Modulation of cadmium induced alterations in murine thymocytes by piperine: oxidative stress, apoptosis, phenotyping and blastogenesis

Adverse effects of cadmium on lymphoid organs, immune cells, and immunological responses

Humans and animals possess robust immune systems to safeguard against foreign pathogens. However, recent reports suggest a greater incidence of immunity breakdown due to exposure to environmental pollutants, with heavy metals emerging as potential candidates in such immuno-toxicological studies. While we have extensive data on the general toxicity resulting from exposure to heavy metals, comprehensive documentation of their role as immune disruptors remains scarce. Cd (Cadmium) exerts immunomodulation by interfering with immune organs and cells, leading to altered structure, physiology, and function, thereby inducing symptoms of immune deregulation, inflammation and/or autoimmunity. This review aims to summarize the link between Cd exposure and immune dysfunction, drawing from case studies on exposed human subjects, as well as research conducted on various model organisms and in-vitro culture systems.

Exploring potential mechanisms of Suhexiang Pill against COVID-19 based on network pharmacology and molecular docking

BACKGROUND

The traditional Chinese medicine prescription Suhexiang Pill (SHXP), a classic prescription for the treatment of plague, has been recommended in the 2019 Guideline for coronavirus disease 2019 (COVID-19) diagnosis and treatment of a severe type of COVID-19. However, the bioactive compounds and underlying mechanisms of SHXP for COVID-19 prevention and treatment have not yet been elucidated. This study investigates the mechanisms of SHXP in the treatment of COVID-19 based on network pharmacology and molecular docking.

METHODS

First, the bioactive ingredients and corresponding target genes of the SHXP were screened from the traditional Chinese medicine systems pharmacology database and analysis platform database. Then, we compiled COVID-19 disease targets from the GeneCards gene database and literature search. Subsequently, we constructed the core compound-target network, the protein-protein interaction network of the intersection of compound targets and disease targets, the drug-core compound-hub gene-pathway network, module analysis, and hub gene search by the Cytoscape software. The Metascape database and R language software were applied to analyze gene ontology biological processes and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Finally, AutoDock software was used for molecular docking of hub genes and core compounds.

RESULTS

A total of 326 compounds, 2450 target genes of SHXP, and 251 genes related to COVID-19 were collected, among which there were 6 hub genes of SHXP associated with the treatment of COVID-19, namely interleukin 6, interleukin 10, vascular endothelial growth factor A, signal transducer and activator of transcription 3 (STAT3), tumor necrosis factor (TNF), and epidermal growth factor. Functional enrichment analysis suggested that the effect of SHXP against COVID-19 is mediated by synergistic regulation of several biological signaling pathways, including Janus kinase/ STAT3, phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt), T cell receptor, TNF, Nuclear factor kappa-B, Toll-like receptor, interleukin 17, Chemokine, and hypoxia-inducible factor 1 signaling pathways. SHXP may play a vital role in the treatment of COVID-19 by suppressing the inflammatory storm, regulating immune function, and resisting viral invasion. Furthermore, the molecular docking results showed an excellent binding affinity between the core compounds and the hub genes.

CONCLUSION

This study preliminarily predicted the potential therapeutic targets, signaling pathways, and molecular mechanisms of SHXP in the treatment of severe COVID-19, which include the moderate immune system, relieves the "cytokine storm," and anti-viral entry into cells.

Cadmium triggers mitochondrial oxidative stress in human peripheral blood lymphocytes and monocytes: Analysis using in vitro and system toxicology approaches

Cadmium (Cd) is a well-known heavy metal that causes environmental pollution and human health problems. Several studies attempted to assess Cd toxicity in vitro and in vivo. However, the systemic profile of cadmium toxicity has not been studied well. In the present study, we assessed the toxicity of Cd on human peripheral blood lymphocytes and monocytes and gene expression, using a system toxicological approach. Cd effect on cell viability and morphology were analyzed by MTT assay and AO/EB staining respectively. Mitochondrial membrane potential depletion and reactive oxygen singlet generation were assessed by flow cytometry. Effects of Cd treatment on gene expression were also studied. Significant reduction in cell viability and disintegration of nuclear morphology were observed in Cd-treated cells. Cd exposure enhanced the loss of mitochondrial membrane potential through oxidative stress. Dose-dependent upregulation of GSTM3 and downregulation of GSR gene expression were observed. TNF gene expression decreased as the level of Cd exposure increased. We analyzed the toxicological effects of Cd on more than 45 proteins for biological target identification. These system toxicological studies suggested that Cd induced toxicity through various biological processes such as oxidative stress, oxidation-reduction, and ROS and hydrogen peroxide generation. Additionally, Cd affects the cellular component network and modulates the expression level of oxidative stress-related genes.

Piperine Triggers Apoptosis of Human Oral Squamous Carcinoma Through Cell Cycle Arrest and Mitochondrial Oxidative Stress

Piperine is a nitrogenous pungent substance exhibiting multifunctional pharmacological properties. However, the mechanism underlying its anticancer potential is not well elucidated in human oral squamous carcinoma (KB) cell line. The anticancer potential of piperine was evaluated through potent biomarkers viz. reactive oxygen species (ROS), cellular apoptosis, and loss of mitochondrial membrane potential (MMP). In addition, cell cycle kinetics and caspases-3 activity were also carried out to confirm anticancer activity of piperine. Results showed that various concentrations (25-300 μM) of piperine exposure reduced the cell viability of KB cells significantly (P < 0.01). Piperine induced significant (P < 0.01) dose-related increment in ROS production and nuclear condensation. Moreover, piperine stimulated cell death by inducing loss of MMP, and caspase-3 activation. Cell cycle study revealed that piperine arrested the cells in G2/M phase and decreased the DNA content. Findings of this study suggest the efficacy of piperine in inducing cell death via the decrease in MMP and ROS liberation followed by caspase-3 activation and cell cycle arrest. Further assessment of the anticancer potency of piperine is needed for anticancer drug development.

Antigenotoxic Effect of Piperine in Broiler Chickens Intoxicated with Aflatoxin B1

Piperine is an abundant amide extracted from black pepper seeds which has been shown to have protective effects against cytotoxic and genotoxic carcinogenesis induced by certain chemical carcinogens and aflatoxin B₁ (AFB₁) in vitro. The aim of this work was to study, in vivo, the antigenotoxic potential of feed-added piperine on broiler chickens experimentally intoxicated with AFB₁, using micronucleus and comet assays. The antigenotoxicity assessment of 9-day-old chicks was performed on a total of 60 chickens divided into four groups of 15 broilers each: (C) control, (P) 60 mg·piperine kg-1 feed, (A) 0.5 mg·AFB₁·kg-1 body weight, (daily by oral route), and (P + A) co-treatment with piperine and AFB₁. The experiment was conducted for 26 days. Chicks intoxicated with AFB₁ showed significant genotoxic effects in the first 24 h post intoxication, and the effects remained in the other periods analyzed (48, 72, and 96 h and 26 days of treatment). The DNA damage in peripheral blood cells, the number of erythrocytes with micronuclei, and polychromatic-to-normochromatic erythrocyte ratio were significantly reduced or absent in the piperine/AFB₁ group. No significant differences were observed between the group piperine/AFB₁ and the control and piperine-alone groups. The addition 60 mg·kg-1 of piperine to the diet of the broiler chicks was safe, promoting beneficial effects in poultry health with respect to the toxic effects 0.5 mg·AFB₁·kg-1 body weight.

Mechanism of immunoprotective effects of curcumin in DLM-induced thymic apoptosis and altered immune function: an in silico and in vitro study

Curcumin, a main component of Curcuma Longa Linn, is a plant polyphenol used as an immune-enhancer in the Indian system of traditional medicine. However, its underlying mechanism of immune-protection remains unknown. The present study is designed to delineate the role of curcumin in deltamethrin (DLM)-induced thymocyte apoptosis and altered immune functions. In silico studies revealed that curcumin has a strong binding affinity toward CD4 and CD8 receptors. DLM (25 µM) induces thymocytes apoptosis through oxidative stress and caspase-dependent pathways. Various concentrations of curcumin (1, 10 and 50 µg/ml), when added along with DLM, caused a concentration- and time-related amelioration in apoptogenic signaling pathways induced by DLM. Inhibition of DLM-induced reactive oxygen species production, replenishment of glutathione and suppression of caspase activities by curcumin may thus be responsible for the suppression of downstream cascade of events, i.e. apoptosis, phenotypic changes and altered cytokine release. Thus, this study clearly demonstrates that the mechanism of immunoprotection of curcumin in DLM-induced thymic apoptosis includes inhibition of oxidative stress and caspase-dependent pathways underlying apoptosis.

Immunomodulatory role of piperine in deltamethrin induced thymic apoptosis and altered immune functions

Deltamethrin (DLM), a well-known pyrethroid insecticide, is a potent immunotoxicant. In rodents, it is primarily characterized by marked thymic apoptosis. Mechanism of DLM induced thymic apoptosis in primary murine thymocytes has been recently explored. Oxidative stress and activation of caspase dependent pathways appear to be involved in the DLM induced thymic injury. Thus, for the amelioration of its effect, this study has been designed to first observe the binding affinity of piperine to immune cell receptors and its protective effects on the DLM induced immunotoxicity under in vitro condition. The docking results demonstrated that piperine has good binding affinity towards CD4 and CD8 receptors. In vitro study results have shown that piperine (1, 10 and 50 μg/ml) increased cell viability in a concentration dependent manner. The early activated markers of apoptosis such as enhanced reactive oxygen species (ROS) and caspase-3 activation by DLM was significantly reduced by piperine treatment. GSH depletion induced by DLM has been also restored by piperine treatment. At 18 h, all concentration of piperine (1, 10 and 50 μg/ml) significantly ameliorated the DLM induced apoptosis. Further, DLM induced phenotypic changes were mitigated by the piperine. In addition, piperine also restored the cytokine levels, which were suppressed by DLM treatment. These findings strongly indicate the anti-oxidative, anti-apoptotic and chemo-protective ability of piperine in the DLM induced thymic apoptosis.

The Effect of Ascorbic Acid on Mancozeb-Induced Toxicity in Rat Thymocytes

Mancozeb, as a dithiocarbamate fungicide, has been found to exhibit toxicological manifestations in different cells, mainly by generation of free radicals which may alter antioxidant defence systems in cells. The effect of mancozeb on the cells of a primary lymphoid organ has not been studied. In the present study, the effects of mancozeb (0.2, 2 and 5 μg/ml) or mancozeb+ascorbic acid (100 μg/ml), or ascorbic acid alone or control medium alone on the levels of cell viability, apoptosis, intracellular reactive oxygen species production (ROS), mitochondrial membrane potential (MMP) and ATP levels in rat thymocytes were examined in vitro. Cells treated with mancozeb displayed a concentration-dependent increase of hypodiploid cells and ROS production followed by markedly decreased viability of the cells, MMP and ATP levels. Application of ascorbic acid significantly reduced cytotoxicity in cell cultures treated with 0.2 and 2 μg/ml of mancozeb, together with significantly decreased ROS levels and increased MMP and ATP levels. In cells treated with 5 μg/ml of mancozeb, ascorbic acid failed to reduce toxicity while simultaneously increasing the apoptosis rate of thymocytes. These results suggest that ROS plays a significant role in mancozeb-induced toxicity, through alteration of mitochondrial function. Ascorbic acid administration reduced the toxicity rate in cells treated with lower mancozeb concentrations, while it may have the ability to shift cells from necrosis to apoptosis in the presence of highest mancozeb concentrations.

Protective effect of hexane and ethanol extract of piper longum L. On gentamicin-induced hair cell loss in neonatal cultures

OBJECTIVES

Gentamicin (GM) is a commonly used aminoglycoside antibiotic that generates free oxygen radicals within the inner ear, which can cause vestibulo-cochlear toxicity and permanent damage to the sensory hair cells and neurons. Piper longum L. (PL) is a well-known spice and traditional medicine in Asia and Pacific islands, which has been reported to exhibit a wide spectrum of activity, including antioxidant activity. In this study, we evaluated the effect of hexane:ethanol (2:8) PL extract (subfraction of PL [SPL] extract) on GM-induced hair cell loss in basal, middle and apical regions in a neonatal cochlea cultures.

METHODS

The protective effects of SPL extract were measured by phalloidin staining of cultures from postnatal day 2-3 mice with GM-induced hair cell loss. The anti-apoptosis activity of SPL extract was measured using double labeling by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and myosin-7a staining. The radical-scavenging activity of SPL extract was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay.

RESULTS

SPL extract at a concentration of 1 µg/mL significantly inhibited GM-induced hair cell loss at basal and middle region of cochlea, while 5 µg/mL was effective against apical region hair cell loss. The protective effect of SPL extract was concentration dependent and hair cells retained their stereocilia in explants treated with SPL extract prior to treatment with 0.3 mM GM. SPL extract decreased GM-induced apoptosis of hair cells as assessed by TUNEL staining. The outer hair and inner hair counts were not decreased in SPL extract treated groups in compare to GM treated explants. Additionally, SPL extract showed concentration dependent radical scavenging activity in a DPPH assay.

CONCLUSION

An anti-apoptosis effect and potent radical scavenger activity of SPL extract protects from GM-induced hair cell loss at basal, middle and apical regions in neonatal cochlea cultures.

Mechanism of cadmium induced apoptosis in human peripheral blood lymphocytes: the role of p53, Fas and Caspase-3

Cadmium (Cd) is a major pollutant of environment. It can be fatal to human. In spite of bulk of research and literatures, the mechanism of a fatality against human is still not understood completely. Toxic and carcinogenic effects of Cd in rodents and humans are well known. However, effects of Cd on induction of apoptosis are still elusive. This study indicates immunosuppression and immunotoxicity due to Cd exposure. Present study was undertaken to determine the mechanism of cell death in vitro in human peripheral blood lymphocytes induced by Cd. Our findings suggest the toxicity due to Cd is attributed to programmed cell death-apoptosis. IC₅₀ was calculated at 21.74 μM. A significant increase of expression of the pro-apoptotic genep53, Fas and Caspase-3 in human lymphocytes was found. Cd induced p53-dependent apoptosis through cooperation between Bak upregulation without changing the Bcl-2 and Bax expression. Data of this study compel to speculate that apoptosis may also be attributed to CD95/Fas complex formation, and p53 direct apoptogenic potential at mitochondria. It was confirmed by the increased expression of Caspase-3. Although, this work does not address all the questions regarding the mechanism of Cd induced apoptosis, but these findings establish an important role of p53 and mitochondrial function during apoptosis in human lymphocyte. Moreover, based upon our findings, the role of Fas in Cd induced apoptosis is also undeniable. Hence further investigations are required to understand the different mechanism involved into apoptosis of lymphocytes due to Cd exposure.

The effect of camphor and borneol on rat thymocyte viability and oxidative stress

Camphor and borneol are wildly distributed in the essential oils of medicinal plants from various parts of the World. Our study has been carried out to evaluate the effect of these two bicyclic monoterpenes on rat thymocytes. Camphor and borneol at concentrations of 0.5 and 5 µg/mL did not induce significant toxicity on the immune system cells, while a significant increase of thymocyte viability was detected when cells were incubated with 50 µg/mL of camphor. A significant increase of cell viability was similarly detected when thymocytes were cultivated with borneol at concentrations of 0.5 and 5 µg/mL. The role of camphor and borneol in reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) disturbances in rat thymocytes as well as their potential mechanism(s) of action were also discussed.

Piperine suppresses tumor growth and metastasis in vitro and in vivo in a 4T1 murine breast cancer model

AIM

To investigate the effects of piperine, a major pungent alkaloid present in Piper nigrum and Piper longum, on the tumor growth and metastasis of mouse 4T1 mammary carcinoma in vitro and in vivo, and elucidate the underlying mechanisms.

METHODS

Growth of 4T1 cells was assessed using MTT assay. Apoptosis and cell cycle of 4T1 cells were evaluated with flow cytometry, and the related proteins were examined using Western blotting. Real-time quantitative PCR was applied to detect the expression of matrix metalloproteinases (MMPs). A highly malignant, spontaneously metastasizing 4T1 mouse mammary carcinoma model was used to evaluate the in vivo antitumor activity. Piperine was injected into tumors every 3 d for 3 times.

RESULTS

Piperine (35-280 μmol/L) inhibited the growth of 4T1 cells in time- and dose-dependent manners (the IC(50) values were 105 ± 1.08 and 78.52 ± 1.06 μmol/L, respectively, at 48 and 72 h). Treatment of 4T1 cells with piperine (70-280 μmol/L) dose-dependently induced apoptosis of 4T1 cells, accompanying activation of caspase 3. The cells treated with piperine (140 and 280 μmol/L) significantly increased the percentage of cells in G(2)/M phase with a reduction in the expression of cyclin B1. Piperine (140 and 280 μmol/L) significantly decreased the expression of MMP-9 and MMP-13, and inhibited 4T1 cell migration in vitro. Injection of piperine (2.5 and 5 mg/kg) dose-dependently suppressed the primary 4T1 tumor growth and injection of piperine (5 mg/kg) significantly inhibited the lung metastasis.

CONCLUSION

These results demonstrated that piperine is an effective antitumor compound in vitro and in vivo, and has the potential to be developed as a new anticancer drug.

A role of piperine on monosodium urate crystal-induced inflammation--an experimental model of gouty arthritis

In the present study, the anti-inflammatory effect of piperine was investigated on monosodium urate crystal-induced inflammation in mice, an experimental model for gouty arthritis, and compared it with that of the nonsteroidal anti-inflammatory drug, indomethacin. The levels of lysosomal enzymes, lipid peroxidation, tumor necrosis factor-α, and paw volume were increased significantly, and the activities of antioxidant status were in turn decreased in monosodium urate crystal-induced mice, whereas these changes were reverted to near normal levels upon piperine (30 mg/kg b.wt, i.p.) treatment. In vitro, piperine (50/100 ug/ml) suppressed the level of β-glucuronidase and lactate dehydrogenase in monosodium urate crystal-incubated polymorphonuclear leucocytes in concentration-dependent manner when compared to control cells. Thus, the present study clearly indicated that piperine inhibit the monosodium urate crystal-induced inflammation and can be regarded as therapeutic drug for the treatment of acute gouty arthritis.

Immunomodulatory role of piperine in cadmium induced thymic atrophy and splenomegaly in mice

Cadmium being a potent immunotoxicant, affects both humoral and cell mediated immunity. In rodents, it is primarily characterized by marked thymic atrophy and splenomegaly. Cadmium induces apoptosis in mice and suppresses the immune functions. Piperine, major alkaloid of Piper longum Linn. and Piper nigrum Linn. with a long history of medicinal value, has shown anti-apoptotic activity in vitro. Thus, to delineate its role in vivo, piperine (2.5mg/kg/day, oral, 7 days) treated Balb/C mice were administered Cd as CdCl(2) (1.8mg/kg, i.p., once, 4th day). The various biochemical indexes of cell damage such as cytotoxicity (MTT assay), oxidative stress (glutathione, reactive oxygen species), apoptosis (mitochondrial membrane potential, caspase-3 activity, phosphatidylserine externalization, apoptotic DNA, intranucleosomal DNA fragmentation) along with lymphocyte phenotyping, cell proliferative response and cytokine secretion (IL-2 and IFNγ) were assessed in thymic and splenic single cell suspensions. Lowering of body weight gain and cellularity and a loss in cell viability seen in Cd group, were abrogated by piperine treatment. Similarly, oxidative stress and apoptotic markers altered by Cd were also modulated by this alkaloid. In addition, a pronounced inhibition of cell proliferative response, alterations in T- and B-cell phenotypes, cytokine release and morphological changes were restored to normalcy. The present in vivo data corroborating with our previous in vitro findings, provide confirmatory evidence of the immuno-protective efficacy of piperine.

Safety evaluation of Trikatu, a generic Ayurvedic medicine in Charles Foster rats

Chemical characterization and acute and sub-acute toxicity study of Trikatu, a generic herbal formulation of Indian system of medicine, was carried out in Charles Foster (CF) rats for safety profiling. In acute toxicity experiment, Trikatu at 2,000 mg/kg body weight once orally was well tolerated by the experimental animals (both male and female) and no changes were observed in mortality, morbidity, gross pathology, gain in weight, vital organ weight, hematological (total white blood cells (WBC) and red blood cells (RBC) count), biochemical parameters such as serum creatinine, serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), serum lipid profile and tissue biochemical parameters such as reduced glutathione and malonaldehyde content as oxidative stress markers. In sub-acute experiment, Trikatu was administered at 5, 50 and 300 mg/kg body weight once daily for 28 days in female CF rats, and non-significant changes were found in most of the parameters studied such as acute experiment except significant increase in low density lipoprotein (LDL) cholesterol level at 50 and 300 mg/kg body weight, decrease in high density lipoprotein (HDL) cholesterol level at 300 mg/kg body weight, increase in SGPT activity at 50 mg/kg body weight and decrease in WBC count at 300 mg/kg body weight on 28(th) day post treatment.

In vivo growth inhibition of sarcoma 180 by piperlonguminine, an alkaloid amide from the Piper species

Many authors have already emphasized that phytochemicals from spices have biological applications. Piperlonguminine is a known alkaloid amide from peppers, including Piper divaricatum. The aim of this study was to investigate the in vitro and in vivo antitumor effects of piperlonguminine in experimental models. In order to evaluate the toxicological aspects related to piperlonguminine treatment, hematological, biochemical, histopathological and morphological analyses of treated animals were performed. Piperlonguminine did not show any significant in vitro cytotoxic effect at experimental exposure levels, but showed an in vivo antitumor effect. After 7 days of treatment, the inhibition rates were 38.71% and 40.68% at doses of 25 mg kg(-1) and 50 mg kg(-1), respectively. The histopathological analysis suggests that the liver and kidney were only weakly affected by piperlonguminine treatment. Neither the enzymatic activity of transaminases (AST and ALT) nor the urea levels were significantly altered. In the hematological analysis, all parameters analysed remained constant after piperlonguminine treatment. In conclusion, these data reinforce the anticancer potential of spice components.

Metals and apoptosis: recent developments

Apoptosis, also known as programmed cell death is a highly regulated and crucial process found in all multicellular organisms. It is not only implicated in regulatory mechanisms of cells, but has been attributed to a number of diseases, i.e. inflammation, malignancy, autoimmunity and neurodegeneration. A variety of toxins can induce apoptosis. Carcinogenic transition metals, viz. cadmium, chromium and nickel promote apoptosis along with DNA base modifications, strand breaks and rearrangements. Generation of reactive oxygen species, accumulation of Ca(2+), upregulation of caspase-3, down regulation of bcl-2, and deficiency of p-53 lead to arsenic-induced apoptosis. In the case of cadmium, metallothionein expression determines the choice between apoptosis and necrosis. Reactive oxygen species (ROS) and p53 contribute in apoptosis caused by chromium. Immuno suppressive mechanisms contribute in lead-induced apoptosis whereas in the case of mercury, p38 mediated caspase activation regulate apoptosis. Nickel kills the cells by apoptotic pathways. Copper induces apoptosis by p53 dependent and independent pathways. Beryllium stimulates the formation of ROS that play a role in Be-induced macrophage apoptosis. Selenium induces apoptosis by producing superoxide that activates p53. Thus, disorders of apoptosis may play a critical role in some of the most debilitating metal-induced afflictions including hepatotoxicity, renal toxicity, neurotoxicity, autoimmunity and carcinogenesis. An understanding of metal-induced apoptosis will be helpful in the development of preventive molecular strategies.

Piperine inhibits TNF-alpha induced adhesion of neutrophils to endothelial monolayer through suppression of NF-kappaB and IkappaB kinase activation

Piperine displays antipyretic, analgesic, insecticidal and anti-inflammatory activities. It is the first amide to be isolated from Piper species. In the process of identifying non-steroidal anti-inflammatory small molecules from the natural sources, we demonstrate here that piperine inhibits adhesion of neutrophils to endothelial monolayer. The inhibition of neutrophils to endothelial monolayer by piperine is due to its ability to block the tumor necrosis factor-alpha (TNF-alpha) induced expression of cell adhesion molecules i.e. ICAM-1 (intercellular adhesion molecule-1), VCAM-1 (vascular cell adhesion molecule-1) and E-selectin as analyzed by cell-ELISA and confirmed by flow cytometry. Further, we demonstrate that inhibition of ICAM-1 by piperine is reversible. As nuclear factor-kappaB (NF-kappaB) is known to control the transcriptional regulation of cell adhesion molecules hence, we measured the effect of piperine on NF-kappaB in the cytoplasm and in the nucleus of endothelial cells. We observed that pretreatment of endothelial cells with piperine blocks the nuclear translocation and activation of NF-kappaB via blocking the phosphorylation and degradation of its inhibitory protein, IkappaBalpha. Piperine blocks the phosphorylation and degradation of IkappaBalpha by attenuating TNF-alpha induced IkappaB kinase activity. These results suggest a possible mechanism of anti-inflammatory activity of piperine. Therefore, piperine or its structural analogues could be used for the development of new anti-inflammatory molecules.

Cytoprotective and immunomodulating properties of piperine on murine splenocytes: an in vitro study

Piper longum Linn. and Piper nigrum Linn. are conventionally used as immuno-enhancers in Indian system of traditional medicine. The underlying mechanism remains unknown. The present study was therefore, undertaken to delineate the role of piperine (major alkaloid) in cadmium (Cd) induced immuno-compromised murine splenocytes. The various biological determinants such as oxidative stress markers (reactive oxygen species and GSH), Bcl-2 protein expression, mitochondrial membrane potential, caspase-3 activity, DNA damage, splenic B and T cell population, blastogenesis and cytokines (Interleukin-2 and gamma-Interferon) were measured to ascertain its cell protective potential. Cadmium induces apoptosis at 6 h onwards. The oxidative stress markers markedly alter prior to a decline in mitochondrial membrane potential, caspase-3 activation and DNA degradation The splenic cell population was observed to change only at 18 h and the release of two cytokines was affected at 72 h. Addition of piperine in various concentrations (1, 10 and 50 microg/ml) ameliorated the above events. The highest dose of piperine could completely abrogate the toxic manifestations of cadmium and the splenic cells behaved similar to control cells. The reported free radical scavenging property of piperine and its antioxidant potential could be responsible for the modulation of intracellular oxidative stress signals. These in turn appear to mitigate the apoptotic pathway and other cellular responses altered by cadmium. The findings strongly indicate the anti-oxidative, anti-apoptotic and chemo-protective ability of piperine in blastogenesis, cytokine release and restoration of splenic cell population and is suggestive of its therapeutic usefulness in immuno-compromised situations.

Inactivation of cadmium induced immunotoxicological alterations in rats by Tunisian montmorillonite clay

Cadmium (Cd(2+)) is a heavy metal that is dispersed throughout the modern environment mainly as a result of pollution from a variety of sources. The aims of the current study were to investigate the efficacy of purified Tunisian montmorillonite clay (TMC) to adsorb Cd, to test the stability of the resulting complex under different conditions in vitro, and to utilize the rat bioassay as an in vivo model to evaluate the protective role of TMC against Cd-induced toxicity and immunodysfunction. In the in vitro study, three concentrations of TMC (0.5, 1.0 and 1.5 g/l aqueous solution) and three concentrations of CdCl(2) (25, 50 and 100 ppm) were tested. The results of the in vitro study showed that TMC had a high capacity of adsorbing Cd at different concentrations tested. The adsorption ranged from 95.7-100% of the available CdCl(2) in aqueous solutions. The complex TMC-Cd was stable at different pHs at 37 degrees C. The in vivo results indicated that treatment with CdCl(2) (2.5 mg/kg BW) for 2 weeks resulted in a significant decrease in triglycerides, total protein, creatinine, creatine kinase, immunoglobulin profile (Ig A and Ig G) and T-cell sub-types (CD3(+), CD4(+), CD8(+) and CD56(+)). Whereas, it significantly increase serum level of AST, ALT, LDH and induced degenerative changes in pro-inflammatory cytokines (TNF-alpha and IL-1). Rats treated with TMC alone (400, 600 and 800 mg/kg BW) were comparable to the control regarding all the tested parameters. The combined treatment of CdCl(2) and TMC at the lowest dose (400 mg/kg BW) showed a significant improvement of all tested parameters. It could be concluded that TMC was effective to protect against Cd hazards at a dose as low as 400 mg/kg BW. These results supported our hypothesis that TMC tightly-bind and immobilized Cd resulted in reduction of metal bioavailability in the gastrointestinal tract.