A sphingolipid rich lipid fraction isolated from attenuated Leishmania donovani promastigote induces apoptosis in mouse and human melanoma cells in vitro

In vivo 'turn on' fluorescence detection of free cysteine in zebrafish kidney and liver

Cysteine is directly associated with a wide range of biological processes. Besides its essential role in protein synthesis, cysteine undergoes a variety of post-translational modifications which modulate several physiological processes. Dysregulated cysteine metabolism is associated with several neurodegenerative disorders. Accordingly, restoring cysteine balance has therapeutic benefits. It is therefore essential to detect the presence of endogenous free cysteine in order to understand different physiological modes of action inside the cell. Here, a carbazole-pyridoxal conjugate system (CPLC) has been developed to detect endogenous free cysteine in the liver and kidney of an adult zebrafish. In consequence, we have also determined the fluorescence intensity statistics of zebrafish kidney and liver images. CPLC interacts in a very fascinating way with two cysteine molecules through chemodosimetric and chemosensing approaches which are conclusively proved by different spectroscopic analyses (UV-vis, fluorescence, NMR) and theoretical calculations (DFT). The detection limit of CPLC towards cysteine is 0.20 μM. Moreover, this preliminary experiment has been done using HuH-7 cell line to check the permeability of CPLC, interaction with cysteine intracellularly, and assessment of the toxicity of CPLC, if any, before performing details in-vivo experiments in zebrafish model.

Cobalt-conjugated carbon quantum dots for in vivo monitoring of the pyruvate dehydrogenase kinase inhibitor drug dichloroacetic acid

Dichloroacetic acid (DCA), an organohalide that present in environmental sample and biological systems, got high attention for its therapeutic potential as the inhibitor of pyruvate dehydrogenase kinase (PDK), elevated in obesity, diabetes, heart disease and cancer. Herein, we developed a Cobalt conjugated carbon quantum dots (N-CQDs/Co) that selectively detect DCA by fluorescence "turn-on" mechanism. Utilizing TEM, DLS, UV-vis and fluorescence spectroscopy, the mechanism has been thoroughly elucidated and is attributed to disaggregation induced enhancement (DIE). The limit of detection of the N-CQDs/Co complex is 8.7 µM. The structural characteristics and size of the N-CQDs and N-CQDS/Co complex have been verified using FT-IR, XPS, HRTEM, DLS, EDX have been performed. Additionally, the complex is used to specifically find DCA in the human cell line and in zebrafish.Journal instruction requires a city for affiliations; however, these are missing in affiliation [4]. Please verify if the provided city is correct and amend if necessary.Kharagpur is the city. The address is okay.

Benzimidazole–acid hydrazide Schiff–Mannich combo ligands enable nano–molar detection of Zn2+ via fluorescence turn–on mode from semi–aqueous medium, HuH–7 cells, and plants

Herein, we have synthesized two unsymmetrical and dipodal Schiff–Mannich combo ligands, benzoic acid (3–benzoimidazol–1–ylmethyl–2–hydroxy–5–methyl–benzylidene)–hydrazide (H2BBH) and the hydroxyl analogue, 2–hydroxy–benzoic acid (3–benzoimidazol–1–ylmethyl–2–hydroxy–5–methyl–benzylidene)–hydrazide (H3BSH) for selective detection of Zn2+ in semi–aqueous...

Differential detection and quantification of cyclic AMP and other adenosine phosphates in live cells

A new naphthol-based rhodamine derivative (NpRD) has been developed for the selective and differential detection of adenosine 3',5'-cyclic monophosphate (cAMP) and adenosine phosphates (APs) (ATP, ADP, and AMP) from other nucleotides. The simple detection and quantification of cAMP in human blood cells and in other samples based on the 'turn on' fluorescence properties of this chemosensor through colorimetry or fluorometry makes it unique for probable application in high throughput screening.

Visualisation of DCP, a nerve agent mimic, in Catfish brain by a simple chemosensor

A chemosensor, 3-aminophenol-based rhodamine conjugate (ARC) has been developed for visualisation of diethylchlorophosphate (DCP), mimic of a chemical warfare agent, in Catfish brain. The simple detection of DCP by "turn-on" fluorescence property of the chemosensor makes it unique for easy and rapid in vivo and in vitro detection of DCP with the detection limit of 5.6 nM.

First Chemosensor for Selective Detection and Quantification of L-4-Hydroxyproline in Collagen and Other Bio Samples

Amino pyridine-based rhodamine conjugate (APR) has been developed as a first chemosensor for selective detection and quantification of L-4-Hydroxyproline (Hyp). The "turn-on" fluorescence property of the chemosensor makes it unique for easy estimation of Hyp in collagen and biological samples.

“Turn-on” fluorescence sensing of cytosine: development of a chemosensor for quantification of cytosine in human cancer cells

Pyrene appended 5-hydroxyisophthalic acid derivative (PIA) has been developed and characterized for selective detection and quantification of cytosine in different human cancer cells.

A rhodamine embedded bio-compatible smart molecule mimicking a combinatorial logic circuit and ‘key-pad lock’ memory device for defending against information risk

A rhodamine-based chemosensor LC with a colorimetric response towards Al³⁺ and Cu²⁺ and only a fluorescence response to Al³⁺ enables us to fabricate a ‘key-pad-logic’ function.

Pyrene appended thymine derivative for selective turn-on fluorescence sensing of uric acid in live cells

A new ‘turn-ON’ fluorescent probe, pyrene appended thymine acetamide (PTA), with high sensitivity and selectivity for the detection of uric acid (UA) was developed and first time imaging of uric acid in living cells in water was achieved.

A water soluble copper(ii) complex as a HSO4− ion selective turn-on fluorescent sensor applicable in living cell imaging

A water soluble non-fluorescent biofriendly cell permeable structurally characterised copper(ii) complex (1) selectively senses HSO₄⁻ ions as low as 3.18 × 10⁻⁷ M in water : DMSO (9 : 1, v/v) HEPES buffer at biological pH.

Dual channel selective fluorescent detection of Al3+ and PPi in mixed aqueous media: DFT studies and cell imaging applications

A new, easily synthesizable chemosensor, DFC-EN-p-Ph-NO2, acts as a dual channel (colori- and fluorimetric) sensor for Al³⁺ and PPi.

A rhodamine-based ‘turn-on’ Al3+ ion-selective reporter and the resultant complex as a secondary sensor for F− ion are applicable to living cell staining

A new cell permeable rhodamine based Schiff base (L) senses nanomolar level of Al³⁺ ions through CHEF process and its Al(iii) complex (2) behaves as a highly F⁻ ions selective biomarker through fluorescence quenching in HEPES buffer.

Gold (I) N-heterocyclic carbene complex inhibits mouse melanoma growth by p53 upregulation

BACKGROUND

Cancer treatment using gold (I) complexes is becoming popular. In this study, a gold (I) N-heterocyclic complex designated as complex 3 was synthesized, its cytotoxicity was examined, and its anti-melanoma activity was evaluated in vitro and in vivo.

METHODS

Viability of cancer cells was determined by MTT assay upon treatment with various concentrations of a gold (I) N-heterocyclic carbene complex (complex 3) in a dose and time dependent manner. Mouse melanoma cells B16F10 were selected for further apoptotic studies, including flowcytometric analysis of annexin binding, cell cycle arrest, intracellular ROS generation and loss in the mitochondrial membrane potential. ELISA based assays were done for caspase activities and western blots for determining the expression of various survival and apoptotic proteins. Immunocytology was performed to visualize the translocation of p53 to the nucleus. B16F10 cells were inoculated into mice and post tumor formation, complex 3 was administered. Immunohistology was performed to determine the expressions of p53, p21, NF-κB (p65 and p50), MMP-9 and VEGF. Student's t test was used for determining statistical significance. The survival rate data were analyzed by Kaplan-Meier plots.

RESULTS

Complex 3 markedly inhibited the growth of HCT 116, HepG2, and A549, and induced apoptosis in B16F10 cells with nuclear condensation, DNA fragmentation, externalization of phosphatidylserine, activation of caspase 3 and caspase 9, PARP cleavage, downregulation of Bcl-2, upregulation of Bax, cytosolic cytochrome c elevation, ROS generation, and mitochondrial membrane potential loss indicating the involvement of an intrinsic mitochondrial death pathway. Further, upregulation of p53, p-p53 (ser 15) and p21 indicated the role of p53 in complex 3 mediated apoptosis. The complex reduced tumor size, and caused upregulation of p53 and p21 along with downregulation of NF-κB (p65 and p50), VEGF and MMP-9. These results suggest that it induced anti-melanoma effect in vitro and in vivo by modulating p53 and other apoptotic factors.

CONCLUSIONS

The gold (I) N-heterocyclic carbene complex (C22H26N6AuO2PF6) designated as complex 3 induced ROS and p53 dependent apoptosis in B16F10 cells involving the mitochondrial death pathway along with suppression of melanoma tumor growth by regulating the levels of pro and anti apoptotic factors (p53, p21, NF-κB, VEGF and MMP-9).

N-heterocyclic carbene supported Au(i) and Au(iii) complexes: a comparison of cytotoxicities

Au(i)–NHC (3) is more potent than Au(iii)–NHC (4) and cisplatin against the four cancer cell lines.

A FRET-based ‘off–on’ molecular switch: an effective design strategy for the selective detection of nanomolar Al3+ ions in aqueous media

A FRET-based ratiometric chemosensor (L1) is highly selective for Al³⁺ ions (as low as 6.19 × 10⁻⁹ M) and could be used to acquire images of Al³⁺ ions in living cells.

A water soluble FRET-based ratiometric chemosensor for Hg(ii) and S2−applicable in living cell staining

A new water soluble rhodamine-based ratiometric dual ‘off–on–off’ probe can selectively detect Hg²⁺ions in ppb level through time dependent FRET process with reversibility in presence of S²⁻anions.

Development of a cell permeable ratiometric chemosensor and biomarker for hydrogen sulphate ions in aqueous solution

A newly designed benzimidazol-based water soluble ratiometric chemosensor selective for HSO₄⁻ ions behaves as an efficient biomarker for the detection of the distribution of HSO₄⁻ ions in living cells in HEPES buffer (1 mM; water : ethanol (v/v), 98 : 2).

A novel copper(II) complex as a nitric oxide turn-on fluorosensor: intracellular applications and DFT calculation

We report, herein, the development of an easily synthesizable novel dansyl-based turn-on NO sensor L2. The UV-Vis titration data of L2 with Cu(2+) display a gradual increase in absorbance at 418 nm with [Cu(2+)], which were analyzed by using a non-linear least-squares computer-fit program yielding K = (1.16 ± 0.36) × 10(6) M(-1) and n = (1.28 ± 0.03) indicating a 1 : 1 complexation. The ground state geometries of L2 as well as its complex [Cu(L2)Cl](+) (1) were optimized by DFT calculations which showed that in complex 1 the central metal ion is in distorted tetrahedral geometry with bond distances very close to those found in analogous Cu(2+) complexes. The fluorescence of L2 was dramatically quenched (∼60-fold) through complexation with paramagnetic Cu(2+) to form [Cu(L2)Cl](+) in MeCN-H2O (9 : 1, v/v) at pH 7.2 in HEPES buffer, which on further treatment with Angeli's salt (Na2N2O3) restores its fluorescence property by ∼15-fold due to the reduction of Cu(2+) to Cu(+) by NO generated in solution from Na2N2O3. The lifetime measurements displayed a substantial decrease in the lifetime of free ligand L2 (τ0 = 12 ns) on complexation with Cu(2+) (τ0 = 2.1 ns). The detection limit of NO calculated by the 3σ method gives a value of 1.6 nM. The NO induced fluorescence enhancement of [Cu(II)(L2)Cl](+) was due to the reduction of [Cu(II)(L2)Cl](+) (1) to [Cu(I)(L2)](+) (2) and is supported by the disappearance of the d-d transition band at 850 nm as well as the X-band EPR signal of 1. The selective "turn on" fluorogenic behavior of L2 was examined on HeLa cells of human cervical cancer origin by fluorescence microscopy which showed very intense intracellular fluorescence that was strongly suppressed by the addition of Cu(2+) but it regains its fluorescence property on further incubation with Angeli's salt (Na2N2O3). The existence of [Cu(II)(L2)Cl](+) and [Cu(I)(L2)](+) in solution was confirmed by ESI-MS(+) (m/z) analysis. The effect of different biologically relevant cations and anions on the fluorescence property of L2 indicates that it was only the [Cu(II)(L2)Cl](+) which displayed high selectivity for NO, indicating its suitability for intracellular application without much worry about its cytotoxicity in a specified dose.

Poly (lactide-co-glycolide) nano-encapsulation of chelidonine, an active bioingredient of greater celandine (Chelidonium majus), enhances its ameliorative potential against cadmium induced oxidative stress and hepatic injury in mice

This study evaluates the possible protective potentials of chelidonine and its poly lactide-co-glycolide (PLGA) encapsulated nano-form against cadmium chloride (CdCl₂) induced oxidative stress and hepatotoxicity in mice, ex vivo and in vivo. Acute exposure to CdCl₂ (1.0 mg/kg b.w; i.p., twice a week for 30 days) generated oxidative stress in mice through accumulation of reactive oxygen species and increased lipid peroxidation, and levels of certain liver marker enzymes (ALT, AST, ALP) with decrease in levels of GSH and certain other antioxidant enzymes (SOD, CAT, GR) in liver. Treatment with nano-chelidonine for 30 days after CdCl₂ intoxication significantly reduced oxidative stress and lipid peroxidation and restored levels of GSH, cholesterol, triglyceride and antioxidant enzymes, showing ameliorative changes in histopathology of liver. Expression pattern of certain inflammatory and apoptotic signal proteins also indicated better hepato-protective abilities of nano-chelidonine, making it a more suitable protective drug than chelidonine against cadmium toxicity in mice.

Amygdalin induces apoptosis in human cervical cancer cell line HeLa cells

Amygdalin, a naturally occurring substance, has been suggested to be efficacious as an anticancer substance. The effect of amygdalin on cervical cancer cells has never been studied. In this study, we found that the viability of human cervical cancer HeLa cell line was significantly inhibited by amygdalin. 4,6-Diamino-2-phenyl indole (DAPI) staining showed that amygdalin-treated HeLa cells developed typical apoptotic changes. The development of apoptosis in the amygdalin-treated HeLa cells were confirmed by double staining of amygdalin-treated HeLa cells with annexin V-FITC and propidium iodide (PI) along with increase in caspase-3 activity in these cells. Further studies indicated that antiapoptotic protein Bcl-2 was downregulated whereas proapoptotic Bax protein was upregulated in the amygdalin-treated HeLa cells implying involvement of the intrinsic pathway of apoptosis. In vivo, amygdalin administration inhibited the growth of HeLa cell xenografts through a mechanism of apoptosis. The results in the present study suggest that amygdalin may offer a new therapeutic option for patients with cervical cancer.

Antihyperglycemic drug Gymnema sylvestre also shows anticancer potentials in human melanoma A375 cells via reactive oxygen species generation and mitochondria-dependent caspase pathway

OBJECTIVE

Ethanolic extract of Gymnema sylvestre (GS) leaves is used as a potent antidiabetic drug in various systems of alternative medicine, including homeopathy. The present study was aimed at examining if GS also had anticancer potentials, and if it had, to elucidate its possible mechanism of action.

METHODS

We initially tested possible anticancer potential of GS on A375 cells (human skin melanoma) through MTT assay and determined cytotoxicity levels in A375 and normal liver cells; we then thoroughly studied its apoptotic effects on A375 cells through protocols such as Hoechst 33258, H2DCFDA, and rhodamine 123 staining and conducted ELISA for cytochrome c, caspase 3, and PARP activity levels; we determined the mRNA level expression of cytochrome c, caspase 3, Bcl2, Bax, PARP, ICAD, and EGFR signaling genes through semiquantitative reverse transcriptase polymerase chain reaction and conducted Western blot analysis of caspase 3 and PARP. We also analyzed cell cycle events, determined reactive oxygen species accumulation, measured annexin V-FITC/PI and rhodamine 123 intensity by flow cytometry.

RESULTS

Compared with both normal liver cells and drug-untreated A375, the mortality of GS-treated A375 cells increased in a dose-dependent manner. Additionally, GS induced nuclear DNA fragmentation and showed an increased level of mRNA expression of apoptotic signal related genes cytochrome c, caspase 3, PARP, Bax, and reduced expression level of ICAD, EGFR, and the anti-apoptotic gene Bcl2.

CONCLUSION

Overall results indicate GS to have significant anticancer effect on A375 cells apart from its reported antidiabetic effect, indicating possibility of its palliative use in patients with symptoms of both the diseases.

Poly(lactic-co-glycolic) acid loaded nano-insulin has greater potentials of combating arsenic induced hyperglycemia in mice: some novel findings

Diabetes is a menacing problem, particularly to inhabitants of groundwater arsenic contaminated areas needing new medical approaches. This study examines if PLGA loaded nano-insulin (NIn), administered either intraperitoneally (i.p.) or through oral route, has a greater cost-effective anti-hyperglycemic potential than that of insulin in chronically arsenite-fed hyperglycemic mice. The particle size, morphology and zeta potential of nano-insulin were determined using dynamic light scattering method, scanning electronic and atomic force microscopies. The ability of the nano-insulin (NIn) to cross the blood-brain barrier (BBB) was also checked. Circular dichroic spectroscopic (CD) data of insulin and nano-insulin in presence or absence of arsenic were compared. Several diabetic markers in different groups of experimental and control mice were assessed. The mitochondrial functioning through indices like cytochrome c, pyruvate-kinase, glucokinase, ATP/ADP ratio, mitochondrial membrane potential, cell membrane potential and calcium-ion level was also evaluated. Expressions of the relevant marker proteins and mRNAs like insulin, GLUT2, GLUT4, IRS1, IRS2, UCP2, PI3, PPARγ, CYP1A1, Bcl2, caspase3 and p38 for tracking-down the signaling cascade were also analyzed. Results revealed that i.p.-injected nano-encapsulated-insulin showed better results; NIn, due to its smaller size, faster mobility, site-specific release, could cross BBB and showed positive modulation in mitochondrial signaling cascades and other downstream signaling molecules in reducing arsenic-induced-hyperglycemia. CD data indicated that nano-insulin had less distorted secondary structure as compared with that of insulin in presence of arsenic. Thus, overall analyses revealed that PLGA nano-insulin showed better efficacy in combating arsenite-induced-hyperglycemia than that of insulin and therefore, has greater potentials for use in nano-encapsulated form.

[6]-Gingerol isolated from ginger attenuates sodium arsenite induced oxidative stress and plays a corrective role in improving insulin signaling in mice

Arsenic toxicity induces type 2 diabetes via stress mediated pathway. In this study, we attempt to reveal how sodium arsenite (iAs) could induce stress mediated impaired insulin signaling in mice and if an isolated active fraction of ginger, [6]-gingerol could attenuate the iAs intoxicated hyperglycemic condition of mice and bring about improvement in their impaired insulin signaling. [6]-Gingerol treatment reduced elevated blood glucose level and oxidative stress by enhancing activity of super oxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and GSH. [6]-Gingerol also helped in increasing plasma insulin level, brought down after iAs exposure. iAs treatment to primary cell culture of β-cells and hepatocytes in vitro produced cyto-degenerative effect and accumulated reactive oxygen species (ROS) in pancreatic β-cells and hepatocytes of mice. [6]-Gingerol appeared to inhibit/intervene iAs induced cyto-degeneration of pancreatic β-cells and hepatocytes, helped in scavenging the free radicals. The over-expression of TNFα and IL6 in iAs intoxicated mice was down-regulated by [6]-gingerol treatment. iAs intoxication reduced expression levels of GLUT4, IRS-1, IRS-2, PI3K, AKT, PPARγ signaling molecules; [6]-gingerol mediated its action through enhancing the expressions of these signaling molecules, both at protein and mRNA levels. Thus, our results suggest that [6]-gingerol possesses an anti-hyperglycemic property and can improve impaired insulin signaling in arsenic intoxicated mice.

Antihyperglycemic potentials of a threatened plant, Helonias dioica: antioxidative stress responses and the signaling cascade

Helonias dioica (HD) is a threatened species of herb growing in North America. It is used as a traditional medicine for treating various ailments particularly related to reproductive issues. The root is reported to contain approximately 10% of a saponin (chamaelirin; C36H62O18) apart from certain other fatty acids. As saponins are known to have hypoglycemic effects, we suspected its possible antihyperglycemic potentials. We injected intraperitoneally alloxan (ALX) at the dose of 200 mg/kg body weight (bw) to induce hyperglycemia in mice and tested possible hypoglycemic effects of HD in vivo by deploying two doses (100 and 200 mg/kg bw, respectively). We also tested its effects on the isolated pancreatic islets cells in vitro. We used various standard protocols like reactive oxygen species (ROS) generation and DNA damage, activities of biomarkers like catalase (CAT), superoxide dismutase (SOD), lipid peroxidase (LPO), reduced glutathione (GSH) of the pancreas tissue and glucokinase and glycogen content of the liver of hyperglycemic mice. With a mechanistic approach, we also tracked down the possible signaling pathway involved. We found an elevated level of ROS generation, LPO and overexpression of inducible nitric oxide synthase (iNOS), tumor necrosis factor α (TNF- α), p38 Map kinase (p38 MAPK), nuclear factor (NF)- κβ, interferon gamma (IFN- γ), cytochrome c, caspase 3, poly [ADP ribose] polymerase (PARP) and cyclo oxygenase 2 (COX2) in ALX-induced diabetic mouse. Treatment of hyperglycemic mice with both the doses of HD showed a significant decrease with respect to all these parameters of study. Thus, our results suggest that HD prevents ALX-induced islet cell damage and possesses antihyperglycemic and antioxidative potentials.

Thujone-Rich Fraction of Thuja occidentalis Demonstrates Major Anti-Cancer Potentials: Evidences from In Vitro Studies on A375 Cells

Crude ethanolic extract of Thuja occidentalis (Fam: Cupressaceae) is used as homeopathic mother tincture (TOΦ) to treat various ailments, particularly moles and tumors, and also used in various other systems of traditional medicine. Anti-proliferative and apoptosis-inducing properties of TOΦ and the thujone-rich fraction (TRF) separated from it have been evaluated for their possible anti-cancer potentials in the malignant melanoma cell line A375. On initial trial by S-diphenyltetrazolium bromide assay, both TOΦ and TRF showed maximum cytotoxic effect on A375 cell line while the other three principal fractions separated by chromatography had negligible or no such effect, because of which only TRF was further characterized and subjected to certain other assays for determining its precise anti-proliferative and apoptotic potentials. TRF was reported to have a molecular formula of C₁₀H₁₆O with a molecular weight of 152. Exposure of TRF of Thuja occidentalis to A375 cells in vitro showed more cytotoxic, anti-proliferative and apoptotic effects as compared with TOΦ, but had minimal growth inhibitory responses when exposed to normal cells (peripheral blood mononuclear cell). Furthermore, both TOΦ and TRF also caused a significant decrease in cell viability, induced inter-nucleosomal DNA fragmentation, mitochondrial transmembrane potential collapse, increase in ROS generation, and release of cytochrome c and caspase-3 activation, all of which are closely related to the induction of apoptosis in A375 cells. Thus, TRF showed and matched all the anti-cancer responses of TOΦ and could be the main bio-active fraction. The use of TOΦ in traditional medicines against tumors has, therefore, a scientific basis.

A two-dimensional coordination compound as a zinc ion selective luminescent probe for biological applications

A 2D coordination compound {[Cu2(HL)(N3)]ClO4}infinity (1; H3L = 2,6-bis(hydroxyethyliminoethyl)-4-methyl phenol) was synthesized and characterized by single-crystal X-ray diffraction to be a polymer in the crystalline state. Each [Cu2(HL)(N3)]+ species is connected to its adjacent unit by a bridging alkoxide oxygen atom of the ligand to form a helical propagation along the crystallographic a axis. The adjacent helical frameworks are connected by a ligand alcoholic oxygen atom along the crystallographic b axis to produce pleated 2D sheets. In solution, 1 dissociates into [Cu2(HL)2(H3L)]2H2O (2); the monomer displays high selectivity for Zn2+ and can be used in HEPES buffer (pH 7.4) as a zinc ion selective luminescent probe for biological application. The system shows a nearly 19-fold Zn2+-selective chelation-enhanced fluorescence response in the working buffer. Application of 2 to cultured living cells (B16F10 mouse melanoma and A375 human melanoma) and rat hippocampal slices was also studied by fluorescence microscopy.

Attenuated Leishmanial sphingolipid induces apoptosis in A375 human melanoma cell via both caspase-dependent and -independent pathways

A fraction of attenuated Leishmanial lipid (ALL) rich in sphingolipids, previously shown to have apoptosis inducing activity in mouse melanoma (B16F10) and human melanoma (A375) cells, was resolved to isolate the bioactive sphingolipid. The mechanism of apoptosis induction by this bioactive attenuated Leishmanial sphingolipid (ALSL) was studied in A375 cells. Apoptosis induced by ALSL in A375 cells was found to be dose and time-dependent. Exposure of cells to ALSL resulted in a rapid increase in reactive oxygen species generation. Pretreatment of cells with the antioxidant N-acetyl-cystein reduced ROS generation and attenuated apoptosis induced by ALSL. Again, ALSL sensitization resulted in the activation of caspase-3 and -9 but not caspase-8. However, inhibitors of these caspases could not protect the cells completely from ALSL-induced apoptosis. N-acetyl-cystein pretreatment was again found to attenuate the activation of caspase-3 and -9. ALSL treatment also resulted in the alteration of mitochondrial membrane potential, and release of pro-apoptotic factors such as cytochrome c and apoptosis inducing factor (AIF) from mitochondria. Furthermore, c-Jun N-terminal kinase was activated that resulted in apoptosis of A375 cells, whereas p38 MAPK was activated to counteract the stress generated in cells in response to ALSL treatment. Taken together, our results indicate that ALSL-induced apoptosis of A375 cells is mediated by both mitochondrial caspase-dependent and -independent pathways and it involves ROS and JNK activation in the mitogen-activated protein kinase cascade.