PRATI PAL SINGH - Academia.edu (original) (raw)

Papers by PRATI PAL SINGH

Journal of Microbial & Biochemical Technology, Jul 25, 2016

Background. Drug resistance has been one of the main obstacles in the fight against vector-borne ... more Background. Drug resistance has been one of the main obstacles in the fight against vector-borne infectious diseases. Among these diseases, malaria represents a serious public health challenge, mainly in the tropics, where vector-favourable climates are a crucial factor. Each of the various anti-malarial drugs currently used against this disease, such as quinolones, sulphonamides and artemisinins are inadequate and new strategies are required. Peptides are known to have a huge number of biological effects. Antimicrobial peptides (AMPs) have been proven to be effective against bacterial, fungal and viral infections. This study explored the effect of the peptide ‘deltorphin-II’ in Plasmodium berghei-infected mice. Materials and Methods. Mean percentage parasitaemia was calculated by studying infected erythrocytes after microscopic examination of 10 erythrocytes from infected mice on days 4, 7, 10, 14 and 21 after infection in all groups. Results. Deltorphin-II shows maximum activity a...

Latent Mycobacterium tuberculosis exhibits metabolic pathways different from normal bacilli. Myco... more Latent Mycobacterium tuberculosis exhibits metabolic pathways different from normal bacilli. Mycobacteria undergo metabolic shift leading to alteration in expression of vital cell proteins like catalase, urease etc., during nutrient starvation conditions. In this study, we determined the activity of catalase and urease in nutrient starved cultures. It was observed that catalase activity declines to 87% and 91%, when compared to log phase cultures as determined by bubble height and spectrophotometric methods, respectively. On the contrary, urease activity increases 18 fold in 42 h nutrient starved mycobacteria as compared log phase bacilli. Latency in nutrient starved bacilli was confirmed by respiration test and sensitivity tests. We also studied the susceptibility of latent bacilli to RNI under nutrient starvation conditions. Bacilli become resistant to acidified sodium nitrite induced RNI (at 0.05, 0.5, 1 µg/ml concentrations) in latency induced by nutrient starvation. Latency in nutrient starved bacilli was confirmed by respiration test and sensitivity tests. These findings suggest that changes in levels of catalase, urease and RNI susceptibility may play critical role in latent TB.

Journal of biotechnology & biomaterials, Aug 11, 2014

European cytokine network

The protective effect of co-administration of recombinant mouse granulocyte-macrophage colony-sti... more The protective effect of co-administration of recombinant mouse granulocyte-macrophage colony-stimulating factor (rmGM-CSF) and synthetic peptide met-enkephalin (M-ENK) against blood-induced Plasmodium berghei infection in Swiss mice was investigated. Mice co-administered with rmGM-CSF (10.0 mug/kg) and M-ENK (2.0 mg/kg) x 3/day, i.p., beginning on day -1 and continuing through day +4 after the initiation of infection, showed significant suppression (p < 0.05) (sometimes even complete elimination) of parasitaemia compared to vehicle-treated controls. However, when administered separately, neither of these agents induced any detectable protective effect. Surprisingly, mice similarly co-administered with rmGM-CSF (10.0 mug/kg) and higher doses of M-ENK (10.0 mg/kg), showed no protection. Polyclonal neutralizing (100%) antibody to rmGM-CSF abrogated the combined protective effect of these agents. Additionally, naloxone (10.0 mg/kg/day x 6, i.p.), a non-selective, opioid receptor ant...

Mycobacterium tuberculosis is a slow-growing bacterium and requires long durations of incubation ... more Mycobacterium tuberculosis is a slow-growing bacterium and requires long durations of incubation (4-6 weeks) for colonies to appear on solid culture resulting in microbial contamination of culture medium. We investigated the effectiveness of antibiotics in controlling microbial contamination in Middlebrook (7H10 and 7H11) medium and BACTEC 12B vials inoculated with mycobacteria. Incorporation of antibiotics in Middlebrook media and BACTEC 12B medium inhibited microbial contamination in media inoculated with organ homogenates and cell lysates of M. tuberculosis H37Rv-infected mice and macrophages, respectively, without significant effect on mycobacterial growth except with amikacin which slightly suppressed mycobacterial growth as well. Similar results were obtained for log-phase cultures of M. tuberculosis H37Rv, M. tuberculosis H37Ra, M. smegmatis BCG, M. tuberculosis Erdman strain and a multidrug resistant (MDR) M. tuberculosis clinical isolate. In conclusion, addition of antibiotics in Middlebrook and BACTEC 12B medium could reduce microbial contamination in experimental samples without significantly affecting mycobacterial growth.

The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.

Journal of Pharmacy and Pharmacology, 2016

Malaria, where the causative agent Plasmodium is rapidly gaining resistance to practically all th... more Malaria, where the causative agent Plasmodium is rapidly gaining resistance to practically all the antimalarial drugs in clinical use, requires the identification of new drug targets to enable the discovery of novel, more effective and safer drugs to treat the disease. Advancements in molecular techniques have provided the proof of existence of autophagy in Plasmodium; however, its role(s) in malaria is only becoming to be understood. Nevertheless, some of the recently explored dimensions of autophagy in Plasmodium have indicated its fairly larger role in parasite survival and growth. But then, autophagy is also essential for host cell survival and defence. There is thus need to explore chemotherapeutic strategies to specifically target autophagy in both the parasite and host. This review focuses on autophagy pathways in Plasmodium and in host with a view to identify autophagy-related new drug targets for the discovery of novel antimalarial drugs.

Life Sciences, 1994

The effect of morphine on immunomodulation and host defense have been investigated during infecti... more The effect of morphine on immunomodulation and host defense have been investigated during infection in BALB/c mice. A single low (5.0 mg/kg) subcutaneous dose of morphine strongly suppressed (sometimes completely eliminated) the parasitaemia, whereas a high dose (80.0 mg/kg) ...

Parasitology International

Journal of Bioequivalence & Bioavailability, Apr 1, 2021

Infectious Diseases and Your Health, 2018

Visceral leishmaniasis (VL) is a neglected tropical parasitic disease in humans caused by protozo... more Visceral leishmaniasis (VL) is a neglected tropical parasitic disease in humans caused by protozoan parasite Leishmania donovani and transmitted to humans by the bite of an infected female sand fly, a haemoflagellate vector. According to WHO, every year 0.7–1 million leishmaniasis cases are reported globally, and over 20,000–30,000 deaths occur. Current anti-leishmanial drug (pentavalent antimonials, miltefosine, amphotericin B, pentamidine and paromomycin) therapy is fraught with several problems and causes serious adverse effects, which limit their clinical application. The emergence of drug resistance and non-availability of an effective vaccine(s) against leishmaniasis poses a serious challenge to leishmaniasis treatment and control. Environmental and socio-economic status of people like deforestation, global warming and poverty exacerbates both parasite survival and disease progression. Pentavalent antimonial-resistant strains of L. donovani are rampant in Bihar, a highly endemic zone of VL in India. Development of co-infections (HIV-VL and Malaria-VL) often leads to poor diagnosis and treatment. There are no proper prognostic and diagnostic markers for VL. Therefore, there is an urgent need for the development of new anti-leishmanial drugs for the treatment and control of devastating VL. Effective immunotherapy/immuno-chemotherapy is considered as a viable alternative to chemotherapy. Cytokines (granulocyte-macrophage colony-stimulating factor, interferon-γ and interleukin-12) both stand-alone and in combination with current anti-leishmanial drugs are being thought to reduce the drug resistance and useful in VL treatment. The development and availability of the reliable models for anti-leishmanial drug screening is very much warranted.

Page 1. Kharatmal et al., IJPSR, 2011; Vol. 2(8): 1875-1887 ISSN: 0975-8232 Available online on w... more Page 1. Kharatmal et al., IJPSR, 2011; Vol. 2(8): 1875-1887 ISSN: 0975-8232 Available online on www.ijpsr.com 1875 IJPSR (2011), Vol. 2, Issue 8 (Review Article) Received on 05 April, 2011; received in revised form 09 July, 2011; accepted 24 July, 2011 ...

Journal of Medicinal Chemistry, 2004

The immunomodulatory effects of opioids are known in various infections. However, little is known... more The immunomodulatory effects of opioids are known in various infections. However, little is known about the effects of opioids in tuberculosis (TB). In the present study, we report the effects of morphine in Mycobacterium smegmatis infection in mice and macrophages. Morphine exerted a dose-dependent suppression of infection in vivo: 50 and 100 mg/kg morphine exerted signifi cant (P<0.05) suppression whereas 5 mg/kg morphine showed no effect. Analogous to the in vivo effects, incubation of M. smegmatis-infected mouse peritoneal macrophages with morphine (100 μM) showed signifi cant reduction in intramacrophage CFU counts. However, morphine did not show any direct antimycobacterial activity in broth dilution assay upto 100 μM concentration. Further, morphine-induced intramacro-phage killing of M. smegmatis was abrogated by naloxone and aminoguanidine indicating the involvement of opioid-receptor activation and nitric oxide production in protective effects of morphine. In conclusion...

The start of my nearly 40 yearlong pharmaceutical research odyssey almost coincides with the begi... more The start of my nearly 40 yearlong pharmaceutical research odyssey almost coincides with the beginning of my association with Hindustan Ciba-Geigy Limited, Research Centre, Goregaon, Bombay (now Mumbai), and satranidazole. Satranidazole, an excellent and relatively superior molecule, is the first and the only antiamoebic drug that has been discovered, developed and marketed from India. In future, it may find therapeutic applications for many more indications. It is a product of long-drawn, very expensive and intense scientific and technological efforts, often marred with uncertainties and serendipity, of the dedicated scientists and technicians. Satranidazole had to survive spates of several squabbles but, in the end, has emerged as a champion and seen the light of day. Satranidazole will definitely go a long way to improve and invigorate the quality of human life. Nonetheless, for the new and budding drug researchers, the success story of satranidazole, full of different hues and s...