Research on natural products has been widely used as a strategy to discover new drugs with potential for applications in complementary medicines because they have fewer side effects than conventional drugs. The aim of the present study was to evaluate the in vitro cytotoxic effects of crude aqueous Catharanthus roseus extract on Jurkat cells and normal peripheral blood mononuclear cells (PBMCs). The aqueous extract was
standardised to vinblastine by high performance liquid chromatography (HPLC) and was used to determine cytotoxicity by the MTS [3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. DNA fragmentation assay was employed to determine if cell death was due to apoptosis. The results showed that the aqueous extract induced cell death of Jurkat cells at 24, 48 and 72 hours posttreatment in a time- and dose-dependent manner. However, cells treated at 48 and 72 hours produced higher cytotoxic effects with half maximal inhibitory concentration (IC50)values of 2.55 µg/ml and 2.38 µg/ml, respectively. In contrast, the extract induced normal PBMC proliferation, especially after 24 hours treatment with 1000 µg/ml. This result indicates that the C. roseus crude aqueous extract showed differential effects of inhibiting the proliferation of the Jurkat cell line and promoting the growth of PBMCs. These data suggest that the extract may be applicable for modulating the normal and transformed immune cells in leukaemia patients.
The biosynthesis of nanoparticles has been proposed as a cost-effective and environmental friendly alternative to chemical and physical methods. The present study was aimed to characterise Catharanthus roseus (C. roseus)-silver nanoparticles (AgNPs) using a standardised C. roseus aqueous extract. Methods: The standardisation was performed by using Liquid Chromatography/Time-of-Flight ion trap Mass Spectrometry. An optimised C. roseus-AgNPs have been previously synthesised. Further characterisation of C. roseus-AgNPs was evaluated by zeta potential analysis and fourier transform infrared spectroscopy (FTIR). Results: The chromatography analysis has revealed presence of thirteen possible indole alkaloids in C. roseus extract which were lochrovicine, lochnerine, vinleurosine, vindolinine, tabersonine, catharanthine, serpentine, catharosine, vincristine, catharine, ajmalicine, vinleurosine, and vindolicine. Zeta potential analysis exhibited the value at -16.6 mV. FTIR spectrum of C. roseus aqueous extract showed the absorption band at 3210.83 cm-1 (C-H stretch), 2934.11 (C-H bond), 1578.15 (N=O stretch), 1388.76 and 1314.89 (N=O bend), 1119.29 (C-O bond) and 729.94 (C-Cl bond). In comparison, FTIR spectrum of C. roseus-AgNP s showed the absorption band at 2925.01 and 2924.97 (C-H bond), 1622.93 (C-C=C symmetric stretch), 1383.19 and 1384.13 (N-O bend), 1037.92/1038.76/1238.3/1117.2 (C-O bond), 3169.4 (O-H bond), 774.59 and 691.53 (C-Cl bond). Conclusion: The present findings have shown that the C. roseus aqueous extract contains alkaloids that may responsible as reducing and stabilising agents in the synthesis of AgNPs.
Introduction: The alkaloids present in Catharanthus roseus (C. roseus), vinblastine and vincristine are important an- ticancer agents that cause cell cycle arrest and apoptosis in various types of cell lines. However, there is no previous reports that emphasized the clear mechanisms of anticancer exerted by a crude aquoeus extract of C. roseus although it has been historically used to treat various diseases. Methods: The cytotoxicity effects of C. roseus aqueous extract on Jurkat cells were evaluated by annexin/PI staining, caspase 3/7 assay, JC-1 assay and cell cycle assay. Gene ex- pression profiling was performed by using SmartChip Real-Time PCR system to evaluate the expression profiles of on- cology-related genes of Jurkat cells treated with C. roseus aqueous extract. Results: Flow cytometry analysis revealed that the extract has caused S-phase arrest and associated with apoptosis through the externalization of phosphati- dylserine and depletion of mitochondrial membrane potential in time-dependent manner. The apoptosis mechanism was mediated through the activation of caspase 3/7. From the gene expression analysis, 8 differentially regulated genes were associated with apoptosis which were CDKN1C, CHI3L2, BIRC8, GFER, ID3-1, BBC3-2, TRAF4 and VCAN. Meanwhile, 7 differentially regulated genes were associated with cell cycle progression which were PIMI-1, CDKN1C, SKP1A, CDC25C, LTBP1, CCNG2 and RBL1. Conclusion: The recent data may facilitate the identification of specific targeting pathways induced by the extract. The information obtained may be used as diagnostic tools, prognostic markers, and predictors of response to C. roseus treatment especially for this particular type of cancer.
CD4+CD25+ Foxp3+ T regulatory cell (Tregs) represents approximately 8-10% of the total CD4+ T cell population and are important for immune homeostasis and preventing autoimmune development. Thus, harnessing their functions as immune modulator may be coupled with the rapid advancement of nanotechnology development. Plant-mediated biosynthesis of silver nanoparticle (AgNP) is noteworthy due to simplicity, rapid rate and potentially render more biocompatibility with biomolecules. This study identified the effect of biosynthesized-AgNPs from Garcinia atroviridis (GA) in modulating inflammatory properties of Treg cells in Non-Obese Resistant (NOR). GA extract was used to biosynthesized AgNPs and was tested on the effect of inducing inflammatory properties in CD4+IL17Rhigh cells following 72hr in vitro treatment. Methods: Conventional CD4+CD25-Foxp3- cells from female NOR mice were sorted using magnetic separation and cultured in RPMI in the presence of anti-CD3/CD28 antibodies, TGF-β and IL-2 cytokines. Cells were then treated with or without GA-AgNPs for 48hr of iTreg cell induction and then re-cultured with new media treated with respective treatments received. After 72hr in vitro culture, cells were stained with fluorochrome-conjugated antibodies for flow cytometry. Results: Current result showed that AgNPs suppress CD4 expression in CD4+IL17Rhigh population. MAPK pathway proteins remain unchanged in both control and AgNP-treated groups. Conclusions: The preliminary findings may suggest the properties of GA-AgNPs in modulating CD4+ T cell population in normal condition. Further studies are necessary to elucidate the molecular mechanisms involve in such interaction. Current findings serve as basis in further identifying the immunomodulatory profile of nanoparticle for potential therapeutic use.