1.Sanren Runchang Formula Regulates Brain-gut Axis to Treat IBS-C: A Randomized Controlled Trial
Teng LI ; Xinrong FAN ; He YAN ; Zhuozhi GONG ; Mengxi YAO ; Na YANG ; Yuhan WANG ; Huikai HU ; Wei WEI ; Tao LIU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(2):154-161
ObjectiveTo observe the clinical efficacy of Sanren Runchang formula in treating constipation-predominant irritable bowel syndrome (IBS-C) by regulating the brain-gut axis and the effects of the formula on serum levels of 5-hydroxytryptamine (5-HT), vasoactive intestinal peptide (VIP), and substance P (SP). MethodsA randomized controlled design was adopted, and 72 IBS-C patients meeting Rome Ⅳ criteria were randomized into observation and control groups (36 cases).The observation group received Sanren Runchang formula granules twice daily, and the control group received lactulose oral solution daily for 4 weeks. IBS Symptom Severity Scale (IBS-SSS), IBS Quality of Life Scale (IBS-QOL), and Bristol Stool Form Scale (BSFS) were used to assess clinical symptoms, and bowel movement frequency was recorded. The Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS) were employed to evaluate psychological status. ELISA was employed to measure the serum levels of 5-HT, VIP, and SP. ResultsThe total response rate in the observation group was 91.67% (33/36), which was higher than that (77.78%, 28/36) in the control group (χ2=4.50, P<0.05). After treatment, both groups showed increased defecation frequency and BSFS scores, decreased IBS-SSS total score, abdominal pain and bloating scores, IBS-QOL health anxiety, anxiety, food avoidance, and behavioral disorders scores, SAS and SDS scores, serum 5-HT and VIP levels, and increased SP levels (P<0.05, P<0.01). Moreover, the observation group showed more significant changes in the indicators above than the control group (P<0.05, P<0.01). The SP level showed no significant difference between the two groups. During the 4-week follow-up, the recurrence rate was 5.88% in the observation group and 31.25% in the control group. No adverse events occurred in observation group, and 2 cases of mild diarrhea occurred in the control group. ConclusionSanren Runchang formula demonstrated definitive efficacy in alleviating gastrointestinal symptoms and improving the psychological status and quality of life in IBS-C patients, with a low recurrence rate. The formula can regulate serum levels of neurotransmitters such as 5-HT and VIP, suggesting its potential regulatory effect on the brain-gut axis through modulating neurotransmitters and neuropeptides. However, its complete mechanism of action requires further investigation through detection of additional brain-gut axis-related biomarkers.
2.Current status of research on the mechanism of action of emodin in the prevention and treatment of chronic liver diseases
Yajie CHEN ; Xin WANG ; Yunjuan WU ; Ying SU ; Yuhan WANG ; Jinxue ZHANG ; Ning YAO ; Ying QIN ; Xiaoning ZUO
Journal of Clinical Hepatology 2026;42(1):228-234
Chronic liver diseases are a group of diseases in which the liver is subjected to a variety of injuries over a long period of time, resulting in irreversible pathological changes that last longer than 6 months. Emodin (EMO) is a natural anthraquinone derivative derived from Rheum officinale, and its pharmacological effect has been extensively studied, exhibiting a variety of biological properties and involving multiple signaling molecules and pathways. Western medicine or surgical treatment is currently the main treatment regimen for chronic liver diseases, and the advance in treatment is limited by various reasons such as side effects and high costs. Due to its natural origin and efficacy, EMO has unique advantages in the treatment of chronic liver diseases and has now become a research hotspot. This article summarizes the therapeutic effect of EMO on chronic liver diseases and its mechanism, in order to provide a certain scientific basis for the traditional Chinese medicine treatment of chronic liver diseases and the development of drugs in clinical practice.
3.Advances in detection techniques for congenital blood group chimerism
Shuo ZHANG ; Hongyan YANG ; Yuhan GAO ; Ranran QIN ; Xinrui WANG ; Ke ZHANG ; Yifan LI ; Ruiqin HOU
Chinese Journal of Blood Transfusion 2026;39(3):402-407
Congenital blood group chimerism refers to the coexistence of two or more distinct blood types within an individual, resulting from the presence of hematopoietic cell populations with different genotypes. Consequently, red blood cells in such individuals may express different blood group antigens. Based on the timing and mechanism of formation, blood group chimerism can be classified as either congenital or acquired. Although congenital blood group chimerism is rare and involves complex mechanisms, it holds significant implications in transfusion medicine, transplantation, and obstetrics. This article reviews the formation mechanisms, detection methods, and clinical significance of congenital blood group chimerism in transfusion medicine. Particular emphasis is placed on the principles, advantages, and limitations of various detection techniques. Furthermore, the potential applications of these technologies in clinical diagnosis are discussed, providing a technical foundation for the development of precise transfusion strategies.
4.Mechanisms of Qizhujianwei Granules in Blocking Malignant Progression of Gastric Intraepithelial Neoplasia
Yuling YU ; Yanmin WANG ; Siqi WANG ; Yateng SUN ; Yunhe WANG ; Yonghuang YAN ; Xinyu YANG ; Siqi HAN ; Yuhong SONG ; Yuhan WANG ; Cai ZHANG ; Zeqi SU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):143-151
ObjectiveTo investigate the effects of Qizhujianwei granules (QZJW) on abnormal proliferation and malignant transformation of gastric mucosal cells in rats with gastric intraepithelial neoplasia (GIN) and to explore the related mechanisms. MethodsA total of 80 SPF male Wistar rats were used. A GIN rat model was established using a four-factor comprehensive method consisting of methylnitronitrosoguanidine (MNNG), ranitidine, irregular feeding patterns, and sodium salicylate. Except for the normal group, after successful modeling, the rats were randomly divided according to body weight into a model group, a Moluodan group (0.55 g·kg-1), and a QZJW group (7.34 g·kg-1), with 12 rats in each group. All groups were treated for 8 weeks. The general characteristics of the rats and morphological changes of the gastric mucosa were observed. Histopathological changes of the gastric mucosa were examined by hematoxylin-eosin (HE) staining. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of pepsinogenⅠ (PGⅠ), pepsinogenⅡ (PGⅡ), and gastrin (G-17), as well as the expression level of transforming growth factor-β1 (TGF-β1) in gastric mucosal tissue, and the PGⅠ/PGⅡ ratio was calculated. Immunohistochemistry (IHC) was used to detect the localization and expression levels of proliferating cell nuclear antigen (Ki-67) and Vimentin in gastric mucosal tissue. Western blot analysis was used to determine the protein expression levels of Wnt family member 3A (Wnt3a), β-catenin, CyclinD1, proto-oncogene Cmyc, transforming growth factor-β receptor Ⅰ (TGFβRⅠ), intracellular signaling transducers Smad2/3, phosphorylated (p)-Smad2/3, twist family transcription factor (Twist1), and Vimentin in gastric mucosal tissue. ResultsCompared with the normal group, the model group showed characteristic changes including dim eyes, pale ears and claws, dark-red tongue, and reduced luster of the tail. The gastric mucosa appeared pale, with surface congestion and erosion. The gastric mucosal glands were disordered, the nuclear-to-cytoplasmic ratio increased, and local tumor cells were observed. Serum PGⅠ and PGⅡ levels and the PGⅠ/PGⅡ ratio were significantly decreased (P<0.01), while the level of G-17 was significantly increased (P<0.01). The protein expression levels of Ki-67, Wnt3a, β-catenin, CyclinD1, Cmyc, TGF-β1, TGFβRⅠ, Smad2/3, Twist1, and Vimentin in gastric mucosal tissue were significantly increased (P<0.05, P<0.01), whereas the ratio of p-Smad2/3 to Smad2/3 was significantly decreased (P<0.05). Compared with the model group, the general characteristics and gastric mucosal conditions of rats in the Moluodan group and the QZJW group were improved. HE staining showed that QZJW could effectively block the malignant progression of GIN. Serum PGⅠ and PGⅡ levels and the PGⅠ/PGⅡ ratio were significantly increased (P<0.05, P<0.01), while the level of G-17 was significantly decreased (P<0.01). The protein expression levels of Ki-67, Wnt3a, β-catenin, CyclinD1, Cmyc, TGF-β1, TGFβRⅠ, Smad2/3, Twist1, and Vimentin in gastric mucosal tissue were significantly decreased (P<0.05, P<0.01). ConclusionQZJW have a therapeutic effect on rats with GIN. The mechanism may involve inhibition of the Wnt/β-catenin signaling pathway to regulate the cell cycle and suppress abnormal cell proliferation. Meanwhile, it may inhibit epithelial-mesenchymal transition by suppressing the TGF-β1/Smad/Twist1 signaling pathway, thereby blocking the malignant progression of GIN.
5.Mechanisms of Qizhujianwei Granules in Blocking Malignant Progression of Gastric Intraepithelial Neoplasia
Yuling YU ; Yanmin WANG ; Siqi WANG ; Yateng SUN ; Yunhe WANG ; Yonghuang YAN ; Xinyu YANG ; Siqi HAN ; Yuhong SONG ; Yuhan WANG ; Cai ZHANG ; Zeqi SU
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(10):143-151
ObjectiveTo investigate the effects of Qizhujianwei granules (QZJW) on abnormal proliferation and malignant transformation of gastric mucosal cells in rats with gastric intraepithelial neoplasia (GIN) and to explore the related mechanisms. MethodsA total of 80 SPF male Wistar rats were used. A GIN rat model was established using a four-factor comprehensive method consisting of methylnitronitrosoguanidine (MNNG), ranitidine, irregular feeding patterns, and sodium salicylate. Except for the normal group, after successful modeling, the rats were randomly divided according to body weight into a model group, a Moluodan group (0.55 g·kg-1), and a QZJW group (7.34 g·kg-1), with 12 rats in each group. All groups were treated for 8 weeks. The general characteristics of the rats and morphological changes of the gastric mucosa were observed. Histopathological changes of the gastric mucosa were examined by hematoxylin-eosin (HE) staining. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum levels of pepsinogenⅠ (PGⅠ), pepsinogenⅡ (PGⅡ), and gastrin (G-17), as well as the expression level of transforming growth factor-β1 (TGF-β1) in gastric mucosal tissue, and the PGⅠ/PGⅡ ratio was calculated. Immunohistochemistry (IHC) was used to detect the localization and expression levels of proliferating cell nuclear antigen (Ki-67) and Vimentin in gastric mucosal tissue. Western blot analysis was used to determine the protein expression levels of Wnt family member 3A (Wnt3a), β-catenin, CyclinD1, proto-oncogene Cmyc, transforming growth factor-β receptor Ⅰ (TGFβRⅠ), intracellular signaling transducers Smad2/3, phosphorylated (p)-Smad2/3, twist family transcription factor (Twist1), and Vimentin in gastric mucosal tissue. ResultsCompared with the normal group, the model group showed characteristic changes including dim eyes, pale ears and claws, dark-red tongue, and reduced luster of the tail. The gastric mucosa appeared pale, with surface congestion and erosion. The gastric mucosal glands were disordered, the nuclear-to-cytoplasmic ratio increased, and local tumor cells were observed. Serum PGⅠ and PGⅡ levels and the PGⅠ/PGⅡ ratio were significantly decreased (P<0.01), while the level of G-17 was significantly increased (P<0.01). The protein expression levels of Ki-67, Wnt3a, β-catenin, CyclinD1, Cmyc, TGF-β1, TGFβRⅠ, Smad2/3, Twist1, and Vimentin in gastric mucosal tissue were significantly increased (P<0.05, P<0.01), whereas the ratio of p-Smad2/3 to Smad2/3 was significantly decreased (P<0.05). Compared with the model group, the general characteristics and gastric mucosal conditions of rats in the Moluodan group and the QZJW group were improved. HE staining showed that QZJW could effectively block the malignant progression of GIN. Serum PGⅠ and PGⅡ levels and the PGⅠ/PGⅡ ratio were significantly increased (P<0.05, P<0.01), while the level of G-17 was significantly decreased (P<0.01). The protein expression levels of Ki-67, Wnt3a, β-catenin, CyclinD1, Cmyc, TGF-β1, TGFβRⅠ, Smad2/3, Twist1, and Vimentin in gastric mucosal tissue were significantly decreased (P<0.05, P<0.01). ConclusionQZJW have a therapeutic effect on rats with GIN. The mechanism may involve inhibition of the Wnt/β-catenin signaling pathway to regulate the cell cycle and suppress abnormal cell proliferation. Meanwhile, it may inhibit epithelial-mesenchymal transition by suppressing the TGF-β1/Smad/Twist1 signaling pathway, thereby blocking the malignant progression of GIN.
6.Lead and cadmium co-exposure triggers genetic damage through oxidative stress and impaired expression of DNA repair genes
Xin LIU ; Zhiyuan HAN ; Kuibin HAN ; Yuhan PANG ; Xiaoyue ZHAO ; Yuting WANG ; Xiaoyan WU ; Tuanwei WANG
Journal of Environmental and Occupational Medicine 2026;43(5):556-564
Background Lead smelting workers are exposed to mixed heavy metals such as lead (Pb) and cadmium (Cd). However, the specific associations and molecular mechanisms by which their combined exposure induces genetic damage remain unclear. Objective To clarify the association between combined Pb-Cd exposure and genetic damage and to explore the possible biological mechanisms through occupational epidemiological investigations and animal experiments. Methods (1) Population study: A cross-sectional study was conducted on 374 lead smelting workers in northern China. Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect urinary levels of 8 metals including Pb and Cd, and graphite furnace atomic absorption spectroscopy (GFAAS) was used to quantify blood levels of Pb and Cd. The cytokinesis-block micronucleus assay (CBMN) was used to assess genetic damage. Poisson regression was used to analyze the association between metal exposure and micronucleus rates. (2) In vivo experiment: Thirty SD rats were randomly assigned to five groups: control (pure water), Pb (300 mg·L−1 lead acetate), Cd (50 mg·L−1 cadmium chloride), combined exposure (Pb + Cd), and resveratrol intervention (Pb + Cd + 50 mg·L−1 resveratrol). After 8 weeks of ad libitum drinking water exposure, liver pathology, oxidative stress indicators [reactive oxygen species (ROS), reduced glutathione (GSH), oxidized glutathione (GSSG), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD)], genetic damage (Comet assay and γ-H2AX) were evaluated. Furthermore, cell cycle distribution, apoptosis rates, and mRNA expression of DNA damage response (DDR), DNA repair, and apoptosis-related genes were measured. Results (1) The geometric mean (GM, 95%CI) of urinary Pb and Cd were 14.69 (13.14, 16.51) µg·L−1 and 2.11 (1.90, 2.33) µg·L−1, respectively; the blood Pb and Cd levels were 117.10 (105.59, 129.87) µg·L−1 and 4.55 (4.23, 4.89) µg·L−1, respectively among the 374 workers. The mean micronucleus rate was (1.64±0.081) ‰, with significantly higher rates in males (1.65±0.083) ‰ than females (1.53±0.334) ‰ (U=4.166, P=0.041). All Pb and Cd biomarkers were positively correlated with micronucleus rate (FR>1, P<0.05), with a significant interaction effect observed between Pb and Cd (FR>1, P<0.05). (2) In rats, co-exposure to Pb and Cd caused liver tissue damage and inflammatory infiltration. Significant increases were observed in lymphocyte ROS; GSSG and MDA in lung tissue increased, while GSH and CAT activity decreased. Comet assay indicators and γ-H2AX levels were significantly elevated. Co-exposure induced S-phase arrest and increased apoptosis. mRNA levels of DDR (ATM, ATR, Chk2, and P53) and pro-apoptotic genes (Bax and Caspase-3) were upregulated, while the anti-apoptotic gene Bcl-2 and DNA repair genes (BRCA1, BRCA2, RAD51, RAD52, and CtIP) were downregulated. Two-way ANOVA confirmed synergistic effects on GSSG, Comet assay indicators, and ATR/Chk2 mRNA expression. Conclusion Occupational co-exposure to Pb and Cd synergistically induces genetic damage. This damage is mediated by oxidative stress and DNA damage, which activates the DDR pathway and inhibits the expression of DNA repair genes, ultimately leading to cell cycle arrest and apoptosis.
7.Lead and cadmium co-exposure triggers genetic damage through oxidative stress and impaired expression of DNA repair genes
Xin LIU ; Zhiyuan HAN ; Kuibin HAN ; Yuhan PANG ; Xiaoyue ZHAO ; Yuting WANG ; Xiaoyan WU ; Tuanwei WANG
Journal of Environmental and Occupational Medicine 2026;43(5):556-564
Background Lead smelting workers are exposed to mixed heavy metals such as lead (Pb) and cadmium (Cd). However, the specific associations and molecular mechanisms by which their combined exposure induces genetic damage remain unclear. Objective To clarify the association between combined Pb-Cd exposure and genetic damage and to explore the possible biological mechanisms through occupational epidemiological investigations and animal experiments. Methods (1) Population study: A cross-sectional study was conducted on 374 lead smelting workers in northern China. Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect urinary levels of 8 metals including Pb and Cd, and graphite furnace atomic absorption spectroscopy (GFAAS) was used to quantify blood levels of Pb and Cd. The cytokinesis-block micronucleus assay (CBMN) was used to assess genetic damage. Poisson regression was used to analyze the association between metal exposure and micronucleus rates. (2) In vivo experiment: Thirty SD rats were randomly assigned to five groups: control (pure water), Pb (300 mg·L−1 lead acetate), Cd (50 mg·L−1 cadmium chloride), combined exposure (Pb + Cd), and resveratrol intervention (Pb + Cd + 50 mg·L−1 resveratrol). After 8 weeks of ad libitum drinking water exposure, liver pathology, oxidative stress indicators [reactive oxygen species (ROS), reduced glutathione (GSH), oxidized glutathione (GSSG), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD)], genetic damage (Comet assay and γ-H2AX) were evaluated. Furthermore, cell cycle distribution, apoptosis rates, and mRNA expression of DNA damage response (DDR), DNA repair, and apoptosis-related genes were measured. Results (1) The geometric mean (GM, 95%CI) of urinary Pb and Cd were 14.69 (13.14, 16.51) µg·L−1 and 2.11 (1.90, 2.33) µg·L−1, respectively; the blood Pb and Cd levels were 117.10 (105.59, 129.87) µg·L−1 and 4.55 (4.23, 4.89) µg·L−1, respectively among the 374 workers. The mean micronucleus rate was (1.64±0.081) ‰, with significantly higher rates in males (1.65±0.083) ‰ than females (1.53±0.334) ‰ (U=4.166, P=0.041). All Pb and Cd biomarkers were positively correlated with micronucleus rate (FR>1, P<0.05), with a significant interaction effect observed between Pb and Cd (FR>1, P<0.05). (2) In rats, co-exposure to Pb and Cd caused liver tissue damage and inflammatory infiltration. Significant increases were observed in lymphocyte ROS; GSSG and MDA in lung tissue increased, while GSH and CAT activity decreased. Comet assay indicators and γ-H2AX levels were significantly elevated. Co-exposure induced S-phase arrest and increased apoptosis. mRNA levels of DDR (ATM, ATR, Chk2, and P53) and pro-apoptotic genes (Bax and Caspase-3) were upregulated, while the anti-apoptotic gene Bcl-2 and DNA repair genes (BRCA1, BRCA2, RAD51, RAD52, and CtIP) were downregulated. Two-way ANOVA confirmed synergistic effects on GSSG, Comet assay indicators, and ATR/Chk2 mRNA expression. Conclusion Occupational co-exposure to Pb and Cd synergistically induces genetic damage. This damage is mediated by oxidative stress and DNA damage, which activates the DDR pathway and inhibits the expression of DNA repair genes, ultimately leading to cell cycle arrest and apoptosis.
8.Preliminary exploration of the symptom fluctuation after acupuncture for idiopathic tinnitus.
Baiqing WANG ; Yuanbo FU ; Baijie LI ; Xueting ZHANG ; Yuhan ZENG ; Yutong NI ; Huilin LIU ; Peng CHEN ; Xiaobai XU ; Bingcong ZHAO
Chinese Acupuncture & Moxibustion 2025;45(10):1477-1483
After being treated with acupuncture, some patients with idiopathic tinnitus may experience a short-term aggravation of tinnitus symptoms on the original basis. These symptoms can be gradually relieved and the overall condition fluctuates towards recovery. This phenomenon has brought some difficulties to patients and clinicians. Based on the academic view of TCM, "destroying pathogens and re-building balance", and in association with the existing understanding of acupuncture in modern medicine for tinnitus, this paper briefly discusses the mechanism and influencing factors of symptom fluctuation in patients with idiopathic tinnitus after acupuncture treatment in terms of both TCM and modern medicine, and proposes the future direction in the research of symptom fluctuation, so as to promote the recognition of clinicians and patients on symptom fluctuation and make rational use of its positive effects. Besides, it is hoped that more researchers will pay attention to symptom fluctuation and advance the exploration of it in academic field.
Humans
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Tinnitus/physiopathology*
;
Acupuncture Therapy
;
Male
;
Female
9.Global burden and trends of gout incidence and prevalence.
Shuai JIN ; Yuhan WANG ; Shuangtong YAN ; Xiaomin FU ; Xiaodong HU ; Zhaohui LYU ; Hongzhou LIU
Chinese Medical Journal 2025;138(23):3153-3162
BACKGROUND:
Gout is a chronic disease primarily caused by elevated urate levels, severely affecting joint health. Its global distribution varies, and updated data for China are lacking. This study aimed to analyze the current burden and trends of gout globally and in China, examining the burden by gender, age, and risk factors while providing future predictions.
METHODS:
This descriptive epidemiological secondary analysis utilized data from the Global Burden of Disease, Injuries, and Risk Factors (GBD) 2021 study. Age-standardized incidence rate (ASIR), prevalence rate (ASPR), and disability-adjusted life years (DALYs) rates (ASDR) were used to assess the gout burden. Trends from 1990 to 2021 were analyzed across global regions, genders, and sociodemographic index (SDI) levels. The burden in China was further examined by gender, age, and associated risk factors. The Bayesian age-period-cohort (BAPC) model was used to predict future trends. Gout burden in China and the United States was compared.
RESULTS:
In 2021, gout affected 57 million people globally, with 9.4 million new cases and 1.75 million DALYs. From 1990 to 2021, the ASIR, ASPR, and ASDR increased by 17.2%, 21.9%, and 21.3%, respectively. Males experienced a significantly higher burden, with greater ASIR, ASPR, and ASDR increasing with higher SDI levels. In China, male ASIR, ASPR, and ASDR were over 2.8 times those of females, and the burden increased with age. In 2021, 31.4% of gout-related DALYs in China were attributed to high body mass index and 7.6% to kidney dysfunction. Between 1990 and 2021, the high body mass index-related burden of gout rose annually for both genders, while the kidney dysfunction-related gout burden remained stable. By 2050, the burden of gout in China is expected to continue increasing, with a slower rise in females and a decline in males after an initial increase. However, the overall burden will remain substantial. In comparison, the gout burden will be higher in the United States than in China.
CONCLUSIONS
Gout is becoming a significant health burden globally and in China, particularly among Chinese males and older individuals. With the aging population and lifestyle changes exacerbating the issue, effective strategies and measures are essential to prevent or reduce gout-related health issues.
Humans
;
Gout/epidemiology*
;
Male
;
Female
;
Incidence
;
Middle Aged
;
Prevalence
;
China/epidemiology*
;
Adult
;
Risk Factors
;
Aged
;
Global Burden of Disease
;
Disability-Adjusted Life Years
;
Young Adult
;
Adolescent
;
Quality-Adjusted Life Years
10.A CYP80B enzyme from Stephania tetrandra enables the 3'-hydroxylation of N-methylcoclaurine and coclaurine in the biosynthesis of benzylisoquinoline alkaloids.
Yaoting LI ; Yuhan FENG ; Wan GUO ; Yu GAO ; Jiatao ZHANG ; Lu YANG ; Chun LEI ; Yun KANG ; Yaqin WANG ; Xudong QU ; Jianming HUANG
Chinese Journal of Natural Medicines (English Ed.) 2025;23(5):630-640
Benzylisoquinoline alkaloids (BIAs) are a structurally diverse group of plant metabolites renowned for their pharmacological properties. However, sustainable sources for these compounds remain limited. Consequently, researchers are focusing on elucidating BIA biosynthetic pathways and genes to explore alternative sources using synthetic biology approaches. CYP80B, a family of cytochrome P450 (CYP450) enzymes, plays a crucial role in BIA biosynthesis. Previously reported CYP80Bs are known to catalyze the 3'-hydroxylation of (S)-N-methylcoclaurine, with the N-methyl group essential for catalytic activity. In this study, we successfully cloned a full-length CYP80B gene (StCYP80B) from Stephania tetrandra (S. tetrandra) and identified its function using a yeast heterologous expression system. Both in vivo yeast feeding and in vitro enzyme analysis demonstrated that StCYP80B could catalyze N-methylcoclaurine and coclaurine into their respective 3'-hydroxylated products. Notably, StCYP80B exhibited an expanded substrate selectivity compared to previously reported wild-type CYP80Bs, as it did not require an N-methyl group for hydroxylase activity. Furthermore, StCYP80B displayed a clear preference for the (S)-configuration. Co-expression of StCYP80B with the CYP450 reductases (CPRs, StCPR1, and StCPR2), also cloned from S. tetrandra, significantly enhanced the catalytic activity towards (S)-coclaurine. Site-directed mutagenesis of StCYP80B revealed that the residue H205 is crucial for coclaurine catalysis. Additionally, StCYP80B exhibited tissue-specific expression in plants. This study provides new genetic resources for the biosynthesis of BIAs and further elucidates their synthetic pathway in natural plant systems.
Cytochrome P-450 Enzyme System/chemistry*
;
Benzylisoquinolines/chemistry*
;
Hydroxylation
;
Plant Proteins/chemistry*
;
Alkaloids/metabolism*
;
Stephania tetrandra/genetics*

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