Electroacupuncture for weight loss by regulating microglial polarization in the arcuate nucleus of the hypothalamus.

Electroacupuncture (EA) has a weight loss effect, but the underlying molecular mechanisms of weight loss with EA have not been fully elucidated. This study aimed to investigate the modulatory effects of EA on the phenotype of hypothalamic microglia in obese mice. A total of 50 male C57BL/6J mice were used in this study. There were three groups in this experiment: The conventional diet group (Chow group), the high-fat diet group (HFD group), and the EA intervention group (HFD + EA group). EA was applied at "Tianshu (ST25)", "Guanyuan (RN4)", "Zusanli (ST36)" and "Zhongwan (RN12)" every day for 10 min. Hematoxylin and eosin (H&E) staining, immunohistochemical staining, and real-time PCR were applied in this study. The results showed that EA intervention was associated with a decrease in body weight, food intake, adipose tissue weight, and adipocyte size. At the same time, EA induced microglia to exhibit an M2 phenotype, representing reduced iNOS/TNF-α and increased Arg-1/IL-10/BDNF, which may be due to the promotion of TREM2 expression. EA also reduced microglia enrichment in the hypothalamic arcuate nucleus and declined TLR4 and IL-6, inhibiting microglia-mediated neuroinflammation. In addition, EA treatment promoted POMC expression, which may be associated with reduced food intake and weight loss in obese mice. This work provides novel evidence of EA against obesity. However, further study is necessary of EA as a therapy for obesity.

Comparative Metabolomics Analysis of Different Perilla Varieties Provides Insights into Variation in Seed Metabolite Profiles and Antioxidant Activities.

Perilla seeds are essential functional foods and key ingredients in traditional medicine. Herein, we investigated the variation in phytochemical profiles and antioxidant activities of twelve different perilla seeds. The seeds showed significant variations in total phenolic and flavonoid contents ranging from 16.92 to 37.23 mg GAE/g (GAE, gallic acid equivalent) and 11.6 to 19.52 mg CAE/g (CAE, catechin equivalent), respectively. LC-QqQ-MS (liquid chromatography triple quadrupole tandem mass spectrometry)-based widely targeted metabolic profiling identified a total of 975 metabolites, including 68-269 differentially accumulated metabolites (DAMs). Multivariate analyses categorized the seeds into four groups based on the seed coat and leaf colors. Most key bioactive DAMs, including flavonoids (quercetin-3'-O-glucoside, prunin, naringenin, naringenin chalcone, butin, genistin, kaempferol-3-O-rutinoside, etc.), amino acids (valine, lysine, histidine, glutamine, threonine, etc.), and vitamins (B1, B3, B6, U, etc.) exhibited the highest relative content in PL3 (brown seed, purple leaf), PL1 (white seed, green-purple leaf), and PL4 (white seed, green leaf) groups, respectively. Meanwhile, key differentially accumulated phenolic acids showed a higher relative content in PL1 and PL4 than in other groups. Both seeds exhibited high antioxidant activities, although those of PL2 (brown seed, green leaf) group seeds were the lowest. Our results may facilitate the comprehensive use of perilla seeds in food and pharmaceutical industries.

Micro-CT and SEM investigation of sound absorption structure and chambers in the otoliths of Giant Panda fish species - Chinese Bahaba (Bahaba taipingensis).

As a critically endangered (CR) fish species, Chinese Bahaba is a unique "Giant Panda" fish species in China and has been listed among the national first-class wildlife protection animals and China's top 10 genetic resources of aquatic products since 2021. This fish species is of high commercial value because its swim bladder is commonly used in traditional Chinese medicine. Its otoliths are the sensory organs immersed in the endolymph for maintaining its balance and hearing. However, rare information has been reported on the sound absorption structure and chambers of otoliths of such "Giant Panda" fish. The big "C" groove was found in the fish's front sagittal otolith with the crystal cluster in the back sagittal otolith, the former of which is a 3D layered structure, that is constructed by elongated prismatic crystals. Besides, there are numerous small holes and adhesion material in this 3D layered structure, where many chambers were also found, indicating that some specific sounds may be captured by this structure and these chambers may then amplify such sounds at a certain wavelength. This finding could be of great importance for protecting and conserving this critically endangered species.

Comparative metabolomics analysis of different sesame (Sesamum indicum L.) tissues reveals a tissue-specific accumulation of metabolites.

BACKGROUND: Sesame (Sesamum indicum L.) leaves, flowers, especially seeds are used in traditional medicine to prevent or cure various diseases. Its seed's market is expanding. However, the other tissues are still underexploited due to the lack of information related to metabolites distribution and variability in the plant. Herein, the metabolite profiles of five sesame tissues (leaves, fresh seeds, white and purple flowers, and fresh carpels) have been investigated using ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS)-based widely targeted metabolomics analysis platform. RESULTS: In total, 776 metabolites belonging to diverse classes were qualitatively and quantitatively identified. The different tissues exhibited obvious differences in metabolites composition. The majority of flavonoids predominantly accumulated in flowers. Amino acids and derivatives, and lipids were identified predominantly in fresh seeds followed by flowers. Many metabolites, including quinones, coumarins, tannins, vitamins, terpenoids and some bioactive phenolic acids (acteoside, isoacteoside, verbascoside, plantamajoside, etc.) accumulated mostly in leaves. Lignans were principally detected in seeds. 238 key significantly differential metabolites were filtered out. KEGG annotation and enrichment analyses of the differential metabolites revealed that flavonoid biosynthesis, amino acids biosynthesis, and phenylpropanoid biosynthesis were the main differently regulated pathways. In addition to the tissue-specific accumulation of metabolites, we noticed a cooperative relationship between leaves, fresh carpels, and developing seeds in terms of metabolites transfer. Delphinidin-3-O-(6"-O-p-coumaroyl)glucoside and most of the flavonols were up-regulated in the purple flowers indicating they might be responsible for the purple coloration. CONCLUSION: This study revealed that the metabolic processes in the sesame tissues are differently regulated. It offers valuable resources for investigating gene-metabolites interactions in sesame tissues and examining metabolic transports during seed development in sesame. Furthermore, our findings provide crucial knowledge that will facilitate sesame biomass valorization.

Genome-Wide Analysis of nsLTP Gene Family and Identification of SiLTPs Contributing to High Oil Accumulation in Sesame (Sesamum indicum L.).

The biosynthesis and storage of lipids in oil crop seeds involve many gene families, such as nonspecific lipid-transfer proteins (nsLTPs). nsLTPs are cysteine-rich small basic proteins essential for plant development and survival. However, in sesame, information related to nsLTPs was limited. Thus, the objectives of this study were to identify the Sesamum indicum nsLTPs (SiLTPs) and reveal their potential role in oil accumulation in sesame seeds. Genome-wide analysis revealed 52 SiLTPs, nonrandomly distributed on 10 chromosomes in the sesame variety Zhongzhi 13. Following recent classification methods, the SiLTPs were divided into nine types, among which types I and XI were the dominants. We found that the SiLTPs could interact with several transcription factors, including APETALA2 (AP2), DNA binding with one finger (Dof), etc. Transcriptome analysis showed a tissue-specific expression of some SiLTP genes. By integrating the SiLTPs expression profiles and the weighted gene co-expression network analysis (WGCNA) results of two contrasting oil content sesame varieties, we identified SiLTPI.23 and SiLTPI.28 as the candidate genes for high oil content in sesame seeds. The presumed functions of the candidate gene were validated through overexpression of SiLTPI.23 in Arabidopsis thaliana. These findings expand our knowledge on nsLTPs in sesame and provide resources for functional studies and genetic improvement of oil content in sesame seeds.

NAD+ administration decreases microvascular damage following cardiac ischemia/reperfusion by restoring autophagic flux.

Microvascular damage is a key pathological change in myocardial ischemia/reperfusion (I/R) injury. Using a rat model of myocardial I/R, our current study has provided the first evidence that nicotinamide adenine dinucleotide (NAD+) administration can significantly attenuate myocardial I/R-induced microvascular damage, including reduced regional blood perfusion, decreased microvessel density and integrity, and coronary microvascular endothelial cells (CMECs) injury. In studies with primary cultured CMECs under hypoxia/reoxygenation (HR) and a rat model of I/R, our results suggested that the protective effect of NAD+ on CMECs exposed to HR or I/R is at least partially mediated by the NAD+-induced restoration of autophagic flux, especially lysosomal autophagy: NAD+ treatment markedly induced transcription factor EB (TFEB) activation and attenuated lysosomal dysfunction in the I/R or HR-exposed cells. Collectively, our study has provided the first in vivo and in vitro evidence that NAD+ significantly rescued the impaired autophagic flux and cell apoptosis that was induced by I/R in rat CMECs, which is mediated in part through the action of TFEB-mediated lysosomal autophagy.

Root diversity in sesame (Sesamum indicum L.): insights into the morphological, anatomical and gene expression profiles.

MAIN CONCLUSION: Sesame harbors a large diversity in root morphological and anatomical traits and a high root biomass improves the plant aboveground biomass as well as the seed yield. Sesame provides one of the most nutritious and healthy vegetable oils, sparking an increasing demand of its seeds. However, with the low yield and productivity of sesame, there is still a huge gap between the seed demand and supply. Improving the root system has a high potential to increase crop productivity, but information on the diversity of the sesame root systems is still lacking. In this study, 40 diverse sesame varieties were grown in soil and hydroponics systems and the diversity of the root system was investigated. The results showed that sesame holds a large root morphological and anatomical diversity, which can be harnessed in breeding programmes. Based on the clustering of the genotypes in hydroponics and soil culture systems, we found that similar genotypes were commonly clustered either in the small-root or in the big-root group, indicating that the hydroponics system can be employed for a large-scale root phenotyping. Our results further revealed that the root biomass positively contributes to increased seed yield in sesame, based on multi-environmental trials. By comparing the root transcriptome of two contrasting genotypes, 2897 differentially expressed genes were detected and they were enriched in phenylpropanoid biosynthesis, starch and sucrose metabolism, stilbenoid, diarylheptanoid and gingerol biosynthesis, flavonoid biosynthesis, suggesting that these pathways are crucial for sesame root growth and development. Overall, this study sheds light on the diversity of sesame root system and offers the basis for improving root traits and increasing sesame seed yield.

Identification of diterpenoid compounds that interfere with Fli-1 DNA binding to suppress leukemogenesis.

The ETS transcription factor Fli-1 controls the expression of genes involved in hematopoiesis including cell proliferation, survival, and differentiation. Dysregulation of Fli-1 induces hematopoietic and solid tumors, rendering it an important target for therapeutic intervention. Through high content screens of a library of chemicals isolated from medicinal plants in China for inhibitors of a Fli-1 transcriptional reporter cells, we hereby report the identification of diterpenoid-like compounds that strongly inhibit Fli-1 transcriptional activity. These agents suppressed the growth of erythroleukemic cells by inducing apoptosis and differentiation. They also inhibited survival and proliferation of B-cell leukemic cell lines as well as primary B-cell lymphocytic leukemia (B-CLL) isolated from 7 patients. Moreover, these inhibitors blocked leukemogenesis in a mouse model of erythroleukemia, in which Fli-1 is the driver of tumor initiation. Computational docking analysis revealed that the diterpenoid-like compounds bind with high affinity to nucleotide residues in a pocket near the major groove within the DNA-binding sites of Fli-1. Functional inhibition of Fli-1 by these compounds triggered its further downregulation through miR-145, whose promoter is normally repressed by Fli-1. These results uncover the importance of Fli-1 in leukemogenesis, a Fli-1-miR145 autoregulatory loop and new anti-Fli-1 diterpenoid agents for the treatment of diverse hematological malignancies overexpressing this transcription factor.

Novel flavagline-like compounds with potent Fli-1 inhibitory activity suppress diverse types of leukemia.

E26 transformation-specific (ETS) gene family contains a common DNA-binding domain, the ETS domain, responsible for sequence-specific DNA recognition on target promoters. The Fli-1 oncogene, a member of ETS gene family, plays a critical role in hematopoiesis and is overexpressed in diverse hematological malignancies. This ETS transcription factor regulates genes controlling several hallmarks of cancer and thus represents an excellent target for cancer therapy. By screening compounds isolated from the medicinal plant Dysoxylum binectariferum in China, we identified two chemically related flavagline-like compounds including 4'-demethoxy-3',4'-methylenedioxyrocaglaol and rocaglaol that strongly inhibited Fli-1 transactivation ability. These compounds altered expression of Fli-1 target genes including GATA1, EKLF, SHIP1, and BCL2. Consequently, the flavagline-like compounds suppressed proliferation, induced apoptosis, and promoted erythroid differentiation of leukemic cells in culture. These compounds also suppressed erythroleukemogenesis in vivo in a Fli-1-driven mouse model. Mechanistically, the compounds blocked c-Raf-MEK-MAPK/ERK signaling, reduced phosphorylation of eukaryotic translation initiation factor 4E (eIF4E), and inhibited Fli-1 protein synthesis. Consistent with its high expression in myelomas, B-cell lymphoma, and B chronic lymphocytic leukemia (B-CLL), pharmacological inhibition of Fli-1 by the flavagline-like compounds or genetic knock-down via shRNA significantly hindered proliferation of corresponding cell lines and patients' samples. These results uncover a critical role of Fli-1 in growth and survival of various hematological malignancies and point to flavagline-like agents as lead compounds for the development of anti-Fli-1 drugs to treat leukemias/lymphomas overexpressing Fli-1.

A screen for Fli-1 transcriptional modulators identifies PKC agonists that induce erythroid to megakaryocytic differentiation and suppress leukemogenesis.

The ETS-related transcription factor Fli-1 affects many developmental programs including erythroid and megakaryocytic differentiation, and is frequently de-regulated in cancer. Fli-1 was initially isolated following retrovirus insertional mutagenesis screens for leukemic initiator genes, and accordingly, inhibition of this transcription factor can suppress leukemia through induction of erythroid differentiation. To search for modulators of Fli-1, we hereby performed repurposing drug screens with compounds isolated from Chinese medicinal plants. We identified agents that can transcriptionally activate or inhibit a Fli-1 reporter. Remarkably, agents that increased Fli-1 transcriptional activity conferred a strong anti-cancer activity upon Fli-1-expressing leukemic cells in culture. As opposed to drugs that suppress Fli1 activity and lead to erythroid differentiation, growth suppression by these new Fli-1 transactivating compounds involved erythroid to megakaryocytic conversion (EMC). The identified compounds are structurally related to diterpene family of small molecules, which are known agonists of protein kinase C (PKC). In accordance, these PKC agonists (PKCAs) induced PKC phosphorylation leading to activation of the mitogen-activated protein kinase (MAPK) pathway, increased cell attachment and EMC, whereas pharmacological inhibition of PKC or MAPK diminished the effect of our PKCAs. Moreover, in a mouse model of leukemia initiated by Fli-1 activation, the PKCA compounds exhibited strong anti-cancer activity, which was accompanied by increased presence of CD41/CD61 positive megakaryocytic cells in leukemic spleens. Thus, PKC agonists offer a novel approach to combat Fli-1-induced leukemia, and possibly other cancers,by inducing EMC in part through over-activation of the PKC-MAPK-Fli-1 pathway.

Immunisation With Immunodominant Linear B Cell Epitopes Vaccine of Manganese Transport Protein C Confers Protection against Staphylococcus aureus Infection.

Vaccination strategies for Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA) infections have attracted much research attention. Recent efforts have been made to select manganese transport protein C, or manganese binding surface lipoprotein C (MntC), which is a metal ion associated with pathogen nutrition uptake, as potential candidates for an S. aureus vaccine. Although protective humoral immune responses to MntC are well-characterised, much less is known about detailed MntC-specific B cell epitope mapping and particularly epitope vaccines, which are less-time consuming and more convenient. In this study, we generated a recombinant protein rMntC which induced strong antibody response when used for immunisation with CFA/IFA adjuvant. On the basis of the results, linear B cell epitopes within MntC were finely mapped using a series of overlapping synthetic peptides. Further studies indicate that MntC113-136, MntC209-232, and MntC263-286 might be the original linear B-cell immune dominant epitope of MntC, furthermore, three-dimensional (3-d) crystal structure results indicate that the three immunodominant epitopes were displayed on the surface of the MntC antigen. On the basis of immunodominant MntC113-136, MntC209-232, and MntC263-286 peptides, the epitope vaccine for S. aureus induces a high antibody level which is biased to TH2 and provides effective immune protection and strong opsonophagocytic killing activity in vitro against MRSA infection. In summary, the study provides strong proof of the optimisation of MRSA B cell epitope vaccine designs and their use, which was based on the MntC antigen in the development of an MRSA vaccine.

Transcriptional profiling by DDRT-PCR analysis reveals gene expression during seed development in Carya cathayensis Sarg.

Hickory (Carya cathayensis Sarg.) seed has one of the highest oil content and is rich in polyunsaturated fatty acids (PUFAs), which kernel is helpful to human health, particularly to human brain function. A better elucidation of lipid accumulation mechanism would help to improve hickory production and seed quality. DDRT-PCR analysis was used to examine gene expression in hickory at thirteen time points during seed development process. A total of 67 unique genes involved in seed development were obtained, and those expression patterns were further confirmed by semi-quantitative RT-PCR and real time RT-PCR analysis. Of them, the genes with known functions were involved in signal transduction, amino acid metabolism, nuclear metabolism, fatty acid metabolism, protein metabolism, carbon metabolism, secondary metabolism, oxidation of fatty acids and stress response, suggesting that hickory underwent a complex metabolism process in seed development. Furthermore, 6 genes related to fatty acid synthesis were explored, and their functions in seed development process were further discussed. The data obtained here would provide the first clues for guiding further functional studies of fatty acid synthesis in hickory.

[Pollution Level and Sources of Organic Phosphorus Esters in Airborne PM2.5 in Chengdu City].

Organic phosphorus esters ( OPEs ) in atmospheric PM2.5 in Chengdu city was quantitatively determined by using gas chromatography-mass spectrometry. The distribution characteristic was discussed, back trajectory model and correlation analysis were used to study the sources of OPEs in PM2.5 in Chengdu city. The results showed that the annual average concentration of Σ7OPEs in atmospheric PM2.5 in Chengdu city was 6.46 ng x m(-3) for the urban site and was 9.38 ng x m(-3) for the suburb site. Due to the waste material recycling industries in the suburb area and the perennial dominant wind direction in Chengdu, the concentration of Σ7OPEs at suburb site was higher than that at urban site (P = 0.013). The atmospheric mixed degree influenced the distribution of OPEs in rural and urban area. The source of Σ7OPEs in atmospheric PM2.5 in Chengdu city was mainly from endogenous pollution which was mainly affected by the local sources around the samoling sites. while the contribution of the exogenous pollution was small.

Liver targeting effect of vinegar-baked Radix Bupleuri on rhein in rats.

Vinegar-baked Radix Bupleuri (VBRB) is usually used to focus other drugs effect on liver in traditional Chinese medicine (TCM). However, no sufficient scientific data are available to support this concept. In this paper, the liver targeting enhancing effect of VBRB on rhein was investigated. 432 of rats were divided into two large groups according to the dose of rhein, low dose group of rhein (LDGR) and high dose group of rhein (HDGR). In each group, the rats were further divided into four subgroups, rhein control and rhein co-administered with three different doses of VBRB peroral. Concentrations of rhein and its metabolite in different tissues were determined by HPLC. Compared to the control group, VBRB significantly increased the distribution of both rhein and its metabolite in liver and meanwhile decreased their distribution in other tissues, indicating a strong liver targeting enhancing effect. This liver targeting effect of VBRB depended on the dose of VBRB and rhein. Low and high dose of VBRB had a more strong effect than medium dose in HDGR; high dose of rhein was more sensitive than low dose of rhein (P<0.05). Rhein existed in two forms after peroral administration in vivo. It was found that the liver targeting effect of VBRB was more remarkable with the native form of rhein compared to its derivative form. The results of this paper demonstrated that co-administration with VBRB is a simple and efficiencient method for liver targeting therapy, and the meridine guide theory of TCM was credible.

Clinical observations on 46 cases of globus hystericus treated with modified Banxia Houpu decoction.

OBJECTIVE: To observe the therapeutic effect and mechanism of modified Banxia Houpu decoction on globus hystericus. METHODS: The 95 patients with globus hystericus were randomly divided into a treatment group of 46 cases treated with modified Banxia Houpu decoction and a control group of 49 cases treated with Manyanshuning (Granula for Clearing the Throat). In addition, a normal group of 24 healthy people was set up. SCL-90 scale was adopted to observe the therapeutic effect, evaluate the psychological state of patients and build a database on combination of four diagnoses. RESULTS: The effect of the modified Banxia Houpo decoction was better than that of the control group in relieving depression, anxiety and improving the psychological state (P<0.05 or P<0.01). CONCLUSION: Modified Banxia Houpu decoction has definite therapeutic effect on globus hystericus. Its mechanism may be related to its function in relieving depression and anxiety and regulating the psychological state.

[Observation on therapeutic effect of Chuzhen therapy on insomnia].

OBJECTIVE: To evaluate the therapeutic effect of Chuzhen therapy on insomnia through clinical randomized controlled trials. METHODS: Sixty cases of insomnia were randomly divided into a Chuzhen group (n=30) and an acupuncture group (n=30). Acupoints of Bazhen (Baihui Bazhen, Fengfu Bazhen, Shendao Bazhen) and Hechelu [from Dazhui (GV 14) to Mingmen (GV 4)] in the Chuzhen group, and Baihui (GV 20), Sishencong (EX-HN 1), etc. in the acupuncture group were selected, respectively. Four weeks treatments were carried out in the two groups, once daily for 5 times on week days. Three months after treatment, they were followed up and the therapeutic effects were assessed by the effective rate of sleep improvement and Pittsburgh Sleep Quality Index (PSQI). RESULTS: After treatment, the sleep quality in the two groups was improved, but there were no differences in the effective rate of sleep improvement and PSQI between the two groups (all P > 0.05). Three months after treatment, the total effective rate of 85.2% in the Chuzhen group was better than 78.6% in the acupuncture group (P < 0.05). The total cumulative score of PSQI, sleep effectiveness and the factors of sleep obstacle in the Chuzhen group were significantly different from those in the acupuncture group (all P < 0.05). CONCLUSION: Chuzhen therapy can increase long-term sleep quality and living quality through improving the effective rate of sleep and reducing the score of PSQI in the patients of insomnia.

Observation on therapeutic effect of Chuzhen therapy on insomnia / 中国针灸

<p><b>OBJECTIVE</b>To evaluate the therapeutic effect of Chuzhen therapy on insomnia through clinical randomized controlled trials.</p><p><b>METHODS</b>Sixty cases of insomnia were randomly divided into a Chuzhen group (n=30) and an acupuncture group (n=30). Acupoints of Bazhen (Baihui Bazhen, Fengfu Bazhen, Shendao Bazhen) and Hechelu [from Dazhui (GV 14) to Mingmen (GV 4)] in the Chuzhen group, and Baihui (GV 20), Sishencong (EX-HN 1), etc. in the acupuncture group were selected, respectively. Four weeks treatments were carried out in the two groups, once daily for 5 times on week days. Three months after treatment, they were followed up and the therapeutic effects were assessed by the effective rate of sleep improvement and Pittsburgh Sleep Quality Index (PSQI).</p><p><b>RESULTS</b>After treatment, the sleep quality in the two groups was improved, but there were no differences in the effective rate of sleep improvement and PSQI between the two groups (all P > 0.05). Three months after treatment, the total effective rate of 85.2% in the Chuzhen group was better than 78.6% in the acupuncture group (P < 0.05). The total cumulative score of PSQI, sleep effectiveness and the factors of sleep obstacle in the Chuzhen group were significantly different from those in the acupuncture group (all P < 0.05).</p><p><b>CONCLUSION</b>Chuzhen therapy can increase long-term sleep quality and living quality through improving the effective rate of sleep and reducing the score of PSQI in the patients of insomnia.</p>

[Quantitative approach for calculation of pharmacodynamic interactions and simulation of combined response].

OBJECTIVE: An approach is set up to calculate pharmacodynamic interaction and simulate the combined response. METHOD: An orthogonal design with 1-level = high dose and 2-level = low dose was adopted. An example of the compound with four components was applied to evaluate this quantitative approach. The bias was evaluated by the both scatter plots. RESULT: This approach can calculate the value of each component with different dose by its contribution to combined response, and the value is related to the importance of a compound. Drug interactions were evaluated among the combinations in each group. The prediction model performed well and simulated the combined response in the different of components in combination. CONCLUSION: The approach can be used in the similar research, and it also provides predictions of component combinations from the other studies by simulation.

Inhibition of MITF and tyrosinase by paeonol-stimulated JNK/SAPK to reduction of phosphorylated CREB.

Tyrosinase and its transcriptional regulator microphthalmia-associated transcription factor (MITF) play critical roles in regulation of melanogenesis, and are required for environmental cues or agents in modulation of melanin synthesis. Identifying the signals regulating tyrosinase and MITF is crucial to understanding how pigmentation responds to extracellular stimuli. In this report, we discovered that paeonol down-regulated melanin production via decreasing MITF expression and consequent mRNA and protein levels of tyrosinase. We also found that paeonol reduced phosphorylation of a cAMP responsive element binding protein (phospho-CREB), which binds and activates MITF. A selective inhibitor of c-jun N-terminal or stress-activated protein kinases (JNK/SAPK)-SP600125 significantly reversed paeonol-induced down-regulation of melanogenesis. Inhibition of cAMP/PKA pathway intensified the hypopigmentation response to paeonol. These results identify a mechanism in which paeonol induces the down-regulation of melanogenesis through inhibition of CREB phosphorylation, leading to the expression reduction of MITF and subsequently tyrosinase. The key kinase mediating the effects of paeonol on melanogenesis in B16F10 cells is JNK/SAPK. Additionally, the cAMP/PKA pathway may take part in this process.