Nanomicellar Formulation of Clotrimazole Improves Its Antitumor Action toward Human Breast Cancer Cells

Clotrimazole reverses macrophage M2 polarization by disrupting the PI3K/AKT/mTOR pathway

Macrophages switch among different activation phenotypes according to distinct environmental stimuli, varying from pro-inflammatory (M1) to alternative (also named resolutive; M2) activation forms. M1-and M2-activated macrophages represent the two extremes of the activation spectrum involving multiple species, which vary in terms of function and the cytokines secreted. The consensus is that molecular characterization of the distinct macrophage population and the signals driving their activation will help in explaining disease etiology and formulating therapies. For instance, myeloid cells residing in the tumor microenvironment are key players in tumor progression and usually display an M2-like phenotype, which help tumor cells to evade local inflammatory processes. Therefore, these specific cells have been proposed as targets for tumor therapies by changing their activation profile. Furthermore, M2 polarized macrophages are phagocytic cells promoting tissue repair and wound healing and are therefore potential targets to treat different diseases. We have already shown that clotrimazole (CTZ) decreases tumor cell viability and thus tumor growth. The mechanism by which CTZ exerts its effects remains to be determined, but this drug is an inhibitor of the PI3K/AKT/mTOR pathway. In this study, we show that CTZ downregulated M2-activation markers in macrophages polarized to the M2 profile. This effect occurred without interfering with the expression of M1-polarized markers or pro-inflammatory cytokines and signaling. Moreover, CTZ suppressed NFkB pathway intermediates and disrupted PI3K/AKT/mTOR signaling. We concluded that CTZ reverses macrophage M2 polarization by disrupting the PI3K/AKT/mTOR pathway, which results in the suppression of NFkB induction of M2 polarization. In addition, we find that CTZ represents a promising therapeutic tool as an antitumor agent.

Development and Validation of Reverse-Phase High-Performance Liquid Chromatography Method for Simultaneous Estimation of Doxorubicin and Clotrimazole

A reverse-phase high-performance liquid chromatographic (RP-HPLC) method was developed to analyze the simultaneous estimation of doxorubicin and clotrimazole. The method was achieved by Nucleodur C18 column with dimension 250 × 4.6 mm (5 μm) using gradient elution. The mobile phase contained 0.2% formic acid (pH 3.2) and acetonitrile. The flow rate was kept at 1.0 mL/min and detection and quantitation of both drugs (doxorubicin and clotrimazole) were achieved using a photodiode array detector at 276 nm, which was the isosbestic point for both drugs. The proposed method was validated according to the current International Council for Harmonization of Technical Requirements of Pharmaceuticals for Human Use guidelines for specificity, linearity, accuracy, precision, and robustness. The developed method showed a linear response (R2 > 0.999), and was accurate (recoveries 97%-103%), precise (resolution ≤1.0%), sensitive, and specific. Thus, the developed RP-HPLC method for the simultaneous estimation of both drugs was successfully validated and can be utilized for the estimation of these drugs in the formulations being developed.

The radical scavenging activity of monocaffeoylquinic acids: the role of neighboring hydroxyl groups and pH levels

Caffeoylquinic acids (CQAs) are well-known antioxidants. However, a key aspect of their radical scavenging activity - the mechanism of action - has not been addressed in detail thus far. Here we report on a computational study of the mechanism of activity of CQAs in scavenging hydroperoxyl radicals. In water at physiological pH, the CQAs demonstrated ≈ 104 times higher HOO˙ antiradical activity than in lipid medium (k(lipid) ≈ 104 M-1 s-1). The activity in the aqueous solution was determined by the hydrogen transfer mechanism of the adjacent hydroxyl group (O6'-H) of the dianion states (Γ = 93.2-95.2%), while the single electron transfer reaction of these species contributed 4.8-6.8% to the total rate constants. The kinetics estimated by the calculations are consistent with experimental findings in water (pH = 7.5), yielding a kcalculated/kexperimental = 2.4, reinforcing the reliability and precision of the computational method and demonstrating its utility for evaluating radical reactions in silico. The results also revealed the pH dependence of the HOO˙ scavenging activity of the CQAs; activity was comparable for all compounds below pH 3, however at higher pH values 5CQA reacted with the HOO˙ with lower activity than 3CQA or 4CQA. It was also found that CQAs are less active than Trolox below pH 4.7, however over pH 5.0 they showed higher activity than the reference. The CQAs had the best HOO˙ antiradical activity at pH values between 5.0 and 8.6. Therefore, in the physiological environment, the hydroperoxyl antiradical capacity of CQAs exhibits similarity to renowned natural antioxidants including resveratrol, ascorbic acid, and Trolox.

Clotrimazole is effective, safe and tolerable for the treatment of endometriosis and functions by downregulating inducible nitric oxide synthase and modulating oxidative stress biomarkers

This study investigated the mechanism of action of clotrimazole (CTZ) and its adverse effects in a model of endometriosis. After autologous endometrial implantation, 18 rats were randomized into two treatment groups: 200 mg/kg CTZ or vehicle for 15 consecutive days. The lesion growth, implant size, glandular atrophy, nitric oxide (NO) serum levels, number of macrophage cells and inducible nitric oxide synthase (iNOS) immunoreactivity were significantly reduced in the CTZ group compared with the control. CTZ (p < 0.05) reduced the lipid peroxidation and protein carbonylation levels in the liver but did not alter the superoxide dismutase (SOD), glutathione (GSH) or glutathione S-transferase (GST) levels in the brain; however, the drug significantly reduced SOD activity and enhanced GST activity in the liver. These results suggest that CTZ interferes with reactive nitrogen species production by downregulating iNOS expression and thus enhances the antioxidant system to promote atrophy and regression of endometriotic lesions, without adverse effects on the brain and/or liver.

Detachment of Hexokinase II From Mitochondria Promotes Collateral Sensitivity in Multidrug Resistant Chronic Myeloid Leukemia Cells

Chronic Myeloid Leukemia is a neoplastic disease characterized by the abnormal expansion of hematopoietic cells with compromised functions. Leukemic cells often display a multidrug resistance phenotype, enabling them to evade a number of structurally unrelated cytotoxic compounds. One of those mechanisms relies on the high expression of efflux transporters, such as the ABC proteins, whose activity depends on the hydrolysis of ATP to reduce intracellular drug accumulation. In the present work, we employed a well-known erythroleukemia cell line, K562, and a multidrug resistant derivative cell, FEPS, to evaluate how hexokinase II, a key regulator for the rate-limiting step glycolysis, contributes to the establishment of the multidrug resistance phenotype. We found that multidrug resistant cells primarily resort to glycolysis to generate ATP. Clotrimazole reduced the expression of mitochondrial hexokinase II, which destabilized bioenergetic parameters such as reactive oxygen species production, ATP, and glutathione levels on multidrug resistant cells. This impaired the activity of ABCC1, leading to increased drug accumulation and cell death. In summary, we propose that decoupling of hexokinase II from the mitochondria emerges as a promising strategy to generate collateral sensitivity and aid in the management of chronic myeloid leukemia in chemotherapy-refractory patients.

Clotrimazole presents anticancer properties against a mouse melanoma model acting as a PI3K inhibitor and inducing repolarization of tumor-associated macrophages

The immune system is a key component of tumorigenesis, with the latter promoting the development of cancer, its progression and metastasis. In fact, abundant infiltration of tumor-associated macrophages (TAM), which are M2-like macrophages, has been associated with a poor outcome in most types of cancers. Here, we show that lactate produced by murine melanoma B16F10 cells induces an M2-like profile in cultured macrophages. Further, we demonstrate that clotrimazole (CTZ), an off-target anti-tumor drug, abolishes lactate effects on the activation of macrophages and induces the expression of M1-like markers. We show that clotrimazole has cytotoxic effects on tumor cells by negatively modulating PI3K, which inhibits glycolytic metabolism and leads to a diminishing lactate production by these cells. These effects are more pronounced in cancer cells exposed to conditioned media of M2-polarized macrophages. Moreover, clotrimazole inhibits tumor growth in a murine model of implanted melanoma, reduces lactate content in a tumor microenvironment and decreases vascular endothelial growth factor expression. Finally, clotrimazole drastically diminishes TAM infiltration in the tumors, thereby inducing M1 polarization. Collectively, these findings identify a new antitumor mechanism of clotrimazole by modulating the tumor microenvironment (TME), particularly the activation and viability of TAM.

Metabolic changes in triple negative breast cancer-focus on aerobic glycolysis

Among breast cancer subtypes, the triple negative breast cancer (TNBC) has the worst prognosis. In absence of any permitted targeted therapy, standard chemotherapy is the mainstay for TNBC treatment. Hence, there is a crucial need to identify potential druggable targets in TNBCs for its effective treatment. In recent times, metabolic reprogramming has emerged as cancer cells hallmark, wherein cancer cells display discrete metabolic phenotypes to fuel cell progression and metastasis. Altered glycolysis is one such phenotype, in which even in oxygen abundance majority of cancer cells harvest considerable amount of energy through elevated glycolytic-flux. In the present review, we attempt to summarize the role of key glycolytic enzymes i.e. HK, Hexokinase; PFK, Phosphofructokinase; PKM2, Pyruvate kinase isozyme type 2; and LDH, Lactate dehydrogenase in TNBCs, and possible therapeutic options presently available.

Clotrimazole is effective for the regression of endometriotic implants in a Wistar rat experimental model of endometriosis

The present work aimed to evaluate molecular, angiogenic and inflammatory changes induced by clotrimazole (CTZ) on endometriosis lesions. For this, thirty female Wistar rats with surgically implanted autologous endometrium were treated with CTZ or vehicle (200 mg/kg) via esophageal gavage for 15 consecutive days. CTZ treatment significantly decreased the growth and the size of the implants, and histological examination indicated regression and atrophy, with no toxicity to the animals. The levels of the angiogenic markers VEGF and VEGFR-2 were significantly decreased in CTZ group. The treatment also promotes a reduction on PGE₂ and TNF-α levels. All these effects involve the amelioration of ERK1/2, Akt, AMPK and PERK signaling upon CTZ treatment. In conclusion, CTZ promoted an overall amelioration of endometriosis in a rat model due to the anti-angiogenic properties of the drug. Therefore, our results support the proposal of a clinical trial using CTZ for the treatment of endometriosis.

Imidazole Antifungal Drugs Inhibit the Cell Proliferation and Invasion of Human Breast Cancer Cells

Breast cancer is currently the most prevalent cancer in women, and its incidence increases every year. Azole antifungal drugs were recently found to have antitumor efficacy in several cancer types. They contain an imidazole (clotrimazole and ketoconazole) or a triazole (fluconazole and itraconazole) ring. Using human breast adenocarcinoma cells (MCF-7 and MDA-MB-231), we evaluated the effects of azole drugs on cell proliferation, apoptosis, cell cycle, migration, and invasion, and investigated the underlying mechanisms. Clotrimazole and ketoconazole inhibited the proliferation of both cell lines while fluconazole and itraconazole did not. In addition, clotrimazole and ketoconazole inhibited the motility of MDA-MB-231 cells and induced G₁-phase arrest in MCF-7 and MDA-MB-231 cells, as determined by cell cycle analysis and immunoblot data. Moreover, Transwell invasion and gelatin zymography assays revealed that clotrimazole and ketoconazole suppressed invasiveness through the inhibition of matrix metalloproteinase 9 in MDA-MB-231 cells, although no significant changes in invasiveness were observed in MCF-7 cells. There were no significant changes in any of the observed parameters with fluconazole or itraconazole treatment in either breast cancer cell line. Taken together, imidazole antifungal drugs showed strong antitumor activity in breast cancer cells through induction of apoptosis and G₁ arrest in both MCF-7 and MDA-MB-231 cells and suppression of invasiveness via matrix metalloproteinase 9 inhibition in MDA-MB-231 cells. Imidazole drugs have well-established pharmacokinetic profiles and known toxicity, which can make these generic drugs strong candidates for repositioning as antitumor therapies.

Yeast caspase-dependent apoptosis in Saccharomyces cerevisiae BY4742 induced by antifungal and potential antitumor agent clotrimazole

Clotrimazole is an antifungal medication commonly used in the treatment of fungal infections. There is also promising research on using clotrimazole against other diseases such as malaria, beriberi, tineapedis and cancer. It was aimed to investigate the apoptotic phenotype in Saccharomyces cerevisiae induced by clotrimazole. The exposure of S. cerevisiae to 10 µM clotrimazole for 3, 6 and 9 h caused to decrease in cell viability by 24.82 ± 0.81, 56.00 ± 1.54 and 77.59 ± 0.53%, respectively. It was shown by Annexin V-PI assay that 110 µM clotrimazole treatment caused to death by 35.5 ± 2.48% apoptotic and only 13.1 ± 0.08% necrotic pathway within 30 min. The occurrence of DNA strand breaks and condensation could be visualised by the TUNEL and DAPI stainings, respectively. Yeast caspase activity was induced 12.34 ± 0.71-fold after 110 µM clotrimazole treatment for 30 min compared to the control. The dependency of clotrimazole-induced apoptosis to caspase was also shown using Δyca1 mutant.

Phosphofructokinase-P Modulates P44/42 MAPK Levels in HeLa Cells

It is known that interfering with glycolysis leads to profound modification of cancer cell proliferation. However, energy production is not the major reason for this correlation. Here, using HeLa cells as a model for cancer, we demonstrate that phosphofructokinase-P (PFK-P), which is overexpressed in diverse types of cancer including HeLa cells, modulates expression of P44/42 mitogen-activated protein kinase (MAPK). Silencing of PFK-P did not alter HeLa cell viability or energy production, including the glycolytic rate. On the other hand, silencing of PFK-P induced the downregulation of p44/42 MAPK, augmenting the sensitivity of HeLa cells to different drugs. Conversely, overexpression of PFK-P promotes the upregulation of p44/42 MAPK, making the cells more resistant to the drugs. These results indicate that overexpression of PFK-P by cancer cells is related to activation of survival pathways via upregulation of MAPK and suggest PFK-P as a promising target for cancer therapy. J. Cell. Biochem. 118: 1216-1226, 2017. © 2016 Wiley Periodicals, Inc.