A novel colorimetric technique for estimating iron in magnetosomes of magnetotactic bacteria based on linear regression.

Magnetotactic bacteria (MTB) use iron from their habitat to create magnetosomes, a unique organelle required for magnetotaxis. Due to a lack of cost-effective assay methods for estimating iron in magnetosomes, research on MTB and iron-rich magnetosomes is limited. A systemized assay was established in this study to quantify iron in MTB using ferric citrate colorimetric estimation. With a statistically significant R2 value of 0.9935, the iron concentration range and wavelength for iron estimation were optimized using linear regression. This colorimetric approach and the inductively coupled plasma optical emission spectrometry (ICP-OES) exhibited an excellent correlation R2 value of 0.961 in the validatory correlative study of the iron concentration in the isolated magnetotactic bacterial strains. In large-scale screening studies, this less-expensive strategy could be advantageous.

Production and characterization of naturally occurring antibacterial magnetite nanoparticles from magnetotactic Bacillus sp. MTB17.

AIMS: This study envisaged the isolation and characterization of magnetite nanoparticles (MNPs) from magnetotactic bacteria (MTB) and the evaluation of their antibacterial efficacy. METHODS AND RESULTS: MNPs were extracted from 20 motile but morphologically different MTB, and they were subjected to antibacterial activity assay. These MNPs were found to be highly effective against Vibrio cholerae. MTB17 was considered as the potent MTB strain based on the antibacterial activity. The MNPs of MTB17 were isolated and validated by UV-Visible spectroscopy, particle size analysis, FTIR analysis, and PXRD. CONCLUSIONS: Isolation and characterization of ~85 nm MNPs from MTB is reported, and it is highly active against all the gram-positive and gram-negative strains tested. SIGNIFICANCE AND IMPACT OF THE STUDY: This study focuses on a novel use of biogenic magnetite MNPs as an antibacterial agent, which can be further explored using in vivo studies.

Effect of Extremely Low Power Time-Varying Electromagnetic Field on Germination and Other Characteristics in Foxtail Millet (Setaria italica) Seeds.

The ability of extremely low, time-varying electromagnetic field (EMF) to improve germination efficacy was studied in Foxtail millet (Setaria italica) seeds using response surface methodology. An optimal factorial central composite design was chosen to optimize the EMF with three critical factors, viz. frequency, intensity, and duration. The adequacy of the model and fitness was evaluated by analysis of variance and regression coefficients. This model suggested that the factors, frequency, and intensity had a significant impact on germination. Optimal conditions for germination were observed to be 10 Hz frequency, 30,007 nT intensity, and 30-min duration with an observed germination percentage of 93.0, and a predicted germination percentage of 92.92. Magneto-priming was found to increase the germination efficacy (15.66%), shoot length (27.78%), total seedling length (20.30%), seedling dry mass (26.49%), and water uptake (34.48% at 80 min) showing significant output when compared with the control and positive controls. Remarkable improvements were observed in germination parameters such as vigor index-1 (39.14%), vigor index-2 (46.28%), speed of germination (27.52%), and emergence index (12.50%). Magneto-priming was found to reduce the levels of germination-specific enzymes, viz. α-amylase, protease, and dehydrogenase, while it enhanced the levels of antioxidant enzymes, viz. catalase (114.63%) and superoxide dismutase (19.62%), triggering fast germination and early vigor of seedlings. This study clearly showed that EMF priming significantly improved the germination effect and other characteristics of Foxtail millet seeds. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.

Enzyme Therapy: Current Perspectives.

Enzymes control all metabolic processes in human system from simple digestion of food to highly complex immune response. Physiological reactions occuring in healthy individuals are disturbed when enzymes are deficient or absent. Enzymes are administered for normalizing biological function in certain pathologies. Initially, crude proteolytic enzymes were used for the treatment of gastrointestinal disorders. Recent advances have enabled enzyme therapy as a promising tool in the treatment of cardiovascular, oncological and hereditary diseases. Now, a spectrum of other diseases are also covered under enzyme therapy. But, the available information on the use of enzymes as therapeutic agents for different diseases is scanty. This review details the enzymes which have been used to treat various diseases/disorders.

Discovery of antibacterial biogenic magnetosome nanoparticles from Providencia sp. MTBPRB-1: Screening, purification and characterization.

Bacterial species referred to as magnetotactic bacteria (MTB) biomineralize iron oxides and iron sulphides inside the cell. Bacteria can arrange themselves passively along geomagnetic field lines with the aid of these iron components known as magnetosomes. In this study, magnetosome nanoparticles, which were obtained from the taxonomically identified MTB isolate Providencia sp. PRB-1, were characterized and their antibacterial activity was evaluated. An in vitro test showed that magnetosome nanoparticles significantly inhibited the growth of Staphylococcus sp., Pseudomonas aeruginosa, and Klebsiella pneumoniae. Magnetosomes were found to contain cuboidal iron crystals with an average size of 42 nm measured by particle size analysis and scanning electron microscope analysis. The energy dispersive X-ray examination revealed that Fe and O were present in the extracted magnetosomes. The extracted magnetosome nanoparticles displayed maximum absorption at 260 nm in the UV-Vis spectrum. The distinct magnetite peak in the Fourier transform infrared (FTIR) spectroscopy spectra was observed at 574.75 cm-1. More research is needed into the intriguing prospect of biogenic magnetosome nanoparticles for antibacterial applications.

Identification of apigenin-4'-glucoside as bacterial DNA gyrase inhibitor by QSAR modeling, molecular docking, DFT, molecular dynamics, and in vitro confirmation studies.

CONTEXT: It is well known that antibiotic resistance is a major health hazard. To eradicate antibiotic-resistant bacterial infections, it is essential to find a novel antibacterial agent. Hence, in this study, a quantitative structure-activity relationship (QSAR) model was developed using 43 DNA gyrase inhibitors, and 700 natural compounds were screened for their antibacterial properties. Based on molecular docking and absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies, the top three leads viz., apigenin-4'-glucoside, 8-deoxygartanin, and cryptodorine were selected and structurally optimized using density functional theory (DFT) studies. The optimized structures were redocked, and molecular dynamic (MD) simulations were performed. Binding energies were calculated by molecular mechanics/Poisson-Boltzmann surface area solvation (MM-PBSA). Based on the above studies, apigenin-4'-glucoside was identified as a potent antibacterial lead. Further in vitro confirmation studies were performed using the plant Lawsonia inermis containing apigenin-4'-glucoside to confirm the antibacterial activity. METHODS: For QSAR modeling, 2D descriptors were calculated by PaDEL-Descriptors v2.21 software, and the model was developed using the DTClab QSAR tool. Docking was performed using PyRx v0.8 software. ORCA v5.0.1 computational package was used to optimize the structures. The job type used in optimization was equilibrium structure search using the DFT hybrid functional ORCA method B3LYP. The basis set was 6-311G (3df, 3pd) plus four polarization functions for all atoms. Accurate docking was performed for optimized leads using the iGEMDOCK v2.1 tool with a genetic algorithm by 10 solutions each of 80 generations. Molecular dynamic simulations were performed using GROMACS 2020.04 software with CHARMM36 all-atom force field.

Enzymes in clinical medicine: an overview.

Enzymes are biocatalysts and because of their remarkable properties, they are extensively used in medical diagnosis. Researches in the last two decades have concentrated more on enzymes such as creatine kinase-MB, alanine transaminase, aspartate transaminase, acid phosphatase, alkaline phosphatase etc. for clinical applications. Enzymes are the preferred markers in various disease states such as myocardial infarction, jaundice, pancreatitis, cancer, neurodegenerative disorders, etc. They provide insight into the disease process by diagnosis, prognosis and assessment of response therapy. Even though the literature on the use of enzymes in various disease conditions has accumulated, a comprehensive analysis is lacking and hence this review.

Effects of testosterone, estrogen and progesterone on TNF-α mediated cellular damage in rat arthritic synovial fibroblasts.

Sexual dimorphism is a well-established phenomenon in rheumatoid arthritis, with women exhibiting higher disease severity. Understanding the role of sex hormones using in vivo animal models is limited due to the systemic effects as well as the difficulty in exploring different dose combinations of the hormones simultaneously. However, cell culture systems pose ideal systems for exploring different combinations and concentrations of the hormones simultaneously. In this study, the procedure for isolation of arthritic fibroblasts was standardized using a combination of collagenase and trypsin based on maximal yield and viability after employing different enzymatic disaggregation procedures. The cultured synovial fibroblasts from arthritic rats did not differ significantly from normal rat fibroblasts in terms of proliferation or secretion of inflammatory mediators. Stimulation of fibroblasts with TNF-α was standardized and TNF-α stimulated rat arthritic synovial fibroblasts exhibited an ideal in vitro system for screening antiinflammatory molecules. The effects of physiological and pharmacological concentrations of testosterone, estrogen and progesterone were studied on TNF-α induced cellular damage in rat arthritic synovial fibroblasts. The results showed that estrogen and testosterone exerted antiinflammatory effects on rat arthritic synovial fibroblasts at physiological and pharmacological concentrations. However, there was no significant difference in the effects between physiological and pharmacological concentrations. Progesterone independently did not show any protective effects. In combination with physiological concentrations of estrogen, progesterone abrogated estrogen's protective effect but it exhibited protection in combination with pharmacological concentrations of estrogen.

4a-methyl-dodecahydro-1H-pyrrolo[3,4-b]quinoline-6-one produced by Endophytic Fungi Aspergillus niger E12 obtained from Dodonaea viscosa Plant Leaves as a Novel Antibacterial Compound.

Endophytic fungi were isolated from forty plant leaf samples from Gudiyam forest. The potent antibacterial strain Aspergillus niger E12 isolated from the plant Dodonaea viscosa showed maximal antibacterial activity against all the test organisms, viz., Staphylococcus aureus, Bacillus coagulans, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The production of the antibacterial compound was optimized using the yeast extract sucrose medium (2% YES) using response surface methodology (RSM). For the production, the optimal parameters were carbon/nitrogen (C:N) ratio, 9:1; temperature, 25 °C; pH, 5.7; incubation time, 240 h; and rpm, 30. A zone of inhibition of 19.33 mm was observed as maximal bioactivity against Pseudomonas aeruginosa. The antibacterial compound was purified by extraction with ethyl acetate, activity-guided fractionation, and preparative high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) studies showed that the Aspergillus niger E12 bioactive substance is 4a-methyl-dodecahydro-1H-pyrrolo [3,4-b] quinoline-6-one.

Therapeutic effects of proanthocyanidins on the pathogenesis of periodontitis--an overview.

Periodontitis is a bacterially induced chronic inflammatory disease that destroys the connective tissue and bone that support teeth. Bacteria initiates periodontitis and destruction of the alveolar bone and periodontal connective tissue is clearly observed. But, the events occuring between these two points of time remain obscure and this study focusses on these aspects. The proanthocyanidins (PC) have variable pharmacological and nutraceutical benefits including improvement of ischemic cardiovascular disease, prevention of atherosclerosis and antiarthritic, anticancer and antimicrobial activities. The benefits associated with the antioxidant activity of PC have been evaluated both in vivo and in vitro. But, reports on the ameliorative effects of PC on oral diseases and specifically on periodontitis are very few. Hence, a novel attempt is made to review the possible protective effects of PC and its mechanism of action in periodontitis and also to show whether PC could be developed as a therapeutic agent for periodontitis.

Myocardial expression of PDECGF is associated with extracellular matrix remodeling in experimental myocardial infarction in rats.

Platelet-derived endothelial cell growth factor (PDECGF) is a potent angiogenic peptide with anti-apoptotic activity expressed widely in tumours. However, its expression in myocardial infarction (MI) is not yet established. This study aimed to assess the myocardial expression of PDECGF in rats after MI. Extracellular matrix (ECM) remodeling plays an important role in angiogenesis; hence, changes in the ECM components were investigated in the myocardium after MI, which was induced in rats by coronary artery ligation (CAL) and verified using biochemical markers and histopathology. Immunohistochemistry, RT-PCR, and activity assays identified the expression pattern of PDECGF on days 1, 2, 4, 8, 16, and 32 after CAL. The levels of TNF-alpha, MMP-2, collagen, and glycosaminoglycans in the ECM were assessed. Studies on immunohistochemistry, RT-PCR, and PDECGF activity demonstrated elevated levels of PDECGF expression from day 2 after CAL. Macrophages, endothelial cells, fibroblasts, and cardiomyocytes, especially at the border region of the lesion, showed an enhanced expression for PDECGF. Remodeling of the ECM was depicted by changes in the levels of TNF-alpha, MMP-2, collagen, and GAG. Hence, this study clearly indicated PDECGF as an important angiogenic molecule expressed during MI and the alterations in ECM components facilitated the process of angiogenesis.

Protective effect of proanthocyanidins on endotoxin induced experimental periodontitis in rats.

The pathogenesis of periodontitis involves anaerobic oral bacteria as well as the host response to infection and several drugs have been developed which can curtail these deleterious effects. Proanthocyanidin, a novel flavanoid extracted from grape seeds, has been shown to provide a significant therapeutic effect on endotoxin (Escherichia coli) induced experimental periodontitis in rats. In this study, protective action of different doses of proanthocyanidins was investigated in blood by assaying the reactive oxygen species such as hydrogen peroxide, superoxide anion, myeloperoxidase and lipid peroxides, lysosomal enzyme activities such as cathepsin B, cathepsin D, beta-glucuronidase and acid phosphatase, nonenzymatic antioxidants such as ascorbic acid, alpha-tocopherol, ceruloplasmin, reduced glutathione and antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase and glutathione-s-transferase. Experimental periodontitis rats showed a reduction in body weight and body weight gain could be noticed when they were administered proanthocyanidins. The levels of reactive oxygen species and lysosomal enzymes were found to increase whereas antioxidant levels were decreased significantly in experimental periodontitis. Proanthocyanidins at an effective dose of 30 mg/kg body weight, sc, for 30 days effected a decrease in serum reactive oxygen species, lipid peroxides, lysosomal enzymes, acute phase proteins and an increase in antioxidant levels. Histopathological evidence of experimental periodontitis showed cellular infiltration of inflammatory cells while proanthocyanidin treated groups demonstrated only scattered inflammatory cells and blood vessels. Thus, the results showed that dietary supplementation of proanthocyanidin enhanced the host resistance as well as the inhibition of the biological and mechanical irritants involved in the onset of gingivitis and the progression of periodontal disease.

Arjunolic acid: a novel phytomedicine with multifunctional therapeutic applications.

Herbal plants with antioxidant activities are widely used in Ayurvedic medicine for cardiac and other problems. Arjunolic acid is one such novel phytomedicine with multifunctional therapeutic applications. It is a triterpenoid saponin, isolated earlier from Terminalia arjuna and later from Combretum nelsonii, Leandra chaeton etc. Arjunolic acid is a potent antioxidant and free radical scavenger. The scientific basis for the use of arjunolic acid as cardiotonic in Ayurvedic medicine is proven by its vibrant functions such as prevention of myocardial necrosis, platelet aggregation and coagulation and lowering of blood pressure, heart rate and cholesterol levels. Its antioxidant property combined with metal chelating property protects organs from metal and drug induced toxicity. It also plays an effective role in exerting protection against both type I and type II diabetes and also ameliorates diabetic renal dysfunctions. Its therapeutic multifunctionality is shown by its wound healing, antimutagenic and antimicrobial activity. The mechanism of cytoprotection conferred by arjunolic acid can be explained by its property to reduce the oxidative stress by enhancing the antioxidant levels. Apart from its pathophysiological functions, it possesses dynamic insecticidal property and it is used as a structural molecular framework in supramolecular chemistry and nanoscience. Esters of ajunolic acid function as gelators of a wide variety of organic liquids. Experimental studies demonstrate the versatile effects of arjunolic acid, but still, further investigations are necessary to identify the functional groups responsible for its multivarious effects and to study the molecular mechanisms as well as the probable side effects/toxicity owing to its long-term use. Though the beneficial role of this triterpenoid has been assessed from various angles, a comprehensive review of its effects on biochemistry and organ pathophysiology is lacking and this forms the rationale of this review.

Platelet-derived endothelial cell growth factor mediates angiogenesis and antiapoptosis in rat aortic endothelial cells.

This study explores the angiogenic and antiapoptotic activities of platelet-derived endothelial cell growth factor (PDECGF) in rat aortic endothelial cells. The effects of PDECGF on rat aortic endothelial cell (RAEC) proliferation, migration, chemotaxis, and tubule formation were investigated in vitro at various concentrations viz., 1, 2, 4, 8, 16, and 32 ng x mL(-1) on endothelial cells. Endothelial cells were induced with hypoxic stress and the antiapoptotic effects of PDECGF were analysed by cell survival assay, fluorescence microscopy, cell viability assay, and flow cytometry. The results demonstrated the angiogenic potential of PDECGF on endothelial cells in a dose-dependent manner. PDECGF at 16 and 32 ng x mL(-1) increased cell proliferation (>80%), induced cell migration (>4 fold), stimulated chemotaxis (>2 fold), and increased tubule formation (>3 fold) compared with the control. Studies on hypoxic stress revealed the antiapoptotic nature of PDECGF on endothelial cells. PDECGF treatment enhanced cell survival by 14%, as well as cell viability by 13%, and decreased the percentage of apoptotic cells by 13% as demonstrated by fluorescence-activated cell sorter studies (FACS). In conclusion, this study demonstrated the angiogenic and antiapoptotic potentials of PDECGF on RAEC.

Low frequency pulsed electromagnetic field--a viable alternative therapy for arthritis.

Arthritis refers to more than 100 disorders of the musculoskeletal system. The existing pharmacological interventions for arthritis offer only symptomatic relief and they are not definitive and curative. Magnetic healing has been known from antiquity and it is evolved to the present times with the advent of electromagnetism. The original basis for the trial of this form of therapy is the interaction between the biological systems with the natural magnetic fields. Optimization of the physical window comprising the electromagnetic field generator and signal properties (frequency, intensity, duration, waveform) with the biological window, inclusive of the experimental model, age and stimulus has helped in achieving consistent beneficial results. Low frequency pulsed electromagnetic field (PEMF) can provide noninvasive, safe and easy to apply method to treat pain, inflammation and dysfunctions associated with rheumatoid arthritis (RA) and osteoarthritis (OA) and PEMF has a long term record of safety. This review focusses on the therapeutic application of PEMF in the treatment of these forms of arthritis. The analysis of various studies (animal models of arthritis, cell culture systems and clinical trials) reporting the use of PEMF for arthritis cure has conclusively shown that PEMF not only alleviates the pain in the arthritis condition but it also affords chondroprotection, exerts antiinflammatory action and helps in bone remodeling and this could be developed as a viable alternative for arthritis therapy.

Comparative studies on the interplay of testosterone, estrogen and progesterone in collagen induced arthritis in rats.

Rheumatoid arthritis (RA) is a sexually dimorphic autoimmune disorder exhibiting a higher disease prevalence and severity among females. This study was carried out to understand the role of the major sex hormones viz., testosterone, estrogen and progesterone on the severity in arthritis. The interplay of the sex hormones was studied in a rat model of collagen induced arthritis (CIA). The parameters used for analyzing the disease severity included paw volume, radiology, histopathology of joint, markers for bone turnover, cytokine profile, levels of pain mediator (prostaglandin E(2)) and immune response to type II collagen. Arthritis induction to castrated and ovariectomised rats resulted in enhanced inflammation thereby indicating the importance of sex hormones. Treatment with physiological doses of dihydrotestosterone and estrogen attenuated the inflammation, with estrogen exhibiting higher potency. Progesterone was not shown to have any significance in disease modification; however, when progesterone was administered in combination with estrogen, the protective effects of estrogen were noticed to decrease.

Estrogen and testosterone attenuate extracellular matrix loss in collagen-induced arthritis in rats.

Rheumatoid arthritis (RA) is a sexually dimorphic, autoimmune inflammatory disorder affecting the joints. Joint disability in RA results primarily from loss of matrix components (collagen and glycosoaminoglycan) in the cartilage and synovium. This study was carried out to understand the effect of physiological levels of testosterone, estrogen, and progesterone on oxidative stress-induced changes in matrix composition in rat synovium in arthritis. Arthritis induction in castrated and ovariectomized rats resulted in enhanced oxidative stress and this was assessed by lipid peroxidation levels and depletion of antioxidants. This, in turn, led to significantly (p < 0.01) increased levels of TNF-alpha and matrix metalloproteinase-2 (MMP-2), subsequently resulting in loss of collagen, elastin, and glycosoaminoglycan (GAG) and disorganization of reticulin as evidenced by biochemical quantitation and also by staining for collagen, reticulin, and elastin. Treatment with physiological doses of dihydrotestosterone (25 mg topically) and estrogen (5 microg/0.1 ml subcutaneously) restored the antioxidant levels significantly (p < 0.05) and reduced the levels of TNF-alpha and MMP-2, with estrogen exhibiting a higher potency. This, in turn, attenuated the damage to reticulin organization as well as the loss of collagen and GAG in the articular tissues. However, elastin loss could not be attenuated by either treatment. Progesterone (2 mg/0.1 ml subcutaneously) was not shown to have any significance in disease modification, and on the contrary, it inhibited the protective effects of estrogen. However, progesterone contributed to increased collagen levels in the tissues.

Low frequency and low intensity pulsed electromagnetic field exerts its antiinflammatory effect through restoration of plasma membrane calcium ATPase activity.

Rheumatoid arthritis (RA) is a chronic inflammatory disorder affecting 1% of the population worldwide. Pulsed electromagnetic field (PEMF) has a number of well-documented physiological effects on cells and tissues including antiinflammatory effect. This study aims to explore the antiinflammatory effect of PEMF and its possible mechanism of action in amelioration of adjuvant induced arthritis (AIA). Arthritis was induced by a single intradermal injection of heat killed Mycobacterium tuberculosis at a concentration of 500 microg in 0.1 ml of paraffin oil into the right hind paw of rats. The arthritic animals showed a biphasic response regarding changes in the paw edema volume. During the chronic phase of the disease, arthritic animals showed an elevated level of lipid peroxides and depletion of antioxidant enzymes with significant radiological and histological changes. Besides, plasma membrane Ca(2+) ATPase (PMCA) activity was inhibited while intracellular Ca(2+) level as well as prostaglandin E(2) levels was noticed to be elevated in blood lymphocytes of arthritic rats. Exposure of arthritic rats to PEMF at 5 Hzx4 microT x 90 min, produced significant antiexudative effect resulting in the restoration of the altered parameters. The antiinflammatory effect could be partially mediated through the stabilizing action of PEMF on membranes as reflected by the restoration of PMCA and intracellular Ca(2+) levels in blood lymphocytes subsequently inhibiting PGE(2) biosynthesis. The results of this study indicated that PEMF could be developed as a potential therapy for RA in human beings.

Mixed substrate solid state fermentation for production and extraction of lipase from Aspergillus niger MTCC 2594.

A novel mixed substrate solid-state fermentation (SSF) process has been developed for Aspergillus niger MTCC 2594 using wheat bran (WB) and gingelly oil cake (GOC) and the results showed that addition of GOC to WB (WB : GOC, 3 : 1, w/w) increased the lipase activity by 36.0% and the activity was 384.3+/-4.5 U/g dry substrate at 30 degrees C and 72 h. Scale up of lipase production to 100 g and 1 kg tray-level batch fermentation resulted in 95.0% and 84.0% of enzyme activities respectively at 72 h. A three-stage multiple contact counter-current extraction yielded 97% enzyme recovery with a contact time of 60 min. However, extraction by simple percolation and plug-flow methods resulted in decreased enzyme recoveries. The mixed substrate SSF process has resulted in a significant increase in specific activity (58.9%) when compared to a submerged fermentation (SmF) system. Furthermore, an efficient process of extraction has been standardized with this process. Use of GOC along with WB as potential raw materials for enzyme production could be of great commercial significance. This is the first report on the production and extraction of lipase from Aspergillus niger using mixed solid substrates, WB and GOC, which are potential raw materials for the production of enzymes and other value-added products.

Effect of a derivatized tetrapeptide from lactoferrin on nitric oxide mediated matrix metalloproteinase-2 production by synovial fibroblasts in collagen-induced arthritis in rats.

Matrix metalloproteinases (MMPs) constitute a family of zinc-dependent proteolytic enzymes, which degrade several components of extracellular matrix, in arthritic synovial cells. In cultured synovial fibroblasts, both nitric oxide (NO) and reactive oxygen species (ROS) are potent inducers of MMPs production. PEP1261, a tetrapeptide derivative used in this study, corresponds to residues of 39-42 human lactoferrin. The parent protein lactoferrin is able to inhibit the production of free radicals in rheumatoid joints and it regulates many aspects of inflammation. This study is aimed to examine the effects of PEP1261 on MMP-2 production in the presence of nitric oxide donor in cultured synovial fibroblasts from collagen-induced arthritic rats. PEP1261 affects a significant reduction in nitrite levels as well as in MMP-2 production in SNAP stimulated synovial fibroblasts and this is validated by gelatin zymography and immunoblot analysis. Furthermore, RTPCR analysis has demonstrated that PEP1261 inhibits MMP-2 mRNA expression in SNAP treated synovial fibroblasts. The results of this study suggest that PEP1261 possesses antiarthritic activity by inhibiting nitrite levels as well as MMP-2 expression better than control peptides viz., KRDS and RGDS.