ABSTRACT
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) infection, is still one of the top killers worldwide among infectious diseases. The escape of Mtb from immunological clearance and the low targeting effects of anti-TB drugs remain the substantial challenges for TB control. Iron is particularly required for Mtb growth but also toxic for Mtb in high dosages, which makes iron an ideal toxic decoy for the 'iron-tropic' Mtb. Here, a macrophage-targeted iron oxide nanoparticles (IONPs)-derived IONPs-PAA-PEG-MAN nanodecoy is designed to augment innate immunological and drug killings against intracellular Mtb. IONPs-PAA-PEG-MAN nanodecoy exhibits preferential uptake in macrophages to significantly increase drug uptake with sustained high drug contents in host cells. Moreover, it can serve as a specific nanodecoy for the 'iron-tropic' Mtb to realize the localization of Mtb contained phagosomes surrounding the drug encapsulated nanodecoys and co-localization of Mtb with the drug encapsulated nanodecoys in lysosomes, where the incorporated rifampicin (Rif) can be readily released under acidic lysosomal condition for enhanced Mtb killing. This drug encapsulated nanodecoy can also polarize Mtb infected macrophages into anti-mycobacterial M1 phenotype and enhance M1 macrophage associated pro-inflammatory cytokine (TNF-α) production to trigger innate immunological responses against Mtb. Collectively, Rif@IONPs-PAA-PEG-MAN nanodecoy can synergistically enhance the killing efficiency of intracellular Mtb in in vitro macrophages and ex vivo monocyte-derived macrophages, and also significantly reduce the mycobacterial burdens in the lung of infected mice with alleviated pathology. These results indicate that Rif@IONPs-PAA-PEG-MAN nanodecoy may have a potential for the development of more effective therapeutic strategy against TB by manipulating augmented innate immunity and drug killings.
Subject(s)
Mycobacterium tuberculosis , Tuberculosis , Humans , Animals , Mice , Macrophages , Tuberculosis/drug therapy , Rifampin/pharmacology , IronABSTRACT
Magnitude and diversity of gut microbiota and metabolic systems are critical in shaping human health and diseases, but it remains largely unclear how complex metabolites may selectively regulate gut microbiota and determine health and diseases. Here, we show that failures or compromised effects of anti-TNF-α therapy in inflammatory bowel diseases (IBD) patients were correlated with intestinal dysbacteriosis with more pro-inflammatory bacteria, extensive unresolved inflammation, failed mucosal repairment, and aberrant lipid metabolism, particularly lower levels of palmitoleic acid (POA). Dietary POA repaired gut mucosal barriers, reduced inflammatory cell infiltrations and expressions of TNF-α and IL-6, and improved efficacy of anti-TNF-α therapy in both acute and chronic IBD mouse models. Ex vivo treatment with POA in cultured inflamed colon tissues derived from Crohn's disease (CD) patients reduced pro-inflammatory signaling/cytokines and conferred appreciable tissue repairment. Mechanistically, POA significantly upregulated the transcriptional signatures of cell division and biosynthetic process of Akkermansia muciniphila, selectively increased the growth and abundance of Akkermansia muciniphila in gut microbiota, and further reprogrammed the composition and structures of gut microbiota. Oral transfer of such POA-reprogrammed, but not control, gut microbiota induced better protection against colitis in anti-TNF-α mAb-treated recipient mice, and co-administration of POA with Akkermansia muciniphila showed significant synergistic protections against colitis in mice. Collectively, this work not only reveals the critical importance of POA as a polyfunctional molecular force to shape the magnitude and diversity of gut microbiota and therefore promote the intestinal homeostasis, but also implicates a new potential therapeutic strategy against intestinal or abenteric inflammatory diseases.
Subject(s)
Colitis , Gastrointestinal Microbiome , Inflammatory Bowel Diseases , Humans , Animals , Mice , Tumor Necrosis Factor Inhibitors/metabolism , Colitis/microbiology , Inflammatory Bowel Diseases/microbiology , Verrucomicrobia/metabolism , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism , Biological Therapy , Dextran Sulfate , Mice, Inbred C57BL , Disease Models, AnimalABSTRACT
Objective: The extent, range, and nature of available research in the field of herbal therapies for osteoarthritis (OA) have not been systematically analyzed. This study aimed to map the literature available on herbal therapies for OA and identify global hotspots and trends in this field. Methods: Studies on herbal therapies for OA published between 2004 and 2022 were searched from the Web of Science Core Collection. Microsoft Excel, SPSS Statistics, and CiteSpace software were used to analyze and visualize the quantity and citations of publications, and the research hotspots and trends in research on herbal therapies for OA. Results: A total of 1649 publications mainly from 76 countries/regions and 270 institutions were included in this study. From 2004 to 2022, there is an upward trend in the publications of herbal therapies for OA. China ranked first in the number of publications (n = 568, 34.45%), followed by the USA (n = 353, 21.41%), South Korea (n = 187, 11.34%), Germany (n = 85, 5.15%), and England (n = 79, 4.79%). Kyung Hee University (n = 46), Xianxiang Liu (n = 25), and Evidence-Based Complementary and Alternative Medicine (n = 74) were the most prolific affiliation, author, and journal, respectively. Felson DT (n = 185) and Arthritis and Rheumatism (n = 1173) held the record for the most cited papers by an author and journal, respectively. Currently, the hot keywords in the field of herbal therapies for OA include knee OA, traditional Chinese medicine (TCM), differentiation, rosa canina, inflammation, oxidative stress, stem cell, and regenerative medicine. The emerging research trends in herbal therapies for OA are herbal medicinal product, chronic knee pain, mesenchymal stem cell, and clinical pharmacology. Conclusions: Research on herbal therapies for OA is flourishing, but communication among countries/regions should be strengthened. Current research on herbal therapies for OA mainly focuses on knee OA, TCM, differentiation, rosa canina, inflammation, oxidative stress, stem cell, and regenerative medicine. The research frontiers are herbal medicinal product, chronic knee pain, mesenchymal stem cell, and clinical pharmacology.
ABSTRACT
Geranium wilfordii Maxim. is a weed of perennial herbs and considerable medicinal plant for treating acute and chronic rheumatalgia in China. In August 2019, leaf spots on G. wilfordii were observed in Harbin (45°60'N, 126°64'E), Heilongjiang Province, China. The disease occurred on 15 to 30% of G. wilfordii leaves in three nurseries (~1.5 ha/each nursery). Initial symptoms were brown necrotic spots with a gray-white center, which enlarged gradually from approximately 1 to 5 mm in diameter, and produced concentric rings and became necrotic. Twelve infected tissues from twelve diseased leaves were surface disinfested in 0.5% NaOCl for 5 min, rinsed three times in sterile distilled water, dried on sterilized filter paper and cultured on potato dextrose agar (PDA) amended with 50 µg/ml streptomycin at 26°C for 5 days. Eight fungal cultures with consistent characteristics were obtained and subcultured by transferring hyphal tips onto fresh PDA. Single-conidium isolates were generated with methods reported previously (Leslie and Summerell 2006). Colonies on PDA consisted of cottony, dense, grayish white mycelium, pale gray colony. Conidia of a representative isolate LGC2 were single-celled, hyaline, cylindrical to slightly curved with a rounded apex and truncated base that measured 16.2 to 22.5 µm (length) × 2.6 to 3.7 µm (width) (n = 50). The appressoria were elliptic to claviform or slightly lobed on synthetic nutrient-poor agar. Based on these characteristics, the eight isolates were identified as Colletotrichum dematium (Damm et al. 2009). Genomic DNA was extracted from representative isolates LGC2, LGC3, LGC5 and the internal transcribed spacer regions (ITS)ï¼beta-tubulin (TUB2) and actin (ACT) were amplified and sequenced using the primers ITS1/ITS4 (Yin et al. 2012), T1/Bt2b (Glass and Donaldson 1995) and ACT-512F/ACT-783R (Carbone and Kohn 1999), respectively. DNA sequences of isolates LGC2, LGC3, and LGC5 were identical and deposited onto the GenBank (accession nos. MW193053.1 for ITS, MZ357349.1 for TUB2, and OL956946.1 for ACT). MegaBLAST analysis showed 100%, 99.7% and 100% identical to C. dematium isolates CBS 125.25 (accession nos. NR_111453.1 for ITS 552/553 bp, GU228113.1 for TUB2 386/387 bp, and GU227917.1 for ACT 231/231 bp respectively. A pathogenicity test was performed on with a representative isolate LGC2 by spraying spore suspension (1 × 106 conidia/ml) on the surfaces of all leaves of ten healthy three-month-old G. wilfordii plants. All leaves of ten control plants were inoculated with sterile water to serve as the control. All plants were placed in a humidity chamber (>95% RH, 26â) for 48 h after inoculation and then transfered in a greenhouse at 22/28°C with a 12:12h light-dark cycle for 10 days. All inoculated leaves showed symptoms similar to those observed in the fields, while no symptoms were observed on the control leaves. The experiment was conducted twice. The fungus was re-isolated from the infected leaves and confirmed to be C. dematium according to morphological and molecular characteristics. C. dematium has previously been reported on common knotgrass (Liu et al. 2016), on piper betle (Sun et al. 2020), peanut anthracnose in China (Yu et al. 2020). To our knowledge, this is the first report of C. dematium causing G. wilfordii anthracnose in China. G. wilfordii anthracnose caused by C. dematium poses a threat to significantly reduce the quality of G. wilfordii. Therefore, its distribution needs to be investigated and effective disease management strategies developed.
ABSTRACT
Pathogenesis hallmarks for tuberculosis (TB) are the Mycobacterium tuberculosis (Mtb) escape from phagolysosomal destruction and limited drug delivery into infected cells. Several nanomaterials can be entrapped in lysosomes, but the development of functional nanomaterials to promote phagolysosomal Mtb clearance remains a big challenge. Here, we report on the bactericidal effects of selenium nanoparticles (Se NPs) against Mtb and further introduce a novel nanomaterial-assisted anti-TB strategy manipulating Ison@Man-Se NPs for synergistic drug-induced and phagolysosomal destruction of Mtb. Ison@Man-Se NPs preferentially entered macrophages and accumulated in lysosomes releasing Isoniazid. Surprisingly, Ison@Man-Se/Man-Se NPs further promoted the fusion of Mtb into lysosomes for synergistic lysosomal and Isoniazid destruction of Mtb. Concurrently, Ison@Man-Se/Man-Se NPs also induced autophagy sequestration of Mtb, evolving into lysosome-associated autophagosomal Mtb degradation linked to ROS-mitochondrial and PI3K/Akt/mTOR signaling pathways. This novel nanomaterial-assisted anti-TB strategy manipulating antimicrobial immunity and Mtb clearance may potentially serve in more effective therapeutics against TB and drug-resistant TB.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Drug Delivery Systems/methods , Isoniazid/chemistry , Macrophages/drug effects , Mycobacterium tuberculosis/drug effects , Nanoparticles/chemistry , Selenium/chemistry , Tuberculosis/drug therapy , Humans , Tuberculosis/pathologyABSTRACT
To predict the targets of active ingredients of Kuihua Hugan Tablets by network pharmacology, and explore the "multi-component-multi-target-multi-pathway" hepatoprotective mechanism of action. First, through traditional Chinese medicine systems pharmacology(TCMSP) and TCM Database@Taiwan Database, main active ingredients of Kuihua Hugan Tablets were screened out based on oral bioavailability(OB), drug-likeness(DL) and effective half-lives(HL). The targets of active ingredients of Kuihua Hugan Tablets were predicted based on the PharmMapper method. Then, the prediction was conducted by screening the target genes associated with chronic hepatitis and early cirrhosis through CooLGeN and GeneCards databases. Target gene functions and signal pathways were analyzed by bioinformatics annotation database Metascape. Cytoscape software was used to construct the Kuihua Hugan Tablets ingredient-target and ingredient-target-pathway network. String database combined with Cytoscape software was used to construct the networks of component-target and component-target-pathway. STRING database was combined with Cytoscape software to draw protein-protein interaction(PPI) network and conduct network topology analysis. Finally, Systems Dock Web Site software was applied in verifying the molecular docking between active ingredients and potential protein targets. A total of 26 compounds and 509 potential targets were screened out from Kuihua Hugan Tablets in the experiment. The results of PPI network analysis indicated that albumin(ALB), insulin-like growth factor 1(IGF1), matrix metalloproteinase-9(MMP9), matrix metalloproteinase-2(MMP2), non-receptor tyrosine kinase proto-oncogene(SRC), estrogen receptor 1(ESR1) and cancer-signal transduction-inflammation-drugs metabolism-related biological processes and metabolic pathways were closely associated with the active ingredients in Kuihua Hugan Tablets. The effects of Kuihua Hugan Tablets in alleviating chronic hepatitis and early cirrhosis indicated the multi-component, multi-target, and multi-pathway characteristics of traditional Chinese medicines, providing new ideas for further research and development of Kuihua Hugan Tablets.
Subject(s)
Drugs, Chinese Herbal/pharmacology , Metabolic Networks and Pathways , Protein Interaction Mapping , Medicine, Chinese Traditional , Molecular Docking Simulation , TabletsABSTRACT
OBJECTIVE: To observe the effect of norcantharidin (NCTD) on collagen-induced arthritis (CIA) rats. METHODS: Sixty Sprague-Dawley(SD) rats were randomly divided into 6 groups (n=10): normal group, CIA model group(model group), NCTD low-dose group [1.35 mg/(kgâ¢d)], NCTD middle-dose group [2.7 mg/(kgâ¢d)], NCTD high-dose group [5.4 mg/(kgâ¢d)] and methotrexate (MTX) group [1.8 mg/(kg/w)]. Anesthetized rats were sacrificed by luxation of cervical vertebra after 4 weeks of administration. The arthritis scores were evaluated twice a week. The pathological changes in the ankle joints of rats were observed by hematoxylin-eosin (H&E) staining. The serum levels of interleukin (IL) 1ß, IL-6, tumor necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), IL-17 and transform growth factor (TGF) ß were detected by enzyme linked immunosorbent assay (ELISA). The mRNA expression of retinoid-related orphan nuclear receptorγt (RORγt) and forkhead box P3 (Foxp3) in peripheral blood lymphocytes were confirmed by real-time polymerase chain reaction. RESULTS: MTX and high-dose NCTD not only decreased the arthritis scores but also alleviated the pathological changes in CIA rats' ankle joints compared with the model group (P<0.05 or P<0.01). All doses of NCTD significantly inhibited the serum levels of IL-6, IL-17 and TNF-α in CIA rats (P<0.05). Only middle- and high-dose of NCTD prominently decreased serum IL-1ß and TGF-ß levels of CIA rats (P<0.05). However, NCTD has no effect on vascular endothelial growth factor (VEGF) level in CIA rats. The Foxp3 mRNA expression in all NCTD groups were increased significantly than in the model group (P<0.05). The mRNA expression of RORγt in NCTD high-dose group was decreased apparently in comparison with the model group (P<0.05). CONCLUSIONS: NCTD showed therapeutic effect on CIA rats by inhibition of cytokines and regulation of Th17/Treg cells.
Subject(s)
Arthritis, Experimental/drug therapy , Bridged Bicyclo Compounds, Heterocyclic/therapeutic use , Animals , Arthritis, Experimental/blood , Arthritis, Experimental/pathology , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Cytokines/blood , Forkhead Transcription Factors/metabolism , Joints/drug effects , Joints/pathology , Male , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats, Sprague-DawleyABSTRACT
While there is an urgent need to develop new and effective drugs for treatment of tuberculosis (TB) and multi-drug resistant TB (MDR-TB), repurposing FDA (U.S. Food and Drug Administration) -approved drugs for development of anti-TB agents may decrease time and effort from bench to bedside. Here, we employed host cell-based high throughput screening (HTS) assay to screen and characterize FDA-approved, off-patent library drugs for anti-Mycobacterium tuberculosis (MTB) activities. The cell-based HTS allowed us to identify an anti-cancer drug of bis-biguanide dihydrochloride (BBD) as potent anti-mycobacteria agent. Further characterization showed that BBD could inhibit intracellular and extracellular growth of M. smegmatis and slow-growing M. bovis BCG. BBD also potently inhibited replication of clinically-isolated MTB and MDR-TB strains. The proof-of-concept study showed that BBD treatment of MTB-infected mice could significantly decrease CFU counts in the lung and spleen. Notably, comparative evaluation showed that MTB CFU counts in BBD-treated mice were lower than those in rifampicin-treated mice. No apparent BBD side effects were found in BBD-treated mice. Thus, our findings support further studies to develop BBD as a new and effective drug against TB and MDR-TB.
Subject(s)
Antitubercular Agents/administration & dosage , Biguanides/administration & dosage , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/drug therapy , Animals , Antitubercular Agents/pharmacology , Biguanides/pharmacology , DNA Replication/drug effects , Disease Models, Animal , Drug Evaluation, Preclinical , Drug Repositioning , Humans , Lung/drug effects , Lung/microbiology , Mice , Mycobacterium bovis/drug effects , Mycobacterium smegmatis/drug effects , Spleen/drug effects , Spleen/microbiology , Tuberculosis, Multidrug-Resistant/microbiologyABSTRACT
OBJECTIVE: To observe the inhibiting effect of acupuncture on blood lipid, myocardial hypertrophy and fibrosis in mice with hyperlipemia, and explore its possible action mechanism. METHODS: Ten inbred mice (C57) were applied. Forty ApoE(-/-) mice who removed gene of apolipoprotein E were randomly divided into a control group, a non-acupoint group, an acupoint group and a medication group. The points 0. 5 cm and 1 cm next to the end of mice tail were respectively punctured in the non-acupoint group; "Neiguan" (PC 6) and "Fenglong" (ST 40) were punctured in the acupoint group; intragastric administration of simvastatin was applied in the medication group. After 8 weeks of treatment, the changes of total cholesterol (TC) and ratio of heart to body mass in each group were measured; changes of cardiac muscle fiber and ventricular wall thickness were observed; enzyme linked immunosorbent assay (ELISA) was used to test the level of angiotensin II (Ang I ) in plasma, and western blotting method was used to test protein content of angiotensin II type 1 receptor (AT1R) and endothelin-1 type A receptor (ETAR) in the heart. RESULTS: After 8 weeks of intervention, compared with the control group, rising range of blood lipid was obviously decreased (P<0.01) in the acupoint group and medication group, ratio of P<0.01), myocardial heart to body mass was decreased (P<0.05), thickness of ventricular wall was reduced (P fibrosis was relieved, levels of Ang II and ET-1 in plasma were decreased (P<0. 05), content of NO was increased (P<0. 05), and protein content of AT1R and ETAR was decreased in the heart (P<0. 05). CONCLUSION: 40) could inhibit the rising of blood lipid in ApoE(-/-) mice, lower the levels of Ang II and ET-1 in peripheral blood, increase the content of NO and inhibit the expression of AT1R and ETAR in heart tissue, which could relieve myocardial hypertrophy and fibrosis to play a protective role on heart.
Subject(s)
Acupuncture Therapy , Heart Diseases/prevention & control , Heart/physiopathology , Hyperlipidemias/therapy , Acupuncture Points , Angiotensin II/metabolism , Animals , Blood Pressure , Disease Models, Animal , Heart Diseases/etiology , Heart Diseases/metabolism , Heart Diseases/physiopathology , Humans , Hyperlipidemias/complications , Hyperlipidemias/physiopathology , Male , Mice , Mice, Inbred C57BL , Myocardium/metabolismABSTRACT
OBJECTIVE: To study the effects of environmental factors on the degree of injury and expression of vascular endothelial growth factor (VEGF) and interleukin-1 (IL-1) in cartilage cells of the joint in a rat model of adjuvant arthritis (AA). METHODS: SD rats aged 10 months were randomly divided into 4 groups that varied by temperature and humidity housing conditions and induction of AA: a control group, a model group, a cold-damp group, and a hot-damp group. All groups except the control group were induced with AA. After 4 w, VEGF and IL-1 expression in cartilage cells of ankle joints of hind limbs were observed. RESULTS: Mean area, optical density, and numbers of VEGF- and IL-1-positive cells in the model group, the cold-damp group, and the hot-damp group were significantly higher than that of the control group (all P < 0.05). Optical density and positive cell numbers in the cold-damp group and the hot-damp group were significantly higher than that of the model group (all P < 0.05). Optical density and positive cell numbers in the hot-damp group were significantly higher than that of the cold-damp group. Bone in the hot-damp and cold-damp groups was severely injured. CONCLUSION: Environmental factors such as high humidity combined with either high or low temperature increase the severity of damage and expression of VEGF and IL-1 in cartilage cells of joints in rats induced with AA.
Subject(s)
Arthritis, Experimental/metabolism , Cartilage, Articular/chemistry , Interleukin-1/analysis , Vascular Endothelial Growth Factor A/analysis , Animals , Cold Temperature , Hot Temperature , Rats , Rats, Sprague-DawleyABSTRACT
OBJECTIVE: To observe the effectiveness and safety of a therapy combining disease with syndrome on rheumatoid arthritis. METHODS: Eighty patients with rheumatoid arthritis belonging to syndrome of damp-heat obstruction were randomly divided into a treatment group and a control group according to stratified blocked randomization method. Forty cases in the control group orally took Loxoprofen Sodium Tablet and Leifumite Tablet and the other 40 cases in the treatment group orally took a Chinese medicine for 12 weeks as a course of treatment. ACR therapeutic effect was used as the standard for evaluating the total therapeutic effect. RESULTS: After 12 weeks of treatment, there was a statistical difference (P < 0.01) in the improvement of VAS score, morning stiffness time, number of swelling joints, index of swelling joints, number of joints with tenderness, index of joints with tenderness, average grip strength of both hands, DSA28 score, HAQ, patient's assessment, physician's assessment, ESR, CRP and RF in both groups. The improvement of morning stiffness time, number of swelling joints, index of swelling joints, grip strength, HAQ and patient's assessment in the treatment group was much better than that in the control groups with statistical difference (P < 0.05). ACR20, ACR50 and ACR70 was 27.5% (11/40), 37.5% (15/40) and 22.5% (9/40) respectively in the treatment group and 40% (16/40), 27.5% (11/42) and 10.0% (4/40) respectively in the control group with statistical difference (P < 0.05) in the superiority of the treatment group over the control group. The incidence of adverse reaction in the control group was higher than that in the treatment group (P < 0.05). CONCLUSION: Definite therapeutic effect and high safety can be achieved in using the therapy combining disease with syndrome to treat rheumatoid arthritis belonging to syndrome of damp-heat obstruction.
Subject(s)
Antirheumatic Agents/therapeutic use , Arthritis, Rheumatoid/drug therapy , Drugs, Chinese Herbal/administration & dosage , Administration, Oral , Adolescent , Adult , Aged , Drugs, Chinese Herbal/adverse effects , Female , Humans , Male , Middle Aged , Treatment Outcome , Young AdultABSTRACT
Inositol monophosphatase is an enzyme in the biosynthesis of myo-inostiol, a crucial substrate for the synthesis of phosphatidylinositol, which has been demonstrated to be an essential component of mycobacteria. In this study, the Rv2131c gene from Mycobacterium tuberculosis H37Rv was cloned into the pET28a vector and the recombinant plasmid was transformed into Escherichia coli BL21 (DE3) strain, allowing the expression of the enzyme in fusion with a histidine-rich peptide on the N-terminal. The fusion protein was purified from the soluble fraction of the lysed cells under native conditions by immobilized metal affinity chromatography (IMAC). The purified Rv2131c gene product showed inositol monophosphatase activity but with substrate specificity that was broader than those of several bacterial and eukaryotic inositol monophosphatases, and it also acted as fructose-1,6-bisphosphatase. The dimeric enzyme exhibited dual activities of IMPase and FBPase, with K(m) of 0.22+/-0.03mM for inositol-1-phosphate and K(m) of 0.45+/-0.05mM for fructose-1,6-bisphosphatase. To better understand the relationship between the function and structure of the Rv2131c enzyme, we constructed D40N, L71A, and D94N mutants and purified these corresponding proteins. Mutations of D40N and D94N caused the proteins to almost completely lose both the inositol monophosphatase and fructose-1,6-bisphosphatase activities. However, L71A mutant did not cause loss either of the activities, but the activity toward the inositol was 12-fold more resistant to inhibition by lithium (IC(50) approximately 60mM). Based on the substrate specificity and presence of conserved sequence motifs of the M. tuberculosis Rv2131c, we proposed that the enzyme belonged to class IV fructose-1,6-bisphosphatase (FBPase IV).