1.Radix Angelica Sinensis and Radix Astragalus ultrafiltration extract improves radiation-induced pulmonary fibrosis in rats by regulating NLRP3/caspase-1/GSDMD pyroptosis pathway
Chun-Zhen REN ; Jian-Fang YUAN ; Chun-Ling WANG ; Xiao-Dong ZHI ; Qi-Li ZHANG ; Qi-Lin CHEN ; Xin-Fang LYU ; Xiang GAO ; Xue WU ; Xin-Ke ZHAO ; Ying-Dong LI
Chinese Pharmacological Bulletin 2024;40(11):2124-2131
Aim To investigate the mechanism of py-roptosis mediated by the NLRP3/caspase-1/GSDMD signaling pathway and the intervention effect of Radix Angelica Sinensis and Radix Astragalus ultrafiltration extract(RAS-RA)in radiation-induced pulmonary fi-brosis.Methods Fifty Wistar rats were randomly di-vided into five groups,with ten rats in each group.Ex-cept for the blank control group,all other groups of rats were anesthetized and received a single dose of 40 Gy X-ray local chest radiation to establish a radiation-in-duced pulmonary fibrosis rat model.After radiation,the rats in the RAS-RA intervention groups were orally administered doses of 0.12,0.24 and 0.48 g·kg-1 once a day for 30 days.The average weight and lung index of the rats were observed after 30 days of contin-uous administration.Hydroxyproline(HYP)content in lung tissue was determined by hydrolysis method.The levels of IL-18 and IL-1 β in serum were detected by ELISA.Lung tissue pathological changes were ob-served by HE and Masson staining.Ultrastructural changes in lung tissue were observed by transmission e-lectron microscopy.The expression levels of NLRP3/caspase-1/GSDMD pyroptosis pathway-related proteins and fibrosis-related proteins in lung tissue were detec-ted by Western blot.Results Compared with the blank group,the HYP content in lung tissue and the levels of IL-18 and IL-1 β in serum significantly in-creased in the model group(P<0.01).HE and Mas-son staining showed inflammatory cell infiltration and collagen fiber deposition.Transmission electron mi-croscopy revealed increased damaged mitochondria,disordered arrangement,irregular morphology,shallow matrix,outer membrane rupture,mostly fractured and shortened cristae,mild expansion,increased electron density of individual mitochondrial matrix,mild sparse structure of lamellar bodies,partial disorder,unclear organelles,and characteristic changes of pyroptosis.Western blot analysis showed increased expression of caspase-1,GSDMD,NLRP3,CoL-Ⅰ,α-SMA,and CoL-Ⅲ proteins(P<0.01).Compared with the model group,the RAS-RA intervention group showed signifi-cant improvement in body mass index and lung index of rats,decreased levels of IL-18 and IL-1 β inflammatory factors(P<0.01),improved mitochondrial structure,reduced degree of fibrosis,and decreased expression of caspase-1,GSDMD,NLRP3,COL-Ⅰ,COL-Ⅲ,and α-SMA proteins in lung tissue(P<0.01).Conclusion RAS-RA has an inhibitory effect on radiation-in-duced pulmonary fibrosis,and its mechanism may be related to the inhibition of pyroptosis through the regu-lation of the NLRP3/caspase-1/GSDMD signaling pathway.
2.Effect of ureteral wall thickness at the site of ureteral stones on the clinical efficacy of ureteroscopic lithotripsy
Wei PU ; Jian JI ; Zhi-Da WU ; Ya-Fei WANG ; Tian-Can YANG ; Lyu-Yang CHEN ; Qing-Peng CUI ; Xu XU ; Xiao-Lei SUN ; Yuan-Quan ZHU ; Shi-Cheng FAN
Journal of Regional Anatomy and Operative Surgery 2024;33(12):1077-1081
Objective To investigate the effect of varying ureteral wall thickness(UWT)at the site of ureteral stones on the clinical efficacy of ureteroscopic lithotripsy(URL).Methods The clinical data of 164 patients with ureteral stones in our hospital were retrospectively analyzed.According to different UWT,the patients were divided into the mild thickening group(84 cases,UWT<3.16 mm),the moderate thickening group(31 cases,UWT 3.16 to 3.49 mm),and the severe thickening group(49 cases,UWT>3.49 mm),and the differences of clinical related indicators among the three groups were compared.Results The incidence of postoperative renal colic and leukocyte disorder in the mild thickening group and the moderate thickening group were lower than those in the severe thickening group,and the differences were statistically significant(P<0.05).The postoperative catheterization time in the mild thickening group and the moderate thickening group were shorter than that in the severe thickening group,and the incidences of secondary lithotripsy,residual stones and stone return to kidney in the mild thickening group and the moderate thickening group were lower than those in the severe thickening group,with statistically significant differences(P<0.05).The length of hospital stay and hospitalization cost in the mild thickening group and the moderate thickening group were shorter/less than those in the severe thickening group,with statistically significant differences(P<0.05).Conclusion With the increase of UWT(especially when UWT>3.49 mm),the incidence of postoperative complications and hospitalization cost of URL increase to varying degrees,and the surgical efficacy decreases.In clinical work,UWT measurement holds potential value in predicting the surgical efficacy and complications of URL.
3.The characteristics and correlations of vaginal flora in women with cervical lesions.
Ming Xuan ZHANG ; Jia Hao WANG ; Le ZHANG ; Jia Xin YAN ; Cai Hong WU ; Rui Xin PEI ; Yuan Jing LYU ; Li SONG ; Meng CUI ; Ling DING ; Zhi Lian WANG ; Jin Tao WANG
Chinese Journal of Oncology 2023;45(3):253-258
Objective: To explore the characteristics and correlations of vaginal flora in women with cervical lesions. Methods: A total of 132 women, including 41 women diagnosed with normal cervical (NC), 39 patients with low-grade cervical intraepithelial neoplasia (CIN 1), 37 patients with high-grade cervical intraepithelial neoplasia (CIN 2/3) and 15 patients with cervical squamous cell carcinoma (SCC), who came from the gynecological clinic of Second Hospital of Shanxi Medical University during January 2018 to June 2018, were enrolled in this study according to the inclusive and exclusive criteria strictly. The vaginal flora was detected by 16S rDNA sequencing technology. Co-occurrence network analysis was used to investigate the Spearman correlations between different genera of bacteria. Results: The dominant bacteria in NC, CIN 1 and CIN 2/3 groups were Lactobacillus [constituent ratios 79.4% (1 869 598/2 354 098), 63.6% (1 536 466/2 415 100) and 58.3% (1 342 896/2 301 536), respectively], while Peptophilus [20.4% (246 072/1 205 154) ] was the dominant bacteria in SCC group. With the aggravation of cervical lesions, the diversity of vaginal flora gradually increased (Shannon index: F=6.39, P=0.001; Simpson index: F=3.95, P=0.012). During the cervical lesion progress, the ratio of Lactobacillus gradually decreased, the ratio of other anaerobes such as Peptophilus, Sneathia, Prevotella and etc. gradually increased, and the differential bacteria (LDA score >3.5) gradually evolved from Lactobacillus to other anaerobes. The top 10 relative abundance bacteria, spearman correlation coefficient>0.4 and P<0.05 were selected. Co-occurrence network analysis showed that Prevotella, Peptophilus, Porphyrinomonas, Anaerococcus, Sneathia, Atopobium, Gardnerella and Streptococcus were positively correlated in different stages of cervical lesions, while Lactobacillus was negatively correlated with the above anaerobes. It was found that the relationship between vaginal floras in CIN 1 group was the most complex and only Peptophilus was significantly negatively correlated with Lactobacillus in SCC group. Conclusions: The increased diversity and changed correlations between vaginal floras are closely related to cervical lesions. Peptophilus is of great significance in the diagnosis, prediction and early warning of cervical carcinogenesis.
Female
;
Humans
;
Vagina/microbiology*
;
Uterine Cervical Neoplasms/genetics*
;
Uterine Cervical Dysplasia
;
Cervix Uteri
;
Lactobacillus/genetics*
;
Papillomavirus Infections
4.Design of intelligent positioning system for mobile medical equipment in operating room based on Bluetooth technology
Zhi-Meng LIU ; Ya-Dong LYU ; Long-Xue QIAO ; Lin-Huai TIAN ; Kun YANG ; Kai-Yuan LI ; Ning-Bo ZHAN ; Ying-Kang WEI ; Yong CHAO
Chinese Medical Equipment Journal 2023;44(9):29-32
Objective To develop an intelligent positioning system for mobile medical equipment in the operating room based on Bluetooth technology to enhance medical equipment management efficiency.Methods The intelligent positioning system for mobile medical equipment used received signal strength indication(RSSI)algorithm and multi-gateway trajectory filtering algorithm to realize Bluetooth positioning,which was composed of Bluetooth gateways,Bluetooth beacons,Bluetooth labels and a background data processing platform.The Bluetooth gateway consisted of an active power over ethernet(POE)module,a DC power module,a CPU,a Wi-Fi module and a Bluetooth module;the Bluetooth beacon included a beacon control unit,a Bluetooth transmitter module and a Bluetooth receiver module;the Bluetooth label was made up of a microcontroller unit(MCU),a Bluetooth module,an anti-temper switch and a accelerometer;the data processing platform had the front end developed with Vue architecture and the back end with Java language.Results The system developed could accurately locate the medical equipment in the operating room without electromagnetic interference to other medical devices.Conclusion The system developed gains advantages in high positioning accuracy,low electromagnetic interference,high stability and reliability and low cost,which improves the positioning and management efficiency of medical equipment under the premise of ensuring safety.[Chinese Medical Equipment Journal,2023,44(9):29-32]
5.Berberine alleviates programmed necrosis of metabolic-associated fatty liver disease via activating Nrf2 pathway in mice.
Ming Yue HAO ; Lin Lin SUN ; Ming Wei SHENG ; Jing Shu LYU ; Yuan Bang LIN ; Yu Hua YANG ; Jia Hao ZHI ; Wen Li YU ; Hong Yin DU
Chinese Journal of Hepatology 2022;30(2):224-229
Objective: To investigate the effect of berberine on programmed necrosis of hepatocytes induced by metabolic-associated fatty liver disease (MAFLD) in mice and its related molecular mechanism. Methods: Twenty male C57BL/6N mice were randomly divided into four groups (n=5 in each group): control group (S), fatty liver group (H), berberine group(B), nuclear factor erythroid 2-related factor 2 inhibitor group (Nrf2), and all-trans-retinoic acid (ATRA) group (A). Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), triglycerides (TG), total cholesterol (TC), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) concentrations were detected at the end of week 12 to calculate fatty liver index (liver mass/body mass ratio). Liver tissue was stained with HE, Masson and Oil Red O, and SAF score was used to evaluate the degree of liver injury. The expression levels of hepatic programmed necrosis-related proteins, namely receptor-interacting protein kinase 3 (RIPK3), phosphorylated mixed series protease-like domain (p-MLKL) and Nrf2 were detected by Western blot method. One-way ANOVA was used for intragroup comparisons and LSD-t tests were used for intergroup comparisons. Results: Compared with S group, H group serum ALT, AST, LDH, TG, TC, TNF-α, IL-1β levels and fatty liver index were significantly increased. The liver tissue was filled with vacuolar-like changes and inflammatory cell infiltration. Numerous red lipid droplets were observed with oil red O staining. Collagen fiber hyperplasia was evident with Masson staining. SAF scores (6.60 ± 0.55 and 0.80 ± 0.45) were significantly increased. The expressions of RIPK3 and p-MLKL were up-regulated. Nrf2 level was relatively increased, and the differences were statistically significant (P < 0.05). Compared with H group, berberine intervention group liver biochemical indexes, lipid levels, pro-inflammatory mediator expression, fatty liver index, and SAF score were significantly reduced, and the expression of RIPK3 and p-MLKL were down-regulated, while Nrf2 levels were further increased, and the differences were statistically significant (P<0.05). Compared with B group, treatment with Nrf2 inhibitor had antagonized the protective effect of berberine on fatty liver. Serum ALT, AST, LDH, TG, TC and TNF-α, IL-1β levels, fatty liver index, and SAF scores were significantly increased and the expressions of RIPK3 and p-MLKL were relatively increased, and the differences were statistically significant (P < 0.05). Conclusion: Berberine can significantly improve the metabolic-associated fatty liver disease injury in mice, and its mechanism is related to activation of Nrf2 and inhibition of programmed necrosis of hepatocytes.
Animals
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Berberine/therapeutic use*
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Fatty Liver
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Male
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Mice
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Mice, Inbred C57BL
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NF-E2-Related Factor 2/metabolism*
;
Necrosis
6.Ethyl Acetate Fraction of Dicliptera chinensis (L.) Juss. Ameliorates Liver Fibrosis by Inducing Autophagy via PI3K/AKT/mTOR/p70S6K Signaling Pathway.
Yuan LIU ; Yan-Meng BI ; Ting PAN ; Ting ZENG ; Chan MO ; Bing SUN ; Lei GAO ; Zhi-Ping LYU
Chinese journal of integrative medicine 2022;28(1):60-68
OBJECTIVE:
To investigate the molecular mechanism underlying the anti-hepatic fibrosis activity of ethyl acetate fraction Dicliptera chinensis (L.) Juss. (EDC) in human hepatic stellate cells (HSCs) in vitro and in a carbon tetrachloride (CCl4)-induced hepatic fibrosis mouse model in vivo.
METHODS:
For in vitro study, HSCs were pre-treated with platelet-derived growth factor (10 ng/mL) for 2 h to ensure activation and treated with EDC for 24 h and 48 h, respectively. The effect of EDC on HSCs was assessed using cell counting kit-8 assay, EdU staining, transmission electron microscopy, immunofluorescence staining, and Western blot, respectively. For in vivo experiments, mice were intraperitoneally injected with CCl4 (2 ° L/g, adjusted to a 25% concentration in olive oil), 3 times per week for 6 weeks, to develop a hepatic fibrosis model. Forty 8-week-old male C57BL/6 mice were divided into 4 groups using a random number table (n=10), including control, model, positive control and EDC treatment groups. Mice in the EDC and colchicine groups were intragastrically administered EDC (0.5 g/kg) or colchicine (0.2 mg/kg) once per day for 6 weeks. Mice in the control and model groups received an equal volume of saline. Biochemical assays and histological examinations were used to assess liver damage. Protein expression levels of α -smooth muscle actin (α -SMA) and microtubule-associated protein light chain 3B (LC3B) were measured by Western blot.
RESULTS:
EDC reduced pathological damage associated with liver fibrosis, downregulated the expression of α -SMA and upregulated the expression of LC3B (P<0.05), both in HSCs and the CCl4-induced liver fibrosis mouse model. The intervention of bafilomycin A1 and rapamycin in HSCs strongly supported the notion that inhibition of autophagy enhanced α -SMA protein expression levels (P<0.01). The results also found that the levels of phosphoinositide (PI3K), p-PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR), p-mTOR, and p-p70S6K all decreased after EDC treatment (P<0.05).
CONCLUSIONS
EDC has anti-hepatic fibrosis activity by inducing autophagy and might be a potential drug to be further developed for human liver fibrosis therapy.
Acetates
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Animals
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Autophagy
;
Carbon Tetrachloride
;
Hepatic Stellate Cells
;
Liver/pathology*
;
Liver Cirrhosis/pathology*
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Male
;
Mice
;
Mice, Inbred C57BL
;
Phosphatidylinositol 3-Kinases
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Ribosomal Protein S6 Kinases, 70-kDa
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Signal Transduction
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TOR Serine-Threonine Kinases/metabolism*
7.A descriptive analysis of tea consumption in adult twins in China.
Zhi Yu WU ; Wen Jing GAO ; Wei Hua CAO ; Jun LYU ; Can Qing YU ; Sheng Feng WANG ; Tao HUANG ; Dian Jian Yi SUN ; Chun Xiao LIAO ; Yuan Jie PANG ; Zeng Chang PANG ; Min YU ; Hua WANG ; Xian Ping WU ; Zhong DONG ; Fan WU ; Guo Hong JIANG ; Xiao Jie WANG ; Yu LIU ; Jian DENG ; Lin LU ; Liming LI
Chinese Journal of Epidemiology 2022;43(8):1241-1248
Objective: To describe the distribution characteristics of tea consumption in adult twins recruited in the Chinese National Twin Registry (CNTR) and provide clues to genetic and environmental influences on tea consumption. Methods: Enrolled in CNTR during 2010-2018, 25 264 twin pairs aged 18 years and above were included in subsequent analysis. Random effect models were used to estimate tea consumption in the population and regional distribution characteristics. The concordance rate of the behavior and difference in consumption volume of tea within pairs were also described. Results: The mean age of all subjects was (35.38±12.45) years old. The weekly tea consumers accounted for 17.0%, with an average tea consumption of (3.36±2.44) cups per day. The proportion of weekly tea consumers was higher among males, 50-59 years old, southern, urban, educated, and the first-born in the twin pair (P<0.05), and lower among unmarried individuals (P<0.001). Within-pair analysis showed that the concordance rate of tea consumption of monozygotic (MZ) twins was higher than that of dizygotic (DZ) twins and the overall heritability of tea consumption was 13.45% (11.38%-15.51%). Stratified by the characteristics mentioned above, only in males, the concordance rate of MZ showed a tendency to be greater than that of DZ (all P<0.05). The differences in consumption volume of tea within twin pairs were minor in MZ among males (P<0.05), while the differences were not significant in female twins. Conclusion: There were discrepancies in the distribution of tea consumption among twins of different demographic and regional characteristics. Tea consumption was mainly influenced by environmental factors and slightly influenced by genetic factors. The size of genetic factors varied with gender, age, and region, and gender was a potential modified factor.
Adult
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China
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Diet
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Female
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Humans
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Male
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Middle Aged
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Tea
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Twins, Dizygotic
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Twins, Monozygotic
;
Young Adult
8.Protective effects of Dendrobium officinale superfine powder against LPS-induced intestinal mucosal injury in mice.
Zhi-Yuan YANG ; Jie SU ; Jing-Jing YU ; Qi-di HUANG ; Si-Min CHEN ; Jian-Zhen CHEN ; Su-Hong CHEN ; Gui-Yuan LYU ; Mei-Qiu YAN
China Journal of Chinese Materia Medica 2021;46(7):1667-1673
This study aims to investigate the preventive effect of Dendrobium officinale in LPS-induced intestinal mucosal damage. Forty SPF-grade C57 BL/6 J male mice were randomly divided into normal group(NC), model group(LPS), and two superfine powder groups of Dendrobium officinale(DOF)(DOF-L, 0.30 g·kg~(-1)and DOF-H, 0.60 g·kg~(-1), respectively), with 10 mice in each group. DOF superfine powder suspension was given via oral administration to mice for 7 days, while the mice in NC and LPS groups received the same volume of saline for 7 days. On the eighth day, the mice in LPS group and DOF treatment groups were injected with LPS(5 mg·kg~(-1)) by intraperitoneal injection to establish the intestinal mucosal injury model, while the mice in NC group were injected with the same volume of sterile saline in the same manner. Six hours after injection with LPS or saline, plasma and the intestinal tissue were collected. The diamine oxidase(DAO) and D-lactate levels in plasma were detected with a biochemical method. The levels of proinflammatory factors interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) in plasma were detected by ELISA. The histomorphology and ultrastructure of mouse ileum tissues were observed by hematoxylin-eosin(HE) staining in optical microscope and transmission electron microscope(TEM). The expression and distribution of tight junction(TJ) proteins claudin-1, occludin and F4/80 were detected by immunohistochemistry while the protein expression levels of Toll-like receptor 4(TLR-4) and nuclear factor kappa B p65(NF-κB p65) in jejunum were detected by Western blot. The experimental results showed that continuous intragastric administration of D. officinale superfine powder for 7 days obviously alleviated the damage and ultrastructural changes of intestinal mucosa induced by LPS; significantly decreased DAO and D-lactate levels in plasma in model group(P<0.05); up-regulated the protein expression of claudin-1 and occludin in ileum tissues; down-regulated the protein expression of TLR-4 and NF-κB p65 in jejunum tissues(P<0.01); significantly decreased TNF-α and IL-6 levels in plasma(P<0.05); and decreased the infiltration of F4/80~+ macrophage cells. Our results suggested that D. officinale had significant protective effects on LPS-induced intestinal mucosal damage and reduced intestinal permeability. The mechanism might be related to its effects of inhibiting inflammation via TLR-4/NF-κB p65, and up-regulating the expression of tight junction proteins.
Animals
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Dendrobium
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Intestinal Mucosa
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Lipopolysaccharides
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Male
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Mice
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NF-kappa B
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Powders
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Tumor Necrosis Factor-alpha/genetics*
9.Current situation of nitrogen application and its effects on yield and quality of Chinese materia medica.
Yang GE ; Chuan-Zhi KANG ; Xiu-Fu WAN ; Sheng WANG ; Chao-Geng LYU ; Wen-Jin ZHANG ; Qing-Jun YUAN ; Bin-Bin YAN ; Lan-Ping GUO
China Journal of Chinese Materia Medica 2021;46(8):1883-1892
Nitrogen fertilizer has been the long-lasting crucial component in cultivation of Chinese materia medica(CMM) and crops for its profound effects on enhancing the productivity. In consideration of its role in better production, intensive and excessive application of N fertilizer is often found in CMM cultivation. Therefore, firstly, this review summarized various concentrations of N application with regards to different CMM and districts from the literatures published in the last two decades. The recommended concentration of nitrogen application of forty seven CMM species were covered in this review. We found that the optimum rates of nitrogen fertili-zer for different medicinal plants species were varied in the range between 0-1 035.55 kg·hm~(-2). Most of the optimum rates of nitrogen fertilizer for CMM in published researches fell between 100-199 kg·hm~(-2). The optimum rate of nitrogen fertilizer is not only related to amount of nitrogen required for different medicinal plants but also to soil fertilities of different fields. In addition, we outlined the diffe-rent effects of proper and excessive nitrogen deposition on yield of CMM. Proper nitrogen deposition benefits the yield of CMM, howe-ver, excessive nitrogen use accounts for a decrease in CMM yield. We elucidated that nutritional content, water use efficiencies, and photosynthesis capacity were major influencing factors. Researches showed that proper nitrogen fertilizer could promote the water use efficiencies of plants and boost photosynthesis. Consequently, the yield of CMM can be enhanced after nitrogen deposition. However, negative effects of nitrogen fertilizer were also found on plant including producing toxic substances to the soil and causing severe pest damages. Lastly we analyzed the impact of N fertilizer application on secondary metabolites which accounts for a large part of active pharmaceutical ingredients of CMM. It usually caused an increase in nitrogen-containing secondary metabolites content and a decrease in non-nitrogen-containing secondary metabolites content respectively. The potential underlying mechanisms are the different synthetic pathways of these metabolites and the plant nutritional status. Synthesis of non-nitrogen-containing secondary metabolites like phenols can be inhibited after nitrogen application because of the competition of the same precursor substances between metabolites synthesis and plant growth. To sum up, impacts and mechanisms of nitrogen fertilizer on yield and quality enhancement of CMM were discussed in this review. Negative effects of excessive nitrogen application on CMM should be paid special attention in CMM cultivation and prescription fertilization based on the field soil quality is strongly recommended. Overall, this review aims to provides insights on improving the proper application of N fertilizer in the cultivation of CMM.
Agriculture
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China
;
Fertilizers
;
Materia Medica
;
Nitrogen/analysis*
;
Soil
10.Effects and mechanisms of nitrogen application on stress resistance of Chinese materia medica.
Yang GE ; Sheng WANG ; Xiu-Fu WAN ; Chuan-Zhi KANG ; Chao-Geng LYU ; Wen-Jin ZHANG ; Tie-Lin WANG ; Qing-Jun YUAN ; Lan-Ping GUO
China Journal of Chinese Materia Medica 2021;46(8):1901-1909
Nitrogen fertilizers play an important role in the regulation of plant stress resistance. Impacts of nitrogen fertilizers on abiotic stress resistance and biotic stress resistance of Chinese materia medica(CMM) were summarized in this study. Adequate nitrogen application improves the abiotic stress resistance and weed resistance of CMM, however adverse effect appears when excess nitrogen is used. Generally, pest resistance decreases along with nitrogen deposition, while effects of nitrogen application on disease resistance vary with different diseases. Mechanisms underlying the impact of nitrogen fertilizers on plant stress resistance were also elucidated in this study from three aspects including physical defense mechanisms, biochemistry mechanisms and molecular defense mechanisms. Nitrogen availability modulates physical barrier of CMM like plant growth, formation of lignin and wax cuticle, and density of stomata. Growth of CMM promoted by nitrogen fertilizer may cause some decrease in pest resistance of CMM due to an increase in hiding places for pest along with plant growth. High ambient humidity caused by excessive plant growth facilitates the growth and development of CMM pathogen. Nitrogen application can also interfere with the accumulation of lignin in CMM which makes CMM more vulnerable to pest and pathogen attack. Stomatal closing delays due to nitrogen application is also a causal factor of increasing pathogen infection after nitrogen deposition. Biochemical defenses of plants are mainly achieved through nutrient elements, secondary metabolites, defense-related enzymes and proteins. Nutritional level of CMM and various antioxidant enzymes and resistance-related protein activities are elevated along with nitrogen deposition. These antioxidant enzymes can reduce the damage of reactive oxygen species content produced by plant in response to adversity and therefore enhance stress resistance of CMM. Researches showed that nitrogen application could also cause an increase in nitrogen-containing secondary metabolites content and a decrease in non-nitrogen-containing secondary metabolites content respectively. Nitrogen-mediated molecular defense mechanisms includes multiple plant hormones and nitric oxide signals. Plant hormones related to plant defense like salicylic acid, jasmonic acid and abscisic acid can be modulated by nitrogen application. Negative effect of nitrogen deposition was found on salicylic acid accumulation and the expression of related plant disease resistance genes. However, jasmonic acid level can be elevated by nitrogen. Nitric oxide signals constitute an important part of nitrogen mediated defense mechanisms. Nitric oxide signaling is related to many aspects of plant immunity. The roles of nitrogen fertilizers in CMM stress resistance are complex and may vary with different CMM varieties and environments. Further studies are urgently needed to provide a comprehensive understanding of how to improve stress resistance of CMM by using fertilizers.
Abscisic Acid
;
China
;
Materia Medica
;
Nitrogen
;
Plant Growth Regulators

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