Antioxidant action of antimalarials

Antiapoptotic Effects of Hydroxychloroquine on Hypoxic-Ischemic Injury in Neonatal Rat Brain: May Hydroxychloroquine Be an Adjuvant Theraphy?

OBJECTIVE

Hydroxychloroquine (HCQ) has immunomodulatory, antithrombotic, cardiovascular, antimicrobial, and antineoplastic effects. In this study, we aimed to investigate the antiapoptotic and immunomodulator effects of intraperitoneal HCQ on hypoxic-ischemic (HI) injury in newborn rats.

STUDY DESIGN

Wistar albino rats, 7 to 10 days old, were randomly divided into three groups: hypoxic-ischemic encephalopathy (HIE) group, HIE treated with HCQ group, and Sham group. Left common carotid artery ligation and hypoxia model were performed in HIE and HCQ groups. The HCQ group was treated with 80 mg/kg intraperitoneal HCQ every 24 hours for 3 days, while Sham and HIE groups were given physiological saline. After 72 hours, rats were decapitated and brain tissues were stained with hematoxylin and eosin, TUNEL, and IL-1β for histopathological grading and neuronal cell injury.

RESULTS

Neuronal apoptosis was statistically lower in all neuroanatomical areas in the HCQ group compared with the HIE group. IL-1β-stained areas were similar in both HCQ and HIE groups but significantly higher compared with the Sham group. Histopathological grading scores were found to be lower in the HCQ group on the left parietal cortex and hippocampus region.

CONCLUSION

In this study, we have shown for the first time that HCQ treatment decreased apoptosis in HI newborn rat model in both hemispheres. HCQ may be a promising adjuvant therapy in neonatal HIE.

KEY POINTS

· HCQ decreased neuronal apoptosis in the ischemic penumbra of the rat brain.. · HCQ attenuates hypoxia-ischemia-induced brain injury in neonatal rats.. · HCQ has no anti-inflammatory effect on HI injury..

Modern Management of Pregnancy in Systemic Lupus Erythematosus: From Prenatal Counseling to Postpartum Support

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that predominantly affects women of childbearing age. Pregnancy in SLE patients poses unique challenges due to the potential impact on maternal and fetal outcomes. We provide an overview of the management of SLE during pregnancy, including preconception risk stratification and counseling, treatment, and disease activity monitoring. These assessments are critical to minimize maternal and fetal adverse events in pregnant patients with SLE. Disease flares, preeclampsia, antiphospholipid syndrome complications, and maternal mortality are the major risks for a woman with SLE during gestation. Timely treatment of SLE relapse, differentiation of preeclampsia from lupus nephritis, and tailored management for antiphospholipid syndrome are essential for a successful pregnancy. Fetal outcomes include neonatal lupus (NL), preterm birth, cesarean delivery, fetal growth restriction (FGR), and small-for-gestational-age (SGA) infants. We focused on NL, linked to maternal anti-Ro/SS-A and anti-La/SS-B antibodies, which can lead to various manifestations, particularly cardiac abnormalities, in newborns. While there is a common consensus regarding the preventive effect of hydroxychloroquine, the role of echocardiographic monitoring and fluorinated steroid treatment is still debated. Finally, close postpartum monitoring and counseling for subsequent pregnancies are crucial aspects of care.

Maternal and fetal outcomes of SLE in pregnancy: a literature review

Systemic Lupus Erythematosus (SLE) is an auto-immune disease in which the immune system assaults its tissues. We aimed to analyse the maternal and foetal outcomes during pregnancy in SLE mothers. A literature search was conducted by two investigators to assess SLE's outcomes on maternal and foetal during pregnancies. We searched PubMed/Medline, Embase, and Google scholar to collect evidence from different research studies, draw the conclusion, and report it. In our investigation, we found out that SLE could cause a spectrum of complications during pregnancy, not only for the mother but also for the foetus. It could affect fertility and cause difficult pregnancies for the couple as well which includes certain complications such as: preterm labour and delivery, high blood pressure (preeclampsia), placental insufficiency, miscarriage or stillbirth, whereas in the foetus SLE can cause mortality, preterm birth, and neonatal lupus (a temporary condition in the baby caused by SLE-related antibodies) and structural abnormalities. The literature suggests that SLE could prove fatal for the foetus and induce many complications in the mother. However, this could be avoided if pregnancy is planned right from the start and proper management is provided to the mother during pregnancy and delivery.p.

SARS-CoV-2 and mitochondrial health: implications of lifestyle and ageing

Infection with SARs-COV-2 displays increasing fatality with age and underlying co-morbidity, in particular, with markers of the metabolic syndrome and diabetes, which seems to be associated with a "cytokine storm" and an altered immune response. This suggests that a key contributory factor could be immunosenescence that is both age-related and lifestyle-induced. As the immune system itself is heavily reliant on mitochondrial function, then maintaining a healthy mitochondrial system may play a key role in resisting the virus, both directly, and indirectly by ensuring a good vaccine response. Furthermore, as viruses in general, and quite possibly this new virus, have also evolved to modulate immunometabolism and thus mitochondrial function to ensure their replication, this could further stress cellular bioenergetics. Unlike most sedentary modern humans, one of the natural hosts for the virus, the bat, has to "exercise" regularly to find food, which continually provides a powerful adaptive stimulus to maintain functional muscle and mitochondria. In effect the bat is exposed to regular hormetic stimuli, which could provide clues on how to resist this virus. In this paper we review the data that might support the idea that mitochondrial health, induced by a healthy lifestyle, could be a key factor in resisting the virus, and for those people who are perhaps not in optimal health, treatments that could support mitochondrial function might be pivotal to their long-term recovery.

Hydroxychloroquine in Dermatology and Beyond: Recent Update

Hydroxychloroquine is one of the most frequently used drugs in dermatology with a wide variety of uses due to its immunomodulatory, anti-inflammatory, photoprotective, and metabolic actions and low side effect profile. Demonstration of its antiviral action in vitro has led to renewed interest by physicians worldwide during the ongoing coronavirus disease of 2019 (COVID-19) pandemic. Like its immunomodulatory action, its antiviral activity is also due to its ability to alkalinize the intracytoplasmic milieu, leading to disordered viral entry/fusion and deranged viral protein synthesis. However, randomized controlled trials are the need of the hour to conclusively determine its clinical efficacy in such infections. A review of the multitude of mechanisms of action, updated screening and monitoring guidelines, drug interactions, side effects, and its use in special populations is described.

Hydroxychloroquine Mitigates the Production of 8-Isoprostane and Improves Vascular Dysfunction: Implications for Treating Preeclampsia

In preeclampsia, widespread maternal endothelial dysfunction is often secondary to excessive generation of placental-derived anti-angiogenic factors, including soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), along with proinflammatory cytokines such as tumour necrosis factor-α (TNF-α) and activin A, understanding of which offers potential opportunities for the development of novel therapies. The antimalarial hydroxychloroquine is an anti-inflammatory drug improving endothelial homeostasis in lupus. It has not been explored as to whether it can improve placental and endothelial function in preeclampsia. In this in vitro study, term placental explants were used to assess the effects of hydroxychloroquine on placental production of sFlt-1, sEng, TNF-α, activin A, and 8-isoprostane after exposure to hypoxic injury or oxidative stress. Similarly, human umbilical vein endothelial cells (HUVECs) were used to assess the effects of hydroxychloroquine on in vitro markers of endothelial dysfunction. Hydroxychloroquine had no effect on the release of sFlt-1, sEng, TNF-α, activin A, or 8-isoprostane from placental explants exposed to hypoxic injury or oxidative stress. However, hydroxychloroquine mitigated TNF-α-induced HUVEC production of 8-isoprostane and Nicotinanamide adenine dinucleotide phosphate (NADPH) oxidase expression. Hydroxychloroquine also mitigated TNF-α and preeclamptic serum-induced HUVEC monolayer permeability and rescued the loss of zona occludens protein zona occludens 1 (ZO-1). Although hydroxychloroquine had no apparent effects on trophoblast function, it may be a useful endothelial protectant in women presenting with preeclampsia.

Therapy and pharmacological properties of hydroxychloroquine and chloroquine in treatment of systemic lupus erythematosus, rheumatoid arthritis and related diseases

OBJECTIVES

This review examines the pharmacokinetics, modes of action and therapeutic properties of the anti-malarial drugs, hydroxychloroquine (HCQ) and chloroquine (CQ), in the treatment of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and related conditions, as well as osteoarthritis (OA).

KEY FINDINGS

Both HCQ and CQ have historically been employed successfully for the treatment of SLE and RA for over 70 years. HCQ has been used extensively for SLE where it has a good reputation for controlling the dermatological complications in SLE. It has also been reported to effectively control the symptoms of Sjøgren's syndrome, as well as preventing thrombosis in phospholipid antibody (aPL) syndrome. In RA and SLE, HCQ is preferred because of the lower incidence of gastrointestinal adverse reactions compared with CQ and it might have a lower risk of ocular adverse reactions. There is increasing evidence that HCQ may reduce atherosclerosis and risks of cardiovascular disease in rheumatic patients. Both HCQ and CQ have been shown to improve glycaemia and reduce the risks of type II diabetes mellitus. Although both HCQ and CQ are effective in low-moderate RA, HCQ is now preferred as part of combination therapy for more severe disease. The advantages of combination therapy are that the doses of the individual drugs may be lowered so reducing adverse reactions. Both HCQ and CQ are diastereoisomers, have basic properties and are given as the sulphate and phosphate salts. While being relatively well absorbed orally and with good bioavailability, they have long and variable plasma terminal elimination half-lives (approximately 40-60 days). This reflects their high volume of distribution, V D (HCQ 44,000L; CQ 65,000L) which extends into aqueous compartments, long mean residence time (HCQ 1300 h; CQ 900 h) and with about half the drugs (metabolites) undergoing renal clearance. The strong binding to melanin reflects the ocular injury and dermatological properties of these drugs. The consensus is that the occurrence of ocular adverse reactions can be minimised by close attention to the dose (which should be set on a body weight basis) with regular (e.g. quarterly) retinal examination. Although HCQ and CQ can pass through the placenta, the use of these drugs during pregnancy does not appear to risk harm to the baby and might be beneficial to the mother with SLE and her child by controlling the SLE disease activity, which is known to be an important factor affecting pregnancy outcome. The modes of action of HCQ and CQ in these arthritides represent somewhat of an enigma. Undoubtedly, these drugs have multiple actions related, in part, their ability to accumulate in lysosomes and autophagosomes of phagocytic cells as well as affecting MHC Class II expression and antigen presentation; actions of the production of pro-inflammatory cytokines [e.g. interleukin-1 (IL-1) tumour necrosis factor-α (TNFα)]; control of toll-like receptor-9 activation; and leucocyte generation of reactive oxygen species (ROS); i.e. antioxidant activity. The actions of these drugs on T and B cells are less clear but may depend on these leucocyte-mediated actions. Anti-malarials also protect against cytokine-mediated cartilage resorption. This and other actions may underlie the potential benefits in treating OA. The exact relationships of these various actions, mostly determined in vitro, have not been specifically defined in vivo or ex vivo in relation to clinical efficacy.

OUTCOMES

HCQ and CQ have a good reputation for being effective and relatively safe treatments in SLE, mild-moderate RA and Sjøgren's syndrome. There is need for (a) more information on their mode of action in relation to the control of these diseases, (b) scope for developing formulations that have improved pharmacokinetic and therapeutic properties and safety, and (c) further exploring their use in drug combinations not only with other disease modifying agents but also with biologics.

Attenuation of stretch-induced histopathologic changes of skeletal muscles by quinacrine

Quinacrine is an inhibitor of phospholipase A(2), an enzyme thought to be involved in activity-related injury of skeletal muscles. Histopathologic changes after injury by stretches of activated plantar-flexor muscles were measured in untreated and quinacrine-treated rats. On day 4 of treatment (50 mg.kg(-1) intraperitoneally for 5 days), 30 stretches were induced by ankle rotation after muscles reached a maximal isometric force. During the stretch protocol, peak stretch forces and isometric force deficits after each stretch [total deficits 56.7 +/- 2.8% (untreated rats) and 59.6 +/- 1.7% (quinacrine-treated rats)] were similar for both groups (n = 6 each). Two days after the stretch protocol, histopathologic changes were evaluated using antibody staining on cross-sections of gastrocnemius medialis muscles. Swollen myofibers devoid of desmin were identified. Similar cells, but not all swollen myofibers, in adjacent sections stained for albumin. Quinacrine reduced the number of desmin-negative and albumin-positive cells by 88% (P < 0.05) and 84% (P < 0.05), indicating that it attenuated histopathologic changes that follow stretch injury of activated skeletal muscles. Histopathologic changes following muscle injury or myopathic disease may thus be reduced or even prevented by selective drug intervention, thereby reducing the risk of muscle fibrosis. Muscle Nerve 27: 65-71, 2003

Antimalarials in cutaneous lupus erythematosus: mechanisms of therapeutic benefit

Antimalarials are arguably the best modality currently available for treating patients with cutaneous lupus erythematosus (LE). Although antimalarials have been used for decades in treating cutaneous LE, the precise mechanisms by which they provide therapeutic benefit are not well defined. The putative mechanisms by which antimalarials might provide therapeutic benefit to patients with cutaneous LE include a number of interrelated anti-inflammatory and immunosuppressive effects that include photoprotection, lysosomal stabilization, suppression of antigen presentation, and inhibition of prostaglandin and cytokine synthesis. If we had a more precise understanding of how antimalarials provide therapeutic benefit in cutaneous LE we might gain better insight into the pathogenic mechanisms of LE and ways of developing better therapies for afflicted patients.

Immunomodulating drugs in the management of psoriatic arthritis

Psoriatic arthritis is a chronic inflammatory arthropathy which can be distinguished from rheumatoid arthritis on the basis of differing patient demographics, genetic predisposition, histopathologic change, radiographic appearance, and clinical course. The cause of psoriatic arthritis remains unknown but appears to be autoimmune in nature as its pathogenesis is characterized by persistent synovial inflammation resulting in damage to the articular cartilage and osteolysis. Compared with rheumatoid arthritis, distinct lymphocyte subpopulations and pro-inflammatory cytokine levels appear to be present within the joint but the importance and therapeutic implications of these differences is uncertain. The clinical presentation of psoriatic arthritis is variable and overlapping patterns of joint involvement affecting both the appendicular and axial skeleton are seen. For patients with mild synovial disease and a favorable prognosis, the use of a nonsteroidal anti-inflammatory drug for symptomatic relief is often sufficient. However, the destructive potential of psoriatic arthritis is increasingly recognized and patients with more synovial disease and radiographic change at presentation appear to be at risk for greater morbidity and increased mortality. Immunomodulating therapy has the potential to suppress joint inflammation and preserve functional capacity but true disease modification has yet to be shown. The toxicity associated with presently available immunomodulatory agents makes careful patient selection and conscientious monitoring essential. The efficacy of methotrexate and sulfasalazine in patients with psoriatic arthritis is well defined while more anecdotal reports of benefit exist for other agents including the antimalarials, azathioprine, colchicine, cyclosporine, and the retinoids. For all treatment regimens, the magnitude of clinical improvement demonstrated to date has been rather small and quite subjective in character with few controlled studies of adequate size and duration having been reported. Emerging biologic therapies, such as those which target tumor necrosis factor, will hopefully provide future treatment options with greater efficacy and improved safety for patients with psoriatic arthritis.

Antimalarial drugs in systemic lupus erythematosus: use in pregnancy

The 4-aminoquinoline radical containing antimalarial drugs are also used in the management of various connective tissue diseases including systemic lupus erythematosus (SLE) and rheumatoid arthritis. These agents are particularly useful for the management of inflammatory polyarthritis and skin disease. By raising the pH in intracellular compartments, these drugs interfere with normal phagocytic function which consequently enables them to interfere with antigen processing. Other actions include inhibition of platelet aggregation, this is advantageous in patients with phospholipid antibodies (aPL) which are known to predispose patients to recurrent arterial and venous clinical thrombotic events. Hydroxychloroquine has also been demonstrated to reduce serum lipid levels including cholesterol, triglycerides and low density lipoproteins. As it is now known that patients with SLE are at risk for accelerated artherogenesis and premature heart disease, this action may be an added benefit for these patients. The use of the 4-aminoquinoline radical containing antimalarial drugs during pregnancy is controversial. It is known that these agents can cross the placenta and are deposited in fetal pigmented tissues. These findings have led to the recommendation that these agents should be discontinued in pregnancy for patients with connective tissue diseases even though they have long been recommended for malarial prophylaxis in pregnant women travelling to malarial infested areas. Flares of SLE disease have been documented when these agents are discontinued and as flares of SLE disease activity are known to be detrimental to pregnancy outcome in patients with SLE, it is our opinion that these drugs should not be discontinued during pregnancy in a patient with lupus, particularly when the known terminal elimination half life is 1 to 2 months.

Cooperation of chloroquine and blood platelets in inhibition of polymorphonuclear leukocyte chemiluminescence

Effect of activated blood platelets and chloroquine on concentration of reactive oxygen species produced by polymorphonuclear leukocytes (PMNL) stimulated with Ca(2+)-ionophore A23187 was investigated. Oxygen metabolites localized outside PMNL were visualized by isoluminol enhanced chemiluminescence, whereas chemiluminescence, enhanced with luminol and measured in the presence of the extracellular scavengers superoxide dismutase and catalase, was used for the detection of radicals originated intracellularly. Significant reduction of chemiluminescence was observed in the presence of platelets (added to PMNL in the physiological cell ratio 50:1) and of chloroquine (10 and 100 micromol/L). Although chloroquine decreased effectively both the extra- as well as the intracellular part of the chemiluminescence signal, the activity of platelets occurred largely outside PMNL. Serotonin liberated from platelets by A23187 appeared to be involved in inhibition of chemiluminescence; its concentrations achieved in platelet supernatants were found to be sufficient for elimination of PMNL-derived oxygen metabolites. The presented results indicated that chloroquine and blood platelets cooperate in inhibition of chemiluminescence because their common effect was found to be much more extensive than reduction induced by these inhibitors separately. Therefore, for accurate prediction of drug effect in the whole organism, the use of multicellular test systems seems to be pertinent.

Chloroquine interferes with lipopolysaccharide-induced TNF-alpha gene expression by a nonlysosomotropic mechanism

Chloroquine (CQ) is a lysosomotropic weak base with over 60 years of clinical use for the treatment of malaria and rheumatologic disorders. Consistent with its anti-inflammatory properties, CQ has been shown to interfere with TNF-alpha release from mononuclear phagocytes. Because it is unclear how CQ mediates these immunomodulatory effects, we set out to elucidate its mechanism of action. CQ exhibited dose-dependent inhibition of LPS-induced TNF-alpha release from human PBMC at therapeutically attainable concentrations. Additional studies to determine the specificity of this effect showed that although CQ reduced IL-1beta and IL-6 release, secretion of RANTES was unaffected. CQ acted by reducing TNF-alpha mRNA accumulation without destabilizing its mRNA or interfering with NF-kappaB nuclear translocation or p50/p65 isoform composition of DNA-binding complexes. Intracellular cytokine staining indicated that CQ reduced TNF-alpha production pretranslationally without interfering with TNF-alpha processing or release. We utilized bafilomycin A1 pretreatment to block the pH-dependent trapping of CQ in endosomes and lysosomes. Although bafilomycin A1 alone did not interfere with TNF-alpha expression, preincubation augmented the ability of CQ to reduce TNF-alpha mRNA levels, suggesting that CQ did not act by a lysosomotropic mechanism. Using confocal microscopy, we showed that bafilomycin A1 pretreatment resulted in a dramatic redistribution of quinacrine, a fluorescent congener of CQ, from cytoplasmic vacuoles to the nucleus. These data indicate that CQ inhibits TNF-alpha gene expression without altering translocation of NF-kappaB p50/p65 heterodimers. This dose-dependent effect occurs over a pharmacologically relevant concentration range and does not require pH-dependent lysosomotropic accumulation of CQ.

Lindane-induced inhibition of spontaneous contractions of pregnant rat uterus

Hexachlorocyclohexanes (HCHs) are prevalent insecticides. Lindane (gamma-HCH) inhibits uterine gap junctions but beta-HCH does not. Because gap junctions promote coordination of oscillatory uterine contractions, we hypothesized that lindane, but not beta-HCH, would inhibit uterine contractions. Uterine strips from midgestation rats were suspended in standard muscle baths and exposed to HCHs in a cumulative manner. Lindane induced concentration-dependent decreases in contraction force (ED50 of 9.2 microM) and complete uterine quiescence at 30 microM. In contrast, beta-HCH had no effect on contraction force, but 20 to 200 microM beta-HCH increased contraction frequency in a concentration-dependent manner. Isomer-specific differences in uterine responses were observed at similar HCH isomer tissue concentrations. Additionally, the phospholipase A2 inhibitor and antioxidant quinacrine increased the ED50 for contraction force inhibition to 84.5 microM lindane. Lindane also increased cAMP concentrations. Lindane and beta-HCH have distinctly different actions in the uterus. Lindane's inhibitory action may involve cAMP, arachidonic acid, or oxidative stress.

4-Aminoquinoline antimalarials enhance UV-B induced c-jun transcriptional activation

Previous work has documented that the earliest observable response in mammalian cells following ultraviolet (UV) irradiation is the activation of plasma membrane-associated Src tyrosine kinases. These molecules then trigger a signalling cascade that results in activation of the transcription factor AP-1 which subsequently transactivates the early immediate genes including c-jun. This pathway has been postulated to play a protective role against UV damage. As aminoquinoline antimalarials such as chloroquine are known to downregulate several photoinduced cutaneous disorders including LE-specific skin disease, we asked whether chloroquine might be capable of modulating this early limb of the UV light response. A431 cells (a human epidermal keratinocyte cell line) that had been transfected with a c-jun luciferase reporter gene construct were then treated with physiologically relevant concentrations of chloroquine followed by exposure to 0-125 J/m2 of UV-B from a bank of unfiltered FS20 lamps. Chloroquine pretreatment resulted in a dose-dependent increase in luciferase activity in permanently transfected A431 cells (luciferase activity was increased by 45% at 2.5 x 10(-5) M chloroquine and 125 J/m2 of UV-B). Hydroxychloroquine pretreatment also resulted in an increase in luciferase activity. Primaquine, an 8-aminoquinoline, did not influence the UV-B induced c-jun activity. Furthermore, chloroquine did not have a similar impact on HSP-70 gene activity during heat shock. These studies suggest that the beneficial effect of the 4-aminoquinoline antimalarials in various photodermatoses including cutaneous LE might result in part from the capacity of these drugs to enhance the protective early limb of the UV response.

Paraquat-induced phosphatidylserine oxidation and apoptosis are independent of activation of PLA2

Paraquat is a pneumotoxin that causes lung injury by enhancing oxidative stress; however, the cellular responses to these redox events are undefined. We previously showed that paraquat produced selective peroxidation of phosphatidylserine that preceded apoptosis in 32D cells. We now report that the phospholipase A2 (PLA2) inhibitor quinacrine can attenuate phosphatidylserine oxidation and also block paraquat-induced apoptosis. Therefore, we investigated the potential for PLA2 to mediate apoptosis after paraquat. We found that, in contrast to quinacrine, the PLA2 inhibitors manoalide, aristolochic acid, and arachidonyl trifluoromethylketone failed to prevent paraquat-induced apoptosis. Moreover, no evidence of PLA2 activation was observed within 7 h after paraquat exposure. Finally, quinacrine failed to inhibit basal and 4-bromo-A-23187-induced release of [3H]arachidonic acid at concentrations that protected paraquat-induced apoptosis. We conclude that paraquat-induced phosphatidylserine oxidation and apoptosis occurred in the absence of PLA2 activation and that quinacrine protected phosphatidylserine and cell viability after paraquat in a PLA2-independent manner.

Are the reactive oxygen-derived species (ROS) interactive properties of the many therapeutic drugs from various categories pertinent to their beneficial effects?

Many pathologic states are known to involve the generation of reactive oxygen species, (ROS). It is not known at present to what extent these phenomena are due to ROS formation, or if their formation is a result of the disease. Many therapeutic drugs either scavenge ROS or inhibit their formation. The purpose of this review is to match the drugs used for certain diseases with their anti-ROS actions. This attempted correlation is made to try to give an answer to the title question.

Epidemiology and socioeconomic impact of skin disease in lupus erythematosus

The prevalence rates of systemic lupus erythematosus (SLE) may vary within 17-48/100,000 population worldwide. Although population-based epidemiological studies are still missing, the cutaneous variants of lupus erythematosus (LE) are 2-3 times more frequent than SLE itself. The most common age of onset is 20-40 y. Overall, cutaneous LE is regarded as a variant with less severe course and better prognosis. However, CDLE and SCLE last for many years and may lead, like SLE, to severe disability for work and limited life quality; also, a small proportion of patients with cutaneous LE develops SLE during the course of their disease. This implies considerable amount of medical management and costs for the community. Early recognition of cutaneous LE patients at risk to develop SLE and preventive measures against disease triggering factors are important tasks for physicians attending with cutaneous LE patients. It seems that signs of nephropathy, elevated ANA-titers and arthralgias may serve as prognostic predictors for transition into SLE. Characteristic features of cutaneous LE are photosensitivity and female predominance. UV light is a major environmental triggering factor in cutaneous LE. Skin lesions may be induced or preexistent lesions may exacerbate due to UV light in up to 80-90% of all patients. Therefore, socioeconomic counseling of the young patients, for example choice of occupation and sun protection, are essentials in compliant patients. Also, since females are 3-6 times more frequently affected than males, the possibility of hormonal influences including pregnancy and estrogen-containing drugs should be discussed. Risk considerations for females wishing to become pregnant are required, and avoidance of estrogen-containing contraceptives should be recommended.

Quinacrine: sclerosing agent of the utero-tubal junction in women, with anticarcinogenic actions in transplanted tumors in mice

Quinacrine, an acridine derivative that was in widespread use as an anti-malarial, has been shown to have both sclerosant and anticarcinogenic actions. The sclerosant action of quinacrine has been used to produce occlusion of Fallopian tube in both experimental animals and women, and several clinical studies are reviewed. Both actions of quinacrine are potentiated by steroidal and non-steroidal antiprostaglandins as well as by ionic copper. Combinations of quinacrine with antiprostaglandin drugs, and also with copper, improved the efficacy of quinacrine when used for female sterilization and reduced side effects. A review of the experimental and epidemiological evidence suggests that quinacrine has no carcinogenic effects.

Mechanism of action of hydroxychloroquine as an antirheumatic drug

The antimalarial agents chloroquine and hydroxychloroquine have been used widely for the treatment of rheumatoid arthritis and systemic lupus erythematosus. These compounds lead to improvement of clinical and laboratory parameters, but their slow onset of action distinguishes them from glucocorticoids and nonsteroidal antiinflammatory agents. Chloroquine and hydroxychloroquine increase pH within intracellular vacuoles and alter processes such as protein degradation by acidic hydrolases in the lysosome, assembly of macromolecules in the endosomes, and posttranslation modification of proteins in the Golgi apparatus. It is proposed that the antirheumatic properties of these compounds results from their interference with "antigen processing" in macrophages and other antigen-presenting cells. Acidic cytoplasmic compartments are required for the antigenic protein to be digested and for the peptides to assemble with the alpha and beta chains of MHC class II proteins. As a result, antimalarials diminish the formation of peptide-MHC protein complexes required to stimulate CD4+ T cells and result in down-regulation of the immune response against autoantigenic peptides. Because this mechanism differs from other antirheumatic drugs, antimalarials are well suited to complement these other compounds in combination drug therapy.

Antimalarials in rheumatic diseases

The antimalarials hydroxychloroquine and chloroquine remain established and effective agents for the treatment of rheumatoid arthritis and systemic lupus erythematosus. Although the mechanisms of action remain uncertain, evidence is accumulating that the antirheumatic and immunological effects of the antimalarials are related to their massive distribution into the cellular acid-vesicle system. These drugs are attracting new interest because their relative safety recommends their use in early rheumatoid arthritis and as a component of second-line antirheumatic drug combinations. The absence of data examining the effect of antimalarials upon radiological progression of rheumatoid arthritis needs to be rectified. Recent understanding of the pharmacokinetics of these drugs reveals that steady-state concentrations are not achieved for at least 3-4 months. Preliminary information also suggests a relationship between blood concentrations and effect. Taken together, these data suggest that more effective dosage regimens will be possible when therapeutic concentration ranges are properly established.

The digestion of bacterial macromolecules by phagocytic cells: the effect of mepacrine and ethanol

The digestion of radiolabelled DNA, RNA and protein from two species of bacteria was measured after their ingestion by neutrophils and monocytes. The Escherichia coli (W3110T-) strain was more susceptible to digestion than Staphylococcus aureus. Monocytes solubilized the majority of bacterial DNA to trichloroacetic acid (TCA)-soluble oligonucleotides, which were released rapidly from the cell, whereas neutrophils digested little DNA and retained most as a high molecular weight residue. Both monocytes and neutrophils released about 30% of DNA as large TCA-insoluble fragments. However, neutrophils were more proficient than monocytes at degrading bacterial RNA. Monocytes and neutrophils digested bacterial protein equally well. The drug mepacrine hydrochloride inhibited phagocytosis of bacteria by both neutrophils and monocytes, although monocytes were more sensitive to the drug. Mepacrine specifically inhibited the terminal digestion of DNA by monocytes to TCA-soluble molecules, whereas digestion to large molecular weight fragments apparently was not affected. Ethanol also inhibited the breakdown of DNA by phagocytic cells.

Biologically-significant scavenging of the myeloperoxidase-derived oxidant hypochlorous acid by some anti-inflammatory drugs

Neutrophils contain the enzyme myeloperoxidase, which oxidizes Cl- ions into the powerful oxidant hypochlorous acid (HOCl). HOCl inactivates alpha 1-antiprotease, permitting uncontrolled protease activities. Most anti-inflammatory drugs tested are capable of reacting with HOCl, but the reactions seem insufficiently rapid under physiological conditions to protect alpha 1-antiprotease against inactivation by HOCl. However, rapid scavenging of HOCl might contribute to the anti-inflammatory effects of penicillamine, gold sodium thiomalate, phenylbutazone and primaquine.

The scavenging of oxidants by sulphasalazine and its metabolites. A possible contribution to their anti-inflammatory effects?

Sulphasalazine (Salazopyrin) and its metabolites sulphapyridine and 5-aminosalicylate are powerful scavengers of the hydroxyl radical, determined by pulse radiolysis and confirmed by assays based on deoxyribose degradation by hydroxyl radicals. 5-Aminosalicylate can also protect alpha 1-antiprotease against attack by the myeloperoxidase-derived oxidant hypochlorous acid. The ability to scavenge oxidants produced at sites of inflammation may contribute to the anti-inflammatory action of sulphasalazine and its metabolites.

Studies on the mechanism of inhibition of chemotactic tripeptide stimulated human neutrophil polymorphonuclear leucocyte superoxide production by chloroquine and hydroxychloroquine

The effect of chloroquine and hydroxychloroquine on neutrophil superoxide release stimulated by the chemotactic tripeptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) was examined. Both drugs caused time and dose dependent inhibition of superoxide release but had no effect on equilibrium binding of [3H]FMLP to its receptor. Preliminary experiments suggest that these drugs may exert their inhibitory effect on superoxide release by inhibiting the FMLP stimulated hydrolysis of phosphoinositides.

Effect of antiinflammatory drugs on human interleukin-1-induced cartilage degradation

Human monocyte IL-1 stimulated the release of proteoglycans from cartilage in organ culture in a concentration-related manner. This stimulation required protein synthesis as shown by inhibition with cycloheximide. The metal chelator, 1,10-phenanthroline, inhibited breakdown, suggesting the involvement of a metalloproteinase. Various nonsteroidal anti-inflammatory drugs (100 microM), and the corticosteroids, dexamethasone and hydrocortisone (1-10 microM), were not effective in blocking proteoglycan release. Of the disease modifying agents tested, levamisole was ineffective while the antimalarials, chloroquine (100 microM) and hydroxychloroquine (100 microM), inhibited the action of IL-1. The free-radical inhibitor SOD (5000 U/ml but not 1000 U/ml) was effective while catalase (8000 U/ml) was not. The protective effects of SOD and the antimalarials suggest that oxygen reactive species may play a role, while lack of inhibition with NSAIDs and corticosteroids indicate that arachidonic acid metabolites may not be important in this degradative process.

Inhibition by nonsteroidal anti-inflammatory drugs of superoxide production and granule enzyme release by polymorphonuclear leukocytes stimulated with immune complexes or formyl-methionyl-leucyl-phenylalanine

The effects of nonsteroidal anti-inflammatory agents on superoxide production and granule enzyme release by human polymorphonuclear leukocytes stimulated with either formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe] or immune complexes were investigated. Cytochrome c reduction and the release of lysozyme, beta-glucuronidase, myeloperoxidase and gelatinase were measured. Auranofin, phenylbutazone, sulfasalazine and the phospholipase A2 inhibitor, 4-bromophenacyl bromide, strongly inhibited these responses in fMet-Leu-Phe stimulated cells, at concentrations below 50 microM. Indomethacin, piroxicam, mefenamic acid, primaquine and quinacrine at 50-250 microM were inhibitory. Up to 1 mM ibuprofen and chloroquine inhibited superoxide production but had little effect on degranulation. With cells stimulated by IgG aggregates (immune complexes), up to 1 mM ibuprofen, mefenamic acid and piroxicam did not inhibit either response. Indomethacin, phenylbutazone, sulfasalazine and primaquine inhibited, but considerably higher concentrations were required than with fMet-Leu-Phe. Quinacrine inhibited superoxide production equally well with both stimuli but inhibited enzyme release only with fMet-Leu-Phe. Only auranofin, 4-bromophenacyl bromide, and the weakly effective chloroquine exerted approximately the same effect with both stimuli. D-Penicillamine did not affect enzyme release with either stimulus and interfered in the superoxide assay. Gelatinase release induced by fMet-Leu-Phe was affected to the same extent, or slightly more, than release of the other granule enzymes. With immune complexes, there was only modest inhibition of gelatinase release by any of the drugs at 250-1000 microM. Our results reinforce previous observations that many anti-inflammatory drugs affect neutrophil functions, but their effects vary with stimulus. The relative insensitivity of immune complex-induced responses to most of the drugs must be taken into account when considering their mode of action.

Uptake of chloroquine and hydroxychloroquine by human blood leucocytes in vitro: relation to cellular concentrations during antirheumatic therapy

The accumulation of chloroquine and hydroxychloroquine in unfractionated mononuclear cells and in purified monocytes, lymphocytes, and neutrophil polymorphonuclear leucocytes (PMN) was measured in vitro. Accumulation of both drugs in leucocytes was time and dose dependent. Cellular levels comparable to those found during antirheumatic therapy were achieved by preincubation for 60 minutes with up to 0.1 mM chloroquine or hydroxychloroquine.