CTC together with Shh and Nrf2 are prospective diagnostic markers for HNSCC

BACKGROUND

The lack of appropriate prognostic biomarkers remains a significant obstacle in the early detection of Head and Neck Squamous Cell Carcinoma (HNSCC), a cancer type with a high mortality rate. Despite considerable advancements in treatment, the success in diagnosing HNSCC at an early stage still needs to be improved. Nuclear factor erythroid 2-related factor 2 (Nrf2) and Sonic Hedgehog (Shh) are overexpressed in various cancers, including HNSCC, and have recently been proposed as possible therapeutic targets for HNSCC. Circulating Tumor Cell (CTC) is a novel concept used for the early detection of cancers, and studies have suggested that a higher CTC count is associated with the aggressiveness of HNSCC and poor survival rates. Therefore, we aimed to establish molecular markers for the early diagnosis of HNSCC considering Shh/Nrf2 overexpression in the background. In addition, the relation between Shh/Nrf2 and CTCs is still unexplored in HNSCC patients.

METHODS

In the present study, we selected a cohort of 151 HNSCC patients and categorized them as CTC positive or negative based on the presence or absence of CTCs in their peripheral blood. Data on demographic and clinicopathological features with the survival of the patients were analyzed to select the patient cohort to study Shh/Nrf2 expression. Shh and Nrf2 expression was measured by qRT-PCR.

RESULTS

Considering significant demographic [smoking, betel leaf (p-value < 0.0001)] and clinicopathological risk factors [RBC count (p < 0.05), Platelet count (p < 0.05), Neutrophil count (p < 0.005), MCV (p < 0.0001), NLR (p < 0.05), MLR (p < 0.05)], patients who tested positive for CTC also exhibited significant overexpression of Shh/Nrf2 in both blood and tissue compared to CTC-negative patients. A strong association exists between CTCs and tumor grade. Following chemotherapy (a combination of Cisplatin, 5FU, and Paclitaxel), the frequency of CTCs was significantly decreased in patients with HNSCC who had tested positive for CTCs. The Kaplan-Meier plot illustrated that a higher number of CTCs is associated with poorer overall survival (OS) in patients with HNSCC.

CONCLUSIONS

Detecting CTCs, and higher expression of Shh and Nrf2 in HNSCC patients' blood, can be a promising tool for diagnosing and prognosticating HNSCC.

Reduced IFN-γ levels along with changes in hematologic and immunologic parameters are key to COVID-19 severity in Bangladeshi patients

The manifestation of coronavirus disease 2019 (COVID-19) severity and mortality has been associated with dysregulation of the immune response, often influenced by racial disparities and conferred by changes in hematologic and immunologic parameters. These biological and hematologic parameters as well as cytokine profiles were investigated in a cohort of 61 COVID-19-positive patients (categorized into mild, moderate, and severe groups) from Bangladesh using standard analytical methods. The data reported that the interleukin (IL)-4 and IL-6 levels were significantly increased, whereas the levels of interferon (IFN)-γ were significantly reduced in patients with severe COVID-19 (p < 0.05) compared with those in patients with mild and/or moderate COVID-19. The extent of erythrocyte sedimentation rate (ESR); neutrophil count; and levels of ferritin, C-reactive protein (CRP), and D-dimer (p < 0.05) were found to be significantly increased, whereas the white blood cell (WBC), lymphocyte, eosinophil, and platelet counts (p < 0.05) were observed to be significantly reduced in patients with severe COVID-19 compared with those in the patients in other 2 groups. Our study exhibited a significantly higher IL-6-to-lymphocyte ratio in patients with severe COVID-19 than in those with mild and moderate COVID-19. The calculated neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and ferritin-to-ESR ratio were significantly increased in patients with severe COVID-19. The increase in the IL-4 and IL-6 levels along with CRP and D-dimer levels may envisage a hyperinflammatory environment and immune dysregulation, which contribute to prolonged viral persistence, leading to severe disease. However, the reduced level of IFN-γ can be attributed to a less fatality toll in Bangladesh compared with that in the rest of the world.

Circulating tumor cells demonstrate a positive biomarker in head and neck squamous cell carcinoma (HNSCC) in tobacco consuming population of Bangladesh

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Background: Tobacco consumption accounts for 1.6 million deaths annually in the South East Asia Region (SEAR). Notably, amongst 10-20% of the global population consuming the betel quid and tobacco, about 81% concentration is in SEAR regions, including India and Bangladesh. The prevalence of HNSCC in these regions is rising alarmingly. For example, HNCs account for 23% of total 156775 cancer incidences in Bangladesh. Liquid biopsy tools are unavailable and expensive for most patients in this region. However, early cancer detection using tumor biomarkers, for example, Circulating Tumor Cells (CTCs) is highly implicated. Furthermore, such biomarkers are being validated and have potential for screening of high-risk patients, such as genetic predisposition, tobacco consumption, etc. We report the first observational study in HNSCC patients in Bangladesh correlating the presence of CTCs to chronic tobacco consumption. Methods: The study involved 70 cancer patients and 10 healthy volunteers (no prior cancer history). 87% of the patients had a specified history of chronic tobacco consumption. CTCs were isolated in 1.5 ml of blood using OncoDiscover Liquid Biopsy Test, which is clinically approved by the Drug Controller General of India, that contains an enriching anti-EPCAM antibody immunomagnetic kit. CTCs are qualified as CK18+, DAPI+and CD45-. Subsequently, CTCs were imaged using Zeiss Axio Observer 7 and quantified for Mean Fluorescence Intensity (MFI) for clinicopathological parameters; age/gender, HNSCC sub-population, and CTC distribution. Results: This is the 1st study on Bangladesh phenotype accounting for the presence of CTCs in HNSCC patients. In this population, 34 males (66%) and 10 females (52%) accounted for 91 CTCs. CTC distribution was 0 to 6 with mean and median ̃ 2.02 and 2, respectively. 25 patients (17 males, 8 females) were negative for any CTCs. Interestingly, 02 patients exhibited CTC clusters indicative of aggressive metastasis in which 01 patient had no prior tobacco usage or family cancer history. There was no correlation between CTC presence in males (66 %) and females (52 %). Healthy volunteer samples exhibited no false positives. The MFI values ranged between 23 and 766, with mean and median MFI values were 157 and 96, respectively, indicative of CK overexpression on CTCs of HNSCC patients. Conclusions: HNSCC patients with a history of chronic tobacco consumption in Bangladesh correlated the presence of CTCs in 64 % of the cases. Prospectively, CTCs may be validated as a biomarker for screening chronic tobacco users in Bangladesh to detect early cancers and HNSCC. Clinical trial information: BMRC/Grants/2018/99 (1-100).

PTHrP, A Biomarker for CNS Metastasis in Triple-Negative Breast Cancer and Selection for Adjuvant Chemotherapy in Node-Negative Disease

Background

Triple-negative breast cancer (TNBC) is characterized by poor prognosis and lack of targeted therapies and biomarkers to guide decisions on adjuvant chemotherapy. Parathyroid hormone-related protein (PTHrP) is frequently overexpressed in breast cancer and involved in proliferation and metastasis, two hallmarks of poor prognosis for node-negative breast cancer. We investigated the prognostic value of PTHrP with respect to organ-specific metastasis and nodal status in TNBC.

Methods

We assessed PTHrP expression using immunohistochemistry in a clinically annotated tissue microarray for a population-based study of 314 patients newly diagnosed with TNBC, then analyzed its correlation to progression and survival using Kaplan-Meier and Cox regression analyses. The Cancer Genome Atlas (TCGA) validation analysis was performed through Bioconductor. All statistical tests were two-sided.

Results

PTHrP overexpression (160 of 290 scorable cases, 55.2%) was statistically significantly associated in univariate analysis with decreased overall survival (OS) in our cohort (P = .0055) and The Cancer Genome Atlas (P = .0018) and decreased central nervous system (CNS)-progression-free survival (P = .0029). In multivariate analysis, PTHrP was a statistically significant independent prognostic factor for CNS-progression-free survival in TNBC (hazard ratio [HR] = 5.014, 95% confidence interval [CI] = 1.421 to 17.692, P = .0122) and for OS selectively in node-negative TNBC (HR = 2.423, 95% CI = 1.129 to 5.197, P = .0231). Strikingly, PTHrP emerged as the only statistically significant prognostic factor (HR = 2.576, 95% CI = 1.019 to 6.513, P = .0456) for OS of low-clinical risk node-negative patients who did not receive adjuvant chemotherapy.

Conclusions

PTHrP is a novel independent prognostic factor for CNS metastasis and adjuvant chemotherapy selection of low-clinical risk node-negative TNBC. Its predictive value needs to be prospectively assessed in clinical trials.

Abstract 4699: Identification of novel potential biomarkers of response to sunitinib in glioblastoma

Introduction: Glioblastoma multiforme (GBM) is the most advanced and aggressive form of primary malignant brain tumors in adults. O6-Methylguanine methyltransferase (MGMT) is a DNA repair protein well known for its role in resistance to temozolomide used in standard treatment of patients newly diagnosed with GBM. Sunitinib is an oral multitargeting receptor tyrosine kinase (RTK) inhibitor with antiangiogenic and antiproliferative activities targeting several RTKs. Our group has previously shown the role of MGMT as a negative regulator of angiogenesis and invasion and the differential antiproliferative effect of sunitinib based on expression of MGMT in GBM. Recent gene expression profiling (GEP) studies showed that besides its effects on RTKs, sunitinib affects the expression level of other genes at the transcriptional level in different cancer types. We hypothesized that: (i) the mechanism of action of sunitinib may not be limited to direct inhibition of its known targets (RTKs) in GBM and (ii) expression of MGMT may affect response of GBM tumor cells to sunitinib. We performed GEP analysis to identify genes that could be potentially modulated in response to sunitinib in GBM cell lines isogenic for MGMT. Empty vector (EV)-transfected T98/EV cells with constitutive expression of MGMT and its knockdown counterpart T98/MGMT-shRNA were treated with sunitinib or vehicle control. Treatment of T98/EV and T98/MGMT-shRNA cell lines with sunitinib significantly changed the expression of over 2,000 gene transcripts (analysis performed at Genome Quebec Innovation center, McGill University). Lists of significant genes were fitted into previously known biochemical pathways, available among the canonical pathways from various databases provided by ConsensusPathDB (CPDB). Strikingly, immune system was among the top significantly enriched pathways (p-value&lt;10-3), with some immune pathways not previously reported for response to sunitinib.

Conclusion: Our study opens new avenues to further understand the mechanisms of action of sunitinib, investigate its immunomodulatory effects, and identify biomarkers for selection of patients who might benefit from the combination of antiangiogenic and immunebased strategies in GBM.

Funding Acknowledgment: Cancer Research Society Operating Grant Competition #22716, and Higher Education Quality Enhancement Project (HEQEP)- Window -4 (Grant Id. CP-4023), University Grant Commission (UGC), Bangladesh.

Citation Format: Abu Shadat Mohammod Noman, Bassam Abdulkarim, Siham Sabri. Identification of novel potential biomarkers of response to sunitinib in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4699.

Arsenic-induced Histological Alterations in Various Organs of Mice

Deposition of arsenic in mice through groundwater is well documented but little is known about the histological changes of organs by the metalloid. Present study was designed to evaluate arsenic-induced histological alterations in kidney, liver, thoracic artery and brain of mice which are not well documented yet. Swiss albino male mice were divided into 2 groups and treated as follows: Group 1: control, 2: arsenic (sodium arsenite at 10 mg/kg b.w. orally for 8 wks). Group 2 showed marked degenerative changes in kidney, liver, thoracic artery, and brain whereas Group 1 did not reveal any abnormalities on histopathology. We therefore concluded that arsenic induces histological alterations in the tested organs.

Associations of total arsenic in drinking water, hair and nails with serum vascular endothelial growth factor in arsenic-endemic individuals in Bangladesh

Arsenic exposure is associated with cancer and vascular diseases. Angiogenesis is an important step for the pathological development of cancer and vascular diseases. Vascular endothelial growth factor (VEGF) is a specific marker for angiogenesis. However, human study showing the association between arsenic exposure and serum VEGF levels has not yet been documented. This study was aimed to investigate the association between arsenic exposure and serum VEGF levels in the arsenic-endemic individuals in Bangladesh. A total of 260 individuals were recruited for this study. Arsenic exposure levels were measured by ICP-MS and VEGF levels were quantified using VEGF immunoassay kit. The study subjects were stratified into tertile (low, medium and high) groups based on the arsenic in water, hair and nails. Serum VEGF levels were correlated with water (rs = 0.363, p < 0.001), hair (rs = 0.205, p < 0.01) and nail (rs = 0.190, p < 0.01) arsenic. Further, VEGF levels showed dose-response relationships with water, hair and nail arsenic. Mean VEGF levels in ⩽ 10 μg L(-1), 10.1-50 μg L(-1) and > 50 μg L(-1) groups were 91.84, 129.54, and 169.86 pg mL(-1), respectively, however, significant (p < 0.01) difference in VEGF levels was only found in > 50 μg L(-1) versus ⩽ 10 μg L(-1) groups. Significant associations of arsenic exposure with VEGF levels were found even after adjusting with relevant covariates. Therefore, these results provide evidence that arsenic exposure has a pro-angiogenic effect on humans, which may be implicated in arsenic-induced tumorigenesis and vascular diseases.

An ADP ribosylation factor-GTPase activating protein negatively regulates the production of proinflammatory mediators in response to lipopolysaccharide

An ADP ribosylation factor-GTPase activating protein (ASAP1) is highly expressed in a variety of tumor cells and is involved in the cell motility, invasion, and metastasis. In order to elucidate the involvement of ASAP1 in lipopolysaccharide (LPS)-mediated inflammatory response, the effect of ASAP1 silencing on LPS-induced proinflammatory mediators production was examined by using RAW 264.7 macrophage-like cells. ASAP1 was constitutively expressed in the cells and the expression was augmented by LPS stimulation. Silencing of ASAP1 with small interfering RNA enhanced the production of tumor necrosis factor-α, interleukin 6, interferon-β, and nitric oxide in response to LPS. ASAP1 silencing augmented the activation of nuclear factor (NF)-κB and several mitogen-activated protein kinases (MAPKs). On the other hand, ASAP1 silencing did not affect the expression of IRAK4, TRAF6, and Akt as the upstream molecules of NF-κB signaling. A series of toll-like receptor ligands as well as LPS augmented the ASAP1 expression. Taken together, ASAP1 was suggested to negatively regulate LPS-induced proinflammatory mediators production through down-regulating LPS signaling. The feedback function of ASAP1 in LPS-mediated inflammatory response is discussed.

Flavopiridol inhibits lipopolysaccharide-induced TNF-α production through inactivation of nuclear factor-κB and mitogen-activated protein kinases in the MyD88-dependent pathway

Flavopiridol is a cyclin-dependent kinase inhibitor and inhibits the growth of various cancer cells. The effect of flavopiridol on lipopolysaccharide (LPS)-induced proinflammatory mediator production was examined in RAW 264.7 macrophage-like cells. Flavopiridol significantly reduced the production of tumor necrosis factor-α and, to a lesser extent, nitric oxide in LPS-stimulated cells. Flavopiridol inhibited the activation of nuclear factor-κB and IκB kinase in response to LPS. Flavopiridol also inhibited the activation of a series of mitogen-activated protein kinases, such as p38, stress-activated protein kinase/c-Jun N-terminal kinase and extracellular signal-regulated kinase 1/2 in response to LPS. However, flavopiridol did not alter the expression of tumor necrosis factor receptor-associated factor 6, myeloid differentiation factor 88 (MyD88) or CD14/toll-like receptor (TLR) 4. Flavopiridol inhibited nitric oxide production induced by a MyD88-dependent TLR2 ligand, but not a MyD88-independent TLR3 ligand. Further, flavopiridol did not alter the phosphorylation of interferon regulatory factor 3 in the MyD88-independent pathway. Therefore, it was suggested that flavopiridol exclusively inhibited the activation of nuclear factor-κB and mitogen-activated protein kinases in the MyD88-dependent pathway. Flavopiridol might be useful for the prevention of LPS-induced inflammatory response.

Endotoxin-induced lung injury in α-galactosylceramide-sensitized mice is caused by failure of interleukin-4 production in lung natural killer T cells

Administration of bacterial lipopolysaccharide (LPS) known as endotoxin into α-galactosylceramide (α-GalCer)-sensitized mice causes severe lung lesions but few hepatic lesions in lethal shock, and interferon (IFN)-γ is suggested to play a pivotal role in preparation of the lung lesions. In order to clarify the mechanism of how α-GalCer sensitization causes lung lesions exclusively in mice, we examined the differential responsiveness of lungs and livers to α-GalCer sensitization. Although lung and liver natural killer T (NK T) cells both produced IFN-γ in response to α-GalCer, IFN-γ signalling was triggered only in the lungs of α-GalCer-sensitized mice. Lung NK T cells did not produce interleukin (IL)-4 in response to α-GalCer and it did not induce the expression of suppressor of cytokine signalling 1 (SOCS1) in the lungs. Conversely, IL-4 produced by liver NK T cells led to the expression of SOCS1 in the livers of the mice. Neutralization of IL-4 reduced SOCS1 expression in the livers and exacerbated LPS-induced hepatic lesions. IL-10 was produced by liver NK T cells but not lung NK T cells. However, IL-10 was produced constitutively by alveolar epithelial cells in normal lung. Lung NK T cells and liver NK T cells might express CD8 and CD4, respectively. Based on the fact that IL-4 inhibited IFN-γ signalling in the livers of α-GalCer-sensitized mice via SOCS1 expression and signal transducer and activator of transcription 1 (STAT-1) activation, no inhibition of the IFN-γ signalling in the lungs caused LPS-induced lung lesions in α-GalCer-sensitized mice. The detailed mechanism of development of the lung lesions in α-GalCer-sensitized mice is discussed.

Retinoblastoma protein-interacting zinc finger 1, a tumor suppressor, augments lipopolysaccharide-induced proinflammatory cytokine production via enhancing nuclear factor-kappaB activation

The involvement of retinoblastoma protein-interacting zinc finger 1 (RIZ1), a tumor suppressor, in lipopolysaccharide (LPS)-induced inflammatory responses was investigated by using RAW 264.7 macrophage-like cells. LPS significantly augmented the expression of RIZ1 and the augmentation was mediated by the activation of nuclear factor (NF)-kappaB and Akt. The silencing of RIZ1 with the siRNA led to the inactivation of NF-kappaB in response to LPS. Moreover, the RIZ1 silencing caused the down-regulation of p53 activation and a p53 pharmacological inhibitor attenuated the RIZ1 expression. LPS-induced tumor necrosis factor-alpha and interleukin-6 production was prevented by RIZ1 siRNA or a p53 pharmacological inhibitor. Therefore, RIZ1 was suggested to augment LPS-induced NF-kappaB activation in collaboration with p53 and enhance the production of proinflammatory cytokines in response to LPS.

Retinoblastoma protein-interacting zinc finger 1 (RIZ1) participates in RANKL-induced osteoclast formation via regulation of NFATc1 expression

The role of retinoblastoma protein-interacting zinc finger 1 (RIZ1) in receptor activator of NF-kappaB ligand (RANKL)-induced osteoclast formation was examined in mouse RAW 264.7 macrophage-like cells. The expression of RIZ1 was significantly augmented by RANKL-treated cells. Silencing of RIZ1 with the siRNA significantly reduced the appearance of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells as osteoclasts in RANKL-treated cells. The expression of nuclear factor of activated T cell 1 (NFATc1) as the terminal transcription factor of osteoclast formation was prevented by RIZ1 siRNA. It was suggested that that RIZ1 might participate in RANKL-induced osteoclast formation through the regulation of NFATc1 expression.

Tumor necrosis factor-a augments lipopolysaccharide-induced suppressor of cytokine signalling 3 (SOCS-3) protein expression by preventing the degradation

The regulatory role of tumour necrosis factor-a (TNF-a) on the expression of suppressor of cytokine signalling 3 (SOCS-3) in response to lipopolysaccharide (LPS) was examined using peritoneal macrophages from TNF-a-deficient mice. The LPS-induced SOCS-3 expression was markedly augmented in macrophages from wild-type mice whereas such augmentation was not seen in the cells from TNF-a-deficient mice. However, there was no significant difference in the level of SOCS-3 messenger RNA expression between macrophages from wild-type mice and those from TNF-a-deficient mice. The addition of exogenous TNF-a augmented the LPS-induced SOCS-3 expression in macrophages from TNF-a-deficient mice. The pulse chase analysis suggested augmented degradation of LPS-induced SOCS-3 protein in macrophages from TNF-a-deficient mice. Moreover, MG 132, a 26S proteasome inhibitor, sustained the LPS-induced SOCS-3 expression in those cells. The tyrosine phosphorylation of SOCS-3 was definitely induced in LPS-stimulated macrophages from TNF-a-deficient mice but not wild-type mice. A tyrosine phosphatase inhibitor enhanced the tyrosine phosphorylation of SOCS-3 in wild-type mice and accelerated the degradation. Therefore, it was suggested that TNF-a prevented the degradation of SOCS-3 protein via inhibition of the tyrosine phosphorylation in LPS-stimulated macrophages.

Interleukin (IL)-10 attenuates lipopolysaccharide-induced IL-6 production via inhibition of IkappaB-zeta activity by Bcl-3

The inhibitory effect of interleukin-10 (IL-10), an anti-inflammatory cytokine, on lipopolysaccharide (LPS)-induced IL-6 production was characterized by simultaneous stimulation of RAW 264.7 cells with LPS and IL-10. The presence of IL-10 significantly inhibited LPS-induced IL-6 production at a transcriptional level. The expression of IkappaB-zeta, which promotes IL-6 production, was induced in response to LPS and it was definitely suppressed in the presence of IL-10. Further, IL-10 inhibited LPS-induced NF-kappaB activation. A pharmacological inhibitor of NF-kappaB prevented LPS-induced IkappaB-zeta expression, suggesting that IL-10 might inhibit LPS-induced IkappaB-zeta expression via the inactivation of NF-kappaB. In LPS- and IL-10-stimulated cells, the expression of Bcl-3 that inhibits NF-kappaB activation was significantly augmented. Introduction of Bcl-3 siRNA abolished IL-10-mediated IkappaB-zeta inhibition. In the presence of Bcl-3, siRNA IL-10 failed to inhibit LPS-induced IL-6 production. Therefore, it was suggested that Bcl-3 induced by IL-10 might reduce LPS-induced IkappaB-zeta activity via inactivation of NF-kappaB and that reduced IkappaB-zeta activity failed to promote LPS-induced IL-6 production.

Novel mechanism of U18666A-induced tumour necrosis factor-alpha production in RAW 264.7 macrophage cells

U18666A is a cholesterol transport-inhibiting agent that is used widely to mimic Niemann-Pick type C disease. The effect of U18666A on tumour necrosis factor (TNF)-alpha production in mouse macrophage cell line, RAW 264.7 cells and peritoneal macrophages was examined. U18666A induced TNF-alpha mRNA expression 48 h after the treatment, and TNF-alpha production 48 and 72 h after stimulation in RAW 264.7 cells. U18666A accumulated intracellular free cholesterol in the culture of normal medium but not cholesterol-free medium. U18666A also induced reactive oxygen species (ROS) generation in normal medium but much less in cholesterol-free medium. Anti-oxidant N-acetyl-L-cysteine (NAC) abolished U18666A-induced TNF-alpha production. U18666A led to the phosphorylation of p38 mitogen-activated protein kinase 24 and 48 h after the stimulation and the p38 activation was inhibited in presence of cholesterol-free medium or NAC. A p38 inhibitor reduced U18666A-induced TNF-alpha production. Taken together, U18666A was suggested to induce TNF-alpha production in RAW 264.7 cells via free cholesterol accumulation-mediated ROS generation.

Biological Screening of a Novel Nickel (II) Tyrosine Complex

A newly synthesized Nickel (II) tyrosine complex was screened as potential antimicrobial agent against a number of medically important bacteria (Bacillus subtilis, Streptococcus β-haemolytica, Escherichia coli, Shigella dysenterae) and fungi (Aspergillus fumigatus, Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium sp.) strains. were used for antifungal activity. The antimicrobial activity was evaluated using the Agar Disc method. Moreover, the minimum inhibitory concentration of the complexes was determined against the same pathogenic bacteria and the values were found between 4~64 µg ml (-1). Brine shrimp bioassay was carried out for cytotoxicity measurements of the complexes. The LC50 values were calculated after probit transformation of the resulting mortality data and found to be 6 µg ml (-1).