ObjectiveTo explore the effects of Yimei Baijiang formula （YMBJF） on colitis-associated colorectal cancer （CAC） and the nuclear factor kappaB （NF-κB） signaling pathway in mice. MethodsSixty male Balb/c mice of 4-6 weeks old were randomized into 6 groups： Normal， model， capecitabine （0.83 g·kg^-1）， and low-， medium-， and high-dose （4.63， 9.25， 18.50 g·kg^-1， respectively） YMBJF. The mouse model of CAC was established by combining azoxymethane （AOM， 10 mg·kg^-1） and dextran sulfate sodium （DSS， 2%）. At the 5^th week after the start of modeling， the capecitabine group and the YMBJF groups were respectively administrated with the corresponding doses of drugs by gavage once a day for a total of 6 weeks. The body weights and general conditions of mice were measured and observed， and the disease activity index （DAI） was scored. The tumors in the colorectal tissue were counted， and the colorectal length was measured. The histological features of the colorectal tissue in each group of mice were observed by hematoxylin-eosin （HE） staining. The levels of inflammatory cytokines including interleukin-6 （IL-6）， interleukin-1β （IL-1β）， and tumor necrosis factor-α （TNF-α） in the serum were determined by enzyme-linked immunosorbent assay （ELISA）. The expression and localization of proliferating cell nuclear antigen-67 （Ki67）， proliferating cell nuclear antigen （PCNA）， and phosphorylated nuclear transcription factor-κB p65 （p-NF-κB p65） proteins were observed by immunohistochemistry （IHC）. The apoptosis of tumor cells was observed by the TUNEL assay. The mRNA levels of IL-6，IL-1β， TNF-α， nuclear transcription factor-κB p65 （NF-κB p65）， NF-κB inhibitor alpha （IκBα）， B-cell lymphoma-2 （Bcl-2）， and Bcl-2-associated X protein （Bax） in the colorectal tissue were quantified by Real-time polymerase chain reaction（Real-time PCR）. The protein levels of NF-κB p65， phosphorylated （p）-NF-κB p65， IκBα， p-IκBα， Bcl-2， and Bax in the colorectal tissue were determined by Western blot. ResultsCompared with the model group， each YMBJF group showed decreases in DAI and tumor number （P0.01）， and the medium-dose and high-dose YMBJF groups showed increases in colorectal length （P0.05）. In addition， each YMBJF group showed alleviated colorectal mucosal pathological injury， declined levels of IL-6， IL-1β， and TNF-α in the serum （P0.05）， reduced expression of Ki67 and PCNA （P0.01）， and down-regulated expression of p-NF-κB p65 （P0.05）. The apoptosis in the medium-dose and high-dose YMBJF groups increased （P0.01）. Each YMBJF group and the capecitabine group showed down-regulated mRNA levels of IL-1β， TNF-α， IL-6， NF-κB p65， and Bcl-2 （P0.05） and up-regulated mRNA levels of IκBα and Bax （P0.05）. The mRNA level of IκBα was up-regulated， and that of Bcl-2 was down-regulated （P0.05） in the high-dose YMBJF group. The protein levels of p-IκBα and Bcl-2 were down-regulated （P0.05） in each YMBJF group. The protein levels of IκBα and Bax were up-regulated in the medium-dose and high-dose YMBJF groups （P0.01）， while those of NF-κB p65 and p-NF-κB p65 were down-regulated （P0.05）. ConclusionYMBJF can reduce the number of tumors， reduce the levels of inflammatory factors， promote tumor cell apoptosis， and inhibit tumor cell proliferation by regulating the direct effector molecules of the NF-κB signaling pathway in the mouse model of CRC.

ObjectiveTo explore the effects of Yimei Baijiang formula （YMBJF） on colitis-associated colorectal cancer （CAC） and the nuclear factor kappaB （NF-κB） signaling pathway in mice. MethodsSixty male Balb/c mice of 4-6 weeks old were randomized into 6 groups： Normal， model， capecitabine （0.83 g·kg^-1）， and low-， medium-， and high-dose （4.63， 9.25， 18.50 g·kg^-1， respectively） YMBJF. The mouse model of CAC was established by combining azoxymethane （AOM， 10 mg·kg^-1） and dextran sulfate sodium （DSS， 2%）. At the 5^th week after the start of modeling， the capecitabine group and the YMBJF groups were respectively administrated with the corresponding doses of drugs by gavage once a day for a total of 6 weeks. The body weights and general conditions of mice were measured and observed， and the disease activity index （DAI） was scored. The tumors in the colorectal tissue were counted， and the colorectal length was measured. The histological features of the colorectal tissue in each group of mice were observed by hematoxylin-eosin （HE） staining. The levels of inflammatory cytokines including interleukin-6 （IL-6）， interleukin-1β （IL-1β）， and tumor necrosis factor-α （TNF-α） in the serum were determined by enzyme-linked immunosorbent assay （ELISA）. The expression and localization of proliferating cell nuclear antigen-67 （Ki67）， proliferating cell nuclear antigen （PCNA）， and phosphorylated nuclear transcription factor-κB p65 （p-NF-κB p65） proteins were observed by immunohistochemistry （IHC）. The apoptosis of tumor cells was observed by the TUNEL assay. The mRNA levels of IL-6，IL-1β， TNF-α， nuclear transcription factor-κB p65 （NF-κB p65）， NF-κB inhibitor alpha （IκBα）， B-cell lymphoma-2 （Bcl-2）， and Bcl-2-associated X protein （Bax） in the colorectal tissue were quantified by Real-time polymerase chain reaction（Real-time PCR）. The protein levels of NF-κB p65， phosphorylated （p）-NF-κB p65， IκBα， p-IκBα， Bcl-2， and Bax in the colorectal tissue were determined by Western blot. ResultsCompared with the model group， each YMBJF group showed decreases in DAI and tumor number （P0.01）， and the medium-dose and high-dose YMBJF groups showed increases in colorectal length （P0.05）. In addition， each YMBJF group showed alleviated colorectal mucosal pathological injury， declined levels of IL-6， IL-1β， and TNF-α in the serum （P0.05）， reduced expression of Ki67 and PCNA （P0.01）， and down-regulated expression of p-NF-κB p65 （P0.05）. The apoptosis in the medium-dose and high-dose YMBJF groups increased （P0.01）. Each YMBJF group and the capecitabine group showed down-regulated mRNA levels of IL-1β， TNF-α， IL-6， NF-κB p65， and Bcl-2 （P0.05） and up-regulated mRNA levels of IκBα and Bax （P0.05）. The mRNA level of IκBα was up-regulated， and that of Bcl-2 was down-regulated （P0.05） in the high-dose YMBJF group. The protein levels of p-IκBα and Bcl-2 were down-regulated （P0.05） in each YMBJF group. The protein levels of IκBα and Bax were up-regulated in the medium-dose and high-dose YMBJF groups （P0.01）， while those of NF-κB p65 and p-NF-κB p65 were down-regulated （P0.05）. ConclusionYMBJF can reduce the number of tumors， reduce the levels of inflammatory factors， promote tumor cell apoptosis， and inhibit tumor cell proliferation by regulating the direct effector molecules of the NF-κB signaling pathway in the mouse model of CRC.

BACKGROUND:Ursolic acid can promote the directed differentiation of bone marrow mesenchymal stem cells into osteoblasts.However,there are few reports on whether ursolic acid has osteogenic effect on human periodontal ligament stem cells. OBJECTIVE:To investigate the effect of ursolic acid on proliferation and osteogenic differentiation of human periodontal ligament stem cells. METHODS:The human periodontal ligament stem cells were isolated and cultured.Passage 3 cells were selected and treated with ordinary medium containing different concentrations(0,1,2,4,6,8 μmol/L)of ursolic acid.After intervention for 1,3,5,7 days,the cell proliferation was detected by CCK-8 assay and the appropriate intervention concentration was screened.Passage 3 human periodontal ligament stem cells were treated with osteogenic induction solution containing 0,1,2,4 μmol/L ursolic acid,respectively.After 7 days of intervention,the mRNA expressions of alkaline phosphatase,Runx2,and osteocalcin were detected by qRT-PCR.After 14 days of intervention,the formation of mineralized nodules was observed by alizarin red staining.Passage 3 human periodontal ligament stem cells were taken and the control group was added with osteogenic induction solution;the ursolic acid group and the antagonist group were added with osteogenic induction solution containing ursolic acid(2 μmol/L)and the bone morphogenetic protein signaling pathway antagonist Noggin,respectively.The ursolic acid+antagonist group was added with osteogenic induction solution containing ursolic acid(2 μmol/L)and Noggin,the inhibitor of bone morphogenetic protein signaling pathway,and cultured for 7 days.qRT-PCR and western blot assay were used to detect the mRNA and protein expressions of bone morphogenetic protein 2,Smad1,osteopontin,and Runx2. RESULTS AND CONCLUSION:(1)1,2,4 μmol/L ursolic acid could promote the proliferation of human periodontal ligament stem cells.6,8 μmol/L ursolic acid could inhibit the proliferation of human periodontal ligament stem cells,and 1,2,4 μmol/L ursolic acid was selected to intervene in subsequent experiments.(2)Compared with 0 μmol/L,1,2,4 μmol/L ursolic acid could promote the expression of alkaline phosphatase,Runx2,and osteocalcin mRNA and the formation of mineralized nodules(P<0.05),and the effect of 2 μmol/L ursolic acid was the most significant.(3)Compared with the control group,the mRNA and protein expressions of bone morphogenetic protein 2,Smad1,osteopontin,and Runx2 in the ursolic acid group were increased(P<0.05),while mRNA and protein expressions of the above indexes were decreased in the antagonist group(P<0.05).Compared with the ursolic acid group,mRNA and protein expressions of above indexes were decreased in ursolic acid+antagonist group(P<0.05).(4)The results indicate that ursolic acid promotes osteogenic differentiation of human periodontal ligament stem cells through bone morphogenetic protein signaling pathway.

BACKGROUND:Exosomes derived from mesenchymal stem cells are prospective cell-free alternatives for treating osteoarthritis.Their therapeutic activity and clinical transformation potential can be further improved by adjusting cell culture condition. OBJECTIVE:To review the effect of cell culture conditions on exosome activity and to analyze its clinical transformation potential. METHODS:Articles concerning osteoarthritis/cartilage repair and mesenchymal stem cell-derived exosomes were retrieved on CNKI and PubMed using"exosomes,mesenchymal stem cells,osteoarthritis or cartilage repair"as Chinese search terms and"exosomes or extracellular vesicles,mesenchymal stem cells,osteoarthritis or cartilage repair"as English search terms.The search time was from 2010 to 2023.Finally,100 articles were included for summary and analysis. RESULTS AND CONCLUSION:(1)During cell culture,providing a physical environment favorable for chondrocyte growth or adding chondroprotective small molecules,chondrogenic factors,or inflammatory factors,can further improve the regulatory activity of exosomes secreted by mesenchymal stem cells in maintaining chondrocyte phenotype,promoting cartilage regeneration,and immunosuppression.Therefore,other physical or chemical factors with similar characteristics may also improve the effects of exosomes secreted by mesenchymal stem cells for treating osteoarthritis.(2)Some treatments during cell culture,such as hypoxia induction,pulsed electromagnetic field stimulation,bioreactor,and chondroprotective molecule(e.g.,human parathyroid hormone 1-34)stimulation are safe and scalable,which allows for the production of clinical-grade exosomes secreted by mesenchymal stem cells for osteoarthritis treatment.(3)Mesenchymal stem cell exosomes are expected to achieve modified treatment of osteoarthritis,and the feasibility of clinical transformation can be further improved by adjusting the cell culture regimen to enhance the therapeutic activity.

BACKGROUND:Crosslinked sodium hyaluronate gel has good mechanical property,biocompatibility,and biodegradability,and can be used as an isolated protective material in tumor radiation therapy to protect endangered organs from damage caused by excess radiation dose. OBJECTIVE:To investigate the safety and efficacy of crosslinked sodium hyaluronate gel in reducing the dose of radiation to dangerous organs during brachytherapy. METHODS:A total of 16 specific pathogen-free Kunming mice of the same age and similar body weight were selected as experimental subjects and divided into experimental group and control group by the random number table method,with 8 mice in each group.125I seeds were implanted subcutaneously in the back of mice in the experimental group,and then crosslinked sodium hyaluronate gel was injected around the radioactive particles.Only 125I seeds were implanted subcutaneously in the back of mice in the control group.After injection,the distance between the radioactive particles and the epidermis was measured by spiral CT scan,and the surface radiation dose was measured by radiation dosimeter.Within 10 weeks after injection,the growth state,survival rate,skin radiation damage,and gel retention of mice were observed. RESULTS AND CONCLUSION:(1)Spiral CT scan showed that the implanted gel was relatively concentrated and created an effective distance between the radioactive seeds and the epidermis.The body surface radiation dose of the experimental group was significantly lower than that of the control group(P<0.01).(2)During the experimental observation period,mice in both groups survived;mice in the control group showed obvious irritability and other unstable behavior in the late experimental period,and some mice in the experimental group showed similar behavior.The daily food intake of mice in the two groups had no significant change,and the body mass showed the same increasing trend.After implantation of radioactive seeds,the two groups of mice showed different degrees of radioactive skin injury.From day 23 after injection to the end of the experiment,the skin radiation injury score of the experimental group was lower than that of the control group(P<0.01).At week 10 after implantation,6 mice in the experimental group had no obvious gel residue under their skin,and 2 mice had a very small amount of scattered gel-like samples under their skin.(3)Therefore,the crosslinked sodium hyaluronate injection technique can increase the space between the radioactive target area of 125I seeds and the organ at risk outside the target through physical space occupying,which can effectively reduce the dose of the organ at risk,and play a role in the isolation and protection of the organ at risk.

BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.

OBJECTIVE:High-intensity interval training(HIIT)and moderate-intensity continuous training(MICT)can improve the quality of life of patients with clinical chronic diseases,but their application effects and regulatory factors in adults with insufficient physical activity are still unclear.This study aimed to explore the application effects and regulatory factors of HIIT and MICT on the quality of life of adults with insufficient physical activity. METHODS:A systematic literature search was conducted in databases including Web of Science Core Collection,Medline(EBSCO Host),PubMed,and Cochrane Library.The search time limit was from the establishment of each database to September 2023.The types of included literature were randomized controlled trials,and the research subjects were physically inactive adults.RevMan 5.4 software and the GRADE evidence evaluation framework were used to assess the quality of the included literature.Main effects pooling of random effects models was performed using R Studio(version 4.2.0).Subgroup analyses,regression analyses,and sensitivity analyzes were used to explore the sources of study heterogeneity and moderators. RESULTS:(1)Thirty-two randomized controlled trials of moderate to high quality were included,involving 2 083 physically inactive adults(HIIT group n=474;MICT group n=708;control group n=901).(2)Compared with the non-training control group,HIIT[Hedges'g=0.61;95%confidence interval(CI):0.40-0.83;I2=45%]and MICT(Hedges'g=0.66;95%CI:0.25-1.08;I2=89%)significantly improved the quality of life.Direct comparison studies of HIIT and MICT found no significant differences in the quality of life(Hedges'g=-0.01;95%CI:-0.23-0.21;I2=0%).(3)Subgroup analysis showed that HIIT and MICT were more effective in improving the physical components of the quality of life(HIIT:Hedges'g=0.82 vs.0.75;MICT:Hedges'g=0.74 vs.0.55),while cycling had a better trend in improving overall quality of life(HIIT:Hedges'g=0.74 vs.0.36;MICT:Hedges'g=1.08 vs.0.52).(4)Additionally,regression analysis did not identify any significant moderators(P>0.05 for all factors).(5)None of the above meta-analyses found publication bias(Egger test P>0.05). CONCLUSION:(1)Moderate to high level evidence shows that both HIIT and MICT can improve the quality of life of adults with insufficient physical activity,and the intervention effects between the two are similar.Therefore,when choosing between these two options,it is necessary to comprehensively consider factors such as time economy,scheduling flexibility,and application feasibility to formulate a personalized exercise plan.(2)This study recommends that when applying HIIT,a low-volume protocol(for example,5 groups each time,1 minute each),3 times/week,and ride at 80%-95%of the maximum heart rate is used to achieve the theoretical best improvement effect.(3)Although MICT improves the quality of life,there is insufficient evidence that increasing exercise duration brings additional benefits.Therefore,this study recommends that when MICT is conducted,it should be carried out more than three times a week,with each training duration controlled between 25 and 60 minutes,and cycling at 50%-75%of the maximum heart rate,in order to achieve the theoretically expected best improvement effect.

Liver cirrhosis is the terminal stage of various chronic liver diseases， with the main clinical manifestation of portal hypertension， which can lead to spontaneous portosystemic shunt （SPSS）. SPSS is very common in clinical practice and is closely associated with the prognosis of patients. This article summarizes the recent studies in the clinical significance of cirrhotic portal hypertension with SPSS， the controversies in studies， and the current status and future prospects and challenges of treatment， in order to provide a reference for the standardized diagnosis and treatment of portal hypertension.

ObjectiveTo explore effect of Xianlian Jiedu prescription on the recurrence of colorectal cancer （CRC） and investigate the related mechanisms. MethodsA postoperative recurrence model was established in 25 Balb/c mice by injecting CT26 cells subcutaneously into the armpit， followed by surgical removal of 99% of the subcutaneous tumor. The mice were randomly divided into model group， low-dose Xianlian Jiedu prescription （XLJDP-L） group （6.45 g·kg^-1·d^-1）， medium-dose Xianlian Jiedu prescription （XLJDP-M） group （12.9 g·kg^-1·d^-1）， high-dose Xianlian Jiedu prescription （XLJDP-H） group （25.8 g·kg^-1·d^-1）， and 5-fluorouracil （5-FU） group （1×10^-3 g·kg^-1·d^-1）. The mice were euthanized after 14 days of continuous intervention， and recurrent tumor tissue was harvested. Hematoxylin and eosin （HE） staining was used to observe pathological and morphological changes in the recurrent tumor tissue. Immunohistochemistry （IHC） was employed to assess the expression of proliferating cell nuclear antigen （Ki67）， vascular endothelial growth factor （VEGF）， and platelet-endothelial cell adhesion molecule （CD31） in recurrent tumor tissue. The Western blot was used to detect the protein expression levels of angiopoietin-2 （ANG-2）， VEGF， phosphorylated-protein kinase B （p-Akt）， protein kinase B （Akt）， phosphorylated-phosphatidylinositol 3-kinase （p-PI3K）， and phosphatidylinositol 3-kinase （PI3K） in recurrent tumor tissue. ResultsBefore treatment， there were no statistical differences in tumor volume， tumor weight， and body mass among the XLJDP-L， XLJDP-M， and XLJDP-H groups and the 5-FU group compared to the model group， indicating model stability. After treatment， compared with those in the model group， the tumor volume and tumor weight in the XLJDP-L， XLJDP-M， and XLJDP-H groups and the 5-FU group were significantly reduced （P<0.01）， showing dose dependency. Meanwhile， there were no significant differences in body weight among the XLJDP-L， XLJDP-M， and XLJDP-H groups and the 5-FU group compared to the model group. HE staining showed that compared with that in the model group， tumor tissue in the XLJDP-L， XLJDP-M， and XLJDP-H groups and the 5-FU group had loosely arranged cells， increased intercellular spaces， small and shriveled nuclei， light staining， fewer mitotic figures and atypical nuclei， and increased necrotic areas. IHC showed that compared with those of the model group， the positive rates of Ki67， VEGF， and CD31 in the recurrent tumor tissue of the XLJDP-L， XLJDP-M， and XLJDP-H groups and the 5-FU group were significantly reduced （P<0.01） in a dose-dependent manner. Western blot results showed that compared with those of the model group， the protein expression levels of ANG-2 and VEGF in the recurrent tumor tissue of the XLJDP-L， XLJDP-M， and XLJDP-H groups and the 5-FU group were significantly downregulated （P<0.05， P<0.01）， and the p-Akt/Akt and p-PI3K/PI3K ratios were significantly decreased in a dose-dependent manner （P<0.05， P<0.01）. ConclusionXianlian Jiedu prescription significantly inhibits the recurrence of CRC in mice after subcutaneous tumor surgery. The mechanism may involve regulating the PI3K/Akt pathway and downregulating key angiogenic proteins such as ANG-2， VEGF， and CD31.

Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.