Toll-like receptor-guided therapeutic intervention of human cancers: molecular and immunological perspectives

Toll-like receptors (TLRs) serve as the body’s first line of defense, recognizing both pathogen-expressed molecules and host-derived molecules released from damaged or dying cells. The wide distribution of different cell types, ranging from epithelial to immune cells, highlights the crucial roles of TLRs in linking innate and adaptive immunity. Upon stimulation, TLRs binding mediates the expression of several adapter proteins and downstream kinases, that lead to the induction of several other signaling molecules such as key pro-inflammatory mediators. Indeed, extraordinary progress in immunobiological research has suggested that TLRs could represent promising targets for the therapeutic intervention of inflammation-associated diseases, autoimmune diseases, microbial infections as well as human cancers. So far, for the prevention and possible treatment of inflammatory diseases, various TLR antagonists/inhibitors have shown to be efficacious at several stages from pre-clinical evaluation to clinical trials. Therefore, the fascinating role of TLRs in modulating the human immune responses at innate as well as adaptive levels directed the scientists to opt for these immune sensor proteins as suitable targets for developing chemotherapeutics and immunotherapeutics against cancer. Hitherto, several TLR-targeting small molecules (e.g., Pam3CSK4, Poly (I:C), Poly (A:U)), chemical compounds, phytocompounds (e.g., Curcumin), peptides, and antibodies have been found to confer protection against several types of cancers. However, administration of inappropriate doses of such TLR-modulating therapeutics or a wrong infusion administration is reported to induce detrimental outcomes. This review summarizes the current findings on the molecular and structural biology of TLRs and gives an overview of the potency and promises of TLR-directed therapeutic strategies against cancers by discussing the findings from established and pipeline discoveries

An improved method for experimental induction of ulcerative colitis in Sprague Dawley rats

Ulcerative colitis (UC) is a chronic inflammatory manifestation of the human colon that is linked with colorectal cancer. Development of an appropriate animal model is crucial to study the immunopathophysiology of UC wherein chemical induction is the most popular method of choice. However, unavailability of an optimum experimental model limits the success of this method. The present study aims to establish an optimized model for acetic acid-induced colitis in Sprague Dawley rats. Response Surface Methodology (RSM) with a six-factors Box-Behnken design was employed to generate an improved method of inducing UC in rat, predicting the case statistics, apposite investigation of quadratic response surfaces, and construction of a second-order polynomial equation. UC was diagnosed through three responses viz. weight loss, severity of diarrhea, and appearance of blood in the stool. Analysis of variance alongside RSM jointly revealed that induction of UC can be achieved with highest probability using the combination of parameters that includes 120 gm body weight, 1.5 ml of 4% acetic-acid v/v in distilled water with a single dose of treatment for 24 h including a pre-induction of 5 mins. This optimized UC-induction model was validated in-vivo through disease scoring index and hematological assessments with satisfactory level of desirability. • An improved experimental method for inducing ulcerative colitis (UC) in Sprague Dawley rats has been developed. • Box-Behnken Design-fitted Response Surface Methodology (RSM) was implicated in optimizing the experimental parameters for generating UC. • This statistically optimized and experimentally validated method resembles the recipe for the generation of UC in animal model with the highest possible desirability

TLR2 and TLR4 mediated host immune responses in major infectious diseases: a review

Abstract During the course of evolution, multicellular organisms have been orchestrated with an efficient and versatile immune system to counteract diverse group of pathogenic organisms. Pathogen recognition is considered as the most critical step behind eliciting adequate immune response during an infection. Hitherto Toll-like receptors (TLRs), especially the surface ones viz. TLR2 and TLR4 have gained immense importance due to their extreme ability of identifying distinct molecular patterns from invading pathogens. These pattern recognition receptors (PRRs) not only act as innate sensor but also shape and bridge innate and adaptive immune responses. In addition, they also play a pivotal role in regulating the balance between Th1 and Th2 type of response essential for the survivability of the host. In this work, major achievements rather findings made on the typical signalling and immunopathological attributes of TLR2 and TLR4 mediated host response against the major infectious diseases have been reviewed. Infectious diseases like tuberculosis, trypanosomiasis, malaria, and filariasis are still posing myriad threat to mankind. Furthermore, increasing resistance of the causative organisms against available therapeutics is also an emerging problem. Thus, stimulation of host immune response with TLR2 and TLR4 agonist can be the option of choice to treat such diseases in future

An approach towards optimization of the extraction of polyphenolic antioxidants from ginger (Zingiber officinale)

The present study aims to maximize the extraction of polyphenols from ginger (Zingiber officinale) through the statistical optimization of three influential process parameters ethanol (EtOH) proportion (%), temperature (°C) and extraction time (min). Response Surface Methodology (RSM) was employed to design experiments and study the interaction effects of these parameters on the extraction process. Analysis of Variance (ANOVA) was used for the analysis of regression coefficient, prediction of equation and case statistics. The optimum conditions for the maximum yield of polyphenols from each gram of ginger were found to be 75 % aqueous EtOH, 40 °C temperature and extraction time of 60 min respectively. The order of relative importance of these three parameters was: EtOH > time > temperature. Antioxidant activity of the extracted polyphenols using optimized parameters was also determined by DPPH assay. DPPH radical scavenging activity of ginger extract was compared with Vitamin C and butyl hydroxy toluene (BHT). Finally, this study revealed a cost effective analytical model to maximize the extraction of polyphenols from ginger with higher antioxidant activity. It was also concluded that at lower concentration ethanolic extract of ginger possess high antioxidant activity in comparison with synthetic antioxidants like vitamin C or BHT and thus it can be applicable as potent natural antioxidant in food and pharmaceutical industries for the preparation of functional food

Optimization of physicochemical parameters for phenol biodegradation by Candida tropicalis PHB5 using Taguchi Methodology

The Taguchi orthogonal array (OA) design of experiments methodology, a quality optimization tool, was used to improve the phenol biodegradation potential of the yeast Candida tropicalis PHB5. At three levels, an OA was selected to analyze the effects of the different physicochemical process factors. Experiments were undertaken to confirm the effectiveness of this method and the main factors affecting the growth of C. tropicalis on phenol and its subsequent degradation were found, together with the optimal factor levels. Predicted results showed that biomass yield could be increased from 1,051.96 to 2,495.74 mg/l and the subsequent amount of phenol degraded could be increased from 879.42 to 2,386.43 mg/l. Based on Taguchi methodology, an overall enhancement of growth by 137.24% and phenol degradation by 171.49% could be attained. Validation experiments showed that the growth and phenol biodegradation was significantly improved by up to 132.4% and 165.64%, respectively

Ginger extract ameliorates phosphamidon induced hepatotoxicity

574-584Organophosphorus (OP) compounds commonly used as pesticides in agriculture cause serious health problems to living beings. The present study enumerates the ameliorating effect of ginger extract (GE) against phosphamidon (PHO, an organophosphorus insecticide) induced hepatotoxicity. GE was prepared from dried ginger and characterized for compound profile and antioxidant activity. Eight groups of albino rats (n=6) were treated with 1/5th lethal dose of PHO for 5-20 days. Out of the treated 8 groups, 4 were simultaneously fed with GE (1 mg/kg body wt.) along with PHO. Alterations in the levels of hepatocellular oxidative stress (OS) markers in the treated groups indicated an enhanced generation of reactive oxygen species (ROS) and oxidative stress (OS). Upregulation of apoptotic markers, DNA fragmentation and appearance of apoptotic nuclei suggested induction of apoptosis in the liver cell that was found to be attenuated after GE treatment. Moreover, no toxicity and mortality was observed up to 100 mg/kg dose of GE for 30 days in the rat model studied. <span style="mso-bidi-font-weight: bold">Thus, GE can be considered as an effective, economical and safe extract to circumvent PHO-induced hepatotoxicity. </span

Wuchereria bancrofti filaria activates human dendritic cells and polarizes T helper 1 and regulatory T cells via toll-like receptor 4

International audienceInteraction between innate immune cells and parasite plays a key role in the immunopathogenesis of lymphatic filariasis. Despite being professional antigen presenting cells critical for the pathogen recognition, processing and presenting the antigens for mounting T cell responses, the dendritic cell response and its role in initiating CD4+ T cell response to filaria, in particular Wuchereria bancrofti, the most prevalent microfilaria is still not clear. Herein, we demonstrate that a 70 kDa phosphorylcholine-binding W. bancrofti sheath antigen induces human dendritic cell maturation and secretion of several pro-inflammatory cytokines. Further, microfilarial sheath antigen-stimulated dendritic cells drive predominantly Th1 and regulatory T cell responses while Th17 and Th2 responses are marginal. Mechanistically, sheath antigen-induced dendritic cell maturation, and Th1 and regulatory T cell responses are mediated via toll-like receptor 4 signaling. Our data suggest that W. bancrofti sheath antigen exploits dendritic cells to mediate distinct CD4+ T cell responses and immunopathogenesis of lymphatic filariasis

Potential use of polyphenol oxidases (PPO) in the bioremediation of phenolic contaminants containing industrial wastewater

The present review emphasizes on the use of Polyphenol oxidase (PPO) enzyme in the bioremediation of phenolic contaminants from industrial wastewater. PPO is a group of enzyme that mainly exists in two forms; tyrosinase (E.C. 1.14.18.1) and laccase (E.C. 1.10.3.1) which are widely distributed among microorganisms, plants and animals. These oxidoreductive enzymes remain effective in a wide range of pH and temperature, particularly if they are immobilized on some carrier or matrices, and they can degrade a wide variety of mono and/or diphenolic compounds. However, high production costs inhibit the widespread use of these enzymes for remediation in industrial scale. Nevertheless, bench studies and field studies have shown enzymatic wastewater treatment to be feasible options for biodegradation of phenols through biological route. Nanomaterials-PPO conjugates have been also applied for removal of phenols which has successfully lower down the drawbacks of enzymatic water treatment. Therefore in this article various approaches and current state of use of PPO in the bioremediation of wastewater, as well as the benefits and disadvantages associated with the use of such enzymes have been overviewed

An Improved Method of Optimizing the Extraction of Polyphenol Oxidase from Potato (Solanum tuberosum L.) Peel

The present study has an objective to optimize the extraction of Polyphenol Oxidase (PPO) from potato (Solanum tuberosum L.) peel. Response surface methodology (RSM) was used to design experiments and study the effect of six influential extraction parameters: extraction buffer concentration (100-500 mM), pH of extraction buffer (4.5-8.5), time (1-12 hours), temperature (4-40C), concentration of PMSF (1-5 mM) and volume of extraction buffer (200-1000 ml) on the extraction of PPO. The dependent variable was considered as response function which was specific activity (SA) of extracted PPO. ANOVA was performed to obtain the regression equation that could predict the responses within given range. From RSM generated model, the optimum conditions for the maximum extraction of PPO were phosphate buffer concentration of 100 mm, buffer pH of 4.5, extraction time of 1 hour, 40C temperature, PMSF concentration of 5 mM and buffer volume of 200 ml. Finally, this study illustrates a cost effective and less time consuming method to maximize the extraction of PPO from a vegetable waste

Polyphenol enriched ethanolic extract of Cajanus scarabaeoides (L.) Thouars exerts potential antifilarial activity by inducing oxidative stress and programmed cell death.

Development of antifilarial drug from the natural sources is considered as one of the most efficacious, safe, and affordable approaches. In this study, we report the antifilarial activity of a leguminous plant Cajanus scarabaeoides (L.) Thouars. The polyphenol-rich ethanolic extract obtained from the stem part of the plant C. scarabaeoides (EECs) was found to be efficient in killing the filarial nematode Setaria cervi in all the three developmental stages viz. oocytes, microfilariae (Mf) and adults with LD50 values of 2.5, 10 and 35 μg/ml, respectively. While studying the molecular mechanism of action, we found that induction of oxidative stress plays the key role in inducing the mortality in S. cervi. The redox imbalance finally results in activation of the nematode CED pathway that executes the death of the parasite. Intriguingly, EECs was found to be selectively active against the worm and absolutely non-toxic to the mammalian cells and tissues. Taken together, our experimental data demonstrate that C. scarabaeoides can be chosen as an affordable natural therapeutic for treating filarial infection in the future with high efficacy and less toxicity