Effects of primaquine and chloroquine on oxidative stress parameters in rats

Hydroxychloroquine attenuated motor impairment and oxidative stress in a rat 6-hydroxydopamine model of Parkinson's disease

PURPOSE

Parkinson's disease (PD) is associated with the destruction of dopaminergic neurons in the substantia nigra (SN). Hydroxychloroquine (HCQ) has the capability to cross the blood-brain barrier and promote a neuroprotective potential. This study evaluated the effects of HCQ on the 6-hydroxydopamine (6-OHDA)-induced PD model in rats.

METHODS

Wistar rats were randomly divided into sham, PD, PD + levodopa and PD + HCQ groups. The PD model was induced by a stereotactic administration of 6-OHDA into the left SN pars compacta (SNpc) and confirmed by rotation and the Murprogo's tests. HCQ (100 mg/kg, p.o.) and levodopa (12 mg/kg, p.o.) were administered once a day for 21 days. Three weeks after surgery, the behavioral tests were performed. Brain lipid peroxidation index (MDA), glutathione peroxidase activity (GPx), total antioxidant capacity (TAC) levels and α-synuclein protein expression in the SN were also measured.

RESULTS

The behavioral tests demonstrated that induction of PD increased the muscle rigidity and the number of rotations, which were reversed by HCQ treatment. Also, induction of PD was associated with an increase in α-synuclein protein levels and MDA and decreased TAC levels and GPx activity. However, HCQ decreased α-synuclein and MDA levels while increased TAC levels and GPx activity. In addition, histopathological data showed that HCQ protects dopaminergic neurons against 6-OHDA-induced toxicity.

CONCLUSION

According to the results, HCQ has a beneficial effect in improving PD-related pathophysiology, in part, by mitigating oxidative stress and protecting the dopaminergic neurons in the SN.

Recent developments in antimalarial drug discovery

Although malaria remains a big burden to many countries that it threatens their socio-economic stability, particularly in the countries where malaria is endemic, there have been great efforts to eradicate this disease with both successes and failures. For example, there has been a great improvement in malaria prevention and treatment methods with a net reduction in infection and mortality rates. However, the disease remains a global threat in terms of the number of people affected because it is one of the infectious diseases that has the highest prevalence rate, especially in Africa where the deadly Plasmodium falciparum is still widely spread. Methods to fight malaria are being diversified, including the use of mosquito nets, the target candidate profiles (TCPs) and target product profiles (TPPs) of medicine for malarial venture (MMV) strategy, the search for newer and potent drugs that could reverse chloroquine resistance, and the use of adjuvants such as rosiglitazone and sevuparin. Although these adjuvants have no antiplasmodial activity, they can help to alleviate the effects which result from plasmodium invasion such as cytoadherence. The list of new antimalarial drugs under development is long, including the out of ordinary new drugs MMV048, CDRI-97/78 and INE963 from South Africa, India and Novartis, respectively.

High-Dose Primaquine Induces Proximal Tubular Degeneration and Ventricular Cardiomyopathy Linked to Host Cells Mitochondrial Dysregulation

Primaquine (PQ) is the only antimalarial medication used to eradicate many species of Plasmodium gametocytes and prevent relapse in vivax and ovale malarias. PQ metabolites induce oxidative stress and impair parasitic mitochondria, leading to protozoal growth retardation and death. Collateral damage is also presented in mammalian host cells, particularly erythrocytes, resulting in hemolysis and tissue destruction. However, the underlying mechanisms of these complications, particularly the mitochondria-mediated cell death of the host, are poorly understood. In the present study, toxicopathological studies were conducted on a rat model to determine the effect of PQ on affected tissues and mitochondrial toxicity. The results indicated that the LD₅₀ for PQ is 200 mg/kg. A high dose of PQ induced hemolytic anemia, elevated a hepatic enzyme (SGPT), and induced proximal tubular degeneration, ventricular cardiomyopathy, and mitochondrial dysregulation. In addition, PQ induced the upregulation of apoptosis-related proteins Drp-1 and caspase-3, with a positive correlation, as well as the pro-apoptotic mitochondrial gene expression of Bax, reflecting the toxic effect of high doses of PQ on cellular damage and mitochondrial apoptosis in terms of hepatotoxicity, nephrotoxicity, and cardiotoxicity. Regarding the risk/benefit ratio of drug administration, our research provides caution for the use of PQ in the treatment of malaria based on its toxicopathological effects.

Plasmodium vivax: the potential obstacles it presents to malaria elimination and eradication

Initiatives to eradicate malaria have a good impact on P. falciparum malaria worldwide. P. vivax, however, still presents significant difficulties. This is due to its unique biological traits, which, in comparison to P. falciparum, pose serious challenges for malaria elimination approaches. P. vivax's numerous distinctive characteristics and its ability to live for weeks to years in liver cells in its hypnozoite form, which may elude the human immune system and blood-stage therapy and offer protection during mosquito-free seasons. Many malaria patients are not fully treated because of contraindications to primaquine use in pregnant and nursing women and are still vulnerable to P. vivax relapses, although there are medications that could radical cure P. vivax. Additionally, due to CYP2D6's highly variable genetic polymorphism, the pharmacokinetics of primaquine may be impacted. Due to their inability to metabolize PQ, some CYP2D6 polymorphism alleles can cause patients to not respond to treatment. Tafenoquine offers a radical treatment in a single dose that overcomes the potentially serious problem of poor adherence to daily primaquine. Despite this benefit, hemolysis of the early erythrocytes continues in individuals with G6PD deficiency until all susceptible cells have been eliminated. Field techniques such as microscopy or rapid diagnostic tests (RDTs) miss the large number of submicroscopic and/or asymptomatic infections brought on by reticulocyte tropism and the low parasitemia levels that accompany it. Moreover, P. vivax gametocytes grow more quickly and are much more prevalent in the bloodstream. P. vivax populations also have a great deal of genetic variation throughout their genome, which ensures evolutionary fitness and boosts adaptation potential. Furthermore, P. vivax fully develops in the mosquito faster than P. falciparum. These characteristics contribute to parasite reservoirs in the human population and facilitate faster transmission. Overall, no genuine chance of eradication is predicted in the next few years unless new tools for lowering malaria transmission are developed (i.e., malaria elimination and eradication). The challenging characteristics of P. vivax that impede the elimination and eradication of malaria are thus discussed in this article.

Chloroquine Attenuates Oxidative Stress in Gentamicin-Induced Nephrotoxicity in Rats

The wider application of gentamicin is limited by potential adverse effects (nephrotoxicity and ototoxicity). The goal of our study was to investigate the effects of chloroquine on biochemical and oxidative stress parameters in gentamicin-induced nephrotoxicity in rats. Animals were randomly divided into 1 of 5 groups. First was Sham group (0.9% NaCl) (n = 8); second group received gentamicin (n = 8); while third (n = 8), fourth (n = 8) and fifth group (n = 8) received gentamicin and chloroquine in a dose of 0.3, 1 and 3 mg/kg, respectively. The urea and creatinine levels were significantly lower in chloroquine treated groups in doses of 0.3 mg/kg and 1 mg/kg (P < 0.001). Total oxidant status and the oxidative stress index showed significantly lower values in all chloroquine treated groups (P < 0.001; P < 0.005). Malondialdehyde was lower in chloroquine treatment in doses of 0.3 mg/kg (P < 0.005) and 3 mg/kg (P < 0.05). Chloroquine treatment markedly reduced the level of superoxide dismutase in doses of 1 mg/kg (P < 0.01) and 3 mg/kg (P < 0.05). Our study showed that chloroquine attenuates gentamicin-induced nephrotoxicity in rats regarding biochemical and oxidative stress parameters.

Oxidative Stress in Malaria: Potential Benefits of Antioxidant Therapy

Malaria is an infectious disease and a serious public health problem in the world, with 3.3 billion people in endemic areas in 100 countries and about 200 million new cases each year, resulting in almost 1 million deaths in 2018. Although studies look for strategies to eradicate malaria, it is necessary to know more about its pathophysiology to understand the underlying mechanisms involved, particularly the redox balance, to guarantee success in combating this disease. In this review, we addressed the involvement of oxidative stress in malaria and the potential benefits of antioxidant supplementation as an adjuvant antimalarial therapy.

Redox aspects of cytotoxicity and anti-neuroinflammatory profile of chloroquine and hydroxychloroquine in serum-starved BV-2 microglia

Chloroquine (CQ) and hydroxychloroquine (HCQ) have long been used worldwide to treat and prevent human malarias. However, these 4-aminoquinolines have also shown promising potential in treating chronic illnesses with an inflammatory component, including neurological diseases. Given the current demand for serum avoidance during pharmacological testing and modeling of some pathologies, we compared cytotoxicities of CQ and HCQ in both serum-deprived and -fed murine BV-2 microglia. Furthermore, we assessed the anti-neuroinflammatory potential of both compounds in serum-deprived cells. Under both conditions, CQ showed higher cytotoxicity than HCQ. However, the comparable MTT-assay-derived data measured under different serum conditions were associated with disparate cytotoxic mechanisms of CQ and HCQ. In particular, under serum starvation, CQ mildly enhanced secondary ROS, mitochondrial hyperpolarization, and decreased phagocytosis. However, CQ promoted G1 phase cell cycle arrest and mitochondrial depolarization in serum-fed cells. Under both conditions, CQ fostered early apoptosis. Additionally, we confirmed that both compounds could exert anti-inflammatory effects in microglia through interference with MAPK signaling under nutrient-deprivation-related stress. Nevertheless, unlike HCQ, CQ is more likely to exaggerate intracellular prooxidant processes in activated starved microglia, which are inefficiently buffered by Nrf2/HO-1 signaling pathway activation. These outcomes also show HCQ as a promising anti-neuroinflammatory drug devoid of CQ-mediated cytotoxicity.

Effects of co-treatment of Plasmodium berghei-infected mice with aqueous extract of Ocimum gratissimum leaves and primaquine on glucose-6-phosphate dehydrogenase activity, hematological, and antioxidant parameters

BACKGROUND

It has been observed that most malaria patients especially G6PD-deficient patients usually experience oxidative stress and severe anemia when treated with primaquine. This calls for the need to search for a treatment option that will ameliorate these side effects.

OBJECTIVE

The effect of co-treatment of malaria with aqueous extract of Ocimum gratissimum leaves (AEOGL) and primaquine on G6PD activity, antioxidant indices and hematological parameters in Plasmodium berghei-infected mice was investigated.

MATERIALS AND METHODS

Thirty mice divided into six groups of five mice each were recruited for this study. Whilst Group 1 (G1) served as the negative control (group not infected with plasmodium parasite), Groups 2 to 6 (G2-G6) were inoculated intraperitoneally with 0.2 ml of 1 × 10⁵/ml Plasmodium berghei (NK 65 strain) infected erythrocytes. G2 (parasite control) received no treatment. Groups 3,4,5 and 6 were administered 0.25 mg/kg bw of primaquine only; 100 mg/kg b. w of AEOGL +0.25 mg/kg bw of primaquine; 200 mg/kg b. w of AEOGL +0.25 mg/kg bw of primaquine; 200 mg/kg b. w of AEOGL respectively, for 14 days.

RESULTS

Treatment with only primaquine gave the highest mean malaria parasite clearance (82.10 ± 0.45 percent), followed by 100 mg/kg b. w of AEOGL + Primaquine (75.59 ± 0.47 percent), 200 mg/kg b. w of AEOGL + Primaquine (67.35 ± 0.67 percent), and AEOGL alone (55 ± 0.56 percent). In comparison with the untreated malaria groups, co-treatment with AEOGL + Primaquine produced a significant (p < 0.05) increase in G6PD activity, serum ascorbate, reduced glutathione, catalase activity, and a significant (p < 0.05) decrease in malondialdehyde level in a dose-dependent pattern and also a significant (p < 0.05) rise in packed cell volume, haemoglobin, and red blood cell count, unlike treatment with only primaquine which resulted in a non-significant (P > 0.05) difference in these parameters.

CONCLUSION

Co-treatment of Plasmodium berghei-infected mice with AEOGL and primaquine improved the G6PD activity, hematological parameters and antioxidant status relative to treatment with only primaquine.

A review on the pharmacokinetic properties and toxicity considerations for chloroquine and hydroxychloroquine to potentially treat coronavirus patients

The SARS-CoV-2 virus, caused a novel emerged coronavirus disease, is growing rapidly worldwide. Few studies have evaluated the efficacy and safety of Chloroquine (CQ), an old antimalarial drug, and Hydroxychloroquine (HCQ) in the treatment of COVID-19 infection. HCQ is derived from CQ by adding a hydroxyl group into it and is a less toxic derivative of CQ for the treatment of COVID-19 infection because it is more soluble. This article summarizes pharmacokinetic properties and toxicity considerations for CQ and HCQ, drug interactions, and their potential efficacy against COVID-19. The authors also look at the biochemistry changes and clinical uses of CQ and HCQ, and supportive treatments following toxicity occurs. It was believed that CQ and HCQ may provide few benefits to COVID-19 patients. A number of factors should be considered to keep the drug safe, such as dose, in vivo animal toxicological findings, and gathering of metabolites in plasma and/or tissues. The main conclusion of this review is that CQ and HCQ with considered to their ADMET properties has major shortcomings and fully irresponsible.

Neurobehavioral, neurochemical and synaptic plasticity perturbations during postnatal life of rats exposed to chloroquine in-utero

Despite reports that quinoline antimalarials including chloroquine (Chq) exhibit idiosyncratic neuropsychiatric effects even at low doses, the drug continues to be in widespread use during pregnancy. Surprisingly, very few studies have examined the potential neurotoxic action of Chq exposure at different points of gestation or how this phenomenon may affect neurophysiological well-being in later life. We therefore studied behavior, and the expression of specific genes and neurochemicals modulating crucial neural processes in offspring of rats exposed to prophylactic dose of Chq during different stages of gestation. Pregnant rats were injected 5 mg/kg/day (3 times) of Chq either during early- (first week), mid- (second week), late- (third week), or throughout- (all weeks) gestation, while controls received PBS injection. Behavioral characterization of offspring between postnatal days 15-20 in the open field, Y-maze, elevated plus and elevated zero mazes revealed that Chq evoked anxiogenic responses and perturbed spatial memory in rats, although locomotor activity was generally unaltered. In the prefrontal cortex (PFC), hippocampus and cerebellum of rats prenatally exposed to Chq, RT-qPCR analysis revealed decreased mRNA expression of presynaptic marker synaptophysin, which was accompanied by downregulation of postsynaptic marker PSD95. Synaptic marker PICK1 expression was also downregulated in the hippocampus but was unperturbed in the PFC and cerebellum. In addition to recorded SOD downregulation in cortical and hippocampal lysates, induction of oxidative stress in rats prenatally exposed to Chq was corroborated by lipid peroxidation as evinced by increased MDA levels. Offspring of rats infused with Chq at mid-gestation and weekly treatment throughout gestation were particularly susceptible to neurotoxic changes, especially in the hippocampus. Interestingly, Chq did not cause histopathological changes in any of the brain areas. Taken together, our findings causally link intrauterine exposure to Chq with postnatal behavioral impairment and neurotoxic changes in rats.

Chloroquine and hydroxychloroquine in the treatment of COVID-19: the never-ending story

Abstract

The anti-malarial drugs chloroquine (CQ) and hydroxychloroquine (HCQ) have been suggested as promising agents against the new coronavirus SARS-CoV-2 that induces COVID-19 and as a possible therapy for shortening the duration of the viral disease. The antiviral effects of CQ and HCQ have been demonstrated in vitro due to their ability to block viruses like coronavirus SARS in cell culture. CQ and HCQ have been proposed to reduce immune reactions to infectious agents, inhibit pneumonia exacerbation, and improve lung imaging investigations. CQ analogs have also revealed the anti-inflammatory and immunomodulatory effects in treating viral infections and related ailments. There was, moreover, convincing evidence from early trials in China about the efficacy of CQ and HCQ in the anti-COVID-19 procedure. Since then, research and studies have been massive to ascertain these drugs’ efficacy and safety in treating the viral disease. In the present review, we construct a synopsis of the main properties and current data concerning the metabolism of CQ/HCQ, which were the basis of assessing their potential therapeutic roles against the new coronavirus infection. The effective role of QC and HCQ in the prophylaxis and therapy of COVID-19 infection is discussed in light of the latest international medical-scientific research results.

Key points

• Data concerning metabolism and properties of CQ/HCQ are discussed.

• The efficacy of CQ/HCQ against COVID-19 has been the subject of contradictory results.

• CQ/HCQ has little or no effect in reducing mortality in SARS-CoV-2-affected patients.

Respiratory RNA Viruses: How to Be Prepared for an Encounter with New Pandemic Virus Strains

The characteristics of the biology of influenza viruses and coronavirus that determine the implementation of the infectious process are presented. With provision for pathogenesis of infection possible effects of serine proteinase inhibitors, heparin, and inhibitors of heparan sulfate receptors in the prevention of cell contamination by viruses are examined. It has been determined that chelators of metals of variable valency and antioxidants should be used for the reduction of replicative activity of viruses and anti-inflammatory therapy. The possibility of a pH-dependent impairment of glycosylation of cellular and viral proteins was traced for chloroquine and its derivatives. The use of low-toxicity drugs as part of adjunct therapy increases the effectiveness of synthetic antiviral drugs and interferons and ensures the safety of baseline therapy.

The past, present and future of RNA respiratory viruses: influenza and coronaviruses

Influenza virus and coronaviruses continue to cause pandemics across the globe. We now have a greater understanding of their functions. Unfortunately, the number of drugs in our armory to defend us against them is inadequate. This may require us to think about what mechanisms to address. Here, we review the biological properties of these viruses, their genetic evolution and antiviral therapies that can be used or have been attempted. We will describe several classes of drugs such as serine protease inhibitors, heparin, heparan sulfate receptor inhibitors, chelating agents, immunomodulators and many others. We also briefly describe some of the drug repurposing efforts that have taken place in an effort to rapidly identify molecules to treat patients with COVID-19. While we put a heavy emphasis on the past and present efforts, we also provide some thoughts about what we need to do to prepare for respiratory viral threats in the future.

Oxidative Stress, Proton Fluxes, and Chloroquine/Hydroxychloroquine Treatment for COVID-19

Chloroquine (CQ) and hydroxychloroquine (HCQ) have been proposed as treatments for COVID-19. These drugs have been studied for many decades, primarily in the context of their use as antimalarials, where they induce oxidative stress-killing of the malarial parasite. Less appreciated, however, is evidence showing that CQ/HCQ causes systemic oxidative stress. In vitro and observational data suggest that CQ/HCQ can be repurposed as potential antiviral medications. This review focuses on the potential health concerns of CQ/HCQ induced by oxidative stress, particularly in the hyperinflammatory stage of COVID-19 disease. The pathophysiological role of oxidative stress in acute respiratory distress syndrome (ARDS) has been well-documented. Additional oxidative stress caused by CQ/HCQ during ARDS could be problematic. In vitro data showing that CQ forms a complex with free-heme that promotes lipid peroxidation of phospholipid bilayers are also relevant to COVID-19. Free-heme induced oxidative stress is implicated as a systemic activator of coagulation, which is increasingly recognized as a contributor to COVID-19 morbidity. This review will also provide a brief overview of CQ/HCQ pharmacology with an emphasis on how these drugs alter proton fluxes in subcellular organelles. CQ/HCQ-induced alterations in proton fluxes influence the type and chemical reactivity of reactive oxygen species (ROS).

Mutagenic, Genotoxic and Immunomodulatory effects of Hydroxychloroquine and Chloroquine: a review to evaluate its potential to use as a prophylactic drug against COVID-19

Hydroxychloroquine (HCQ) and Chloroquine (CQ) are two anti-malarial drugs that are now being extensively used by front-line healthcare workers and other common people as a prophylactic drug against the Corona Virus Disease − 19 (COVID-19) in India and as well as in many parts of the world. While only a few in vitro studies have pointed to some efficacy of these drugs as a prophylactic against COVID-19, to date, there are no clinical studies that have established any clinical efficacy of these drugs as a prophylactic. These drugs are commonly used for the treatment of Rheumatoid Arthritis (RA) and Systemic Lupus Erythematosus (SLE) because of its immunomodulatory effects. Previously, we have evaluated the genetic toxicology of different drugs and chemicals including antimalarial drug CQ both in vitro and in vivo. Thus, we recognize the need to critically review the mutagenic, genotoxic, and immunomodulatory effects of these drugs, to find out whether it is safe to use as a prophylactic drug against COVID-19. Existing literature suggests that CQ can induce mutagenic and genotoxic effects in multiple test systems and both the drugs have immunomodulatory effects. There was no data available to evaluate the mutagenicity and genotoxicity for HCQ. However, during metabolism about 60% of both the drugs remain unchanged and about 40% of the drugs are metabolized into two metabolites, desethylchloroquine and bisdesethylchloroquine by the action of the cytochrome P450 (CYP) enzymes in the liver. Both HCQ and CQ are immunomodulatory drugs and have the potential to suppress normal immune system activation. In this review, we have elucidated the mechanism of immunomodulation by both HCQ and CQ and highlighted the mutagenic and genotoxic effects from the available literature. This article is written with the sole objective that the reader will be able to recognize the adverse effects of these drugs when consumed by healthy individuals as a prophylactic. Current literature indicates that healthy individuals should refrain from the use of these drugs until further investigation.

Therapeutic blockade of inflammation in severe COVID-19 infection with intravenous N-acetylcysteine

Glucose 6-phosphate dehydrogenase (G6PD) deficiency facilitates human coronavirus infection due to glutathione depletion. G6PD deficiency may especially predispose to hemolysis upon coronavirus disease-2019 (COVID-19) infection when employing pro-oxidant therapy. However, glutathione depletion is reversible by N-acetylcysteine (NAC) administration. We describe a severe case of COVID-19 infection in a G6PD-deficient patient treated with hydroxychloroquine who benefited from intravenous (IV) NAC beyond reversal of hemolysis. NAC blocked hemolysis and elevation of liver enzymes, C-reactive protein (CRP), and ferritin and allowed removal from respirator and veno-venous extracorporeal membrane oxygenator and full recovery of the G6PD-deficient patient. NAC was also administered to 9 additional respirator-dependent COVID-19-infected patients without G6PD deficiency. NAC elicited clinical improvement and markedly reduced CRP in all patients and ferritin in 9/10 patients. NAC mechanism of action may involve the blockade of viral infection and the ensuing cytokine storm that warrant follow-up confirmatory studies in the setting of controlled clinical trials.

Re-purposing Chloroquine for Glioblastoma: Potential Merits and Confounding Variables

There is a growing evidence that antimalarial chloroquine could be re-purposed for cancer treatment. A dozen of clinical trials have been initiated within the past 10 years to test the potential of chloroquine as an adjuvant treatment for therapy-refractory cancers including glioblastoma, one of the most aggressive human cancers. While there is considerable evidence for the efficacy and safety of chloroquine the mechanisms underlying the tumor suppressive actions of this drug remain elusive. Up until recently, inhibition of the late stage of autophagy was thought to be the major mechanism of chloroquine-mediated cancer cells death. However, recent research provided compelling evidence that autophagy-inhibiting activities of chloroquine are dispensable for its ability to suppress tumor cells growth. These unexpected findings necessitate a further elucidation of the molecular mechanisms that are essential for anti-cancer activities of CHQ. This review discusses the versatile actions of chloroquine in cancer cells with particular focus on glioma cells.