Antibacterial mechanism with consequent cytotoxicity of different reinforcements in biodegradable magnesium and zinc alloys: A review

Benefits achieved by the biodegradable magnesium(Mg) and zinc(Zn) implants could be suppressed due to the invasion of infectious microbial, common bacteria, and fungi. Postoperative medications and the antibacterial properties of pure Mg and Zn are insufficient against biofilm and antibiotic-resistant bacteria, bringing osteomyelitis, necrosis, and even death. This study evaluates the antibacterial performance of biodegradable Mg and Zn alloys of different reinforcements, including silver(Ag), copper(Cu), lithium(Li), and gallium(Ga). Copper ions(Cu^(2+)) can eradicate biofilms and antibiotic-resistant bacteria by extracting electrons from the cellular structure. Silver ion(Ag^(+)) kills bacteria by creating bonds with the thiol group. Gallium ion(Ga^(3+)) inhibits ferric ion(Fe^(3+)) absorption, leading to nutrient deficiency and bacterial death. Nanoparticles and reactive oxygen species(ROS) can penetrate bacteria cell walls directly, develop bonds with receptors, and damage nucleotides. Antibacterial action depends on the alkali nature of metal ions and their degradation rate, which often causes cytotoxicity in living cells. Therefore, this review emphasizes the insight into degradation rate, antibacterial mechanism, and their consequent cytotoxicity and observes the correlation between antibacterial performance and oxidation number of metal ions.

Echinoside A from Pearsonothuria graeffei Exert the Cytotoxicity to MDA-MB-231 Cells via Mitochondrial Membrane and Modulation of PI3K/Akt/mTOR Pathway

A kind of triterpene glycosides echinoside A(EA)was extracted from sea cucumber Pearsonothuria graeffei,and its yield was about 0.78%.The purity of EA was 99.0%,and its molecular weight was 1206 Da.EA was a linear tetrasaccharide attached to a pentacyclic triterpene aglycon.It inhibited the growth of MDA-MB-231 cells in vitro.The antitumor effect was related to elevate ROS level,decrease mitochondrial membrane potential,enhance caspase-3 expression,induce cells apoptosis and arrest cell cycle at G2/M phase.EA also dose-dependently suppressed the expressions of phophorylation proteins p-PI3K,p-Akt,and p-mTOR as analyzed by western blotting.These results suggested that EA caused MDA-MB-231 cells apoptosis via intrinsic mitochondrial and PI3K/Akt/mTOR pathway.EA can be a potential anti-breast cancer agent to enhance the clinical efficacy.

Cytotoxic synergism of Clostridioides difficile toxin B with proinflammatory cytokines in subjects with inflammatory bowel diseases

Clostridioides difficile(C.difficile)is progressively colonizing humans and animals living with humans.During this process,hypervirulent strains and mutated toxin A and B of C.difficile(TcdA and TcdB)are originating and developing.While in healthy subjects colonization by C.difficile becomes a risk after the use of antibiotics that alter the microbiome,other categories of people are more susceptible to infection and at risk of relapse,such as those with inflammatory bowel disease(IBD).Recent in vitro studies suggest that this increased susceptibility could be due to the strong cytotoxic synergism between TcdB and proinflammatory cytokines the tumor necrosis factor-alpha and interferon-gamma(CKs).Therefore,in subjects with IBD the presence of an inflammatory state in the colon could be the driver that increases the susceptibility to C.difficile infection and its progression and relapses.TcdB is internalized in the cell via three receptors:chondroitin sulphate proteoglycan 4;poliovirus receptor-like 3;and Wnt receptor frizzled family.Chondroitin sulphate proteoglycan 4 and Wnt receptor frizzled family are involved in cell death by apoptosis or necrosis depending on the concentration of TcdB and cell types,while poliovirus receptor-like 3 induces only necrosis.It is possible that cytokines could also induce a greater expression of receptors for TcdB that are more involved in necrosis than in apoptosis.Therefore,in subjects with IBD there are the conditions:(1)For greater susceptibility to C.difficile infection,such as the inflammatory state,and abnormalities of the microbiome and of the immune system;(2)for the enhancement of the cytotoxic activity of TcdB+Cks;and(3)for a greater expression of TcdB receptors stimulated by cytokines that induce cell death by necrosis rather than apoptosis.The only therapeutic approach currently possible in IBD patients is monitoring of C.difficile colonization for interventions aimed at reducing tumor necrosis factor-alpha and interferon-gamma levels when the infection begins.The future perspective is to generate bacteriophages against C.difficile for targeted therapy.

Cytotoxic and antibacterial substances against multi-drug resistant pathogens from marine sponge symbiont:Citrinin,a secondary metabolite of Penicillium sp.

Objective:To Isolate,purify,characterize,and evaluate the bioaclive compounds from the sponge-derived fungus Penicillium sp.FF001 and to elucidate its structure.Methods:The fungal strain FF001 with an interesting bioactivity profile was isolated from a marine Fijian sponge Melophlus sp.Based on conidiophores aggregation,conidia development and mycelia morphological characteristics,the isolate FF001 was classically identified as a Penicillium sp.The bioactive compound was identified using various spectral analysis of UV,high resolution electrospray ionization mass spectra,1H and 13C NMR spectral data.Further minimum inhibitory concentrations(MICs)assay and brine shrimp cytotoxicity assay were also carried out to evaluate the biological properties of the purified compound.Results:Bioassay guided fractionation of the EtOAc extract of a static culture of this Penicillium sp.by different chromatographic methods led the isolation of an antibacterial,anticryptococcal and cytotoxic active compound,which was identified as citrinin(1).Further,citrinin(1)is reported for its potent antibacterial activity against methicillin-resistant Staphylococcus aureus(S.aureus),rifampicin-resistant 5.aureus,wild type S.aureus and vancomycin-resistant Enterococcus faecium showed MICs of 3.90,0.97,1.95 and7.81μg/mL,respectively.Further citrinin(1)displayed significant activity against the pathogenic yeast Cryptococcus neoformans(MIC 3.90μg/mL),and exhibited cytotoxicity against brine shrimp larvae LD_(50)of 96μg/mL.Conclusions:Citrinin(1)is reported from sponge associated Penicillium sp.from this study and for its strong antibacterial activity against multi-drug resistant human pathogens including cytotoxicity against brine shrimp larvae,which indicated that sponge associated Penicillium spp.are promising sources of natural bioactive metabolites.

Cytotoxic effect of Spirulina platensis extracts on human acute leukemia Kasumi-1 and chronic myelogenous leukemia K-562 cell lines

Objective: To evaluate the cytotoxic effects of Spirulina platensis extracts on acute leukemia Kasumi-1 and chronic leukemia K-562 cancer cell lines.Methods: Various concentrations of Spirulina platensis extracts(0.25–50.00 mg/m L)obtained with different solvents were used to treat cell lines for 72 h. For cytotoxic effect studies, cell viability test with trypan blue solution, MTT assay and microscopic cytomorphological assessment were done.Results: Spirulina extract obtained with 70% ethanol showed significant cytotoxicity in K562 and Kasumi-1 cell lines. With trypan blue solution, IC_(50) values were found to be4.64 mg/m L for K-562 and 3.68 mg/m L for Kusumi-1 cell lines. Spirulina aqueous extract also showed cytotoxicity with trypan blue method, at a slightly higher dose; where IC_(50) values were 12.68 mg/m L for K-562 and 2.13 mg/m L for Kusumi-1 cell lines. The IC_(50) values were found 0.40 mg/m L for K-562 and 0.31 mg/m L for Kusumi-1 cell lines for the 70% ethanol extract according to the MTT assay. Spirulina extract obtained with water also showed cytotoxicity but the dose was a little higher where IC_(50) values were15.77 mg/m L for K-562 and 9.44 mg/m L for Kusumi-1 cell lines. The effect of cytotoxicity with ethanol extract is quite comparable with that observed for cyclophosphamide, which is a chemical used as anticancer agent.Conclusions: The cytotoxicity exhibited by Spirulina extract to cancer cell lines might be due to the presence of phytopigments(carotenoids, chlorophyll, phycocyanin) as well as polysaccharides that were reported previously as constituents of the extract. So crude extracts of Spirulina can be used as a source to develop anticancer drugs.

Characterization of cytotoxic compound from mangrove derived fungi Irpex hydnoides VB4

Objective:To investigate the cytotoxic activity of endophytic fungi isolated from mangrove fungi.Methods:In the present study the DNA was isolated and the ITS region of 5.8s rRNA was amplified using specific primers ITS 1 and ITS4 and sequence was determined using automated sequencers.Blast search sequence similarity was found against the existing non redundant nucleotide sequence database thus,identified as Aspergilus flavus,Hyporcaea lixii,Aspergillus niger,Eutorium amstelodami,Irpex hydnoides and Neurospora crassa.Among the seven isolates, one fungi Irpex hydnoides was selected for further studies.The fungi were grown in sabouraud broth for five days and filtrate were separated and subjected to ethyl acetate for further studies. Results:Nearly half(49.25%) of the extracts showed activity(IC_(50) of 125 μ g/mL).These values were within the cutoff point of the National Cancer Institute criteria for cytotoxicity(IC_(50)<20 μ g/mL) in the screening of crude plant extracts.The GC MS analysis revealed that the active principals might be Tetradecane(6.26%) with the RT 8.606.Conclusions:It is clear from the present study that mangrove fungi with bioactive metabolites can be expected to provide high quality biological material for high throughout biochemical,anti cancer screening programmes.The results help us conclude that me potential of using metabolic engineering and post genomic approaches to isolate more novel bioactive compounds and to make their possible commercial application is not far off.

Identification of the epitopes on HCV core protein recognized by HLA-A2 restricted cytotoxic T lymphocytes

AIM To identify hepatitis C virus (HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL).METHODS Utilizing the method of computer prediction followed by a 4 h 51 Cr-release assay confirmation.RESULTS The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide 'ALAHGVFAL (core TS0-158)'.The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%,respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis.But blocking of CTL response with anti-CD8 mAb could abolish the Iysis.CONCLUSION The peptide (core 150 - 158 ) is the candidate epitope recognized by HLA-A2 restricted CTL.

Antimicrobial activity,cytotoxicity,and phytochemical screening of Voacanga globosa(Blanco) Merr.leaf extract(Apocynaceae)

Objective:To determine the antibacterial,antifungal,antiprotozoal,cytotoxic,and phytochemical properties of ethanol extracts of leaves of Voacanga globosa(Blanco) Merr.(V.globosa). Methods:The extracts were tested against bacteria and fungus through disc diffusion assay; against protozoa through growth curve determination,antiprotozoal and cytotoxicity assays. Results:The extract revealed antibacterial activities,inhibiting the growth of Staphylococcus aureus,Bacillus cereus,Pseudomonas aeruginosa,Micrococcus luteus,and Salmonella typhimurium.Antifungal assay showed that it inhibited Candida albicans.The antiprotozoal assay against Trichomonas vaginalis and Entamoeba histolytica showed that V.globosa can inhibit the parasites,wherein the action can be comparable to metronidazole.With the in situ cell death detection kit.Trichomonas vaginalis and Entamoeba histolytica exposed to V.globosa leaf extract was observed to fluoresce simultaneously in red and yellow signals signifying apoptotic-like changes.Preliminary phytochemical screening revealed the chemical composition of plant extract containing alkaloids,saponins,2-deoxysugars,and hydrolysabie tannins.Conclusions: Thus,thus study provides scientific evidence on the traditional use of V.globosa leaf extract in treating microbial diseases.Further,the leaf extract can possibly be used to produce alternative forms of antimicrobials.

Microwave-induced Apoptosis and Cytotoxicity of NK Cells through ERK1/2 Signaling

Objective To investigate microwave-induced morphological and functional injury of natural killer(NK) cells and uncover their mechanisms. Methods NK-92 cells were exposed to 10, 30, and 50 m W/cm^2 microwaves for 5 min. Ultrastructural changes, cellular apoptosis and cell cycle regulation were detected at 1 h and 24 h after exposure. Cytotoxic activity was assayed at 1 h after exposure, while perforin and NKG2 D expression were detected at 1 h, 6 h, and 12 h after exposure. To clarify the mechanisms, phosphorylated ERK(p-ERK) was detected at 1 h after exposure. Moreover, microwave-induced cellular apoptosis and cell cycle regulation were analyzed after blockade of ERK signaling by using U0126. Results Microwave-induced morphological and ultrastructural injury, dose-dependent apoptosis(P < 0.001) and cell cycle arrest(P < 0.001) were detected at 1 h after microwave exposure. Moreover, significant apoptosis was still detected at 24 h after 50 m W/cm^2 microwave exposure(P < 0.01). In the 30 m W/cm^2 microwave exposure model, microwaves impaired the cytotoxic activity of NK-92 cells at 1 h and down regulated perforin protein both at 1 h and 6 h after exposure(P < 0.05). Furthermore, p-ERK was down regulated at 1 h after exposure(P < 0.05), while ERK blockade significantly promoted microwave-induced apoptosis(P < 0.05) and downregulation of perforin(P < 0.01). Conclusion Microwave dose-dependently induced morphological and functional injury in NK-92 cells, possibly through ERK-mediated regulation of apoptosis and perforin expression.

Cytotoxicity evaluation and hepatoprotective potential of bioassay guided fractions from Feronia limmonia Linn leaf

Objective:To evaluate the cytotoxicity and hepatoprotective potentials of extracts,fractions or isolated compound from the leaves of Feronia limonia(F.limonia).Methods:Qualitative phytochemical analysis of extracts,fractions or compound was performed by means of thin layer chromatography and spectroscopic assays.The%purity of compound was measured by analytical HPLC.Extracts,fractions or compound have been individually evaluated for their cytotoxicity effects(10,20,100,250,500,750 and 1 000 μg/mL).Based on the inhibitory concentration(IC_(50)) obtained from the cell viability assay,graded concentrations of extracts,fractions or isolated compound were assessed(10,20,50,100,200 μg/mL) for its hepatoprotective potential against CCl_4-induced hepatotoxicity by monitoring activity levels of serum glutamatic pyruvatic transaminase(SGPT) and serum glutamic oxaloacetic transaminase(SGOT).Results:Results indicated that the methanol extract of F.limonia was non-toxic and hepatoprotective in nature as compared with the petroleum ether extract.The acetone fraction of methanolic extract also showed similar properties but the subsequent two fractions were cytotoxic.However,the pure compound isolated from the penultimate fraction of methanolic extract was non-toxic and hepatoprotective in nature.Biochemical investigations(SCOT,SCPT) further corroborated these cytological observations.Conclusions:It can be concluded from this study that F.limonia methanol extract,some fractions and pure isolated compound herein exhibit hepatoprotective activity.However,cytotoxicity recorded in the penultimate fraction and investigation of structural details of pure compound warrants further study.

Cytotoxic effect of methanolic extracts of Fritillaria imperialis bulbs and Eryngium caucasicum leaves on hepatoma and colon cancer cells

Objective: To evaluate antitumor activities of Fritillaria imperialis and Eryngium caucasicum methanolic extracts on human hepatoma (HepG2) and colon cancer (HCT116) cell lines in comparison to human foreskin fibroblasts as the normal cells. Methods: Methanolic extracts of Fritillaria imperialis and Eryngium caucasicum were prepared by the maceration method. The effect of the extracts at various concentrations (100, 200, 400, 600, and 800 μg/mL) on cell survival was evaluated using the MTT method. Besides, fluorescence staining was used to evaluate death patterns of the cells. Results: MTT assay showed that Fritillaria imperialis significantly decreased the viability of all cell lines after 24 and 48 hours of treatments. However, Eryngium caucasicum extract did not show any significant cytotoxicity effect on the cell lines. Fluorescence staining revealed that Fritillaria imperialis induced apoptosis of HCT116 cells at 550 μg/mL. Conclusions: Fritillaria imperialis extract has antiproliferative and cytotoxic effects on HCT116 and HepG2 cancer cells and therefore, may serve as an anticancer agent.

In vitro antioxidant,cytotoxic,thrombolytic activities and phytochemical evaluation of methanol extract of the A.philippense L.leaves

Objective:To study the leaves of Adiantum philippense L.for their antioxidant,cytotoxicity and thrombolytic activities and to perform phytochemical evaluation.Methods:In-vitro antioxidant activity of extract was studied using DPPH radical scavenging,reducing power,total phenol and total flavonoid content determination assays.The cytotoxic activity was determined using brine shrimp lethality bioassay,thrombolytic activity by clot disruption and phytochemical potential by qualitative analysis.Results:The antioxidant activity of the extracts was found promising.The reducing power of this crude extract increase with the increase of concentration;IC_(50)values of DPPH scavenging activity was(140.00±0.86)μg/mL as compared to ascorbic acid[IC_(50)(130.00±0.76)μg/mL];Total phenol and total flavonoids content were(148.26±0.24)mg/mL and(163.06±0.56)mg/mL respecnvely.In cytotoxicity assay the LC_(50)values of the sample was(106.41±0.78)μg/mL where as for standard vincristin sulphate was(08.50±0.24)μg/mL as a positive control and the extract shows(12.8611.02)%clot lytic whereas standard streptokinase shows(30.86+0.44%clot lytic activity in thrombolytic assay.The phytochemical evaluation indicates the presence of chemical constituents including carbohydrates,alkaloids,saponins,glycosides,flavonoids.Conclusions:This study shows that the methanol extract of leaves of Adiantum philippense L.has bioactivitv but further compound isolation is necessary to confirm the activities of individual compounds.

Antioxidant and cytotoxic activity of Acanthus ilicifolius flower

Objective:To investigate the antioxidant and cytotoxic activity of the flower of Acanthus ilicifolius(A.ilicifolius).Methods:Antioxidant activity was determined as antiradical efficiency with diphenyl picrylhydrazil(DPPH)method and cytotoxic assay was undertaken using brine shrimp lethal toxicity test.Results:A.ilicifolius flower contained terpenoid,phenolic compounds,and alkaloid.The methanol extract of A.ilicifolius flower showed the highest antiradical efficiency(AE=1.41×10^(-3))against DPPH radicals and the highest cytotoxicity(LC_(50)=22μg/mL)against brine shrimp nauplii.Conclusions:It is suggested that active compounds of A.ilicifolius flower solved in methanol play a role to inhibit free radical activity and kill Artemia salina nauplii.The substances can be considered as potential antioxidant and cytotoxic agents as well as imminent candidate for cancer therapy.

Characterization of cytotoxic compound from marine sediment derived actinomycete Streptomyces avidinii strain SU4

Objective:To investigate the cytotoxic activity of actinomycete isolated from marine sediment.Methods:In the present study the DNA was isolated and the ITS region of 16s rRNA was amplified by polymerase chain reaction,using two universal bacterial primers,1492K(5'-GGTTACCTTG'TTAC GACTT-3')and Eubac27F(5'-AGAGTTTGATCCTGGCTC AG-3').The amplified products were purified using TIANgel mini purification kit,ligated to MD18-T simple vector(TaKaRa),and transformed into competent cells of Escherichia coli DH5α.16S rRNA gene fragment was sequenced using forward primer M13F(-47)and reverse primer M13R(-48).Blast search sequence similarity was found against the existing non-redundanl nucleotide sequence database thus,identified as Streptomyces sp SU,Streptomyces rubralavandulae strain SU1,Streptomyces cacaoi strain SU2,Streptomyces cavourensis strain SU3,Streptomyces avidinii strain SU4,Streptomyces globisporus strain SU5,Streptomyces variabilis strain SU6,Streptomyces coelicolor strain SU 7.Among the eight identified isolates,one actinomycete Streptomyces avidinii strain SU4 was selected for further study.Results:Crude extract of the actinomycete isolate exhibited IC_(50)in 64.5μg against Hep-2 cell line,250μg in VERO cell line.This value is very close to the criteria of cytotoxicity activity for the crude extracts,as established by the American National Cancer Institute(NCI)is in IC_(50)<30μg/mL.The CC MS analysis showed that the active principle might be 1,2-benzenedicarboxylic acid,bis(2-methylpropyl)ester(12.17%),isooctyl phthalate(15.29%)with the retention time 15.642 and 21.612,respectively.Conclusions:This study clearly proves that the marine sediment derived actinomycetes with bioactive metabolites can be expected to provide high quality biological material for high throughout biochemical and anticancer screening programs.These results help us to conclude that the potential of using metabolic engineering and post genomic approaches to isolate more bioactive compounds and make their possible commercial application is not far off.

Isolation and characterization of marine-derived actinomycetes with cytotoxic activity from the Red Sea coast

Objective: To isolate and evaluate the cytotoxic activity of different actinomycetes species isolated from the Red Sea coast in Sharm el-Sheikh, Egypt.Methods: Forty actinomycetes strains were isolated from different sediments and seawater samples collected from the Red Sea coast in Egypt. Actinomycetes were recognized by morphological and microscopic examinations. Cell viability and cytotoxicity induced by the crude extracts on breast cancer cell lines MDA-MB-231 were assessed using methylene blue assay. The strains with promising cytotoxic activity were identified by sequencing and amplifying the 16 S r RNA genes. The antibacterial activities of the crude extracts were performed using Kirby–Bauer disc diffusion method.Results: The results indicated that five ethyl acetate extracts exhibited cytotoxicity towards breast cancer cell lines MDA-MB-231. The highest cytotoxic activity was found for the ethyl acetate extracts of EGY2 and EGY39. The isolate EGY3 was identified as a new Streptomyces species, while the actinomycete EGY22 was found to be a member of the genus Nocardiopsis sp. The crude extract of the isolate EGY8 showed slightly high antimicrobial activity against different test microorganisms.Conclusions: The results of the present study reveal that marine sediments of the Red Sea are a potent source of novel species of actinomycetes. The isolates may be useful in discovery of novel bioactive compounds and an important step in the development of microbial natural product research.

Cytotoxicity screening of Melastoma malabathricum extracts on human breast cancer cell lines in vitro

Objective:To screen the cytotoxic activity of Melasloma malabathricum(M,malubathricum)against human breast carreer cell line(MCF-7)in vitro.Methods:A three steps extraction protocol using n-hexane,chloroform and methanol as the solvents systems was carried out on leaves,stems and flowers of M.nalabathricum.Dimethyl sulfoxide was used in extracts dilution and serial dilutions were conducted to obtain five different extract concentrations(100μg/mL,50μg/mL,25μg/mL,123μg/rnL and 6.25μg/mL).The evaluation of cell growth was determined using methylene blue assay.Results:Methanol extract from the leaves showed significant anticancer activity against MCF-7cell lines with the TC_(50)value of 7.14μg/ml while methanol and chloroform extract from the flowers exhibited a moderate activity towards MCF-7 cell line,with the IC_(50)value of 33.63μg/mL and 45.76μg/mL respectively after 72 h of treatment.Conclusions:The extracts from leaves and flowers of M.nulabatkricum showed promising anticancer activity toward human breast cancer cell lines with the lowest IC_(50)at 7.14μg/mL while the extracts from stems showed less growth inhibition activity.

Evaluation of cytotoxic and anti-tumor activity of partially purified serine protease isolate from the Indian earthworm Pheretima posthuma

Objective:To isolate,partially purify and evaluate the cytotoxic and antitumor activity of a serine protease from the chosen Indian earthworm Pheretima posthuma.Methods:Whole animal extract was prepared and purified its protein constituents by size and charge based chromatographic separation techniques using Sephadex G-50 and DEAE-Cellulose resin respectively.Average molecular weight of the protein isolate was determined and analyzed for its cytotoxic property against Vero cells in different dilutions(1:20 and 1:40)and anti-tumor activity by MTT assay(a colorimetric assay)using breast cancer cell line MCF-7,with tamoxifen as standard.Results:One of the protein constituents after purification was characterized as serine protease by Caseinolytic plate diffusion assay.Average molecular weight of this purified isolate was determined,by SDS-PAGE analysis with standard protein ladder,as of 15 kDa.The performed tests suggested that the 15kDa fraction has potent cytotoxic activity and satisfactory antitumor activity as well in vitro.Conclusions:Exact molecular mechanism of the cytotoxic and antitumor activities is yet to be explored and currently we are working on ultra-purification and biophysical characterization of this fraction.Further investigation into the mechanism(s)of cytotoxic and antitumor activities at molecular level would be useful in treatment of various classes of cancer and viral infections in future.

Effect of IFNα-2a on Fas expression and apoptosis rate of peripheral blood cytotoxic T cells in patients with hepatitis B

Interferon(IFN) with antiviral and im-munomodulatory activities is one of the most important therapeutic agents for the treatment of chronic hepatitis. The apoptotic effect of IFN is influenced by cell type and the types of IFN, which suppresses proliferation and induces apoptosis in some cell types while inhibiting apoptosis in others. The aim of this study was to explore the effect of IFNα-2a on Fas expression and the apoptosis rate of peripheral blood cytotoxic T cells (CTLs) in patients with hepatitis B. METHODS:Peripheral blood mononuclear cells were isolated from 26 patients with hepatitis B including 16 patients with chronic hepatitis B and 10 patients with chronic severe hepatitis B. Fas expression and apoptosis rate of CTLs were analyzed with flow cytometry before and after IFNα-2a treatment. RESULTS:Before IFNα-2a treatment, Fas expression and apoptosis rate of CTLs from patients with chronic hepatitis B were significantly higher than those from patients with chronic severe hepatitis B and healthy controls respectively. No significant difference was observed between Fas expression and apoptosis rate of CTLs from patients with chronic severe hepatitis B and healthy controls. After IFNα-2a treatment,Fas expression and apoptosis rate of CTLs from different groups were compared with those before IFNα-2a treatment, showing no significant difference despite alternation of different degree. CONCLUSIONS:Activation induced cell death (AICD) exists in peripheral blood CTLs from patients with hepatitis B. No effect of IFNα-2a exerts on Fas expression and apoptosis rate of Fas in patients with hepatitis B.

Cytotoxicity and genotoxicity assessment of Euphorbia hirta in MCF-7cell line model using comet assay

Objective:To evaluate the cytotoxicity and genotoxicity activity of Euphorbia hirta(E.hirta)in MCF-7 cell line model using comet assay.Methods:The cytotoxicity of E.hirta extract was investigated by employing brine shrimp lethality assay and the genotoxicity of E.hirta was assessed by using Comet assay.Results:Both toxicity tests exhibited significant toxicity result.In the comet assay,the E.hirta extract exhibited genotoxicity effects against MCF-7 DNA in a time-dependent manner by increasing mean percentage of DNA damage.The extract of E.hirta showed significant toxicity against brine shrimp with an LC_(50)value of 620.382μg/mL(24 h).Comparison with positive control potassium dichroniate signifies that cytotoxicity exhibited by the methanol extract might have moderate activity.Conclusion:The present work confirmed the cytotoxicity and genotoxicity of E.hirta.However,the observed toxicity of E.hta extracts needs to be confirmed in additional studies.

Phytochemical screening and evaluation of cytotoxic and hypoglycemic properties of Mangifera indica peels

Objective: To investigate the presence of different phytoconstituents in Mangifera indica(M. indica) peel and evaluate its cytotoxicity to Artemia salina and hypoglycemic potential in Swiss albino mice.Methods: The methanolic extract of M. indica peel was used to determine the presence of phytoconstituents. Brine shrimp lethality bioassay method was followed to determine the cytotoxic potential of plant extract. In the case of hypoglycemic activity, oral administration of extract at 200 and 400 mg/kg and standard glibenclamide at 10 mg/kg was done, followed by determining the percentage of reduction of plasma glucose from the initial level.Results: The methanolic extract of M. indica peel showed the presence of flavonoid,saponin, steroid, tannins, terpenoids, glycosides and alkaloids. In brine shrimp lethality bioassay, the LC_(50) of the extract and standard vincristine sulfate was found to be 2.04 and0.41 mg/mL, respectively. After 90 and 150 min, the methanolic extract at 200 and 400 mg/kg showed prominent plasma glucose reduction of 13.95%, 22.48% and 14.16%,26.18% respectively compared to standard glibenclamide showing 14.90% and 20.67% plasma glucose reduction.Conclusions: This current research affirms prominent cytotoxic and moderate hypoglycemic potential of M. indica peel. Further bioactivity guided isolation of phytoconstituents and investigation on higher animals can lead to development of new drug molecules.