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Background: Treatment of leishmaniasis is a challenge due to problems such as high price and dose of the drug, drug resistance and side effects. Objective: The study aims to introduce plants compounds, which their antileishmanial effects were approved in vivo conditions. Methods: This study as a review article was performed by searching the keywords of “medicinal plants with in vivo antileishmanial effects, nanocarrier, clinical trials, and mechanism of action” in the well-known databases to 2018. In this study, 14 medicinal plant compounds with antileishmanial effects were reviewed and mechanism of action and their in vivo therapeutic effect were evaluated. Results: It was found that while some of these compounds had low antileishmanial effects, their efficacy against leishmaniasis was significantly increased through loading into nanocarriers. Conclusion: This study indicated that active component of medicinal plants especially along with nano carriers can be of interest for the treatment of Leishmania.

Background: The amniotic membrane plays an important role in maintaining a healthy pregnancy. The main population cells from amniotic membrane include human amnion epithelial cells (hAECs) which have been shown to possess immunomodulatory properties. Objective: The proximity of hAECs with monocyte leads to the generation of tollerogenic dendritic cells. Materials and Methods: hAECs were obtained from normal pregnancy. Peripheral blood monocytes were isolated by anti-CD14 MACS method. Co-cultures of monocytes and hAECs were established in Transwell chambers supplemented with granulocytemacrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) in the absence and presence of lipopolysaccharide (LPS) to produce immature and mature DCs, respectively. Immunophenotyping of the obtained DCs was done through flow cytometry and the production of cytokines was measured by ELISA. Mixed leukocyte Reaction (MLR) was also performed for the functional assessment of DCs. Results: Immunophenotyping of [hAECs - Immature DC (iDC)] and [hAECs - iDC] + LPS cells revealed that the expression of CD1a, CD80, CD86, CD40, HLA-DR, and CD83 markers showed no significant difference as compared with the control group (iDCs and mDCs alone). In the [hAECs-iDCs] + LPS cells, the percentage of CD14 cells at the ratio of 1:2.5 showed significant differences compared to the control group. The production of IL-10 and IL-12 showed no significant difference in any of the cultures as compared to the control groups. Also, co-cultured DCs did not inhibit proliferation of lymphocyte. Conclusion: Our findings show that factors secreted from cultured hAECs are unable to generate of tollerogenic dendritic cells. To achieve a better understanding of other mechanisms more investigations are needed. Key words: Amniotic membrane, Dendritic cells, Human placenta, Immunomodulation, Monocyte.

Background: Acinetobacter baumannii is an opportunistic and antibiotic-resistant pathogen that predominantly causes nosocomial infections. There is urgent need for development nonantibiotic-based treatment strategies. We developed novel monoclonal antibody (mAb) against a peptide of conserved outer membrane protein A (OmpA) and evaluated its reactivity with different pulsotypes of A.baumannii. Materials and Methods: Peptide derived from A.baumannii OmpA was conjugated to keyhole limpet hemocyanin and injected into Balb/c mice. Splenocytes of immunized mice were fused with SP2/0 myeloma cells followed by selection of antibody-producing hybridoma cells. After screening of different hybridoma colonies by ELISA, one monoclone was selected as 3F10-C9 and the antibody was tested for reaction with five different Acinetobacter pulsotypes that were resistant to carbapenem antibiotics. The affinity constant was measured by ELISA. The ELISA, Western blotting, indirect immunofluorescence (IFA), and in vitro Opsonophagocytosis assays were used to evaluate the reactivity of generated mAb. Results: The anti-OmpA antibody reacted with the immunizing peptide and had a high affinity (around 1.94 × 10 − 9 M) for its antigen in the ELISA. Specific binding of mAb to OmpA was confirmed in Western blot. IFA assays revealed that mAb recognized specific OmpA on the pulsotypes. Opsonophagocytosis assays showed that the mAb increased bactericidal activity of macrophage cells. The antibody function was higher in the presence of serum complement. Conclusion: The peptide-based mAb demonstrated optimal performance in laboratory experiments which may be appropriate in investigation on OmpA in Acinetobacter pathogenesis and development of passive immunization as novel therapeutic approach.

Background and Objectives: Immunization is a promising strategy to combat against the life-threatening infections by Multi Drug Resistance Acinetobacter baumannii. In this study, we directed to design and evaluate the efficacy of a recombi- nant multi-epitope protein against this pathogen. Materials and Methods: Epitopes prediction was performed for candidate proteins OmpA and BAM complex (BamA, BamB, BamC, BamD, BamE) from A. baumannii, using immune-informatics tools with high affinity for the human HLA alleles. After expression and purification of the recombinant protein, its functional activity was confirmed by interaction with positive sera. Results: Cloning and expression of the desired multi-epitopes protein were verified. Circular Dichroism study showed the secondary structure and proper refolding of the recombinant protein was achieved and matched with computational predic- tion. There was a significant interaction between designed protein with antibodies presented in ICU patients' and staff's sera. Conclusion: The interaction of the recombinant protein with patients' sera antibodies suggests that it may be a promising determinant protein for immunization against of MDR A. baumannii.

Nosocomial infections caused by Acinetobacter baumannii (A. baumannii) nosocomial infections caused by Acinetobacter baumannii (A. baumannii) are considered as a global serious problem in hospitalized patients because of emerging antibiotic resistance. Immunotherapy approaches are promising to prevent such infections. In our previous study, five antigenic epitopes of outer membrane protein A (OmpA), as the most dangerous virulence molecule in A. baumanii, were predicted in silico. In this study, the investigators evaluated some immunological aspects of the peptides. Five peptides were separately injected into C5BL/6 mice; then the cytokine production (interleukin-4 and interferon-gamma) of splenocytes and opsonophagocytic activity of immunized serum were assessed. To identify the protective function of the peptides, animal models of sepsis and pneumonia infections were actively and passively immunized with selected peptides and pooled sera of immunized mice, respectively. Then, survival rates of them were compared with the non-infected controls. Based on the results, activated spleen cells in P127 peptide-immunized mice exhibited an increase level of IFN-γ compared with the other experimental groups, but not about the IL-4 concentration. The results of opsonophagocytic assay revealed an appropriate killing activity of produced antibodies against A. baumannii in a dose-dependent manner. Further, the survival rates of the mice under passive immunization with the immunized sera or active immunization with P127 peptide were significantly more than those in the control group. Moreover, the survival rate of the P127 peptide immunized group was considerably higher than that among the other peptide-immunized group. In conclusion, findings indicated that peptides derived from outer membrane protein-A can be used as a promising tool for designing the epitope-based vaccines against infections caused by A. baumannii.

Background: Pneumocystis pneumonia (PCP) incidence in acute myeloid leukemia (AML) patients have not been well described and some studies have shown the risk of this infection in these groups of patients. In this systematic review, we reviewed the published studies about PCP in AML to evaluate the PCP incidence and outcomes in these patients and then focuses on its immunological mechanism. Method: All articles reviewed in this collection are from recruited sites: PubMed and Embase databases. No time limit was considered for article searching. The following keywords were used: (“Pneumonia, Pneumocystis” OR Pneumocystis Pneumonia” OR “Pneumocystis jirovecii”), AND (“leukemia, myeloid, acute OR acute myeloid leukemia”). Our search strategy yielded 356 articles. After implementing the exclusion and inclusion criteria, the final papers were selected and reviewed. Result: By our search, 356 articles were found (316 in PubMed and 40 in Embase). After the implementation of inclusion and exclusion criteria, seven papers remained. A total of seven articles with a total number of 41 patients were included. Conclusion: Affected patients appear to have a clear resistance to PCP infection despite chemotherapy and bone marrow suppression due to the preservation of a specific immunological milieu in the lung. In fact, may be due to immunological stability of the lungs that remains intact. Further studies are needed.

The presence of ambient particulate matter (PM) poses more dangers to human health than that of other common air pollutants such as Carbon dioxide (Co2) and ozone. Epidemiologic studies show a direct correlation between PM and the risk of respiratory and cardiovascular diseases. The immune system seems to play a critical role in the process of these diseases. The main goal of this study was to investigate the effect of Tehran particulate matter in two aerodynamic diameters (PM2.5 and PM10) on alveolar macrophages (AM) from C57/BL6 mice. To evaluate the inflammatory effects of PMs, cultured alveolar, and peritoneal macrophages were treated with PM2.5 & PM10 (concentrations of 5 µg/mL and 10 µg/mL). Tumor necrosis factor-alpha (TNF-α) and IL-10 (representatives of inflammatory and anti-inflammatory cytokines, respectively) were assessed in the culture supernatant by ELISA. Expression of arginase and inducible nitric oxide synthase (iNOS) genes was carried out by quantitative real-time PCR. Different functional types of cultured alveolar macrophages (M1, M2) were also determined in this study. Our results suggest that PM2.5 induces M1 inflammatory phenotype in comparison with PM10. We found Also, an increase in TNF-α and M1-related gene expression (iNOS), as well as a decrease in both IL-10 and M2 phenotype genes (Arginase). Moreover, a reduction in phagocytic capacity and increased apoptosis function of macrophage cells were detected. PM2.5 as a major component in hydrocarbons has a considerable effect on polarizing the alveolar macrophages to an inflammatory phenotype and eliciting lung inflammation in mice.

Toxoplasma gondii (T. gondii) is an intracellular parasitic protozoan infecting homoeothermic animals and about a third of the world's population. Inflammasomes are intracellular multi-protein complex, which are activated by many factors. Inflammasomes are activated during toxoplasmosis; however, there are a lot of obscure aspects. THP-1 monocyte cells were converted to M0 macrophages by PMA and treated by 100 μg/mL soluble total Ag (STAg) derived from T. gondii strain RH for two time points 3 h and 24 h. After total RNA extraction and cDNA synthesis, the expression pattern of NLRP1, NLRP3, NLRC4, AIM2, IL1β, and IL18 was evaluated by relative real-time PCR. In addition, the cytokine release of IL1β and TNFα was evaluated in the supernatant of each well. The results showed statistically significant time-dependent overexpression of inflammasomes. NLRP1 and NLRP3 showed the higher and lower expression, respectively, during 3 h and 24 h after exposure. Both IL1β and IL18 downregulated 3 h after exposure. IL18 presented statistically significant upregulation after 24 h, but IL1β showed statistically significant downregulation after 24 h. The release of IL1β increased after 3 h, but it slightly decreased during 24 h after exposure. The concentration of TNFα showed an insignificant decrease compared to control, while it increased during 24 h after exposure. Taken together, this study suggested that T. gondii STAg induces NLRP1 more than NLRP3, NLRC4, and AIM2. Our findings also proposed that T. gondii STAg downregulates the gene expression of IL1β, but increases the release of this cytokine. It seems that Toxoplasma STAg probably increase the release of IL1β via activating NLRPs and AIM2 to cleave pro-caspase 1 to caspase 1 that leads to conversion of pro IL1β to mature IL1β.

Background Infection caused by Acinetobacter baumannii has emerged as a significant clinical problem with unacceptably high mortality rate due to the increase in antibiotic-resistant strains. Producing novel monoclonal antibody (MAb) against outer membrane protein A (OmpA) could be considered as a potential tool to improve treatment of A. baumannii infections. Objectives In this study, we aimed to produce murine MAbs against OmpA peptide of A. baumannii. Materials and methods BALB/c mice were immunized with 18-mer amino acid peptide as a part of the OmpA protein. Four antibody-secreting hybridomas were obtained using hybridoma technology and then characterized according to isotypes, affinity constant, reactivity in ELISA, flow cytometry, indirect immunofluorescence (IFA) and opsonophagocytic killing assays. Results All four produced MAbs (1A1-D10, 1G1-E7, 2C11-F10, and 4H2-H9) had IgG1 isotype with Kappa light chain. One of these MAbs, 1G1-E7 was purified and selected for further characterizations. 1G1-E7 showed a high reactivity with both immunogenic peptide and A. baumannii in ELISA. Our results indicated that 1G1-E7 MAb reacted with 95.3% of A. baumannii in flow cytometry as well as IFA. Moreover, the affinity of the 1G1-E7 MAb was measured 1.37 × 108 M−1. The 1G1-E7 significantly improved opsonophagocytic killing of a clinical isolate of A. baumannii. Conclusion Our findings showed that the OmpA can be identified by produced MAbs. The efficacy of novel anti-OmpA antibodies in A. baumannii targeting needs to be further investigated in challenging models, and then could be subjected for genetic engineering to produce therapeutic antibody against A. baumannii.

Regarding the antiparasitic effects of Betulinic acid (B) against Leishmaniasis, it was loaded into nanochitosan (K) for the first time in order to improve its therapeutic effects and decrease its side effects for the treatment of Leishmania major-infected Balb/c mice. Improvement the therapeutic efficacy of Bas an anti-leishmania agent through increasing the effective dose was achieved by using a novel solvent and phase separation method for K synthesis. The synthesized K with the size of 102 nm and Betulinic acid-nanochitosan (BK) with the size of 124 nm and drug loading efficiency of 93%, cellular uptake of 97.5% with the slow drug release pattern was prepared. To increase the therapeutic dose, a modified 10% acetic acid solvent was used. The in vitro and in vivo results showed that the nanodrug of BK was non toxic by 100% and BK20 mg/kg could completely performed the wound healing and inhibit the parasite in a large extent (P ˂ 0.001) compared to other groups. Therefore, BK could be considered as an alternative regimen for treatment of L. major.

The ability of nematodes to manipulate the immune system of their host towards a Th2 and T regulatory responses has been proposed to suppress the inflammatory response. Clinical trials have proposed a useful effect of helminth infections on improvement of inflammatory disorders. In this study, we investigated the immunomodulatory effect of Syphacia obvelata infection to induce intestinal tolerance in C57BL/6 mice. Mice were infected through the cagemates with self-infected BALB/c mice. Four weeks post-infection, expression levels of IFN-γ, TNF-α, IL-17, and IL-10 were assessed in the supernatant of mesenteric lymph node (MLN) culture. Foxp3+Treg were measured in MLN cells by flow cytometry. In the S. obvelata-infected group, the percentage of Tregs (5.2±0.4) was significantly higher than the control (3.6±0.5) (P

Chlorella vulgaris (CV) has exhibited immune-enhancing and protective activities against cancer and infections. However, there is an increasing concern about the use of Chlorella species in human, regarding its various molecules with antigenic features found in infectious microorganisms. Our goal was to investigate the impact of higher concentrations of CV on tumor growth in spontaneous mouse mammary tumor (SMMT) models. Balb/c mice were daily given CV powder at doses of 0, 200, or 300 mg/kg for 42 days (CONTROL, CV200, and CV300 groups, respectively; n = 6/group). On day 14, the SMMT was inoculated. Tumor volume (TV) and body weight (BW) were monitored on 5-day intervals following tumor challenge. On day 43, blood, spleen, lungs, and tumor tissues were collected. Histopathological examinations on lungs and tumor tissues were performed following hematoxylin–eosin staining. Intratumor expression of 27 genes was assessed by real-time PCR. Total IgG, IFNγ, and IL-4 levels in serum and spleen culture supernatant were measured by ELISA. The TV/BW index showed significant increase in the CV200 group compared to the CONTROL (p = 0.047). The CV200 tumors exhibited more malignant phenotype, higher angiogenesis rate, and lower peritumoral neutrophil and macrophage-to-lymphocyte infiltration ratio compared to the CONTROL. Serum concentrations of IFNγ, IL-4, and IgG were declined, and the spleen IFNγ and IgG production was higher in the CV200 compared to the CONTROL. The IL-1β, IL-10, TGFβ1, FOXP3, HO-1, Gr1, CD11b, PCNA, LCN2, iNOS2, VEGFR2, CD31, and CD105L expressions were markedly increased in the CV200 tumors compared to the CONTROL (p = 0.001, 0.002, 0.006, 0.021, 0.004, 0.030, 0.016, 0.031, 0.025, 0.008, 0.014, 0.022, and 0.037, respectively). The changes in cytokine, IgG and gene expression values considerably correlated with tumor size, as well as with each other. Our data provided evidence that C. vulgaris at a specific dose (200 mg/kg) promoted tumor growth in a mammary tumor model. This consequence might reflect an immune derangement in favor of developing a protumor microenvironment. However, this hypothesis needs to be further investigated in future.

Acinetobacter baumannii is a Gram-negative bacterium that has recently been identified as a leading nosocomial pathogen. Infections by this pathogen result in significant mortality due to antibiotic resistance. An effective vaccine would help alleviate the burden of disease incurred by this pathogen; however, there are currently no licensed vaccines offering protection against Acinetobacter baumannii infection. In this study, considering the fact that outer membrane protein A is one of the most promising vaccine candidates, we predicted T cell and B cell epitopes on this protein using sequence-based epitope prediction tools and determined whether or not mice immunized with these peptides induce an immune response. We selected consensus epitopes including five peptides in different tools with the highest score. 48 female C5BL/6 SPF injected subcutaneously with the peptides (peptide1 to peptide 5 separately) in 100 μL of the solution and sham groups received adjuvant and PBS alone on the same schedule: on day 0 (primary dose) and two booster doses were administered on days 14 and 28. At the end of time, animals euthanized by Isoflurane, and collected sera for assessment of specific antibodies against each peptide by ELISA (Enzyme-linked immunosorbent assay). Immunization of mice showed one of the novel synthetic peptides (peptide 1 (24-50 amino acids)) elicited immune responses. We conclude to combine theoretical methods of epitope prediction and evaluating the potential of immunogenicity for developing vaccines is important.

Background: Nowadays, nanocarriers are used for leishmaniasis treatment due to development of drug resistance and several side effects with conventional therapeutics. Objectives: In this study we aimed to evaluate in vivo effects of four synthesized nanodrugs including amphotericin B-nanochitosan (AK), betulinic acid-nanochitosan (BK), amphotericin B-dendrimer (AD), and betulinic acid-dendrimer (BD) in the treatment of Leishmania major infection (L. major) in mice model by using pathological analyses to choose the most effective nanodrug in leishmaniasis. Methods: The four nanodrugs efficacy in the improvement of L. major lesion in a mice model was evaluated by using pathological analyses including measurement of organs size and parasite number. Additionally, the nanodrugs toxicity was evaluated by measurement of various blood factors. Results: The histopathological results of the present study showed that BK, at the dose of 20 mg/kg, and AK, at the dose of 10 mg/kg, were more effective in decreasing the parasite number in the kidney, liver, and spleen. Moreover, BK20 mg/kg and AK10 mg/kg decreased the organs size significantly while AD50 mg/kg and BD40 mg/kg were less effective. However, none of the four nanodrugs had increased the blood factors and they were not toxic. Conclusions: Overall, the pathologic findings of various mice organs treated with different formulations showed that AK10 mg/kg and BK20 mg/kg were more effective in recovery of L. major’s pathological effects in comparison to AD50 mg/kg and BD40 mg/kg. Therefore, it seems that AK and BK, in this mentioned dosage, could be considered as a proper candidate for treatment of leishmaniasis.

Nosocomial infections with a bacterial origin are considered one of the most dangerous threats to global health. Among the causes of these infections, Acinetobacter baumannii is playing a significant role, and the present study aimed‏ to determine the immunogenic proteins of this bacteria. Clinical isolates of A. baumannii were obtained from positive sputum cultures of intensive care unit (ICU) patients confirmed by Polymerase chain reaction (PCR) of the OXA-51 gene, and sera was obtained from 20 colonized patients. In addition, 20 and 30 serum samples were collected from ICU nurses and healthy controls, respectively. All the samples were screened in the presence of antibodies against A. baumannii by enzyme-linked immunosorbent assay (ELISA). IgG purified from the serum samples by affinity chromatography was used to isolate the bacteria by the Magnetic-activated cell sorting (MACS) procedure. After the bacteria were cultured, the identified antigen proteins were studied by western blotting and Mass spectrometry (MS). The MS results were analyzed with MASCOT software and revealed a 35 KD protein, which corresponds to outer membrane protein A (OmpA) of A. baumannii, a 25 KD band, which is a carbapenem-associated resistance protein precursor, and a 60 KD protein band, identified as a stress-induced bacterial acidophilic repeat motif protein. According to the properties of immunogen antigens and bio informatics tools, the outer membrane proteins (OMPs) can be used as a vaccine candidate in animal models.

This study aimed to identify the effects of olive leaf extract (OLE) on IFNγ, TNFα, TGFβ and nitric oxide (NO) resulted from macrophages infected with Leishmania major (L. major) amastigotes in the culture medium. High-performance liquid chromatography (HPLC) was used to analyse the level of Oleuropein in plant extract. To evaluate the immunomodulatory effects of OLE, the isolated BALB/c mice peritoneal macrophages were infected with L. major promastigotes and treated with 6.25, 12.5 and 25 μg/mL concentrations of OLE. To assess the cytokines, supernatants of cell cultures were harvested after 12, 24 and 48 hours. Cytokine production was evaluated by ELISA. Nitrite accumulation in the culture medium was assessed using the Griess reaction. The level of Oleuropein in the extract was 18.45% by HPLC. According to results, the production of IFNγ and TNFα was significantly increased when the infected and/or not infected macrophages with L. major promastigotes were affected by different concentrations of OLE. Conversely, the production of TGFβ was significantly decreased under the same conditions. Furthermore, the colorimetric determination of NO accumulation in the culture medium indicated that OLE has no effect on NO production. The study corroborates the immunomodulatory effects of OLE on L. major-infected macrophages.

We hypothesized that Tumor cell lysate (TCL) prepared from spontaneous mouse mammary tumor (SMMT) may elicit IgG production by spleen mononuclear cells (SMCs) in ex vivo.The SMCs from healthy mice (HM, n = 6) and four-week SMMT-bearing mice (TBM, n = 6) was cultured in presence of TCL and mitogen for 42 hr at 37°C, separately. Serum and SMCs culture supernatant levels of IFNγ, IL-4, and total IgG were measured using special ELISA kits.Serum IgG level of TBM was significantly higher than that of HM group (P = 0.019), while serum IFNγ and IL-4 did not differ between two groups (P0.05). Mitogen significantly induced ex vivo production of both IFNγ (P = 0.013) and IL-4 (P = 0.015) by SMCs from HM group, and only IL-4 (P = 0.049) by SMCs from TBM group. In contrast, TCL increased ex vivo production of IgG by SMCs from both HM (P = 0.034) and TBM (P = 0.016) groups. The ex vivo IgG revealed a moderate positive correlation with tumor size (r = 0.578, P = 0.422).It seems that TCL prepared from SMMT are potent inducers of IgG production. This may propose TCL as a potential tool for monitoring of humoral immunity in animal models.

Background Hepatitis infection represents one of the important causes of morbidity and mortality in developing countries, however there is not any effective vaccine against hepatitis C which is one of the significant problems in vaccine project. Objectives The aim of the present study is to evaluate the role of HCV core protein in inducing IFN-Gamma secretion and TCL activities as a vaccine in Balb/C mice. Material and Methods Our previous cloned plasmid (HCV Core gene into pETDuet-1) applied for protein expression in bacteria. The expressed and purified recombinant protein together with Freund’s adjuvant was injected to 15 Balb/c mice. The total IgG and IgG2a of immunized mice sera were evaluated after a week. Two weeks after booster injection, we studied the proliferation and IFNγ secretion of spleens, inguinal and popliteal lymph nodes lymphocytes by ELISA and ELISPOT. Results The FSFC (Frequency of spot forming cells) of secreting cells of immunized mice with HCV/Core protein and sera IgG2a were considerably higher than the control groups. Conclusions The core protein together with proper adjuvant can be a candidate vaccine against of HCV infection.

Leishmania exhibit many unusual features, one of which is the pteridine metabolic pathway essential for the growth for these parasites. Leishmania have evolved a complex and versatile pteridine salvage network capable of scavenging a wide array of conjugated and unconjugated pteridines. The L. major PTR1 gene was cloned into pcDNA3 digested with KpnI and BamHI. The gene was cloned antiparallel to the promoter and named pcDNA-Rptr. L. major promastigotes were divided into two groups. One group was transfected with 50 &x03BC;g of pcDNA-Rptr, whereas the other group was electroporated with pcDNA3. Mentioned cells were cultured and plated onto semi-solid media.Western blotting was performed on extracts from transfected promastigotes of L. major using an leishmania major PTR1 antibody. The PTR1 protein was not expressed in pcDNA-Rptr-tansfected promastigotes, 'Our results indicate that our system may be useful for studying the pteridine salvage pathway in Leishmania as a possible drug target.

The aerial parts of Tanacetum balsamita subsp. balsamita were collected at full flowering stage from Tabriz, Iran. The essential oil was isolated by hydrodistillation and analyzed by combination of capillary GC and GC-MS. Twenty seven components were identified, representing 99.2% of the total oil. Carvone (51.0%), β-thujone (20.8%), 1,8-cineole (4.4%) and α-thujone (3.2%) were the main components. The in vitro antimicrobial activity of the essential oil of T. balsamita subsp. balsamita was studied against eight Gram-positive and Gram-negative bacteria ( Bacillus subtilis, B. pumulis, Enterococcus faecalis, Staphylococcus aureus, S. epidermidis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) and three fungi ( Candida albicans, Saccharomyces cerevisiae and Aspergillus niger). The results of the antimicrobial activity of the essential oil according to the disc diffusion method and MIC values indicated that the oil exhibited moderate to high antimicrobial activity. The in vitro toxicological study based on the MTT cytotoxicity assay on human fetal skin fibroblast (HFSF) and Monkey kidney (Vero) cell lines showed IC50 values of 2500 and 1250 μg/mL, respectively.