82 research outputs found
Isolation and Identification by PCR and Analysis for Probiotic Properties of Lactobacillus spp from Dairy Products.
Lactic acid bacteria (LAB) are very significant to human health and due to their ability to produce some antibacterial substances and ability to inhibit pathogenic bacteria, they are commonly used as a natural food preservative to improve food safety and stability,. The present study was focused on isolation and characterization of Lactobacillus spp from dairy products at local markets of Babylon province of Iraq, by conventional and molecular methods using PCR. Additionally, the study and to demonstrate some of probiotic properties of these isolates. All isolates were phenotypically characterized including studying the microbiological, biochemical, effect of sodium chloride and pH during growth, carbohydrates test and characterizing the antimicrobial activity of Lactobacillus spp against pathogens. The present study demonstrates that Lactobacillus spp produced a bacteriocin- like inhibitory substance with a broad spectrum of antimicrobial activity directed against pathogenic indicator organism suggesting its protective value against enteric pathogens. Keywords: Lactobacillus, identification, PCR, dairy product, antimicrobial activity, probiotic
Early Invasion of Brain Parenchyma by African Trypanosomes
Human African trypanosomiasis or sleeping sickness is a vector-borne parasitic disease that has a major impact on human health and welfare in sub-Saharan countries. Based mostly on data from animal models, it is currently thought that trypanosome entry into the brain occurs by initial infection of the choroid plexus and the circumventricular organs followed days to weeks later by entry into the brain parenchyma. However, Trypanosoma brucei bloodstream forms rapidly cross human brain microvascular endothelial cells in vitro and appear to be able to enter the murine brain without inflicting cerebral injury. Using a murine model and intravital brain imaging, we show that bloodstream forms of T. b. brucei and T. b. rhodesiense enter the brain parenchyma within hours, before a significant level of microvascular inflammation is detectable. Extravascular bloodstream forms were viable as indicated by motility and cell division, and remained detectable for at least 3 days post infection suggesting the potential for parasite survival in the brain parenchyma. Vascular inflammation, as reflected by leukocyte recruitment and emigration from cortical microvessels, became apparent only with increasing parasitemia at later stages of the infection, but was not associated with neurological signs. Extravascular trypanosomes were predominantly associated with postcapillary venules suggesting that early brain infection occurs by parasite passage across the neuroimmunological blood brain barrier. Thus, trypanosomes can invade the murine brain parenchyma during the early stages of the disease before meningoencephalitis is fully established. Whether individual trypanosomes can act alone or require the interaction from a quorum of parasites remains to be shown. The significance of these findings for disease development is now testable
Novel quinazoline-based sulfonamide derivative (3D) induces apoptosis in colorectal cancer by inhibiting JAK2–STAT3 pathway
Introduction: Colorectal cancer (CRC) is a major worldwide health problem owing to its high
prevalence and mortality rate. Developments in screening, prevention, biomarker, personalized
therapies and chemotherapy have improved detection and treatment. However, despite these
advances, many patients with advanced metastatic tumors still succumb to the disease. New
anticancer agents are needed for treating advanced stage CRC as most of the deaths occur due to
cancer metastasis. A recently developed novel sulfonamide derivative 4-((2-(4-(dimethylamino)
phenyl)quinazolin-4-yl)amino)benzenesulfonamide (3D) has shown potent antitumor effect;
however, the mechanism underlying the antitumor effect remains unknown.
Materials and methods: 3D-mediated inhibition on cell viability was evaluated by MTT and
real-time cell proliferation was measured by xCelligence RTDP instrument. Western blotting
was used to measure pro-apoptotic, anti-apoptotic proteins and JAK2-STAT3 phosphorylation.
Flow cytometry was used to measure ROS production and apoptosis.
Results: Our study revealed that 3D treatment significantly reduced the viability of human CRC
cells HT-29 and SW620. Furthermore, 3D treatment induced the generation of reactive oxygen
species (ROS) in human CRC cells. Confirming our observation, N-acetylcysteine significantly
inhibited apoptosis. This is further evidenced by the induction of p53 and Bax; release of cytochrome
c; activation of caspase-9, caspase-7 and caspase-3; and cleavage of PARP in 3D-treated cells. This
compound was found to have a significant effect on the inhibition of antiapoptotic proteins Bcl2 and
BclxL. The results further demonstrate that 3D inhibits JAK2–STAT3 pathway by decreasing the
constitutive and IL-6-induced phosphorylation of STAT3. 3D also decreases STAT3 target genes
such as cyclin D1 and survivin. Furthermore, a combination study of 3D with doxorubicin (Dox)
also showed more potent effects than single treatment of Dox in the inhibition of cell viability.
Conclusion: Taken together, these findings indicate that 3D induces ROS-mediated apoptosis
and inhibits JAK2–STAT3 signaling in CRC
Synthesis and evaluation of anticancer, antiphospholipases, antiproteases, and antimetabolic syndrome activities of some 3H-quinazolin-4-one derivatives
Some new 3H-quinazolin-4-one derivatives were synthesised and screened for anticancer, antiphospholipases, antiproteases, and antimetabolic syndrome activities. Compound 15d was more potent in reducing the cell viabilities of HT-29 and SW620 cells lines to 38%, 36.7%, compared to 5-FU which demonstrated cell viabilities of 65.9 and 42.7% respectively. The IC50 values of 15d were ∼20 µg/ml. Assessment of apoptotic activity revealed that 15d decreased the cell viability by down regulating Bcl2 and BclxL. Moreover, compounds, 8j, 8d/15a/15e, 5b, and 8f displayed lowered IC50 values than oleanolic acid against proinflammatory isoforms of hGV, hG-X, NmPLA2, and AmPLA2. In addition, 8d, 8h, 8j, 15a, 15b, 15e, and 15f showed better anti-α-amylase than quercetin, whereas 8g, 8h, and 8i showed higher anti-α-glucosidase activity than allopurinol. Thus, these compounds can be considered as potential antidiabetic agents. Finally, none of the compounds showed higher antiproteases or xanthine oxidase activities than the used reference drugs
The platinum coordination complex inhibits cell invasion-migration and epithelial-to-mesenchymal transition by altering the TGF-β-SMAD pathway in colorectal cancer
Introduction: There is a steady increase in colorectal cancer (CRC) incidences worldwide; at diagnosis, about 20 percent of cases show metastases. The transforming growth factor-beta (TGF-β) signaling pathway is one of the critical pathways that influence the expression of cadherins allowing the epithelial-to-mesenchymal transition (EMT), which is involved in the progression of the normal colorectal epithelium to adenoma and metastatic carcinoma. The current study aimed to investigate the impact of a novel coordination complex of platinum (salicylaldiminato) PT(II) complex with dimethyl propylene linkage (PT-complex) on TGF-β and EMT markers involved in the invasion and migration of the human HT-29 and SW620 CRC cell lines.Methods: Functional study and wound healing assay showed PT-complex significantly reduced cell motility and the migration and invasion of CRC cell lines compared to the untreated control. Western blot performed in the presence and absence of TGF-β demonstrated that PT-complex significantly regulated the TGF-β-mediated altered expressions of EMT markers.Results and Discussion: PT-complex attenuated the migration and invasion by upregulating the protein expression of EMT-suppressing factor E-cadherin and suppressing EMT-inducing factors such as N-Cadherin and Vimentin. Moreover, PT-complex significantly suppressed the activation of SMAD3 in both CRC cell lines. Further, the microarray data analysis revealed differential expression of genes related to invasion and migration. In conclusion, besides displaying antiproliferative activity, the PT complex can decrease the metastasis of CRC cell lines by modulating TGF-β-regulated EMT markers. These findings provide new insight into TGF-β/SMAD signaling as the molecular mechanism involved in the antitumoral properties of novel PT-complex
Schistosomiasis Mansoni: Novel Chemotherapy Using a Cysteine Protease Inhibitor
BACKGROUND: Schistosomiasis is a chronic, debilitating parasitic disease infecting more than 200 million people and is second only to malaria in terms of public health importance. Due to the lack of a vaccine, patient therapy is heavily reliant on chemotherapy with praziquantel as the World Health Organization–recommended drug, but concerns over drug resistance encourage the search for new drug leads. METHODS AND FINDINGS: The efficacy of the vinyl sulfone cysteine protease inhibitor K11777 was tested in the murine model of schistosomiasis mansoni. Disease parameters measured were worm and egg burdens, and organ pathology including hepato- and splenomegaly, presence of parasite egg–induced granulomas in the liver, and levels of circulating alanine aminotransferase activity as a marker of hepatocellular function. K11777 (25 mg/kg twice daily [BID]), administered intraperitoneally at the time of parasite migration through the skin and lungs (days 1–14 postinfection [p.i.]), resulted in parasitologic cure (elimination of parasite eggs) in five of seven cases and a resolution of other disease parameters. K11777 (50 mg/kg BID), administered at the commencement of egg-laying by mature parasites (days 30–37 p.i.), reduced worm and egg burdens, and ameliorated organ pathology. Using protease class-specific substrates and active-site labeling, one molecular target of K11777 was identified as the gut-associated cathepsin B1 cysteine protease, although other cysteine protease targets are not excluded. In rodents, dogs, and primates, K11777 is nonmutagenic with satisfactory safety and pharmacokinetic profiles. CONCLUSIONS: The significant reduction in parasite burden and pathology by this vinyl sulfone cysteine protease inhibitor validates schistosome cysteine proteases as drug targets and offers the potential of a new direction for chemotherapy of human schistosomiasis
Drug Discovery for Schistosomiasis: Hit and Lead Compounds Identified in a Library of Known Drugs by Medium-Throughput Phenotypic Screening
The flatworm disease schistosomiasis infects over 200 million people with just one drug (praziquantel) available—a concern should drug resistance develop. Present drug discovery approaches for schistosomiasis are slow and not conducive to automation in a high-throughput format. Therefore, we designed a three-component screen workflow that positions the larval (schistosomulum) stage of S. mansoni at its apex followed by screens of adults in culture and, finally, efficacy tests in infected mice. Schistosomula are small enough and available in sufficient numbers to interface with automated liquid handling systems and prosecute thousands of compounds in short time frames. We inaugurated the workflow with a 2,160 compound library that includes known drugs in order to cost effectively ‘re-position’ drugs as new therapies for schistosomiasis and/or identify compounds that could be modified to that end. We identify a variety of ‘hit’ compounds (antibiotics, psychoactives, antiparasitics, etc.) that produce behavioral responses (phenotypes) in schistosomula and adults. Tests in infected mice of the most promising hits identified a number of ‘leads,’ one of which compares reasonably well with praziquantel in killing worms, decreasing egg production by the parasite, and ameliorating disease pathology. Efforts continue to more fully automate the workflow. All screen data are posted online as a drug discovery resource
Novel derivative of aminobenzenesulfonamide (3c) induces apoptosis in colorectal cancer cells through ROS generation and inhibits cell migration
Background: Colorectal cancer (CRC) is the 3rd most common type of cancer worldwide. New anti-cancer agents
are needed for treating late stage colorectal cancer as most of the deaths occur due to cancer metastasis. A
recently developed compound, 3c has shown to have potent antitumor effect; however the mechanism underlying
the antitumor effect remains unknown.
Methods: 3c-induced inhibition of proliferation was measured in the absence and presence NAC using MTT in
HT-29 and SW620 cells and xCELLigence RTCA DP instrument. 3c-induced apoptotic studies were performed using
flow cytometry. 3c-induced redox alterations were measured by ROS production using fluorescence plate reader
and flow cytometry and mitochondrial membrane potential by flow cytometry; NADPH and GSH levels were
determined by colorimetric assays. Bcl2 family protein expression and cytochrome c release and PARP activation
was done by western blotting. Caspase activation was measured by ELISA. Cell migration assay was done using the
real time xCELLigence RTCA DP system in SW620 cells and wound healing assay in HT-29.
Results: Many anticancer therapeutics exert their effects by inducing reactive oxygen species (ROS). In this study,
we demonstrate that 3c-induced inhibition of cell proliferation is reversed by the antioxidant, N-acetylcysteine,
suggesting that 3c acts via increased production of ROS in HT-29 cells. This was confirmed by the direct
measurement of ROS in 3c-treated colorectal cancer cells. Additionally, treatment with 3c resulted in decreased
NADPH and glutathione levels in HT-29 cells. Further, investigation of the apoptotic pathway showed increased
release of cytochrome c resulting in the activation of caspase-9, which in turn activated caspase-3 and −6. 3c also
(i) increased p53 and Bax expression, (ii) decreased Bcl2 and BclxL expression and (iii) induced PARP cleavage in
human colorectal cancer cells. Confirming our observations, NAC significantly inhibited induction of apoptosis, ROS
production, cytochrome c release and PARP cleavage. The results further demonstrate that 3c inhibits cell migration
by modulating EMT markers and inhibiting TGFβ-induced phosphorylation of Smad2 and Samd3.
Conclusions: Our findings thus demonstrate that 3c disrupts redox balance in colorectal cancer cells and support
the notion that this agent may be effective for the treatment of colorectal cancer
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