Tehran University Medical Journal

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Background: The objective of this study was to investigate the relationship between glucose-6-phosphate dehydrogenase inhibition in macrophages treated with 6-Aminonicotinamide, the amount of nitric oxide (NO) production and the resistance of infected macrophages against Leishmania major infection.
Methods: Peritoneal macrophages of BALB/c mice were isolated and treated with different concentrations (1.25, 2.5, 5, 10 mM) of 6-aminonicotinamide. After 24 hours, the viability of treated macrophages was measured by MTT assay at 540 nm. G6PD activity was measured in the cell extracts 24 hours later. Macrophages were then infected with leishmanial amastigotes and after 18 hours NO production was determined using Griess-reagent. In order to study the inhibition of macrophage activity, 5 mM concentration of 6-AN was used and number of leishmanial amastigotes was recorded in these cells from day 1 to7.
Results: Different concentrations of 6-AN were shown to cause a significant increase in cell death and decrease in G6PD activity and NO production in macrophages. Also, the number of amastigotes in macrophages was increased significantly (p < 0.05).
Conclusion: The concentration of 6-aminonicotinamide and G6PD activity affect the viability of BALB/c mice peritoneal macrophages through production of NO. Inhibition of G6PD activity leads to decreased leishmani-cidal activity of mouse peritoneal macrophages.

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Background: There is a growing interest in understanding the biological effects of time-tested folk medicinal plants including the green leafy vegetables, which supply minerals and vitamins to the diet. Trigonella foenum-graecum L (fenugreek) is a dietary vegetable and there are reports concerning its antinociceptive effects in Iranian traditional medicine. Its seeds are also known for their carminative, tonic, antidiabetic, antineoplastic and restorative properties. These reports and the hypoglycemic effect of fenugreek leaf extract encouraged us to assay fenugreek aqueous extract for cytotoxicity on NIH3T3 mouse fibroblast cells.

Methods: The NIH3T3cell line was purchased from National Research Center for Genetic Engineering and Biotechnology of Iran. The cells were plated in 24-well microtiter plates with DMEM+F12 medium containing 10% fetal calf serum supplemented with 445 mg/L L-glutamine and maintained at 37^oC with 5% CO₂/95% air. Following a 24-hr incubation period, various concentrations (0.01-20 mg) of the extract to the culture wells. Cell viability was assessed using trypan blue and MTT assays after five days of incubation.

Results: The results show that the IC₅₀ of the fenugreek extract as calculated from the trypan blue and MTT assays were 1.25 and 2.5 mg/mL, respectively.

Conclusions: Our findings, therefore, suggest that the aqueous extract of fenugreek is classified as nontoxic. This observed cytotoxicity is not specific and could be due to membrane disturbances.

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Background: Lactobacillus species are genetically diverse groups of Lactic Acid Bacteria (LAB) that have been introduced as probiotics, because of some characteristics such as their anti-tumor properties, helping the intestinal flora balance, production of antibiotics, stimulation of host immune response, etc. The aim of this study was to investigate the effects of cytoplasmic extraction and cell wall of Lactobacillus species isolated from the intestine of common carp on human chronic myelocytic leukemia or K562 cancer cell lines.
Methods: The intestinal contents of 115 common carp captured from the natural resources of West Azerbaijan province in Iran were examined for LAB. After isolation, the identification of Lactobacilli was done according to traditional and molecular bacteriological tests. Subsequently, a suspension of each bacterium was prepared and the protein content of the cytoplasm was extracted. Cell wall disintegration was done by cell lysis buffer and sonication. The effects of cytoplasmic extraction and cell wall on K562 cell line proliferation were investigated by MTT assays.
Results: The cytoplasmic extraction of the isolated Lactobacilli had significant (p<0.05) anti-proliferative effects on K562 cells. The cytoplasmic extractions of Lactobacillus paracasei and Lactobacillus casei inhibited K562 cell proliferation by 66.56% and 54.28% at 83.33 μg/ml concentration, respectively.Nevertheless, the Lactobacillus cell wall could not inhibit the proliferations of K562 cells (p<0.05).
Conclusion: In this study, the cytoplasmic extractions of the isolated Lactobacilli from the intestine of common carp had anti-proliferative effects on K562cell line.