Do antioxidant strategies work against aging and age-associated disorders? Propargylamines: a possible antioxidant strategy

Deprenyl reduces inflammation during acute SIV infection

In the era of antiretroviral therapy, inflammation is a central factor in numerous HIV-associated comorbidities, such as cardiovascular disease, cognitive impairment, and neuropsychiatric disorders. This highlights the value of developing therapeutics that both reduce HIV-associated inflammation and treat associated comorbidities. Previous research on monoamine oxidase inhibitors (MAOIs) suggests this class of drugs has anti-inflammatory properties in addition to neuropsychiatric effects. Therefore, we examined the impact of deprenyl, an MAOI, on SIV-associated inflammation during acute SIV infection using the rhesus macaque model of HIV infection. Our results show deprenyl decreased both peripheral and CNS inflammation but had no effect on viral load in either the periphery or CNS. These data show that the MAOI deprenyl may have broad anti-inflammatory effects when given during the acute stage of SIV infection, suggesting more research into the anti-inflammatory effects of this drug could result in a beneficial adjuvant for antiretroviral therapy.

Intersection between metabolic dysfunction, high fat diet consumption, and brain aging

Deleterious neurochemical, structural, and behavioral alterations are a seemingly unavoidable aspect of brain aging. However, the basis for these alterations, as well as the basis for the tremendous variability in regards to the degree to which these aspects are altered in aging individuals, remains to be elucidated. An increasing number of individuals regularly consume a diet high in fat, with high-fat diet consumption known to be sufficient to promote metabolic dysfunction, although the links between high-fat diet consumption and aging are only now beginning to be elucidated. In this review we discuss the potential role for age-related metabolic disturbances serving as an important basis for deleterious perturbations in the aging brain. These data not only have important implications for understanding the basis of brain aging, but also may be important to the development of therapeutic interventions which promote successful brain aging.

Antioxidant and antibacterial activity of two compounds (forsythiaside and forsythin) isolated from Forsythia suspensa

Forsythia suspensa (Thunb.) Vahl. has been widely used in traditional medicines in Asia to treat gonorrhoea, erysipelas, inflammation, pyrexia, ulcer and other diseases. Recently the investigation has been focused on the antioxidant and antibacterial activity of this plant. However, limited scientifically proven information is available. We isolated two compounds (forsythiaside and forsythin) from this plant. The aims of this investigation, therefore, were to assay antioxidant activity and antibacterial properties of the two main and distinctive compounds isolated and to exploit antioxidants and antibacterial agents from natural compounds. The antioxidant activity was estimated using the 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity method and the in-vitro antimicrobial activity was evaluated by microtitre plate method. Forsythiaside was found to possess strong antioxidant and antibacterial activity but forsythin was much weaker. Owing to these properties, the study can be further extended to exploit the possible application of forsythiaside as an alternative antioxidant and antibacterial agent of natural origin.

Lifelong aspirin supplementation as a means to extending life span

Arising from an initiative by the National Institute of Aging (NIA) requesting novel proposals challenged with increasing lifespan and longevity, our laboratory has generated a hypothesis to test the efficacy of lifelong, low-dosage aspirin administration as a means to achieving this goal. The intervention testing program (currently underway) proposing aspirin as an anti-aging agent evolved from the multitude of properties encompassed in aspirin and the potential of these attributes to prevent the cellular and functional declines, particularly from inflammatory and oxidative sources, evidenced to contribute to aging. Aspirin is a widely administered, cheap, anti-inflammatory, and antioxidant compound that has a variety of positive effects on the immune system and cardiovascular health. Notably, aspirin may affect oxidant production, cytokine responses, and block glycooxidation reactions, thus posing it as a triple threat against the symptoms of aging. Whether aging is molded by interplay between oxidative stress and inflammatory mediators has received little attention; however, we and other laboratories have explored this notion and have observed an elevated inflammatory status with age. Stemming from these observations and in view of the limited success of antioxidant therapies in improving lifespan in long-lived species, in this article we propose a protocol to examine life-long use of a very low dose anti-inflammatory compound such as aspirin to engage the inflammatory and endogenous oxidative insults accompanying aging and, in so doing, attempt to increase maximum and mean life span.

Oxidative mechanisms and tardive dyskinesia

Tardive dyskinesia has been and continues to be a significant problem associated with long-term antipsychotic use, but its pathophysiology remains unclear. In the last 10 years, preclinical studies of the administration of antipsychotics to animals, as well as clinical studies of oxidative processes in patients given antipsychotic medications, with and without tardive dyskinesia, have continued to support the possibility that neurotoxic free radical production may be an important consequence of antipsychotic treatment, and that such production may relate to the development of dyskinetic phenomena. In line with this hypothesis, evidence has accumulated for the efficacy of antioxidants, primarily vitamin E (alpha-tocopherol), in the treatment and prevention of tardive dyskinesia. Early studies suggested a modest effect of vitamin E treatment on existing tardive dyskinesia, but later studies did not demonstrate a significant effect. Because evidence has continued to accumulate for increased oxidative damage from antipsychotic medications, but less so for the effectiveness of vitamin E, especially in cases of long-standing tardive dyskinesia, alternative antioxidant approaches to the condition may be warranted. These approaches may include the use of antioxidants as a preventive measure for tardive dyskinesia or the use of other antioxidants or neuroprotective drugs, such as melatonin, for established tardive dyskinesia.

Pharmacological interventions in aging and age-associated disorders: potentials of propargylamines for human use

Past studies including our own have confirmed that chronic administration of deprenyl can prolong life spans of at least four different animal species. Pretreatment with the drug for several weeks increases activities of superoxide dismutase (SOD) and catalase (CAT) in selective brain regions. An up-regulation of antioxidant enzyme activities can also be induced in organs such as the heart, kidney, spleen, and adrenal gland, and all are accompanied by an increase in mRNA levels for SODs in these organs. The effect of deprenyl on enzyme activities has a dose-effect relationship of a typical inverted U shape. A similar inverted U shape also has emerged for the drug's effect on survival of animals. An apparent parallelism observed between these two effects of the drug seems to support our contention that the up-regulation of antioxidant enzymes is at least partially responsible for the life-prolonging effect on animals. Further, when a clinically applied dose of the drug for patients with Parkinson's disease was given to monkeys, SOD and CAT activities were increased in striatum of these monkeys, which suggests potential for the drug's applicability to humans. The drug was also found to increase concentrations of cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) in the above rat organs. Together with past reports demonstrating that deprenyl increases natural killer (NK) cell functions and interferon-gamma, and prevents the occurrence of malignant tumors in rodents and dogs, the mobilization of these humoral factors may therefore be included as possible mechanisms of action of deprenyl for its diverse antiaging and life-prolonging effects. The potentials of propargylamines, (-)deprenyl in particular, for human use as antiaging drugs remain worthy of exploration in the future.