Quinacrine revised

The modulation of sirtuins by natural compounds in the management of cisplatin-induced nephrotoxicity

Cisplatin is a highly effective antitumor agent. However, its use is limited due to severe adverse effects, particularly nephrotoxicity, which occurs in approximately 30% of patients. There is a need for novel renoprotective compounds. Sirtuins play a vital role in various physiological and pathological processes such as oxidative stress, apoptosis, inflammation, and mitochondrial bioenergetics. It has been shown that sirtuins can exert a protective effect on cisplatin-induced acute kidney injury by targeting multiple signaling pathways. Besides, sirtuins not only did not reduce the anticancer effect of cisplatin but also increased it. Several natural compounds have been reported to inhibit cisplatin-mediated nephrotoxicity through sirtuin stimulation. These compounds exert their therapeutic effects on cisplatin-induced renal injury by targeting various signaling pathways including Sirt1/p53, Sirt1/NF-κb/p56, AMPK/Sirt1, Sirt1/PGC-1α, and/or by enhancing mitochondrial function.

Quinacrine, an Antimalarial Drug with Strong Activity Inhibiting SARS-CoV-2 Viral Replication In Vitro

Quinacrine (Qx), a molecule used as an antimalarial, has shown anticancer, antiprion, and antiviral activity. The most relevant antiviral activities of Qx are related to its ability to raise pH in acidic organelles, diminishing viral enzymatic activity for viral cell entry, and its ability to bind to viral DNA and RNA. Moreover, Qx has been used as an immunomodulator in cutaneous lupus erythematosus and various rheumatological diseases, by inhibiting phospholipase A2 modulating the Th1/Th2 response. The aim of this study was to evaluate the potential antiviral effect of Qx against denominated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Vero E6 cells. The cytotoxicity of Qx in Vero E6 cells was determined by the MTT assay. Afterwards, Vero E6 cells were infected with SARS-CoV-2 at different multiplicities of infections (MOIs) of 0.1 and 0.01 in the presence of Qx (0-30 µM) to determinate the half maximal effective concentration (EC50). After 48 h, the effect of Qx against SARS-CoV-2 was assessed by viral cytotoxicity and viral copy numbers, the last were determined by digital real-time RT-PCR (ddRT-PCR). Additionally, electron and confocal microscopy of Vero E6 cells infected and treated with Qx was studied. Our data show that Qx reduces SARS-CoV-2 virus replication and virus cytotoxicity, apparently by inhibition of viral ensemble, as observed by ultrastructural images, suggesting that Qx could be a potential drug for further clinical studies against coronavirus disease 2019 (COVID-19) infection.

Targeting tumor hypoxia and mitochondrial metabolism with anti-parasitic drugs to improve radiation response in high-grade gliomas

High-grade gliomas (HGGs), including glioblastoma and diffuse intrinsic pontine glioma, are amongst the most fatal brain tumors. These tumors are associated with a dismal prognosis with a median survival of less than 15 months. Radiotherapy has been the mainstay of treatment of HGGs for decades; however, pronounced radioresistance is the major obstacle towards the successful radiotherapy treatment. Herein, tumor hypoxia is identified as a significant contributor to the radioresistance of HGGs as oxygenation is critical for the effectiveness of radiotherapy. Hypoxia plays a fundamental role in the aggressive and resistant phenotype of all solid tumors, including HGGs, by upregulating hypoxia-inducible factors (HIFs) which stimulate vital enzymes responsible for cancer survival under hypoxic stress. Since current attempts to target tumor hypoxia focus on reducing oxygen demand of tumor cells by decreasing oxygen consumption rate (OCR), an attractive strategy to achieve this is by inhibiting mitochondrial oxidative phosphorylation, as it could decrease OCR, and increase oxygenation, and could therefore improve the radiation response in HGGs. This approach would also help in eradicating the radioresistant glioma stem cells (GSCs) as these predominantly rely on mitochondrial metabolism for survival. Here, we highlight the potential for repurposing anti-parasitic drugs to abolish tumor hypoxia and induce apoptosis of GSCs. Current literature provides compelling evidence that these drugs (atovaquone, ivermectin, proguanil, mefloquine, and quinacrine) could be effective against cancers by mechanisms including inhibition of mitochondrial metabolism and tumor hypoxia and inducing DNA damage. Therefore, combining these drugs with radiotherapy could potentially enhance the radiosensitivity of HGGs. The reported efficacy of these agents against glioblastomas and their ability to penetrate the blood-brain barrier provides further support towards promising results and clinical translation of these agents for HGGs treatment.

Beyond DNA binding - a review of the potential mechanisms mediating quinacrine's therapeutic activities in parasitic infections, inflammation, and cancers

This is an in-depth review of the history of quinacrine as well as its pharmacokinetic properties and established record of safety as an FDA-approved drug. The potential uses of quinacrine as an anti-cancer agent are discussed with particular attention to its actions on nuclear proteins, the arachidonic acid pathway, and multi-drug resistance, as well as its actions on signaling proteins in the cytoplasm. In particular, quinacrine's role on the NF-κB, p53, and AKT pathways are summarized.

A lytic mechanism based on soluble phospholypases A2 (sPLA2) and β-galactoside specific lectins is exerted by Ciona intestinalis (ascidian) unilocular refractile hemocytes against K562 cell line and mammalian erythrocytes

Hemocytes from the ascidian Ciona intestinalis exert in vitro Ca²+-dependent cytotoxic activity toward mammalian erythrocytes and K562 cells. To examine the lytic mechanism, hemocyte populations were separated (B1-B6 bands) through a Percoll discontinuous density gradient, the hemocyte cytotoxic activity (HCA) and the lytic activity of the hemocyte lysate supernatant (HLS) were assayed. In addition the separated hemocytes were cultured and the cell-free culture medium (CFM) assayed after 3 h culture. Results support that unilocular refractile hemocytes (URGs), enriched in B5, are cytotoxic. The B5-HLS contains lysins and the activity of B5-CFM shows that lysins can be released into a culture medium. The B5 activity was blocked by D-galactose, α-lactose, lactulose, LacNAc, thiodigalactoside (TDG), L-fucose, D-mannose, D-glucose, sphingomyelin (SM), and soluble phospholipase A2 (sPLA2) inhibitors (dibucain, quinacrine). Accordingly, HLS chemico-physical properties (alkaline medium, high thermostability, Ca²+-dependence, trypsin treatment, protease inhibitors) and SEM observations of the affected targets suggested that sPLA2 could be responsible for changes and large alterations of the target cell membrane. An apoptotic activity, as recorded by a caspase 3, 7 assay, was found by treating K562 cells with very diluted HLS. A lytic mechanism involving sPLA2 and lectins promptly released by URGs and morula cells respectively is suggested, whereas target cell membrane SM could be a modulator of the enzyme activity.

Mepacrine treatment attenuates allergic airway remodeling segregated from airway inflammation in mice

Asthma is a chronic airway disease characterized by increased airway hyperresponsiveness, airway inflammation, and airway remodeling including collagen deposition in subepithelial regions. We have shown earlier that mepacrine has anti-inflammatory activity and decreased the features of airway remodeling in a subacute model of asthma, when administered during the inflammatory phase. But it was not clear whether the reduction of airway remodeling by mepacrine was a direct effect or indirectly related to the reduction in the airway inflammation. In this study, we determined the effect of mepacrine on airway remodeling and airway hyperresponsiveness (AHR) in a chronic model of asthma which showed the features of airway inflammation in the initial stage (inflammation predominant stage) and airway remodeling with mild airway inflammation in a later stage (remodeling predominant stage). Mepacrine was administered only in the later stage that more accurately simulates human asthma, where airway remodeling already exists at the time of diagnosis. The remodeling predominant stage was associated with high levels of Th2 cytokines like IL-4 and IL-13, increase in the levels of profibrotic mediators such as arginase and TGF-β, and increased collagen deposition. These were efficiently attenuated by mepacrine treatment and led to a significant reduction in AHR. Thus, we conclude from this study that mepacrine has direct effects on established airway remodeling independent of its anti-inflammatory effects.

Scuticociliatosis and its recent prophylactic measures in aquaculture with special reference to South Korea Taxonomy, diversity and diagnosis of scuticociliatosis: Part I Control strategies of scuticociliatosis: Part II

Scuticociliatosis caused by about 20 species belonging to the Phylum Ciliophora has been recognized as an emerging problem inflicting significant economic loss in aquaculture industry in the world. Among these Philasterides dicentrarchi, Miamiensis avidus, and Uronema marinum are the three species responsible for scuticociliatosis in olive flounder farms of South Korea. Some of the parasites living or scavenger ciliates also have become parasites of aquaculture fish. The major clinico-pathological manifestations of scuticociliatosis infected fishes are anemia, weight loss, dark coloration, enteritis, excessive body mucus, yellowish intestinal mucus, loss of scales, hemorrhagic and/or bleached spots on the skin, and dermal necrotic lesions that finally destroy tissues lead to high mortalities. Affected fish exhibit organ-specific pathological changes in the brain, eyes, muscle, gills, liver, kidney, intestine, and stomach that lead to severe mortality. At present, farmers in South Korea manage scuticociliatosis by using therapeutic measures, such as application of antibiotics like oxytetracycline, gentamycine, tetracycline, amoxycililin, and cefazolin and chemicals, such as formalin, hydrogen peroxide, malachite green, and jenoclean at a concentration of 350 +/- 150 ppm. However till date, no systematic scientific study has been conducted under field condition on the efficacy of these management measures. Under laboratory condition the ciliate can be effectively controlled with the antibiotics and chemicals while on the host, but on entering the host no systemic chemotherapeutic treatment has been yet proven effective. Furthermore the indiscriminate uses of harmful chemicals in aquaculture are increasingly becoming a cause of concern. Recently formalin and malachite green, the most widely used chemicals have been banned in food fish production by FDA as not consumer friendly and being carcinogenic respectively. Vaccines and immunostimulants can induce good immune response and protect against scuticociliatosis as it has been proved in the case of freshwater Ich. Now a days a number of probiotics and herbal formulations are in use against freshwater bacterial and fungal diseases, while, little information is available regarding the different prophylactic measures against marine scuticociliatosis. This review attempts to provide information on the various prophylaxic measures practiced against scuticociliatosis with special reference to olive flounder farms in South Korea.

Mepacrine inhibits subepithelial fibrosis by reducing the expression of arginase and TGF-beta1 in an extended subacute mouse model of allergic asthma

Asthma is a dynamic disorder of airway inflammation and airway remodeling with an imbalance in T helper type 1 (Th(1))/Th(2) immune response. Increased Th(2) cytokines such as IL-4 and IL-13 induce arginase either directly or indirectly through transforming growth factor-beta(1) (TGF-beta(1)) and lead to subepithelial fibrosis, which is a crucial component of airway remodeling. Synthetic antimalarials have been reported to have immunomodulatory properties. Mepacrine is known for its reduction of airway inflammation in short-term allergen challenge model by reducing Th(2) cytokines and cysteinyl leukotrienes, which has an important role in the development of airway remodeling features. Therefore, we hypothesized that mepacrine may reduce airway remodeling. For this, extended subacute ovalbumin mice model of asthma was developed; these mice showed an increased expression of profibrotic mediators, subepithelial fibrosis, and goblet cell metaplasia along with airway inflammation, increased Th(2) cytokines, allergen-specific IgE, IgG(1), increased cytosolic PLA(2) (cPLA(2)), and airway hyperresponsiveness. Presence of intraepithelial eosinophils and significant TGF-beta(1) expression in subepithelial mesenchymal regions by repeated allergen exposures indicate that asthmatic mice of this study have developed human mimicking as well as late stages of asthma. However, mepacrine treatment decreased Th(2) cytokines and subepithelial fibrosis and alleviated asthma features. These reductions by mepacrine were associated with a decrease in levels and expression of TGF-beta(1) and the reduction in activity, expression of arginase in lung cytosol, and immunolocalization in inflammatory cells present in perivascular and peribronchial regions. These results suggest that mepacrine might reduce the development of subepithelial fibrosis by reducing the arginase and TGF-beta(1). These effects of mepacrine likely underlie its antiairway remodeling action in asthma.

Quinacrine sterilization for human immunodeficiency virus-positive women

OBJECTIVE

To evaluate the safety of nonsurgical quinacrine sterilization for HIV-positive (HIV+) women.

DESIGN

An open trial of quinacrine sterilization was carried out in women infected with HIV and women who were HIV negative (HIV-). Comparison of the results with the two groups provided an assessment of the safety and effectiveness of quinacrine sterilization for HIV+ women.

SETTING

University Medical School outpatient services.

PATIENT(S)

A total of 258 women who desired sterilization were offered quinacrine sterilization as a means of limiting family size. Sixty-four were HIV+, and 194 were HIV-. Women who were HIV+ had CD4 counts >200 and were otherwise healthy.

INTERVENTION(S)

A modified Copper T intrauterine device inserter was used to place 252 mg of quinacrine, divided into seven pellets (36 mg each) into the uterine cavity. Three insertions of this formulation were performed, 1 month apart. Viral load and CD8 and CD4 lymphocytes were measured both before and after quinacrine sterilization and at follow-up visits. Pregnancies and adverse events were recorded carefully. A decrement life table was made to statistically analyze results. RESULT(S) AND MAIN OUTCOME MEASURE(S): No serious adverse event occurred in any patient in this study. Adverse effects related to quinacrine sterilization were abdominal cramping, vulvar itching, nausea, and vaginal bleeding. Vaginal bleeding was the only short-term side effect noted to occur more frequently in HIV-infected women after quinacrine sterilization. Among HIV+ women, 35.9% had complaints of increased bleeding, whereas only 8.2% of those who were HIV- had such complaints, which probably were insertion related. Viral load and the CD4+ and CD8+ lymphocyte measures displayed no statistically significant difference after quinacrine sterilization.

CONCLUSION(S)

Quinacrine sterilization is a safe method for the sterilization of HIV-infected women and has no short-term effect on the pathology of the disease.

Long-term follow-up after quinacrine sterilization in Vietnam. Part I: interim efficacy analysis

OBJECTIVE

To determine the long-term efficacy of nonsurgical sterilization with quinacrine.

DESIGN

Observational cohort study.

SETTING

Rural provinces in northern Vietnam.

PATIENT(S)

Two thousand seven hundred and nine women who had quinacrine insertions between 1989 and 1993.

INTERVENTION(S)

Interviews in 1994, 1995, and 1996 and review of available medical records. Pregnancy rates were corrected for problems in detecting and confirming pregnancies.

MAIN OUTCOME MEASURE(S)

Pregnancy rates.

RESULT(S)

Over 90% of women were interviewed at least once. Uncorrected cumulative pregnancy rates were 12.9% at 5 y after two insertions and 27.3% after one insertion. Effectiveness varied by age group: the partially corrected pregnancy rates after two insertions were 6.8% in women 35 or older at the time of insertion and 13.0% in women under 35. A subgroup of women who received oral papaverine at the time of quinacrine insertion had lower pregnancy rates, with a cumulative uncorrected rate of 5.3% at 4 years among women of all ages.

CONCLUSION(S)

Efficacy of quinacrine appears reasonable for two insertions of quinacrine in women 35 and older. It may be possible to improve efficacy by the use of papaverine or the Hieu insertion technique.