Papers by Mohd. Islamuddin
Parasites & Vectors, 2015
Background: Exploration of immunomodulatory antileishmanials of plant origin is now being strongl... more Background: Exploration of immunomodulatory antileishmanials of plant origin is now being strongly recommended to overcome the immune suppression evident during visceral leishmaniasis (VL) and high cost and toxicity associated with conventional chemotherapeutics. In accordance, we assessed the in vitro and in vivo antileishmanial and immunomodulatory potential of ethanolic fractions of Azadirachta indica leaves (ALE) and seeds (ASE). Methods: A. indica fractions were prepared by sequential extraction of the powdered plant parts in hexane, ethanol and water. Erythrosin B staining was employed to appraise the anti-promastigote potential of ALE and ASE. Cytostatic or cytocidal mode of action was ascertained and alterations in parasite morphology were depicted under oil immersion light microscopy. Study of apoptotic correlates was performed to deduce the mechanism of induced cell death and anti-amastigote potential was assessed in Leishmania parasitized RAW 264.7 macrophages. In vivo antileishmanial effectiveness was evaluated in L. donovani infected BALB/c mice, accompanied by investigation of immunomodulatory potential of ALE and ASE. Adverse toxicity of the bioactive fractions against RAW macrophages was studied by MTT assay. In vivo side effects on the liver and kidney functions were also determined. Plant secondary metabolites present in ALE and ASE were analysed by Gas chromatography-mass spectrometry (GC-MS). Results: ALE and ASE (500 μg ml −1 ) exhibited leishmanicidal activity in a time-and dose-dependent manner (IC 50 34 and 77.66 μg ml −1 , respectively) with alterations in promastigote morphology and induction of apoptosis. ALE and ASE exerted appreciable anti-amastigote potency (IC 50 17.66 and 24.66 μg ml −1 , respectively) that was coupled with profound in vivo therapeutic efficacy (87.76% and 85.54% protection in liver and 85.55% and 83.62% in spleen, respectively). ALE exhibited minimal toxicity with selectivity index of 26.10 whereas ASE was observed to be non-toxic. The bioactive fractions revealed no hepato-and nephro-toxicity. ALE and ASE potentiated Th1-biased cell-mediated immunity along with upregulation of INF-γ, TNF-α and IL-2 and decline in IL-4 and IL-10 levels. GC-MS analysis revealed several compounds that may have contributed to the observed antileishmanial effect.
Journal of Colloid and Interface Science, 2014
Hypothesis: Artemisinin, a potential antileishmanial compound with poor bioavailability and stabi... more Hypothesis: Artemisinin, a potential antileishmanial compound with poor bioavailability and stability has limited efficacy in visceral leishmaniasis. Encapsulating artemisinin into poly lactic-co glycolic nanoparticles may improve its effectiveness and reduce toxicity. Experiments: Artemisinin-loaded nanoparticles were prepared, optimized (using Box-Behnken design) and characterized by dynamic light scattering technique, Atomic force microscopy (AFM), Transmission electron microscopy (TEM) and Fourier Transform-Infra Red spectroscopy. Release kinetics of artemisinin from optimized nanoformulation was studied by dialysis method at pH 7.4 and 5.5. Cytotoxicity and antileishmanial activity of these nanoparticles was tested on murine macrophages by MTT assay and macrophage-infested Leishmania donovani amastigotes ex vivo, respectively. Findings: Artemisinin-loaded nanoparticles were 221 ± 14 nm in diameter, with polydispersity index, zeta potential, drug loading and entrapment efficiency of 0.1 ± 0.015, À9.07 ± 0.69 mV, 28.03 ± 1.14 and 68.48 ± 1.97, respectively. AFM and TEM studies indicated that the particles were spherical in shape. These colloidal particles showed a sustained release pattern in vitro. Treatment with artemisinin-loaded nanoparticles significantly reduced the number of amastigotes per macrophage and percent infected macrophages ex vivo compared to free artemisinin. These nanoparticles were also non-toxic to macrophages compared to artemisinin alone.
Parasites & Vectors, 2015
Background: Exploration of immunomodulatory antileishmanials of plant origin is now being strongl... more Background: Exploration of immunomodulatory antileishmanials of plant origin is now being strongly recommended to overcome the immune suppression evident during visceral leishmaniasis (VL) and high cost and toxicity associated with conventional chemotherapeutics. In accordance, we assessed the in vitro and in vivo antileishmanial and immunomodulatory potential of ethanolic fractions of Azadirachta indica leaves (ALE) and seeds (ASE). Methods: A. indica fractions were prepared by sequential extraction of the powdered plant parts in hexane, ethanol and water. Erythrosin B staining was employed to appraise the anti-promastigote potential of ALE and ASE. Cytostatic or cytocidal mode of action was ascertained and alterations in parasite morphology were depicted under oil immersion light microscopy. Study of apoptotic correlates was performed to deduce the mechanism of induced cell death and anti-amastigote potential was assessed in Leishmania parasitized RAW 264.7 macrophages. In vivo antileishmanial effectiveness was evaluated in L. donovani infected BALB/c mice, accompanied by investigation of immunomodulatory potential of ALE and ASE. Adverse toxicity of the bioactive fractions against RAW macrophages was studied by MTT assay. In vivo side effects on the liver and kidney functions were also determined. Plant secondary metabolites present in ALE and ASE were analysed by Gas chromatography-mass spectrometry (GC-MS). Results: ALE and ASE (500 μg ml −1 ) exhibited leishmanicidal activity in a time-and dose-dependent manner (IC 50 34 and 77.66 μg ml −1 , respectively) with alterations in promastigote morphology and induction of apoptosis. ALE and ASE exerted appreciable anti-amastigote potency (IC 50 17.66 and 24.66 μg ml −1 , respectively) that was coupled with profound in vivo therapeutic efficacy (87.76% and 85.54% protection in liver and 85.55% and 83.62% in spleen, respectively). ALE exhibited minimal toxicity with selectivity index of 26.10 whereas ASE was observed to be non-toxic. The bioactive fractions revealed no hepato-and nephro-toxicity. ALE and ASE potentiated Th1-biased cell-mediated immunity along with upregulation of INF-γ, TNF-α and IL-2 and decline in IL-4 and IL-10 levels. GC-MS analysis revealed several compounds that may have contributed to the observed antileishmanial effect.
Open Journal of Medical Microbiology
Visceral leishmaniasis (VL) is a pestilent form of leishmaniasis that chiefly impinges the poores... more Visceral leishmaniasis (VL) is a pestilent form of leishmaniasis that chiefly impinges the poorest sections of the society. The prototypical therapeutic interventions in vogue are handicapped due to toxicity and alarming increase in drug resistance. In the absence of vaccines, progressive emergence of HIV-VL co-infection and relapse in the form of post kala-azar dermal leishmaniasis, have fuelled the quest for alternative therapies. Herein, we report antileishmanial activity of Piper nigrum, which is endowed with multifarous medicinal properties. Hexane (PNH) and ethanolic (PNE) extracts of P. nigrum substantially inhibited the growth of Leishmania donovani promastigotes with 50% inhibitory concentration (IC50) of 31.6 and 37.8 µg·ml −1 , respectively. Growth reversibility analysis revealed the leishmanicidal effect of PNH which caused cell shrinkage and flagellar disruption. In contrast, PNE treated promastigotes showed partial effect. PNH and PNE also abrogated the growth of intra-macrophagic Leishmania amastigotes with IC50 of 14.6 and 18.3 µg·ml −1 , respectively. Anti-amastigote efficacy of PNH was accompanied by higher selectivity over host macrophages than PNE. Gas-Chromatography-Mass Spectrometry showed the presence of several secondary metabolites such as trans-β-caryophyllene, piperine, β-bisabolene and other sesquiterpenes in PNH and piperine, δ-(sup 9)-cis oleic acid and piperyline in PNE. Conclusively, our work revealed discernible antileishmanial activity of P. nigrum extracts.
PLoS Neglected Tropical Diseases, 2015
Background: In the absence of vaccines and limitations of currently available chemotherapy, devel... more Background: In the absence of vaccines and limitations of currently available chemotherapy, development of safe and efficacious drugs is urgently needed for visceral leishmaniasis (VL) that is fatal, if left untreated. Earlier we reported in vitro apoptotic antileishmanial activity of n-hexane fractions of Artemisia annua leaves (AAL) and seeds (AAS) against Leishmania donovani. In the present study, we investigated the immunostimulatory and therapeutic efficacy of AAL and AAS.
Journal of Colloid and Interface Science, 2014
Hypothesis: Artemisinin, a potential antileishmanial compound with poor bioavailability and stabi... more Hypothesis: Artemisinin, a potential antileishmanial compound with poor bioavailability and stability has limited efficacy in visceral leishmaniasis. Encapsulating artemisinin into poly lactic-co glycolic nanoparticles may improve its effectiveness and reduce toxicity. Experiments: Artemisinin-loaded nanoparticles were prepared, optimized (using Box-Behnken design) and characterized by dynamic light scattering technique, Atomic force microscopy (AFM), Transmission electron microscopy (TEM) and Fourier Transform-Infra Red spectroscopy. Release kinetics of artemisinin from optimized nanoformulation was studied by dialysis method at pH 7.4 and 5.5. Cytotoxicity and antileishmanial activity of these nanoparticles was tested on murine macrophages by MTT assay and macrophage-infested Leishmania donovani amastigotes ex vivo, respectively. Findings: Artemisinin-loaded nanoparticles were 221 ± 14 nm in diameter, with polydispersity index, zeta potential, drug loading and entrapment efficiency of 0.1 ± 0.015, À9.07 ± 0.69 mV, 28.03 ± 1.14 and 68.48 ± 1.97, respectively. AFM and TEM studies indicated that the particles were spherical in shape. These colloidal particles showed a sustained release pattern in vitro. Treatment with artemisinin-loaded nanoparticles significantly reduced the number of amastigotes per macrophage and percent infected macrophages ex vivo compared to free artemisinin. These nanoparticles were also non-toxic to macrophages compared to artemisinin alone.
Frontiers in Immunology, 2014
Leishmaniasis is a pestilent affliction that importunately needs better therapeutics necessitated... more Leishmaniasis is a pestilent affliction that importunately needs better therapeutics necessitated by the absence of effective vaccine, emergence as HIV co-infection, and the dread of debilitating chemotherapy. The Leishmania parasites incapacitate host macrophages by preventing the formation of phagolysosomes, impeding antigen presentation to T cells, leading to suppression of cell-mediated immunity. An ideal approach to cure leishmaniasis includes administration of antileishmanial compounds that can concomitantly establish an effective Th1 response via restoration of requisite signaling between macrophages and T cells, for subsequent activation of macrophages to eliminate intracellular amastigotes. Plants have provided an opulent treasure of biomolecules that have fueled the discovery of antileishmanial drugs. Modulation of immune functions using medicinal plants and their products has emerged as an effective therapeutic strategy. Herein, we review the plant extracts and natural products that have resulted in therapeutic polarization of host immunity to cure leishmaniasis.These immunostimulatory phytochemicals as source of potential antileishmanials may provide new strategies to combat leishmaniasis, alone or as adjunct modality.
Journal of Medical Microbiology, 2012
Leishmaniasis is one of the major tropical parasitic diseases, and the condition ranges in severi... more Leishmaniasis is one of the major tropical parasitic diseases, and the condition ranges in severity from self-healing cutaneous lesions to fatal visceral manifestations. There is no vaccine available against visceral leishmaniasis (VL) (also known as kala-azar in India), and current antileishmanial drugs face major drawbacks, including drug resistance, variable efficacy, toxicity and parenteral administration. We report here that n-hexane fractions of Artemisia annua leaves (AAL) and seeds (AAS) possess significant antileishmanial activity against Leishmania donovani promastigotes, with GI 50 of 14.4 and 14.6 mg ml "1 , respectively, and the IC 50 against intracellular amastigotes was found to be 6.6 and 5.05 mg ml "1 , respectively. Changes in the morphology of promastigotes and growth reversibility analysis following treatment confirmed the leishmanicidal effect of the active fractions, which presented no cytotoxic effect on mammalian cells. The antileishmanial activity was mediated via apoptosis, as evidenced by externalization of phosphatidylserine, in situ labelling of DNA fragments by terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling (TUNEL) and cell-cycle arrest at the sub-G 0 /G 1 phase. High-performance thin-layer chromatography (HPTLC) fingerprinting showed that the content of artemisinin in crude bioactive extracts (~1.4 mg per 100 mg n-hexane fraction) was too low to account for the observed antileishmanial activity. Characterization of the active constituents by GC-MS showed that a-amyrinyl acetate, b-amyrine and derivatives of artemisinin were the major constituents in AAL and cetin, EINECS 211-126-2 and artemisinin derivatives in AAS. Our findings indicate the presence of antileishmanial compounds besides artemisinin in the n-hexane fractions of A. annua leaves and seeds.
Journal of Medical Microbiology, 2014
Leishmaniasis consists of a complex spectrum of infectious diseases with worldwide distribution o... more Leishmaniasis consists of a complex spectrum of infectious diseases with worldwide distribution of which visceral leishmaniasis or kala-azar caused by Leishmania donovani is the most devastating. In the absence of vaccines, chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice are expensive and associated with multiple adverse side effects. Because of these limitations, the development of new antileishmanial compounds is imperative and plants offer prospects in this regard. The present work was conducted to study the antileishmanial potential of oil from Syzygium aromaticum flower buds (clove). The S. aromaticum oil was characterized by gas chromatography and GC-MS and eugenol as well as eugenyl acetate were found to be the most abundant compounds, composing 59.75 % and 29.24 %, respectively of the oil. Our findings have shown that eugenol-rich essential oil from S. aromaticum (EROSA) possesses significant activity against L. donovani, with 50 % inhibitory concentration of 21±0.16 mg ml "1 and 15.24±0.14 mg ml "1 , respectively, against promastigotes and intracellular amastigotes. Alterations in cellular morphology and growth reversibility assay substantiated the leishmanicidal activity of EROSA. The leishmanicidal effect was mediated via apoptosis as confirmed by externalization of phosphatidylserine, DNA nicking by TdT-mediated dUTP nick-end labelling (TUNEL) assay, dyskinetoplastidy, cell cycle arrest at sub-G 0 -G 1 phase, loss of mitochondrial membrane potential and reactive oxygen species generation. EROSA presented no adverse cytotoxic effects against murine macrophages even at 200 mg ml "1 . Our studies authenticate the promising antileishmanial activity of EROSA, which is mediated by programmed cell death, and, accordingly, EROSA may be a source of novel agents for the treatment of leishmaniasis.
BMC Complementary and Alternative Medicine, 2014
ABSTRACT Fumaria parviflora Lam. (Fumaraceae) is widely used in traditional as well as folkloric ... more ABSTRACT Fumaria parviflora Lam. (Fumaraceae) is widely used in traditional as well as folkloric system of medicine from ancient. It is commonly known as 'Pitpapra' or 'Shahtrah' in Indian traditional system of medicine and used for treating numerous ailments like diarrhea, fever, influenza, blood purifier and other complications. The object of the present study was to evaluate the Antileishmanial, antibacterial, antifungal and cytotoxic potential of isolated compound. Methanolic extract of whole plant of Fumaria parviflora was dried under reduced pressure to obtain a dark brown residue which was adsorbed on silica gel column grade (60-120 mesh) to obtain a slurry and chromatographed over silica gel loaded column in petroleum ether - chloroform (3:1, 1:1 and 1:3 v/v). The in vitro antileishmanial evaluation of isolated compound against Leishmania donovani promastigotes was investigated by growth kinetics assay, reversibility assay, analysis of cellular morphology, adverse toxicity and determination of 50% growth inhibitory concentration (GI50). Disc diffusion and broth micro dilution methods were used to study the antibacterial (Gram + Staphylococcus epidermidis and Bacillus subtilis; Gram - Escherichia coli and Salmonella typhimurium) and antifungal (Candida albicans and Aspergillus niger) potential in vitro. Structure elucidation by spectral data analysis revealed a novel compound, n-octacosan-7beta-ol (OC), yield (0.471%), having significant antimicrobial activity against Leishmania donovani promastigotes, Staphylococcus epidermidis, Escherichia coli, Candida albicans and Aspergillus niger in vitro with GI50 = 5.35, MIC 250, MIC 250 and MFC 500 and MIC 250 mug ml-1 respectively. The isolated compound did not show adverse effect against mammalian macrophages. The available evidence of compound suggested that it may be used as antimicrobial agent in future and may provide new platform for drug discovery programmes for leishmaniasis.
Leishmaniasis is one of the major tropical parasitic diseases, and the condition ranges in severi... more Leishmaniasis is one of the major tropical parasitic diseases, and the condition ranges in severity from self-healing cutaneous lesions to fatal visceral manifestations. There is no vaccine available against visceral leishmaniasis (VL) (also known as kala-azar in India), and current antileishmanial drugs face major drawbacks, including drug resistance, variable efficacy, toxicity and parenteral administration. We report here that n-hexane fractions of Artemisia annua leaves (AAL) and seeds (AAS) possess significant antileishmanial activity against Leishmania donovani promastigotes, with GI 50 of 14.4 and 14.6 mg ml "1 , respectively, and the IC 50 against intracellular amastigotes was found to be 6.6 and 5.05 mg ml "1 , respectively. Changes in the morphology of promastigotes and growth reversibility analysis following treatment confirmed the leishmanicidal effect of the active fractions, which presented no cytotoxic effect on mammalian cells. The antileishmanial activity was mediated via apoptosis, as evidenced by externalization of phosphatidylserine, in situ labelling of DNA fragments by terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling (TUNEL) and cell-cycle arrest at the sub-G 0 /G 1 phase. High-performance thin-layer chromatography (HPTLC) fingerprinting showed that the content of artemisinin in crude bioactive extracts (~1.4 mg per 100 mg n-hexane fraction) was too low to account for the observed antileishmanial activity. Characterization of the active constituents by GC-MS showed that a-amyrinyl acetate, b-amyrine and derivatives of artemisinin were the major constituents in AAL and cetin, EINECS 211-126-2 and artemisinin derivatives in AAS. Our findings indicate the presence of antileishmanial compounds besides artemisinin in the n-hexane fractions of A. annua leaves and seeds.
Colloids and Surfaces B: Biointerfaces, 2015
Visceral leishmaniasis (VL) is a fatal vector-borne parasitic syndrome attributable to the protoz... more Visceral leishmaniasis (VL) is a fatal vector-borne parasitic syndrome attributable to the protozoa of the Leishmania donovani complex. The available chemotherapeutic options are not ideal due to their potential toxicity, high cost and prolonged treatment schedule. In the present study, we conjectured the use of nano drug delivery systems for plant-derived secondary metabolite; artemisinin as an alternative strategy for the treatment of experimental VL. Artemisinin-loaded poly lactic co-glycolic acid (ALPLGA) nanoparticles prepared were spherical in shape with a particle size of 220.0±15.0 nm, 29.2±2.0% drug loading and 69.0±3.3% encapsulation efficiency. ALPLGA nanoparticles administered at doses of 10 and 20mg/kg body weight showed superior antileishmanial efficacy compared with free artemisinin in BALB/c model of VL. There was a significant reduction in hepatosplenomegaly as well as in parasite load in the liver (85.0±5.4%) and spleen (82.0±2.4%) with ALPLGA nanoparticles treatment at 20mg/kg body weight compared to free artemisinin (70.3±0.6% in liver and 62.7±3.7% in spleen). In addition, ALPLGA nanoparticle treatment restored the defective host immune response in mice with established VL infection. The protection was associated with a Th1-biased immune response as evident from a positive delayed-type hypersensitivity reaction, escalated IgG2a levels, augmented lymphoproliferation and enhancement in proinflammatory cytokines (IFN-γ and IL-2) with significant suppression of Th2 cytokines (IL-10 and IL-4) after in vitro recall, compared to infected control and free artemisinin treatment. In conclusion, our results advocate superior efficacy of ALPLGA nanoparticles over free artemisinin, which was coupled with restoration of suppressed cell-mediated immunity in animal models of VL.
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Papers by Mohd. Islamuddin