-inflammatory cytokine IL-10 level. It also stimulated Dectin-1, TLR2 and TLR4 as well as expression of their downstream effector NF-κB in colonic tissue. After PAE treatment, the adverse impacts of C. albicans on colitis were relieved, via decreased receptor-associated local and systemic inflammation. Our study suggests that PAE should be a candidate for treatment of fungal dysbiosis-associated UC and may act through the Dectin-1/NF-κB pathway in collaboration with TLR2 and TLR4. Candida albicans is believed to be an important stimulator in ulcerative colitice (UC) development. Suppressing the growth of intestinal C. albicans can be contributory to the amelioration of UC. Paeonol (PAE) is a commonly used traditional medicine with multiple biological functions. In this study, we observed that PAE could alleviate symptoms in mice UC model accompanying with burden reduction of C. albicans. Therefore, we suppose that PAE can be a candidate in the treatment of C. albicans-associated UC.

Alcoholic liver disease (ALD) is caused by long-term consumption of alcohol and has become an important social and medical problem. Intestinal fungal flora (mycobiota) play an important role in ALD, so we used the mycobiota as an entry point to explore the mechanism of action of Paeonol against ALD. Here, we found that Paeonol is effective against ALD inflammatory lesions and relieves liver fat lesions. Furthermore, we found that after the treatment of Paeonol, the fungal dysbiosis is improved, and the fungal abundance is reduced, and the translocation of β-glucan to the liver and its mediated Dectin-1/IL-1β signaling pathway is blocked. Our study shows that paeonol ameliorated acute ALD-related inflammatory injury to the liver by alleviating intestinal fungal dysbiosis and inhibiting the mycobiota-mediated Dectin-1/IL-1β signaling pathway.