Nanoencapsulation of triterpene 3ß,6ß,16ß-trihydroxylup-20(29)-ene from Combretum leprosum as strategy to improve its cytotoxicity against cancer cell lines.

The pentacyclic triterpene 3ß,6ß,16ß-tri-hydroxilup-20(29)-ene is a natural product produced by the Brazilian medicinal plant Combretum leprosum. Its cytotoxicity has been previously reported against breast cancer cell lines. The low water solubility of this natural product, that hampers its bioavailability, motivated the investigation of a new nanoparticle formulation containing the triterpene in order to improve its bioactivity. The triterpene was encapsulated in polycaprolactone (PCL) polymer by nanoprecipitation, producing homogenic nanoparticles with nanometer sizes (122.7 ± 2.06 nm), which were characterized by FT-IR, SEM imaging and DSC. The cytotoxicity (MTT method) of the nanoparticle containing the triterpene 1, besides the free natural product and the nanoparticle control (without 1), was assayed against three human tumor cell lines [human colon carcinoma line (HCT116), prostate (PC3) and glioblastoma (SNB19)] and the normal epithelial embryo kidney human cell line (Hek293T). The nanocarrier produced a significative effect in the cytotoxicity of the natural product in the nanoformulation (IC50 0.11-0.26 µg mL-1) when compared with its free form (IC50 1.07-1.44 µg mL-1). Additionally, higher selectivity of the triterpene to the tumor cells was found when it was encapsulated (SI 1.92-4.54) than in its free form (SI 0.42-0.56). In this case, the nanoencapsulated triterpene was more selective to PC3 (SI 3.33) and SNB19 (SI 4.54) tumor cells.

Calotropis gigantea extract induces apoptosis through extrinsic/intrinsic pathways and reactive oxygen species generation in A549 and NCI-H1299 non-small cell lung cancer cells.

BACKGROUND: Calotropis gigantea (CG) is a tall and waxy flower that is used as a traditional remedy for fever, indigestion, rheumatism, leprosy, and leukoderma. However, the precise mechanisms of its anticancer effects have not yet been examined in human non-small cell lung cancer (NSCLC) cells. In this study, we investigated whether CG extract exerted an apoptotic effect in A549 and NCI-H1299 NSCLC cells. METHODS: The ethanol extract of CG was prepared, and its apoptotic effects on A549 and NCI-H1299 NSCLC cells were assessed by using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, annexin V-fluorescein isothiocyanate/propidium iodide (PI) staining, cell cycle analysis, real-time polymerase chain reaction (RT-PCR), western blotting, JC-1 staining, and ROS detection assay. RESULTS: The CG extract induced apoptosis through the stimulation of intrinsic and extrinsic signaling pathways in A549 and NCI-H1299 lung cancer cells. Cell cycle arrest was induced by the CG extract in both cell lines. Reactive oxygen species (ROS), which can induce cell death, were also generated in the CG-treated A549 and NCI-H1299 cells. CONCLUSIONS: These data confirmed that CG caused apoptosis through the activation of extrinsic and intrinsic pathways, cell cycle arrest, and ROS generation in A549 and NCI-H1299 lung cancer cells. Thus, CG can be suggested as a potential agent for lung cancer therapy.

In Vitro Anti-proliferative Activity and Mechanism of Action of Anemone nemorosa.

Anemone nemorosa is part of the Ranunculaceae genus Anemone (order Ranunculales) which comprises more than 150 species. Various parts of the plant have been used for the treatment of numerous medical conditions such as headaches, tertian agues, rheumatic gout, leprosy, lethargy, eye inflammation as well as malignant and corroding ulcers. The Anemone plants have been found to contain various medicinal compounds with anti-cancer, immunomodulatory, anti-inflammatory, anti-oxidant and anti-microbial activities. To date there has been no reported evidence of its use in the treatment of cancer. However, due to the reported abundance of saponins which usually exert anti-cancer activity via cell cycle arrest and the induction of apoptosis, we investigated the mode of cell death induced by an aqueous A. nemorosa extract by using HeLa cervical cancer cells. Cisplatin was used as a positive control. With a 50% inhibitory concentration (IC50) of 20.33 ± 2.480 µg/mL, treatment with A. nemorosa yielded a delay in the early mitosis phase of the cell cycle. Apoptosis was confirmed through fluorescent staining with annexin V-FITC. Apoptosis was more evident with A. nemorosa treatment compared to the positive control after 24 and 48 h. Tetramethylrhodamine ethyl ester staining showed a decrease in mitochondrial membrane potential at 24 and 48 h. The results obtained imply that A. nemorosa may have potential anti-proliferative properties.

Antitumor activity of the bioreductive prodrug 3-(2-nitrophenyl) propionic acid-paclitaxel nanoparticles (NPPA-PTX NPs) on MDA-MB-231 cells: in vitro and in vivo.

BACKGROUND: 3-(2-Nitrophenyl) propionic acid-paclitaxel (NPPA-PTX) is a paclitaxel (PTX) bioreductive prodrug synthesized by our lab. We hypothesize that NPPA-PTX can self-assemble to form nanoparticles (NPs). MATERIALS AND METHODS: In the present research, the theoretical partition coefficient (XlogP) and Hansen solubility parameters of NPPA-PTX were calculated. NPPA-PTX nanoparticles prepared by NPPA-PTX and DSPE-PEG (NPPA-PTX:DSPE-PEG =1:0.1, w/w) (NPPA-PTX@PEG NPs) were prepared and characterized. The cellular uptake, in vitro antitumor activity, in vivo targeting effect, tumor distribution, in vivo antitumor activity, and safety of NPPA-PTX@PEG NPs were investigated. RESULTS: Our results indicate that NPPA-PTX can self-assemble to form NPPA-PTX@PEG NPs. Both the cellular uptake and safety of NPPA-PTX@PEG NPs were higher than those of Taxol. NPPA-PTX@PEG NPs could target tumor tissues by a passive targeting effect. In tumor tissues, NPPA-PTX@PEG NPs could completely transform into active PTX. The in vivo antitumor activity of NPPA-PTX@PEG NPs was confirmed in MDA-MB-231 tumor-bearing nude mice. CONCLUSION: The bioreductive prodrug NPPA-PTX could self-assemble to form NPs. The safety and antitumor activity of NPPA-PTX@PEG were confirmed in our in vitro and in vivo experiments. The NPPA-PTX@PEG NPs developed in this study could offer a new way of preparing bioreductive prodrug, self-assembled NPs suitable for antitumor therapy.

Controlling the surface structure of electrospun fibers: Effect on endothelial cells and blood coagulation.

The influence of nano- or micron-sized structures on polymer films as well as the impact of fiber diameter of electrospun membranes on endothelial cell (EC) and blood response has been studied for vascular tissue engineering applications. However, the influence of surface structures on micron-sized fibers on endothelial cells and blood interaction is currently not known. In this work, electrospun membranes with distinct fiber surface structures were designed to study their influence on the endothelial cell viability and thrombogenicity. The thermodynamically derived Hansen-solubility-parameters model accurately predicted the formation of solvent dependent fiber surface structured poly(caprolactone) membranes. The electrospun membranes composed of microfibers (MF) or structured MF were of similar fiber diameter, macroscopic roughness, wettability, and elastic modulus. In vitro evaluation with ECs demonstrated that cell proliferation and morphology were not affected by the fiber surface structure. Similarly, investigating the blood response to the fiber meshes showed comparable fibrin network formation and platelet activation on MF and structured MF. Even though the presented results provide evidence that surface structures on MF appear neither to affect EC viability nor blood coagulation, they shed light on the complexity and challenges when studying biology-material interactions. They thereby contribute to the understanding of EC and blood-material interaction on electrospun membranes.

Are biological control agents, isolated from tropical fruits, harmless to potential consumers?

Postharvest losses of fruits and vegetables can reach up to 25% in developed and up to 50% in developing countries. (Sub)tropical fruits are especially susceptible because their protecting peel can easily be damaged. Traditionally used pesticides are associated to environmental pollution and possible harmful health effects. An alternative are biocontrol agents (BCA), means bacteria or yeasts applied onto the fruits to inhibit the growth of phytopathogens. Many reports on their effectiveness have been published, however, reports on their harmlessness to consumers are still rare. Culture extracts of six BCAs, tested on two human lines (Caco-2, HeLa), exhibited no cytotoxic effect, when used directly (1×) to protect the fruits; however, when they are 5×overconcentrated, the confluence of proliferating cells was reduced, but not of differentiated Caco-2. In both cases necrosis was not increased. On proliferating cells, the 5×-extract from Cryptococcus laurentii or Debaryomyces hansenii reduced lysosome functionality and the 6.25×extract from Meyerozyma guilliermondii or Candida famata increased membrane permeability, while only the 25×-extract from M. guilliermondii or M. caribbica reduced slightly the metabolic activity. The extract of Bacillus subtilis showed no cytotoxic effect up to 10× concentration. Overall, their low cytotoxicity combined with high biodegradability make these products suitable for sustainable agriculture.

Anti-cancer effect of clofazimine as a single agent and in combination with cisplatin on U266 multiple myeloma cell line.

Multiple Myeloma (MM) is a malignant neoplasm of bone marrow plasma B cells with high morbidity. Clofazimine (CLF) is an FDA-approved leprostatic, anti-tuberculosis, and anti-inflammatory drug that was previously shown to have growth suppression effect on various cancer types such as hepatocellular, lung, cervix, esophageal, colon, and breast cancer as well as melanoma, neuroblastoma, and leukemia. The objective of this study was to evaluate the anticancer effect and mechanism of CLF on U266 MM cell line. CLF (10µM, 24h) treatment resulted up to 72% growth suppression on a panel of hematological cell lines. Dose-response study conducted on U266 MM cell line revealed an IC50 value of 9.8±0.7µM. CLF also showed a synergistic inhibition effect in combination with cisplatin. In mechanistic assays, CLF treatment caused mitochondrial membrane depolarization, change in cell membrane asymmetry and increase in caspase-3 activity; indicating to an intrinsic apoptosis mechanism. This study provides new evidence for the anticancer effect of CLF on U266 cell line. Further in vivo and clinical studies are warranted to evaluate its therapeutic potential for MM treatment.

Anti-proliferative and anti-inflammatory effects of 3ß,6ß,16ß-Trihydroxylup-20(29)-ene on cutaneous inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: 3ß,6ß,16ß-Trihydroxylup-20(29)-ene (TTHL) is a triterpene isolated from the flowers of Combretum leprosum, a plant used in folk medicine in the north of Brazil for the treatment of skin disorders. AIM OF THE STUDY: In the present study, TTHL was evaluated as a potential topical anti-inflammatory and anti-proliferative agent through in vivo and in vitro models. MATERIAL AND METHODS: Anti-inflammmatory and anti-proliferative effects of TTHL were assessed using Swiss mice in acute and chronic models of skin inflammation induced by 12-O-tetradecanoylphorbol-acetate (TPA) application. Anti-proliferative activity was proved through in vitro experiments with the HaCaT human keratinocyte cell line. RESULTS: Treatment with TTHL inhibited inflammatory parameters such as oedema formation and cellular infiltration in acute and chronic models. In the chronic model, TTHL also inhibited epidermal hyperproliferation, as evidenced by reduction of epidermis thickness and proliferating cell nuclear antigen expression. The anti-proliferative effect was confirmed by the capability of TTHL in reducing the proliferation and inducing cell apoptosis of HaCaT cells. Suggesting a mechanism of action, TTHL showed activation of corticosteroid receptors, but without the induction of corticosteroid-related cutaneous side effects. CONCLUSION: Our results demonstrate consistent anti-inflammatory and anti-proliferative activity and assign TTHL as a valuable tool in the development of a new treatment for skin inflammatory and proliferative diseases, such as psoriasis.

In Vitro Activity of Selected West African Medicinal Plants against Mycobacterium ulcerans Disease.

Buruli ulcer (BU) is the third most prevalent mycobacteriosis, after tuberculosis and leprosy. The currently recommended combination of rifampicin-streptomycin suffers from side effects and poor compliance, which leads to reliance on local herbal remedies. The objective of this study was to investigate the antimycobacterial properties and toxicity of selected medicinal plants. Sixty-five extracts from 27 plant species were screened against Mycobacterium ulcerans and Mycobacterium smegmatis, using the Resazurin Microtiter Assay (REMA). The cytotoxicity of promising extracts was assayed on normal Chang liver cells by an MTT assay. Twenty five extracts showed activity with minimal inhibitory concentration (MIC) values ranging from 16 µg/mL to 250 µg/mL against M. smegmatis, while 17 showed activity against M. ulcerans with MIC values ranging from 125 µg/mL to 250 µg/mL. In most of the cases, plant extracts with antimycobacterial activity showed no cytotoxicity on normal human liver cells. Exception were Carica papaya, Cleistopholis patens, and Polyalthia suaveolens with 50% cell cytotoxic concentrations (CC50) ranging from 3.8 to 223 µg/mL. These preliminary results support the use of some West African plants in the treatment of Buruli ulcer. Meanwhile, further studies are required to isolate and characterize the active ingredients in the extracts.

Enriched glucose and dextrin mannitol-based media modulates fibroblast behavior on bacterial cellulose membranes.

Bacterial cellulose (BC) produced by Gluconacetobacter hansenii is a suitable biopolymer for biomedical applications. In order to modulate the properties of BC and expand its use as substrate for tissue engineering mainly in the form of biomembranes, glucose or dextrin were added into a BC fermentation mannitol-based medium (BCGl and BCDe, respectively) under static culture conditions. SEM images showed effects on fiber density and porosity on both sides of the BC membranes. Both enriched media decreased the BET surface area, water holding capacity, and rehydration rate. Fourier transform infrared (attenuated total reflectance mode) spectroscopy (FTIR-ATR) analysis revealed no change in the chemical structure of BC. L929 fibroblast cells were seeded on all BC-based membranes and evaluated in aspects of cell adhesion, proliferation and morphology. BCG1 membranes showed the highest biological performance and hold promise for the use in tissue engineering applications.

Combretum leprosum Mart. (Combretaceae): potential as an antiproliferative and anti-inflammatory agent.

ETHNOPHARMACOLOGICAL RELEVANCE: Combretum leprosum is a species that is popularly used in Brazil as a healing agent to treat skin problems and lesions. In this study we investigated the possible potential of this extract to treat inflammatory and hyperproliferative skin conditions. MATERIALS AND METHODS: Classical models of skin inflammation such as TPA- and croton oil-induced mouse ear oedema were applied in order to verify the potential topical anti-inflammatory activity of the ethanolic extract from flowers of Combretum leprosum. RESULTS: Topical application of ethanolic extract promoted a dose-dependent inhibition of phorbol ester-induced ear oedema, reduced myeloperoxidase activity and IL-6 tissue levels with inhibition comparable to dexamethasone (positive control). Histological and immunohistochemical analysis revealed that ethanolic extract also suppressed cell infiltration. Ethanolic extract altered inflammatory parameters on a chronic skin inflammation model induced by repeated applications of croton oil, decreasing ear oedema, epidermal hyperproliferation and cell infiltration. In addition, immunohistochemical analysis showed that the extract decreased PCNA expression on the epidermis. CONCLUSION: Taken together, these results suggest that the extract from flowers of Combretum leprosum could be considered as a new potential tool for the treatment of several skin inflammatory diseases since it reversed the skin inflammatory and hyperproliferative process in a very significant manner. Further investigations are needed in order to verify the cellular mechanism and safety of Combretum leprosum extract.

Unresponsiveness of Mycobacterium w vaccine in managing acute and chronic Leishmania donovani infections in mouse and hamster.

The role of Mycobacterium w (Mw) vaccine as an immunomodulator and immunoprophylactant in the treatment of mycobacterial diseases (leprosy and pulmonary tuberculosis) is well established. The fact that it shares common antigens with leishmanial parasites prompted its assessment as an immunostimulant and as an adjunct to known anti-leishmanials that may help in stimulating the suppressed immune status of Leishmania donovani-infected individuals. The efficacy of Mw vaccine was assessed as an immunomodulator, prophylactically either alone or in combination with anti-leishmanial vaccine, as well as therapeutically as an adjunct to anti-leishmanial treatment in L. donovani-infected hamsters, representing a chronic human Visceral Leishmaniasis (VL) model. Similarly, its efficacy was also evaluated in L. donovani-infected BALB/c mice, representing an acute VL model. The preliminary studies revealed that Mw was ineffective as an immunostimulant and/or immunoprophylactant in hamsters infected with L. donovani, as estimated by T-cell immunological responses. However, in the BALB/c mice-VL model it appeared as an effective immunostimulant but a futile prophylactic agent. It is therefore inferred that, contrary to its role in managing tuberculosis and leprosy infections, Mw vaccine has not been successful in controlling VL infection, emphasizing the need to find detailed explanations for the failure of this vaccine against the disease.

Development of melanocye-keratinocyte co-culture model for controls and vitiligo to assess regulators of pigmentation and melanocytes.

BACKGROUND: There is a need to develop an in vitro skin models which can be used as alternative system for research and testing pharmacological products in place of laboratory animals. Therefore to study the biology and pathophysiology of pigmentation and vitiligo, reliable in vitro skin pigmentation models are required. AIM: In this study, we used primary cultured melanocytes and keratinocytes to prepare the skin co-culture model in control and vitiligo patients. METHODS: The skin grafts were taken from control and patients of vitiligo. In vitro co-culture was prepared after culturing primary melanocytes and keratinocytes. Co- cultures were treated with melanogenic stimulators and inhibitors and after that tyrosinase assay, MTT assay and melanin content assay were performed. RESULTS: Melanocytes and keratinocytes were successfully cultured from control and vitiligo patients and after that co-culture models were prepared. After treatment of co-culture model with melanogenic stimulator we found that tyrosinase activity, cell proliferation and melanin content increased whereas after treatment with melanogenic inhibitor, tyrosinase activity, cell proliferation and melanin content decreased. We also found some differences in the control co-culture model and vitiligo co-culture model. CONCLUSION: We successfully constructed in vitro co-culture pigmentation model for control and vitiligo patients using primary cultured melanocytes and keratinocytes. The use of primary melanocytes and keratinocytes is more appropriate over the use of transformed cells. The only limitation of these models is that these can be used for screening small numbers of compounds.

Seagrass as a potential source of natural antioxidant and anti-inflammatory agents.

CONTEXT: Halophila spp. is a strong medicine against malaria and skin diseases and is found to be very effective in early stages of leprosy. Seagrasses are nutraceutical in nature and therefore of importance as food supplements. OBJECTIVE: The antibacterial, antioxidant, and anti-inflammatory activities of Halophila ovalis R. Br. Hooke (Hydrocharitaceae) methanol extract were investigated and the chemical constituents of purified fractions were analyzed. MATERIALS AND METHODS: Plant materials were collected from Pondicherry coastal line, and antimicrobial screening of crude extract, and purified fractions was carried out by the disc diffusion method and the minimum inhibitory concentration (MICs) of the purified fractions and reference antibiotics were determined by microdilution method. Antioxidant and anti-inflammatory activities were investigated in vitro. Chemical constituents of purified fractions V and VI were analyzed by gas chromatography-mass spectrometry (GC-MS), and the phytochemicals were quantitatively determined. RESULTS: Methanol extract inhibited the growth of Bacillus cereus at a minimum inhibitory concentration of 50 µg/mL and other Gram-negative pathogens at 75 µg/ml, except Vibrio vulnificus. Reducing power and total antioxidant level increased with increasing extract concentration. H. ovalis exhibited strong scavenging activity on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals at IC(50) of 0.13 and 0.65 mg/mL, respectively. Methanol extract of H. ovalis showed noticeable anti-inflammatory activity at IC(50) of 78.72 µg/mL. The GC-MS analysis of H. ovalis revealed the presence of triacylglycerols as major components in purified fractions. Quantitative analysis of phytochemicals revealed that phenols are rich in seagrass H. ovalis. DISCUSSION AND CONCLUSION: These findings demonstrated that the methanol extract of H. ovalis exhibited appreciable antibacterial, noticeable antioxidant, and anti-inflammatory activities, and thus could be use as a potential source for natural health products.

In vitro and in vivo immunostimulatory activity of Woodfordia fruticosa flowers on non-specific immunity.

CONTEXT: Woodfordia fruticosa Kurz. (Lythraceae), a non-rasayana immunomodulatory Indian medicinal plant, used traditionally as an anthelmintic, in dysentery, leprosy, blood diseases, leucorrhea, and menorrhagia. OBJECTIVE: To investigate the effect of ethanol extract of W. fruticosa flowers on non-specific immune responses in mice. MATERIALS AND METHODS: In vitro immunomodulatory activity of the extract was examined on murine peritoneal macrophage phagocytosis (nitroblue tetrazolium (NBT) dye reduction, lysosomal enzyme activity, nitric oxide and myeloperoxidase) and on proliferation of bone marrow cells by sulforhodamine B (SRB) assay, while the in vivo potential on macrophages and bone marrow cells was evaluated by using carbon clearance test and cyclophosphamide-induced myelosuppression, respectively. RESULTS: Significant increase in the release of myeloperoxidase, nitric oxide lysosomal enzyme and superoxide from macrophages along with significant increase in phagocytic index in carbon clearance test indicate stimulatory activity of the extract on macrophages. The extract also demonstrated 60% increase in bone marrow cell proliferation and offer protection towards cyclophosphamide-induced myelosuppression which represents the stimulation of bone marrow activity. DISCUSSION: Significant increase in mediators released from macrophages and phagocytic index in carbon clearance test suggests the release of cytokines from macrophages and stimulation of reticulo-endothelial system. Proliferation of bone marrow cells indicates the plausible release of colony stimulating factors, which further stimulates the immune system through generation of immune cells. CONCLUSION: The result described here indicates the immunostimulatory activity of ethanol extract of W. fruticosa flowers by stimulating non-specific immune responses, macrophages and bone marrow cells.

Thalidomide inhibited the synthesis of IgM and IgG whereas Thalidomide+Dexamethasone and Dexamethasone alone acted as co-stimulants with pokeweed and enhanced their synthesis.

Thalidomide (Thal) provides effective treatment for erythema nodosum leprosum (ENL). In combination with Dexamethasome (Dex) it is an effective treatment for multiple myeloma (MM) and Waldenström's macroglobulinemia (WM). Thal's mechanism(s) of action in the treatment of these diverse medical conditions is not known, but it could be suppression of immunoglobulin (Ig) synthesis. Mononuclear cells were stimulated with pokeweed (PWM), and treated with Thal, Thal+Dex or Dex. The cultures were assayed for IgM and IgG. The maximum synthesis was expected to occur in cultures stimulated with PWM at 0.5, 5.0 or 10 microg/ml. The test agents at 15 microM each were expected to alter the response. Compared to cultures stimulated with PWM alone, there was significantly less Ig in the cultures containing Thal+PWM, and significantly more Ig in the cultures containing Thal+Dex+PWM or Dex+PWM (Wilcoxon). The median % of maximum was 57 for cultures treated with Thal+PWM; 184 for cultures treated with Thal+Dex+PWM, and 139 for cultures treated with Dex+PWM. Thal also acted as a co-stimulant with PWM and enhanced the synthesis of IL-2, IL-6 and DNA; whereas, Thal+Dex or Dex enhanced Ig synthesis, but suppressed IL-2, IL-6 and cell proliferation. Thal's ability to suppress Ig may explain its activity in ENL, MM and WM. The enhancement of Ig by Dex does not help to explain a role for Dex alone or in combination with Thal for the treatment of MM and WM.

Mycobacterial antigen(s) induce anergy by altering TCR- and TCR/CD28-induced signalling events: insights into T-cell unresponsiveness in leprosy.

Present study investigates the role of Mycobacterium leprae (M. leprae) antigens on TCR- and TCR/CD28-induced signalling leading to T-cell activation and further correlates these early biochemical events with T-cell anergy, as prevailed in advanced stages of leprosy. We observed that both whole cell lystae (WCL) and soluble fraction of M. leprae sonicate (MLSA) not only inhibited TCR, thapsigargin and ionomycin induced calcium fluxes by diminishing the opening of calcium channels, but also TCR- or TCR/CD28-induced proximal signalling events like phosphorylation of Zap-70 and protein kinase-C (PKC) activity. Study of TCR- and TCR/CD28-induced downstream signals revealed that M. leprae antigens curtail phosphorylation of both Erk1/2 and p38MAPK, consequently altering terminal signalling events like reduced binding of NFAT on IL-2 promoter and transcription of IL-2 gene, diminished expression of activation markers (CD25 and CD69). Furthermore, M. leprae fractions significantly inhibited IL-2 secretion and T-cell blastogenesis in healthy individuals. Altogether, results suggest that M. leprae interferes with TCR/CD28-induced upstream as well as downstream signalling events resulting in reduced IL-2 production and thus inhibition in T-cell proliferation, which might be responsible for T-cell unresponsiveness leading to stage of immunosuppression and consequently, for the progression of disease.

Leaves of Cassia tora as a novel cancer therapeutic--an in vitro study.

Cassia tora Linn (Leguminacea) is a medicinal plant traditionally used as laxative, for the treatment of leprosy and various skin disorders. Preliminary phytochemical analysis of leaf showed the presence of polyphenols (3.7 mg gallic acid equivalent per gram dried leaves). The presence of phenolic compound prompted us to evaluate its antioxidant and antiproliferative potential. In the present study C. tora methanolic leaf extract (CTME) was evaluated for its nitric oxide scavenging activity and reducing power assays using Rutin and BHT as standards. The extract was studied for its lipid peroxidation inhibition assay using rat liver and brain. In all assays, a correlation existed between concentration of extract and percentage inhibition of free radical, reducing power and inhibition of lipid peroxidation. The antiproliferative activity of CTME with Cisplatin, anticancer drug was studied using human cervical cancer cells (HeLa). Proliferation of HeLa was measured by MTT assay, cell DNA content by modified diphenylamine method and apoptosis by Caspase 3 activity. The plant extract induced a marked concentration dependent inhibition on proliferation, reduced DNA content and apoptosis in HeLa. These results clearly indicate that C. tora is effective against free radical mediated diseases.