Priya Roy

Evidence of reactive oxygen species (ROS) mediated apoptosis in Setaria cervi induced by green silver nanoparticles from Acacia auriculiformis at a very low dose.

Green synthesis of silver nanomaterial plays a pivotal role in the growing field of nanotechnology. Development of anti-parasitic drugs from plant metabolites has been in regular practice from the ancient period but most of them were discarded due to their inefficiency to control diseases effectively. At present, nanoparticles are used for developing anti-parasitic therapy for their unique properties such as smallest in size, bio-ability, bio-compatibility and penetration capacity into a cell. The present study aims at synthesis of silver nanoparticles (AgNPs) by using funicles extract of Acacia auriculiformis and tests its efficacy as antifilarial. Experimental evidence show that AgNPs are effective at a very low concentration compared to crude plant extracts. Synthesis of these nanoparticles is a single-step, biogenic, cost effective and eco-friendly process. Synthesized nanoparticles were characterized by UV-Vis spectroscopy, TEM, SAED, FTIR, EDX, FESEM and Z-potential. The antifilarial efficacy of AgNPs was tested against different life cycle stages of bovine filarial parasite Setaria cervi by morphological study, motility assessment and viability assay. These nanoparticles are found to have antifilarial activity with LC50 of 5.61 μg/mL and LC90 of 15.54 μg/mL against microfilaria of S. cervi. The microscopic findings and the detailed molecular studies confirmed that green synthesized AgNPs were effective enough to induce apoptosis through up regulation of ROS (reactive oxygen species).

Development of chitosan based gold nanomaterial as an efficient antifilarial agent: A mechanistic approach

The gold nanoparticles (AuNPs) have been synthesized biogenically by using black pepper (Piper nigrum) extract according to the principles of green chemistry in presence and absence of a biopolymer, chitosan. A comprehensive study (up to cellular level) on the antifilarial (against Setaria cervi) activity of AuNPs has been made for the first time with a view to use it clinically. The bioactivity of biopolymer capped biogenic AuNP increases significantly compared to simple biogenic AuNP. The biopolymer plays an important role in inspiring AuNP through its inherent positive charges and hydrophobicity. The developed nanomaterial boosts the production of ROS (reactive oxygen species) and misbalances the antioxidant parameters of parasites such as GSH, GST, GPx, SOD and catalase. The produced ROS ultimately induces oxidative stress, which leads to apoptotic cell death in filarial worms. The synthesized nanomaterials exhibit negligible toxicity towards human PBMCs. The present study may serve as a fruitful platform to explore biopolymer capped gold nanoparticles as efficient antifilarial therapeutics.

Molecular evidence on the occurrence of co-infection with Pichia guilliermondii and Wuchereria bancrofti in two filarial endemic districts of India

BackgroundLymphatic filariasis (LF), a vector-borne parasitic disease, is endemic in several parts of India and mostly affects the poor or those with a low-income. The disease results in huge numbers of morbidities, disabilities, and deaths every year. Association of co-infection with other pathogens makes the condition more severe. Although co-infection is becoming a growing area of research, it is yet to emerge as a frontier research topic in filarial research specifically. This study reports the occurrence of a fungal infection in a large number of patients suffering from bancroftian filariasis in two districts of West Bengal, India.MethodsNocturnal blood samples from filarial patients containing parasites and fungus were initially co-cultured, and further the fungus was isolated and characterized. Molecular identification of the isolate was carried out by PCR-based selective amplification and sequencing of highly-conserved D1/D2 region of 26S rDNA, whereas pathogenicity was determined by amplification of the RPS0 gene. A phylogenetic tree was constructed to study the relationship between the isolate and common pathogenic yeasts. The isolate was studied for antibiotic sensitivity, whereas morphological characterization was performed by microscopic techniques.ResultsThe isolate was identified as Pichia guilliermondii and this fungus was found to exist in co-infection with Wuchereria bancrofti in filarial patients. The fungus showed resistance to azole antifungals, griseofulvin, and, amphotericin B, whereas significant susceptibility was evident in cases of nystatin and cycloheximide. A total of 197 out of 222 patients showed this co-infection.ConclusionThis study revealed, for the first time, that P. guilliermondii exists as a co-infection in microfilaraemic individuals living in a filarial endemic zone. The findings are important and have relevance to human health, especially for filarial patients.

Carbohydrate polymer inspired silver nanoparticles for filaricidal and mosquitocidal activities: A comprehensive view.

The carbohydrate polymer inspired silver nanoparticles (AgNPs) are designed and synthesized through ultrasound assisted green process using unique combination of a biomolecule (tyrosine) and a natural polymer (starch). A comprehensive mechanistic study on the reactive oxygen species (ROS) mediated filaricidal (against Setaria cervi) and mosquitocidal (against second and fourth instar larvae of Culex quinquefasciatus) activities of AgNPs has been made for the first time for controlling filariasis by taking care of both filariid and its vector. The mechanism may help in formulating antifilarial drug based on carbohydrate polymer inspired AgNPs. The role of carbohydrate polymer in inspiring bioactivity of AgNPs has been looked into and its activities have been compared with the commercially available AgNPs. Cytotoxicity of AgNPs on macrophages of Wistar rat has been evaluated to ensure its selectivity towards filariid and larvae.

C-cinnamoyl glycosides as a new class of anti-filarial agents.

A series of C-cinnamoyl glycosides has been synthesized in good yield by the BF3·OEt2 catalyzed aldol condensation of C-glycosylated acetone derivative with a variety of aromatic aldehydes. The synthesized compounds were evaluated for their potential as anti-filarial agents against bovine filarial parasite Setaria cervi and human filariid Wuchereria bancrofti using a number of biological assays such as relative movability (RM) assessment and MTT reduction assay. Among twenty seven test compounds six compounds were found active in terms of MIC, IC50 and LC50 values. Further biological studies were carried out using three lead compounds because of their significantly low MIC values and IC50 values compared to the standard anti-filarial drug Ivermectin. In addition, structure activity relationship study of the test compounds has been carried out using 3D-QSAR analysis.

In vitro antifilarial activity of Azadirachta indica aqueous extract through reactive oxygen species enhancement.

OBJECTIVE To evaluate an aqueous preparation from the Azadirachta indica leaves (AEA) against Setaria cervi (S. cervi), a model filarial parasite. METHOD In vitro efficacy of AEA was evaluated against S. cervi through estimation of relative motility value, dye exclusion test and MTT assay. Visible morphological alterations were monitored using conventional microscopic techniques in microfilariae and haematoxylin-eosin stained sections of AEA-treated adults. RESULTS Enhancement of reactive oxygen species in S. cervi treated with AEA was established through alteration in the activity of glutathione S-transferase, superoxide dismutase, catalase, peroxidase and level of superoxide anion and reduced glutathione. CONCLUSION In vitro filaricidal activity of AEA is possibly through disturbing redox homeostasis by down-regulating and altering the level of some key antioxidants and regulatory enzymes like reduced glutathione, glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase of S. cervi.

Phenolics and Terpenoids; the Promising New Search for Anthelmintics: A Critical Review.

Ailments caused by helminth parasites are global causing different types of clinical complications with permanent and long term morbidity in humans. Although huge advances have been made in medical sciences the effectiveness of available anthelmintics are still quite limited. Starting from the 50s, most importance was given to synthetic compounds for developing remedies from them, however, the traditional knowledge of medicine of different countries continued to provide us clues against this widespread health problem. Natural products or structural analogs with diverse structures are always been the major sources for discovering new therapeutics and in recent past different active compounds have also been identified form these plant sources having anthelmintic properties. Although compounds of diverse chemical nature and classes were identified most active ones belong to either phenol or terpene in broad chemical nature. The mechanism of action of these phytotherapeutics is usually multi-targeted and can act against the helminth parasites through diverse spectrum of activities. In this reviewwe summarized the effective anthelmintics belong to either phenolics or terpenoids and highlighted the major way of their effectiveness. This also highlights the recent development of new therapeutic strategies against helminth parasites in the light of recent advances of knowledge. In addition, developing efficient strategies to promote apoptosis and disturbing redox status in them by natural products can provide us a clue in antifilarial drug developmental research and crucial unmet medical need.

Exploration of antifilarial activity of gold nanoparticle against human and bovine filarial parasites: A nanomedicinal mechanistic approach

The present work seeks to explore the antifilarial activity of biopolymer functionalized gold nanoparticles (AuNPs) against human filarial parasite (Wuchereria bancrofti) through Nrf2 signaling for the first time. A natural polymer, chitosan is used along with Terminalia chebula extract to synthesize AuNPs following the principles of green chemistry. The probable mode of action of AuNPs as filaricidal agent has been investigated in detail using model filarial parasite, Setaria cervi (bovine parasite). Biopolymers inspired AuNPs exhibit superior antifilarial activity against both human and bovine filarial parasites, and are able to induce oxidative stress and apoptotic cell death in filarial parasites mediated through mitochondria. AuNPs also alter the Nrf2 signaling. In addition, the synthesized nanomaterials appear to be nontoxic to mammalian system. Thus the present mechanistic study, targeting human filarial parasites, has the potential to increase the therapeutic prospects of AuNPs to control lymphatic filariasis in the upcoming days.

An approach toward optimization of the influential growth determinants of opportunistic yeast isolate Pichia guilliermondii

ABSTRACT The present study reports statistical optimization of growth conditions of an opportunistic fungal strain Pichia guilliermondii, isolated from the blood of patients suffering from bancroftian filariasis. Seven key determinants, namely, primary inoculums size (%), volume (mL) and pH of media, serum proportion, temperature (°C), incubation time (hr), and agitation speed (rpm) that influence in vitro growth of the pathogen were optimized statistically using response surface methodology (RSM). RSM with seven factors and two-level Box–Behnken design was employed for designing experimental run, prediction of case statistics, suitable exploration of quadratic response surfaces, and constructing a second-order polynomial equation. Analysis of variance (ANOVA) showed that primary inoculums size, volume of culture media, temperature, incubation time, and agitation speed exert most significant influence over fungal growth. The RSM study predicted that optimum fungal growth can be obtained using 10% primary inoculums size in 100 mL culture media with pH 6.0, 6.28% serum, 32.5°C temperature, and 24 hr of incubation, alongside agitation speed at 400 rpm. The desirability of the optimized growth model for P. guilliermondii is 99.123%, which indicated its accuracy and acceptability. Finally, the optimized growth module illustrated in the study could be useful in improving in vitro growth of clinically important P. guilliermondii.

Diospyros perigrena bark extract induced apoptosis in filarial parasite Setaria cervi through generation of reactive oxygen species

Abstract Context: Lymphatic filariasis is a major neglected tropical disease. Diospyros perigrena Gurke (Ebenaceae) was selected for antifilarial chemotherapy because of unavailability of proper medicine. In India, different parts of this plant were used for the treatment of diabetes, diarrhea, dysentery, cholera, mouth ulcers, and wounds. Objective: The present study was undertaken to access antifilarial potential and mechanism of action of n-butanol extract (NBE) of D. perigrena stem bark on Setaria cervi Rudolphi (Onchocercidae). Materials and methods: In vitro efficacy and apoptotic mechanism were evaluated by Hoechst, TUNEL, DNA fragmentation assay, pro- and anti-apoptotic gene expression in NBE (250, 125, 62.5, 31.25, and 15.6 µg/ml)-treated S. cervi after 24 h of incubation. Reactive oxygen species (ROS) up-regulation was also determined by GSH, GST, SOD assays, and super oxide anion level. Results: Significant in vitro antifilarial activity of NBE was found 50% inhibitory concentration (IC50): adult = 57.6 μg/ml, microfilariae (mf) = 56.1 μg/ml, and lethal dose (LD100) in mf is 187.17 μg/ml) after 24 h of treatment. NBF-induced apoptosis was proved by Hoechst, TUNEL, RT-PCR, and Western blot method. NBF (250 µg/ml) decreased the level of GSH (17.8%) and GST (65.4%), increased SOD activity (1.42-fold) and super oxide anion production (1.32-fold) in the treated parasite which culminated into ROS up-regulation. Discussion and conclusion: NBE induced apoptosis in different life cycle stages of S. cervi. In future, a detailed study of NBF will give us a novel antifilarial compound which will be used for antifilarial chemotherapy.