1.The Mechanism of Blue Light in Inactivating Microorganisms and Its Applications in The Food and Medical Fields
Ruo-Hong BI ; Rong-Qian WU ; Yi LÜ ; Xiao-Fei LIU
Progress in Biochemistry and Biophysics 2025;52(5):1219-1228
Blue light inactivation technology, particularly at the 405 nm wavelength, has demonstrated distinct and multifaceted mechanisms of action against both Gram-positive and Gram-negative bacteria, offering a promising alternative to conventional antibiotic therapies. For Gram-positive pathogens such as Bacillus cereus, Listeria monocytogenes, and methicillin-resistant Staphylococcus aureus (MRSA), the bactericidal effects are primarily mediated by endogenous porphyrins (e.g., protoporphyrin III, coproporphyrin III, and uroporphyrin III), which exhibit strong absorption peaks between 400-430 nm. Upon irradiation, these porphyrins are photoexcited to generate cytotoxic reactive oxygen species (ROS), including singlet oxygen, hydroxyl radicals, and superoxide anions, which collectively induce oxidative damage to cellular components. Early studies by Endarko et al. revealed that (405±5) nm blue light at 185 J/cm² effectively inactivated L. monocytogenes without exogenous photosensitizers, supporting the hypothesis of intrinsic photosensitizer involvement. Subsequent work by Masson-Meyers et al. demonstrated that 405 nm light at 121 J/cm² suppressed MRSA growth by activating endogenous porphyrins, leading to ROS accumulation. Kim et al. further elucidated that ROS generated under 405 nm irradiation directly interact with unsaturated fatty acids in bacterial membranes, initiating lipid peroxidation. This process disrupts membrane fluidity, compromises structural integrity, and impairs membrane-bound proteins, ultimately causing cell death. In contrast, Gram-negative bacteria such as Salmonella, Escherichia coli, Helicobacter pylori, Pseudomonas aeruginosa, and Acinetobacter baumannii exhibit more complex inactivation pathways. While endogenous porphyrins remain central to ROS generation, studies reveal additional photodynamic contributors, including flavins (e.g., riboflavin) and bacterial pigments. For instance, H. pylori naturally accumulates protoporphyrin and coproporphyrin mixtures, enabling efficient 405 nm light-mediated inactivation without antibiotic resistance concerns. Kim et al. demonstrated that 405 nm light at 288 J/cm² inactivates Salmonella by inducing genomic DNA oxidation (e.g., 8-hydroxy-deoxyguanosine formation) and disrupting membrane functions, particularly efflux pumps and glucose uptake systems. Huang et al. highlighted the enhanced efficacy of pulsed 405 nm light over continuous irradiation for E. coli, attributing this to increased membrane damage and optimized ROS generation through frequency-dependent photodynamic effects. Environmental factors such as temperature, pH, and osmotic stress further modulate susceptibility, sublethal stress conditions (e.g., high salinity or acidic environments) weaken bacterial membranes, rendering cells more vulnerable to subsequent ROS-mediated damage. The 405 nm blue light inactivates drug-resistant Pseudomonas aeruginosa through endogenous porphyrins, pyocyanin, and pyoverdine, with the inactivation efficacy influenced by bacterial growth phase and culture medium composition. Intriguingly, repeated 405 nm exposure (20 cycles) failed to induce resistance in A. baumannii, with transient tolerance linked to transient overexpression of antioxidant enzymes (e.g., superoxide dismutase) or stress-response genes (e.g., oxyR). For Gram-positive bacteria, porphyrin abundance dictates sensitivity, whereas in Gram-negative species, membrane architecture and accessory pigments modulate outcomes. Critically, ROS-mediated damage is nonspecific, targeting DNA, proteins, and lipids simultaneously, thereby minimizing resistance evolution. The 405 nm blue light technology, as a non-chemical sterilization method, shows promise in medical and food industries. It enhances infection control through photodynamic therapy and disinfection, synergizing with red light for anti-inflammatory treatments (e.g., acne). In food processing, it effectively inactivates pathogens (e.g., E. coli, S. aureus) without altering food quality. Despite efficacy against multidrug-resistant A. baumannii, challenges include device standardization, limited penetration in complex materials, and optimization of photosensitizers/light parameters. Interdisciplinary research is needed to address these limitations and scale applications in healthcare, food safety, and environmental decontamination.
2.mfat-1 gene therapy prevents and ameliorates multiple sclerosis in mice
Min-Yi TANG ; Xin-Yun BI ; Shuai WANG ; Chao-Feng XING ; Xiao-Li WU ; Zi-Jian ZHAO ; Fang-Hong LI
Chinese Pharmacological Bulletin 2024;40(10):1930-1936
Aim To investigate the preventive and therapeutic effects of the mfat-1 gene therapy on exper-imental autoimmune encephalomyelitis in mice.Meth-ods mfat-1 gene therapy was used to render the host endogenous capability of producing ω-3 PUFAs,con-comitantly reduce the levels of ω-6 PUFAs,and change the proportion of ω-3/ω-6 PUFAs.Then,the levels of PUFAs in blood were analyzed by gas chromatography.The neurological deficits in mice were evaluated by neurological dysfunction score.HE staining and LFB staining of mouse spinal cord slices were used to ob-serve central nervous system inflammation infiltration and demyelinating lesions.Flow cytometry microsphere microarray technology was used to detect the content of cytokines in serum.Results The mfat-1 gene therapy could significantly raise the proportion of ω-3/ω-6 PU-FAs(P<0.05),markedly delay the incubation period and peak period and reduce neurological dysfunction scores(P<0.05),and improve inflammation and de-myelination of spinal cords(P<0.05).It could also greatly increase the levels of IL-2,IFN-γ,IL-4 and IL-17 in serum(P<0.05).Conclusion The pro-portion of ω-3/ω-6 PUFAs in blood circulation en-hanced by mfat-1 gene therapy can effectively prevent and treat experimental autoimmune encephalomyelitis in mice.
3.Therapeutic effect of platelet lysate on spinal cord injury in rats
Ling WANG ; Hong-Xu JIN ; Ying LIU ; Zhe-Yuan CHEN ; Liang-Bi XIANG
Journal of Regional Anatomy and Operative Surgery 2024;33(7):566-570
Objective To verify the therapeutic effect of platelet lysate(PL)on spinal cord injury in rats.Methods Thirty male SD rats were randomly divided into the sham operation group,the injury group and the treatment group,with 10 rats in each group.Rats in the sham operation group did not smash the spinal cord after exposure;rats in the injury group were established the rat spinal cord injury model by smashing the spinal cord with a 20 g of self-made smashing machine weights from a height of 5 cm for 5 seconds after exposure;rats in the treatment group were given intraperitoneal injection of 2 mL of PL once a day for 19 days after established the spinal cord injury model.The hind limb function was evaluated by Basso Beattie Bresnahan(BBB)score and slope experiment;six rats were randomly selected from each group,and the spinal cords of the rats were taken on the 7th day after surgery for HE staining and electron microscopy scanning to observe their pathological changes.Results There were statistically significant differences in BBB scores on the 3rd,7th and 14th days after surgery among the three groups(P<0.05),and the BBB scores of the treatment group were higher than those of the injury group(P<0.05).There were statistically significant differences in the results of slope experiment on the 7th and 14th days after surgery between the treatment group and the injury group(P<0.01).HE staining showed that the neuronal degeneration and necrosis decreased,the cell swelling improved and the microglial phagocytosis decreased in the treatment group compared with those in the injury group.The results of electron microscopy showed that the astrocyte cytoplasmic swelling and local cell membrane damage were alleviated,and the mitochondrial swelling and degeneration in the treatment group were relieved compared with those in the injury group.Conclusion PL can improve the hind limb function and reduce the pathological changes after spinal cord injury in rats,which has therapeutic effect on spinal cord injury in rats.
4.Radiofrequency ablation on prosthetic valve for atrial tachycardia after transcatheter aortic valve replacement
Hong-Xiao LI ; Bi-Jun HUANG ; Lu-Xin WANG ; Xing-Xu WANG ; Yun-Kai WANG ; Xiao-Yan HE ; Jian-Qiang ZHANG
Chinese Journal of Interventional Cardiology 2024;32(4):232-235
Transcatheter aortic valve replacement(TAVR)has emerged as a promising therapeutic alternative for addressing aortic valve-related pathologies.However,the occurrence of rapid arrhythmias linked to TAVR procedures is progressively drawing scrutiny.Presently,pharmacologic interventions constitute the mainstay of managing atrial arrhythmias related to TAVR,while the potential of ablation as a viable treatment modality remains undefined.Notably,in cases where the arrhythmia's genesis is presumed to be intricately linked to the prosthetic valve,the practicality and safety of ablation procedures remain unverified.Our institution has successfully ventured into radiofrequency ablation for a distinctive patient presenting with this intricate condition,thereby tentatively affirming the efficacy and safety of catheter ablation administered on the surface of prosthetic valves.
5.Antimicrobial resistance and resistance gene carriage by Salmonella bacteria in environmental sewage in Guangzhou
Bi-Hui SU ; Guang-Hong DU ; Xiao-Ying WU ; Gang HE ; Jun YUAN ; Chao-Jun XIE
Chinese Journal of Zoonoses 2024;40(5):442-447
This study explored the antibiotic resistance and resistance gene carriage of 140 Salmonella strains isolated from environmental sewage in Guangzhou city between March 1,2022,and November 30,2022.The micro broth dilution method was used to select 17 antibiotics for susceptibility testing.According to whole genome sequencing results,the CARD resistance database was used to obtain corresponding resistance genes.High antimicrobial resistance rates above 80%were observed a-gainst ampicillin,tetracycline,streptomycin,chloramphenicol,and cotrimoxazole.The intermediation rate of polymyxin E and ciprofloxacin exceeded 60%.The multiple drug resistance status was severe,and the rate of multiple drug resistance was as high as 92.86%.The strains carried multiple types of resistance genes,particularly for aminoglycosides,with a carriage rate as high as 92.68%.The resistance of Salmonella in environmental wastewater in Guangzhou to one or more drugs was severe,and the overall multi-drug resistance rate gradually increased over time.The resistance spectrum was diverse,and the resistance mechanism,mediated by mobile genetic elements such as re-sistance genes,was found to be the main cause of resistance to one or more drugs.
6.Different Prophylaxis Strategies for Central Nervous System Recurrence of Diffuse Large B-Cell Lymphoma
Shuang QU ; Li-Sheng LIAO ; Yan-Bin ZHENG ; Jie-Song WANG ; Hong-Ming HE ; Bi-Yun CHEN ; Hong SUN
Journal of Experimental Hematology 2024;32(5):1401-1406
Objective:To analyze the effects of highdose methotrexate(HD-MTX)and lenalidomide as central nervous system(CNS)prophylaxis strategies in patients with diffuse large B-cell lymphoma(DLBCL).Methods:The data of DLBCL patients with high risk of CNS recurrence who were initially treated in Fujian Provincial Hospital and Fujian Cancer Hospital from January 2012 to June 2022 were analyzed retrospectively.The patients were divided into HD-MTX group and lenalidomide group according to different prophylaxis strategies.Each group was further divided into high-risk group and medium-risk group based on CNS-IPI score and/or testicular involvement.The CNS relapse-free survival(CRFS)rate,adverse effects,and the effects of different prophylaxis strategies on overall survival(OS)rate and progression-free survival(PFS)rate were evaluated in different groups and subgroups.Results:There were 200 patients enrolled in this study,80 cases in lenalidomide group and 120 cases in HD-MTX group.According to the delivery timing of prophylactic HD-MTX,the patients in HD-MTX group were further divided into two groups:80 cases at the end of induction chemotherapy and 40 cases during chemotherapy interval.At a median follow-up of 48(14-133)months,the 4-year CRFS rate,4-year PFS rate,and 4-year OS rate of the HD-MTX group was 93.6%,57.2%,and 68.8%,respectively,while that of the lenalidomide group was 90.4%,69.4%and 75.6%.There were no significant differences in 4-year CRFS rate,4-year PFS rate,and 4-year OS rate between HD-MTX group and lenalidomide group(all P>0.05),but lenalidomide group showed a trend of improvement in PFS.Further subgroup analysis showed that there was no significant difference in 4-year CRFS rate between high-risk patients of the two groups(91.7%vs 83.4%,P>0.05),while 4-year PFS rate showed difference(49.5%vs 64.2%,P<0.05).A total of 248 cycles were collected for adverse reaction analysis in the HD-MTX group,and 25 cycles occurred neutropenia accompanied with infection(10.1%),while in lenalidomide group 240 cycles were collected in which 20 cycles occurred neutropenia accompanied with infection(8.3%).Both the two groups had no treatment-related deaths.Conclusion:Compared with HD-MTX,lenalidomide combined with immunochemotherapy can prevent CNS relapse,at the same time,improve prognosis,which is a safe and well tolerated central prophylaxis strategy.
7.Changes in Neutrophil Percentage-to-Albumin Ratio and Its Relationship with Short-Term Prognosis in Patients with Multiple Myeloma Treated with VRD
Xiao-Long LI ; Bi-Wei WANG ; Hui SUN ; Hong-Tao LIU ; Xi CHEN ; Huan WANG
Journal of Experimental Hematology 2024;32(6):1759-1763
Objective:To analyze the dynamic changes of neutrophil percentage-to-albumin ratio (NPAR) during treatment with bortezomib-lenalidomide-dexamethasone (VRD) in patients with multiple myeloma (MM),and explore the relationship between NPAR value and short-term prognosis of MM patients. Method:The data of 80 MM patients who underwent VRD chemotherapy at Tangshan Workers Hospital from January 2019 to April 2021 were retrospectively analyzed. NPAR levels were measured before VRD chemotherapy (T0),and on the first day of the third (T1),sixth (T2),and eighth (T3) chemotherapy cycles. All patients were followed up for 1 year,with the recurrence,progression,or death occurring within 1 year after the completion of VRD treatment as the endpoint event. The patients were divided into a good prognosis group and a poor prognosis group based on the follow-up results. The changes in NPAR at T0,T1,T2,and T3 in the two groups were statistically analyzed. The restricted cubic spline method was used to analyzed the relationship between NPAR and adverse short-term prognosis in MM patients undergoing VRD chemotherapy. Results:Among the 80 MM patients,25 cases (31.25%) had poor short-term prognosis,including 19 cases (23.75%) of progression or recurrence,and 6 cases (7.50%) of all-cause mortality. The levels of neutrophils and NPAR in the poor prognosis group at T0,T1,T2 and T3 were higher than those in the good prognosis group at the same period,while the albumin levels in the poor prognosis group at T0,T1,and T2 were lower than those in the good prognosis group at the same period (P<0.05);There was no significant difference in albumin levels between the poor prognosis group and the good prognosis group at T3 (P>0.05). Within the poor prognosis group and the good prognosis group,the levels of neutrophils and NPAR decreased sequentially at T0,T1,T2,and T3,while the levels of albumin increased sequentially,and the differences between each stage were statistically significant (P<0.05). The restricted cubic spline model showed an approximate J-shaped curve between the risk of poor short-term prognosis and the pre-treatment NPAR level in MM patients (P<0.05). If the pre-treatment NPAR>0.52,the risk of poor short-term prognosis in MM patients increased with the increase of NPAR value. Conclusion:After VRD treatment,the NPAR value of MM patients gradually decreases,and there is a correlation between the NPAR value before VRD treatment and the risk of poor prognosis after treatment. If NPAR>0.52 before treatment,the higher the NPAR value,the higher the risk of poor short-term prognosis in MM patients.
8.Clinical effects of Polygonum cuspidatum on patients with type 2 diabetes mellitus of Dampness-Heat Pattern
Yuan-Ying XU ; Wen-Wen KONG ; Hong-Ping YIN ; Hui-Hui ZHANG ; Xing-Hua CAI ; Bi-Lin XU ; Wen-Jun SHA ; Tao LEI
Chinese Traditional Patent Medicine 2024;46(8):2596-2600
AIM To explore the clinical effects of Polygonum cuspidatum Sieb.et Zucc.on patients with type 2 diabetes mellitus of Dampness-Heat Pattern.METHODS One hundred and forty patients were randomly assigned into control group(70 cases)for 8-week intervention of conventional treatment,and observation group(70 cases)for 8-week intervention of both P.cuspidatum granules and conventional treatment.The changes in body weight,BMI,blood glucose indices(FBG,2 h PG,HbA1C,GA),blood lipid indices(TC,TG,HDL-C,LDL-C,ApoA-I,ApoB,ApoA,ApoE,sdLDL-C),liver function indices(ALT,AST),fatty liver progression,TyG,HSI,TCM syndrome score and effects were detected.RESULTS The observation group demonstrated higher total effective rates of TCM syndromes than the control group(P<0.01),along with slighter fatty liver progression(P<0.01).After the treatment,the observation group displayed decreased body weight,BMI,FBG,GA,TG,ApoE,TyG,HSI,ALT and TCM syndrome score(P<0.05,P<0.01),and 2 h PG,TyG,HSI,ALT,TCM syndrome score were lower than those in the control group(P<0.05,P<0.01).CONCLUSION For the patients with type 2 diabetes mellitus of Dampness-Heat Pattern,P.cuspidatum can improve glucose and lipid metabolism disorders,which is worthy of clinical popularization and application.
9.Chemical constituents from the leaves of Citrus reticulata and their anti-inflammatory activities
Fa-Ke YANG ; Xing YANG ; Zhi-Bi ZHANG ; Rui YIN ; Hong-Chuan ZHANG ; Xu-Li DENG ; Wei-Mao DONG ; Yi-Mou WANG ; Hong-Ping HE ; Fa-Wu DONG
Chinese Traditional Patent Medicine 2024;46(9):2972-2979
AIM To study the chemical constituents from the leaves of Citrus reticulata Blanco and their anti-inflammatory activities.METHODS The 85%ethanol extract from the leaves of C.reticulata was isolated and purified by silica gel,D101 macroporous resin,MCI,ODS and Sephadex LH-20,then the structures of obtained compounds were identified by physicochemical properties and spectral data.The Griess method was used to determine their inhibitory activities on lipopolysaccharide-induced NO production in macrophages RAW 264.7 cells.The mice foot swelling inflammation model induced by carrageenan was established,and the levels of IL-1β,TNF-α were detected.RESULTS Twelve compounds were isolated and identified as nobiletin(1),tangeretin(2),5-demethylinoblitin(3),5,4'-dihydroxy-6,7,8,3'-tetramethoxy flavone(4),5-hydroxy-7,8,3',4'-trimethoxyflavanone(5),3,5,6,7,8,3',4'-heptamethoxyflavanone(6),hesperetin(7),5-hydroxy-6,7,3',4'-tetramethoxyphenone(8),β-balsam alcohol(9),stigmaster-5-en-3β-alcohol(10),p-hydroxybenzaldehyde(11),vanillin(12).Compounds 1,4,6,7,10 and 12 had strong inhibitory activites on NO release in LPS-induced RAW 264.7 cells,and the IC50 values were(25.21±2.10),(37.77±0.50),(38.19±1.58),(21.89±1.73),(43.81±1.18),(47.98±2.55),(41.23±1.11),(43.80±1.43)μmol/mL,respectively.Compounds 2-3 reduced IL-1β and TNF-α levels(P<0.05,P<0.01).CONCLUSION Compounds 6-7,9 are isolated from this plant for the first time.Compounds 1-4,8 exhibit strong in vitro anti-inflammatory activities,and compounds 2-3 exhibit significant in vivo anti-inflammatory activities.
10.PI3K/Akt pathway-based investigation of total Astragalus saponins on sarcopenia in a rat model of type 2 diabetes mellitus
Lei-Lei MA ; Ji-An LI ; Wen-Xuan XU ; Jing-Ya WANG ; Zhao-Yang TIAN ; Jia-Yu LI ; Ru-Jie HAN ; Xiao-Jin LA ; Chun-Yu TIAN ; Hong CHANG ; Zi-Yang DAI ; Bi-Wei ZHANG
Chinese Traditional Patent Medicine 2024;46(11):3612-3619
AIM To investigate the effects of total Astragalus saponins on the improvement of sarcopenia in a rat model of type 2 diabetes mellitus(T2DM).METHODS The rats were divided into the normal group for a normal feeding and the model group for the feeding of high-sugar and high-fat diet combined with intraperitoneal injection of STZ to establish a T2DM model.The successful model rats were randomly divided into the model group,the metformin group(0.2 g/kg)and the total Astragalus saponins group(80 mg/kg),and given corresponding doses of drugs by gavage.After 12 weeks administration,the rats had their FBG,postprandial blood glucose(PG2h)and wet weight of skeletal muscle measured;their serum levels of INS,C-peptide(C-P),IGF-1,TNF-α and IL-1β detected by ELISA;their morphological changes of skeletal muscle observed by HE staining;their protein expressions of PI3K,p-Akt,mTOR,S6K1,FoxO1 and Murf1 in skeletal muscle detected by Western blot;and their mRNA expressions of Pi3k,Akt and mtor in skeletal muscle detected by RT-qPCR method.RESULTS Compared with the model group,the total Astragalus saponins group displayed decreased levels of FBG,PG2h,OGTT-AUC,HOMA-IR,TNF-α and IL-1β(P<0.01);increased levels of INS,C-P,IGF-1 and wet weight of skeletal muscle(P<0.05,P<0.01);improved skeletal muscle atrophy and increased protein expressions of PI3K,p-Akt,mTOR and S6K1 in skeletal muscle(P<0.05,P<0.01);decreased protein expressions of FoxO1 and Murf1(P<0.05,P<0.01);and increased mRNA expressions of Pi3k,Akt and mtor(P<0.01).CONCLUSION The improvement effects of total Astragalus saponins on sarcopenia in T2DM rats may be associated with the regulation of PI3K/Akt/mTOR and PI3K/Akt/FoxO1 pathways.

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