Extracellular polymeric substances in electroactive biofilms play a crucial role in improving the efficiency of microbial fuel and electrolysis cells.

In microbial electrochemical cells (MECs), electroactive microbial biofilms can transmit electrons from organic molecules to anodes. To further understand the production of anodic biofilms, it is essential to investigate the composition and distribution of extracellular polymeric substance (EPS) in the MECs. In this study, the structure of EPS was examined in microbial electrolysis cells from mixed cultures forming biofilm using carbon fiber fabric anode. EPS was extracted from the anode biofilm of microbial electrolysis cells inoculated with mixed microbial culture. The anode biofilm yielded 0.4 mg of EPS, of which 51.2% was humic substance, 16.2% was protein, 12.6% was carbohydrates, and 20% consisted of undetermined substances. Using epifluorescence microscopy, the composition of bacterial cells and their location inside EPS were studied, and the distribution of microbial communities was compared based on current density results in the presence of various carbohydrates. On the electrode surface, bacteria and EPS gathered or overlapped in various locations can affect microbial electrochemical performance. Our findings showed that EPS formation in electroactive biofilms would be important for enhanced efficiency of electricity- or hydrogen-producing microbial electrolysis cells.

Resin extract obtained from Cilician fir (Abies Cilicica) inhibits glucose dependent inflammation in vitro.

OBJECTIVE: The potential anti-inflammatory efficacy of resin extract of Abies cilicica in glucose dependent inflammation and tumor necrosis factor alpha (TNF-a) induced inflammation models was investigated. Its effects on monocyte adhesion, gene expression levels of P-selectin, ICAM-1, VCAM1 and transendothelial migration for the two in vitro models were measured. Also, total flavonoid and total phenolic contents of the extract were determined. OBJECTIVE: Monocyte adhesion tests showed that the extract increased 100% inflammatory effect of TNF-a induced inflammation. On the other hand, it did not change number of adherent monocytes in glucose dependent inflammation model. Although the extract has trigger effect on monocyte adhesion, it did not change migration of leukocytes across ECV304 cells after administration of TNFa on ECV304 cells. The number of migrated monocytes was similar with only TNFa incubation experiment results. However, it significantly decreased monocyte migration in glucose dependent inflammation model. In our both experimental inflammation model, ICAM-1 expression significantly decreased. Although it is known that triggering effect of TNF-a on ICAM-1 expression, the content of of resin extract of A. cilicica prevented this effect. Phenolic antioxidant capacity of the extract are higher than its flavonoid contents.This study provides the first evidence that the extract inhibits glucose dependent inflammation. It may serve as an anti-inflammatory agent in the treatment of chronic inflammation caused by diabetes.

The effects of vitamins and selenium mixture against brain tissue induced by d-galactosamine.

Brain damage is a major complication of fulminant hepatic failure. d-Galactosamine (d-GalN)-induced liver toxicity causes damage to brain. The effects of vitamins and selenium mixture against d-GalN stimulated brain injury were investigated in this study. Sprague-Dawley female rats aged 2.0-2.5 months were used for the study. The rats were divided into four categories. A 0.9% NaCl solution was intraperitoneally given to the experimental rats in the first group. Using gavage technique, the second group of animals were subjected to a formulation consisting of 100 mg·kg-1 ·day-1 vitamin C, 15 mg·kg-1 ·day-1 of ß-carotene, 100 mg·kg-1 ·day-1 of α-tocopherol in addition to 0.2 mg·kg-1 ·day-1 of sodium selenate for 3 days. The third group was given a single dose of d-GalN hydrochloride at the concentration of 500 mg·kg-1 through a saline injection. The final group was given similar concentrations of both the antioxidant combination and d-GalN. Tissue samples were collected under ether anesthesia. The rats treated with d-GalN showed brain damage; increased myeloperoxidase, catalase, glutathione peroxidase, glutathione-S-transferase, lactate dehydrogenase, and superoxide dismutase activities; and decreased glutathione levels. Treatment with vitamins and selenium combination resulted in alleviation of these alterations in the rats. These findings suggest that administration of the vitamins and selenium combination suppresses oxidative stress and protects brain cells from injury induced by d-GalN.

A combined treatment using ethylmethane sulfonate and ultraviolet light to compare amylase production by three Bacillus sp. isolates.

In this study, three Bacillus sp.-producing amylase enzymes were isolated from soil samples and identified using 16S rDNA sequence analysis. Amylase production and total protein productions were spectrophotometrically measured. The following media were tested to increase enzyme production: LB medium and molasses. Three Bacillus sp. were identified as follows: Bacillus subtilis subtilis, Bacillus thuringiensis, and Bacillus cereus. Amylase production levels were in the range of 10 U/mL, whereas total protein production levels were at 15 mg/mL. Higher amylase activity was found in the Bacillus subtilis isolate. Ethylmethane sulfonate (EMS) and ultraviolet (UV) mutagenesis in combination were applied to compare amylase production. Amylase activity was increased to around 58% in the treatment with 0.03 mL of EMS and UV when compared to the control group. A pilot scale bioreactor with a total working volume of 10 liters was used to produce amylase by B. subtilis subtilis. In conclusion, B. subtilis subtilis can be used to produce amylase enzyme for various industrial purposes, and, for the first time, the amylase activities of B. subtilis can be enhanced with EMS and UV treatment.

Hydrogen production profiles using furans in microbial electrolysis cells.

Microbial electrochemical cells including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are novel biotechnological tools that can convert organic substances in wastewater or biomass into electricity or hydrogen. Electroactive microbial biofilms used in this technology have ability to transfer electrons from organic compounds to anodes. Evaluation of biofilm formation on anode is crucial for enhancing our understanding of hydrogen generation in terms of substrate utilization by microorganisms. In this study, furfural and hydroxymethylfurfural (HMF) were analyzed for hydrogen generation using single chamber membrane-free MECs (17 mL), and anode biofilms were also examined. MECs were inoculated with mixed bacterial culture enriched using chloroethane sulphonate. Hydrogen was succesfully produced in the presence of HMF, but not furfural. MECs generated similar current densities (5.9 and 6 mA/cm2 furfural and HMF, respectively). Biofilm samples obtained on the 24th and 40th day of cultivation using aromatic compounds were evaluated by using epi-fluorescent microscope. Our results show a correlation between biofilm density and hydrogen generation in single chamber MECs.

Olive mill wastewater treatment in single-chamber air-cathode microbial fuel cells.

Olive mill wastewaters create significant environmental issues in olive-processing countries. One of the most hazardous groups of pollutants in these wastewaters is phenolic compounds. Here, olive mill wastewater was used as substrate and treated in single-chamber air-cathode microbial fuel cells. Olive mill wastewater yielded a maximum voltage of 381 mV on an external resistance of 1 kΩ. Notable decreases in the contents of 3,4-dihydroxybenzoic acid, tyrosol, gallic acid and p-coumaric acid were detected. Chemical oxygen demand removal rates were 65 % while removal of total phenolics by the process was lower (49 %). Microbial community analysis during the olive mill wastewater treating MFC has shown that both exoelectrogenic and phenol-degrading microorganisms have been enriched during the operation. Brevundimonas-, Sphingomonas- and Novosphingobium-related phylotypes were enriched on the anode biofilm, while Alphaproteobacteria and Bacteriodetes dominated the cathode biofilm. As one of the novel studies, it has been demonstrated that recalcitrant olive mill wastewaters could be treated and utilized for power generation in microbial fuel cells.

Hydrogen production using cocaine metabolite in microbial electrolysis cells.

In this study, the effects of cocaine metabolite, benzoylecgonine, commonly found in wastewater on hydrogen production were investigated using microbial electrolysis cells. Benzoylecgonine dissolved in synthetic urine and human urine containing benzoylecgonine were inoculated to evaluate hydrogen production performance in microbial electrolysis cells. Microbial electrolysis cells were inoculated with synthetic urine and human urine containing the cocaine metabolite benzoylecgonine for hydrogen gas production performance. Gas production was observed and measured daily by gas chromatography. GC-MS was used to analyze the compounds found in human urine before and after operation in microbial electrolysis cells. The metabolite's pH values and optical density in microbial electrolysis cells were analyzed spectrophotometrically. Hydrogen gas was successfully produced in microbial electrolysis cells (~ 5.5 mL) at the end of the 24th day in the presence of benzoylecgonine in synthetic urine. Human urine containing benzoylecgonine also generated hydrogen in microbial electrolysis cells. In conclusion, microbial electrolysis cells can be used to remove cocaine metabolites from contaminated wastewater generating hydrogen gas. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03805-7.

Therapeutic effect of microRNA-21 on differentially expressed hub genes in gastric cancer based on systems biology.

Gastric cancer (GC) is a leading cause of mortality for many people. Cancer's initiating factors are poorly understood. miR-21 has a crucial function in several malignancies, particularly GC. Furthermore, it has been shown that miR-21 is critical for the emergence and advancement of GC. This work intends to identify new genes which expression is associated with the activity of mir-21 in GC and to investigate the effect of downregulation of mir-21 on these genes and gastric tumorigenesis. We utilized the gene expression profiles of GCs from an Array database (GSE13911) from the Gene Expression Omnibus (GEO) dataset to find differentially expressed genes (DEGs) between control and gastric cancer groups. Using weighted gene correlation network analysis (WGCNA) in R, the Gene co-expression network was reconstructed. The microRNA-mRNA network was then reconstructed using the miRWalk database, and by investigating the microRNA-mRNA network, the genes that have an association with mir-21 were found. To implement the functional investigation, MKN and AGS cell lines were transfected with anti-miR-21 next. Subsequently, MTT proliferation was utilized to assess the cell's vitality. qRT-PCR was then used to evaluate the anticipated levels of gene expression in both GC cell lines. This study discovered and predicted CCL28, NR3C2, and SNYPO2 as the targets of miR-21 (GC), which are downregulated through gastric tumorigenesis, showing great potential as therapeutic and diagnostic targets. The suppression of miR-21 in gastric GC cells led to the inhibition of cell proliferation and decreased expression of CCL28, NR3C2, and SNYPO2 genes. This study established that miR-21, via downregulating these genes, contributes significantly to the development of GC. In addition, systems biology techniques identified CCL28, NR3C2, and SNYPO2 genes as possible GC surveillance and therapy components.

Study of azo dye decolorization and determination of cathode microorganism profile in air-cathode microbial fuel cells.

Five textile azo dyes, as part of an artificial mixture, were treated in single-chamber air-cathode microbial fuel cells while simultaneously utilizing acetate for electricity production. Remazol Black, Remazol Brilliant Blue, Remazol Turquoise Blue, Reactive Yellow and Reactive Red at concentrations of 40 or 80 mg L(-1) were decolorized to a similar extent, at averages of 78, 95, 53, 93 and 74%, respectively, in 24 hours. During the process of decolorization, electricity generation from acetate oxidation continued. Power densities obtained in the presence of textile dyes ranged from 347 to 521 mW m(-2) at the current density range of 0.071 - 0.086 mA cm(-2). Microbial community analyses of cathode biofilm exhibited dynamic changes in abundant species following dye decolorization. Upon the addition of the first dye, a major change (63%) in microbial diversity was observed; however, subsequent addition of other dyes did not affect the community profile significantly. Actinobacteria, Aquamicrobium, Mesorhizobium, Ochrobactrum, Thauera, Paracoccus, Achromobacter and Chelatacoccus affiliated phylotypes were the major phylotypes detected. Our results demonstrate that microbial fuel cells could be a promising alternative for treatment of textile wastewaters and an active bacterial community can rapidly be established for simultaneous azo dye decolorization and sustainable electricity generation.

Hydrogen production in single-chamber microbial electrolysis cells using Ponceau S dye.

In this study, Ponceau S dye, which is one of the hazardous dyes found in industrial wastewater, was examined for hydrogen production in single chamber-free membrane-free microbial electrolysis cells at different concentrations (10-40 mg L-1). A gas content analysis (hydrogen, carbon dioxide, and methane) was measured daily using gas chromatography to determine the effects of the Ponceau S on hydrogen production levels. Hydrogen was successfully produced in the presence of Ponceau S dye, but the gas production levels were affected by the concentrations of Ponceau S. The maximum hydrogen production was measured as 18 mL at a concentration level of 20 mg L-1. Decolorization ratios of Ponceau S were in the range of 85-100%. Hydrogen production rates increased in the presence of Ponceau S (20 mg L-1); however, yield (%) of the production decreased when compared to the control group. The percentage of COD removal was 94.78% in the presence of 40 mg L-1 of Ponceau S. In conclusion, hydrogen can be generated using wastewaters contaminated with azo dyes such as Ponceau S, and decolorization of the dye can be achieved, simultaneously.

Protective effects of antioxidant combination against D-galactosamine-induced kidney injury in rats.

The protective effects of an antioxidant combination in kidney injury induced by the injection of D-galactosamine (D-GaIN) were examined in the present study. Sprague Dawley female rats were used and divided into four groups as follows: (1) animals injected physiological saline solution, intraperitoneally, (2) animals treated with the combination of ascorbic acid (100 mg kg(-1) day(-1)), beta-carotene (15 mg kg(-1) day(-1)), alpha-tocopherol (100 mg kg(-1) day(-1)), and sodium selenate (0.2 mg kg(-1) day(-1)) for three days orally, (3) rats injected D-GaIN (500 mg kg(-1)) intraperitoneally as a single dose, and (4) animals treated with the antioxidant combination for three days, then injected D-GaIN. The tissue and blood samples of animals were collected for morphological and biochemical evaluations. Histopathological injury in kidney tissues was observed together with a significant increase in tissue lipid peroxidation (LPO) level, myeloperoxidase (MPO), lactate dehydrogenase, catalase and superoxide dismutase (SOD) activities, and serum creatinine and urea levels, and a significant decrease in glutathione level and glutathione peroxidase activity in D-GaIN injected rats. However, a decrease in the degenerative changes was detected in the kidney tissue of D-GaIN + antioxidant group, and biochemical results showed reversed effects. In conclusion, it seems reasonable to conclude that the treatment of the antioxidant combination has a protective effect on D-GaIN-induced kidney injury of rats.

Dataset on Catal's reagent: Sensitive detection of iron (II) sulfate using spectrophotometry.

Catal's reagent is characterized by spectroscopic methods such as fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), ultraviolet (UV)-visible spectrophotometry. Effects of different solvents such as methanol and ethanol on absorption spectrum of 1-(Dodecylthio)anthracene-9,10-dione (3) were present. Detection range of iron (II) sulfate using Catal's reagent was analyzed. Synthesis of 1-(Dodecylthio)anthracene-9,10-dione (3) was explained, and absorbances of various concentrations of iron (II) sulfate (0- 10 mg mL-1) were measured. The possible detection mechanism was also explained. The dataset is useful to improve the detection of iron (II) sulfate in various application fields such as environmental, agricultural, sensor, food, textile and cement industries. The study refers to: F. Ozkok, Y.M. Sahin, V. Enisoglu-Atalay, K. Asgarova, N. Onul, T. Catal, Sensitive Detection of Iron (II) Sulfate with a Novel Reagent using Spectrophotometry, Spectchim. Acta. A, 240 (2020), 118631. https://doi.org/10.1016/j.saa.2020.118631.

Sensitive detection of iron (II) sulfate with a novel reagent using spectrophotometry.

In this study, a novel reagent was developed for sensitive detection of iron (II) sulfate, spectrophotometrically. A novel thio-anthraquinone derivative, 1-(Dodecylthio)anthracene-9,10-dione (3), was synthesized from the chemical reaction of 1-Chloroanthraquinone (1) and 1-Dodecanethiol (2) by an original reaction method and was used in the preparation of the novel reagent called Catal's reagent. A synthesized thio-anthraquinone analogue (3) was purified by column chromatography, and its chemical structure was characterized by spectroscopic methods such as Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and ultraviolet (UV)-visible spectrophotometry. The chemical and molecular structure of the developed thio-antraquinone derivative (3) was illuminated using computational methods with the GaussView5 and Gaussian09 programs. Various solvents including ethanol, methanol, and acetonitrile were examined in the preparation of the reagent. A concentration range from 0.2 mg mL-1 up to 10 mg mL-1 of iron (II) sulfate heptahydrate solution in distilled water was prepared. The absorption spectra of Catal's reagent (0.816 mM) showed three peaks between 185 nm-700 nm of wavelength. However, after the reaction with H2O2 and the 30 mM trisodium citrate dihydrate mixture in the presence of an iron sulfate (II) solution, a single peak was observed, producing a stable and reddish/brownish homogenous solution (λ max = 304 nm). The following concentrations of iron (II) sulfate heptahydrate was examined using developed protocol and the reagent, and the concentrations were measured spectrophotometrically at 304 nm, 0.2-1 mg mL-1. Absorbances of reaction mixtures of iron (II) sulfate remained stable up to 48 h. The results indicated that the novel Catal's reagent can be used for sensitive spectrophotometric detection of iron (II) sulfate in aqueous solutions.

Removal of selenite from wastewater using microbial fuel cells.

Simultaneous electricity generation and selenium removal was evaluated in single-chamber microbial fuel cells (MFCs) with acetate and glucose as carbon sources. Power output was not affected by selenite up to 125 mg l(-1) with glucose as substrate. Coulombic efficiencies of MFCs with glucose increased from 25% to 38% at 150 mg Se l(-1). About 99% of 50 and 200 mg Se l(-1) selenite was removed in 48 and 72 h for MFCs fed with acetate and glucose, respectively, demonstrating the potential of using MFC technology for Se remediation.

Combination of selenium and three naturally occurring antioxidants administration protects D-galactosamine-induced liver injury in rats.

D-Galactosamine (D-GaIN) is a highly selective hepatotoxin that causes liver injury similar to human viral hepatitis via depletion of uridine nucleotides, which subsequently diminishes synthesis of RNA and proteins. The aim of this study was to investigate the role of selenium, ascorbic acid, beta-carotene, and alpha-tocopherol on D-GaIN-induced liver injury of rats by morphological and immunohistochemical means. In this study, Sprague-Dawley female rats were divided into four groups. Group I consists of rats injected physiologic saline solution intraperitoneally. Group II consists of rats given selenium (0.2 mg/kg per day), ascorbic acid (100 mg/kg per day), beta-carotene (15 mg/kg per day), and alpha-tocopherol (100 mg/kg per day) for 3 days via gavage method. Group III consists of the single dose of D-GaIN (500 mg/kg)-injected animals. Group IV are the D-GaIN-injected animals given the same antioxidant combination. In situ terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick-end labeling (TUNEL) assay was applied to determine apoptosis for paraffin sections of the liver samples. Moreover, caspase-3 and proliferating cell nuclear antigen antibody were applied for paraffin sections. In the group given D-GaIN, apoptotic cells with TUNEL assays and caspase-3 activity, which are liver injury markers induced by D-GaIN, the hepatocyte proliferation with cell proliferation assay increased. However, selenium and other three antioxidants combination clearly suppressed an increase in apoptotic cells with TUNEL assay and caspase-3 activity. In addition, it suppressed D-GaIN-induced cell proliferation in the liver. As a result, these results indicate that selenium and three naturally occurring antioxidants shows a protective effect against liver injury induced by D-GaIN. These results suggest that supplementation with the combination of selenium, ascorbic acid, beta-carotene, and alpha-tocopherol may help prevent the development of liver injury.

Selenium induces manganese-dependent peroxidase production by the white-rot fungus Bjerkandera adusta (Willdenow) P. Karsten.

In this study, selenium (Se) induction of the ligninolytic enzyme manganese-dependent peroxidase (MnP) production, and the effects on the oxidative state in the white-rot fungus Bjerkandera adusta (Willdenow) P. Karsten were demonstrated. Low concentration of Se (0.5 mM) caused up to a twofold increase in MnP production (0.81 +/- 0.05 U/ml) when compared to control (0.39 +/- 0.07 U/ml), whereas higher concentrations of Se (200 mM) inhibited (0.03 +/- 0.01 U/ml) MnP production. Addition of high concentration of Se also caused up to a twofold increase in lipid peroxidation levels. These results demonstrate for the first time that Se may induce or reduce MnP production and lipid peroxidation levels which play a significant role in lignin degradation by white-rot fungi.

The influence of selenium on expression levels of the rbcL gene in Chlorella vulgaris.

In this study, the effects of selenium on the microalgae Chlorella vulgaris were examined. Four groups of C. vulgaris were cultivated using Bristol medium: group I (control), no sodium selenite (Se); group II, 1 µM Se; group III, 10 µM Se; and group IV, 100 µM Se. Algal biomass samples were collected for biochemical evaluation and gene expression studies on the 21st day of cultivation. The following parameters were investigated: chlorophyll a (Cla), chlorophyll b (Clb) and total carotene content, total protein, and total glutathione (GSH) and malondialdehyde (MDA) levels. Gene expression levels of large subunits of Rubisco (rbcL) were analyzed using real-time quantitative polymerase chain reaction. Total Cla and total carotene in C. vulgaris decreased in high concentrations of Se (100 µM) (around 23 and 42%, respectively) when compared to controls while, Clb content increased by about 10%. 10 µM of Se led to increased GSH levels (3.04 ± 0.02 µg GSH/mg protein) and decreased MDA levels (2.02 ± 0.1 µmol MDA/mg protein) when compared to control groups (1.18 ± 0.04 µg GSH/mg protein and 0.94 ± 0.23 µmol MDA/mg protein), while a significant decrease in GSH and an increase in MDA levels in the presence of 100 µM Se showed the opposite effect. rbcL gene expression increased 1.76 ± 1.37-fold and 0.86 ± 1.33-fold in 10 and 100 µM selenium experiments when compared to control groups. Our results suggest both pro-oxidant and antioxidant activities of Se on C. vulgaris and upregulation of the rbcL gene for the first time. Treatment with low concentrations of Se improves the antioxidant features of the microalgae, C. vulgaris.

Monitoring of neomycin sulfate antibiotic in microbial fuel cells.

Indirect detection and quantification of the neomycin sulfate antibiotic was accomplished in microbial fuel cells. Performance of the microbial fuel cells was examined on the basis of the following parameters; voltage generation, power density, current density and coulombic efficiencies. Removal of neomycin sulfate was monitored using LC-MS/MS in parallel with chemical oxygen demand and total carbohydrate removal. While neomycin sulfate was partially degraded, microbial fuel cell performance appeared to be affected and eventually inhibited by neomycin sulfate on a concentration-based fashion. In order to further examine the neomycin sulfate bio-sensing activity of the microbial fuel cell, a computational chemistry approach was used to obtain the information about the highest occupied molecular orbital-lowest unoccupied molecular orbital energy values of outer electron orbitals, their distribution, and ionization potentials (IPs). The results showed that electroactive bio-film-based MFCs can be used for sensitive detection of neomycin sulfate found in wastewaters.

Chemical and molecular characterization of metabolites from Flavobacterium sp.

In this study, a Flavobacterium sp. is isolated from natural spring, and identified using molecular techniques. Extracellular and intracellular secondary metabolites are identified using solid phase microextraction gas chromatography-mass spectrometry and ultra performance liquid chromatography. Cytotoxic activity of the extracellular compounds produced by the Flavobacterium sp. and quercetin as the standard are measured using ECV304 human endothelial cells in vitro. Our results show that Flavobacterim sp. isolate has the highest percentage of similarity with Flavobacterium cheonhonense strain ARSA-15 (99%). Quercetin is detected as the major extracellular compound produced by the Flavobacterium sp. Methanol extract of Flavobacterium sp. resulted in a higher cell viability results when compared to DMSO extracts. Computational chemistry approach was used and it has been found that polar solvent (methanol) contributed to higher antioxidant activity. In conclusion, Flavobacterium sp. can be used to produce quercetin for industrial purposes.

Apoptotic Effect of Nigella sativa on Human Lymphoma U937 Cells.

OBJECTIVE: Nigella sativa is from botanical Ranunculaceae family and commonly known as black seed. Apoptotic effect of N. sativa and its apoptotic signaling pathways on U937 lymphoma cells are unknown. MATERIALS AND METHODS: In this study, we investigated selective cytotoxic and apoptotic effects of N. sativa extract and its apoptotic mechanisms on U937 cells. In addition, we also studied selective cytotoxic activity of thymoquinone that is the most active essential oil of N. sativa. RESULTS: Our results showed that N. sativa extract has selective cytotoxicity and apoptotic effects on U937 cells but not ECV304 control cells. However, thymoquinone had no significant cytotoxicity against on both cells. N. sativa extract increased significantly caspase-3, BAD, and p53 gene expressions in U937 cells. CONCLUSIONS: N. sativa may have anticancer drug potential and trigger p53-induced apoptosis in U937 lymphoma cells. SUMMARY: This is the first study showing the apoptotic effect of Nigella sativa extract on U937 cells. Abbreviations used: CI: Cytotoxicity index, DMEM: Dulbecco's Modified Eagle Medium, HL: Hodgkin's lymphoma, MTT: 3-(4,5-dimethy lthiazol-2yl)-2,5-diphenyl tetrazolium bromide, RPMI: Roswell Park Memorial Institute medium.