Exploring the Prospective Role of Propolis in Modifying Aging Hallmarks

Aging populations worldwide are placing age-related diseases at the forefront of the research agenda. The therapeutic potential of natural substances, especially propolis and its components, has led to these products being promising agents for alleviating several cellular and molecular-level changes associated with age-related diseases. With this in mind, scientists have introduced a contextual framework to guide future aging research, called the hallmarks of aging. This framework encompasses various mechanisms including genomic instability, epigenetic changes, mitochondrial dysfunction, inflammation, impaired nutrient sensing, and altered intercellular communication. Propolis, with its rich array of bioactive compounds, functions as a potent functional food, modulating metabolism, gut microbiota, inflammation, and immune response, offering significant health benefits. Studies emphasize propolis' properties, such as antitumor, cardioprotective, and neuroprotective effects, as well as its ability to mitigate inflammation, oxidative stress, DNA damage, and pathogenic gut bacteria growth. This article underscores current scientific evidence supporting propolis' role in controlling molecular and cellular characteristics linked to aging and its hallmarks, hypothesizing its potential in geroscience research. The aim is to discover novel therapeutic strategies to improve health and quality of life in older individuals, addressing existing deficits and perspectives in this research area.

COVID-19 associated cranial nerve neuropathy: A systematic review

The involvement of cranial nerves is being increasingly recognized in COVID-19. This review aims to summarize and discuss the recent advances concerning the clinical presentation, pathophysiology, diagnosis, treatment, and outcomes of SARS-CoV-2 associated cranial nerve mononeuropathies or polyneuropathies. Therefore, a systematic review of articles from PubMed and Google Scholar was conducted. Altogether 36 articles regarding SARS-CoV-2 associated neuropathy of cranial nerves describing 56 patients were retrieved as per the end of January 2021. Out of these 56 patients, cranial nerves were compromised without the involvement of peripheral nerves in 32 of the patients, while Guillain-Barre syndrome (GBS) with cranial nerve involvement was described in 24 patients. A single cranial nerve was involved either unilaterally or bilaterally in 36 patients, while in 19 patients multiple cranial nerves were involved. Bilateral involvement was more prevalent in the GBS group (n = 11) as compared to the cohort with isolated cranial nerve involvement (n = 5). Treatment of cranial nerve neuropathy included steroids (n = 18), intravenous immunoglobulins (IVIG) (n = 18), acyclovir/valacyclovir (n = 3), and plasma exchange (n = 1). The outcome was classified as “complete recovery” in 21 patients and as “partial recovery” in 30 patients. One patient had a lethal outcome. In conclusion, any cranial nerve can be involved in COVID-19, but cranial nerves VII, VI, and III are the most frequently affected. The involvement of cranial nerves in COVID-19 may or may not be associated with GBS. In patients with cranial nerve involvement, COVID-19 infections are usually mild. Isolated cranial nerve palsy without GBS usually responds favorably to steroids. Cranial nerve involvement with GBS benefits from IVIG.

Early life handling decreases serotonin turnover in the nucleus accumbens and affects feeding behavior of adult rats

In our previous studies, we reported that neonatally handled rats have an increased ingestion of sweet food but are resistant to the damaging effects of a chronic exposure to a highly palatable diet. Accumbal serotonin (5-HT) is important for feeding behavior and plays a role in the vulnerability to diet-induced obesity. Therefore, our hypotheses were (1) 5-HT turnover in the nucleus accumbens is altered in neonatally handled animals and plays a role in their differential feeding behavior and (2) if this is so, a chronic pharmacological treatment affecting 5-HT reuptake (chronic imipramine) would be able to revert the behavioral findings. Litters were divided into nonhandled and handled (10 min/day, Days 1-10 after birth). In Experiment 1, we demonstrated that a decreased 5-HT metabolism in the nucleus accumbens was observed in adult handled animals. In Experiment 2, the two previous groups were subdivided and assigned to receive imipramine diluted in water or water alone. After 30 days of treatment, we evaluated their weight gain and feeding behavior. Handled rats weighed less than nonhandled rats, and all imipramine-treated rats showed a reduction in weight gain after 60 days of treatment. Imipramine reverted the increased sweet food consumption seen in neonatally handled rats. We conclude that serotonin is involved in the altered feeding behavior of neonatally handled rats, and this protocol is an important tool for studying the mechanisms by which early life events have a long-term impact on feeding preferences.

p-Methylthioamphetamine and 1-(m-chlorophenyl)piperazine, two non-neurotoxic 5-HT releasers in vivo, differ from neurotoxic amphetamine derivatives in their mode of action at 5-HT nerve endings in vitro

The mechanism underlying the serotoninergic neurotoxicity of some amphetamine derivatives, such as p-chloroamphetamine (pCA) and 3,4-methylenedioxymethamphetamine (MDMA), is still debated. Their main acute effect, serotonin (5-HT) release from nerve endings, involves their interaction with 5-HT transporters (SERTs), as substrates. Although this interaction is required for the neurotoxic effects, 5-HT release alone may not be sufficient to induce long-term 5-HT deficits. Some non-neurotoxic compounds, including p-methylthioamphetamine (MTA) and 1-(m-chlorophenyl)piperazine (mCPP), have 5-HT releasing properties in vivo and in brain slices comparable to that of neurotoxic amphetamine derivatives. We measured 5-HT release in superfused rat brain synaptosomes preloaded with [3H]5-HT, a model that distinguishes a releasing effect from reuptake inhibition. MTA and mCPP induced much lower release than pCA and MDMA. The striking difference between our findings in synaptosomes and those obtained in vivo or in brain slices is probably related to a different compartmentalisation of 5-HT in the different experimental models. Studies in synaptosomes, where the vesicular storage of 5-HT is predominant, could therefore bring to light differences between neurotoxic and non-neurotoxic 5-HT releasing agents which cannot be appreciated in other experimental models and might be useful to identify the mechanisms responsible for the neurotoxicity induced by amphetamine derivatives.

ALEPH-2, a suspected anxiolytic and putative hallucinogenic phenylisopropylamine derivative, is a 5-HT2a and 5-HT2c receptor agonist

To assess the pharmacodynamic profile of ALEPH-2, a phenylisopropylamine derivative with alleged anxiolytic and hallucinogenic properties, Xenopus laevis oocytes were microinjected with either of the rat cRNA for the 5-HT2A or the 5-HT2C receptor. Concentration-response curves were obtained following the exposure of the oocytes to varying concentrations of either ALEPH-2 or 5-hydroxytryptamine (5-HT) for 10 s. ALEPH-2 is a partial agonist on the 5-HT2A receptor with a similar potency to 5-HT. In contrast, ALEPH-2 is a full 5-HT2C receptor agonist and is about 15-fold less potent than 5-HT. Pre-application of 1 microM ritanserin antagonized the responses induced by 5-HT and ALEPH-2 to the same extent; however, the 5-HT2A receptor is more sensitive to ritanserin blockade than the 5-HT2C receptor.

Effects of 5-HT-releasing agents on the extracellullar hippocampal 5-HT of rats. Implications for the development of novel antidepressants with a short onset of action

The effects of two selective 5-HT-releasing agents, 4-methylthioamphetamine (MTA) and 5-methoxy-6-methyl-2-aminoindan (MMAI), on the extracellular 5-HT concentration in the dorsal hippocampus was determined by microdialysis in anesthetized rats. After i.p. administration of 1 or 5 mg/kg of either compound, a rapid and significant increase of 5-HT basal release was observed. MTA (5 mg/kg) induced a maximal increase of about 2000% over the basal value 40 min after injection, which declined slowly, whereas MMAI (5 mg/kg) induced a maximal response of about 1350% which showed a rapid decline. Monoamine oxidase-A inhibitory properties of MTA, and MMAI's lack of similar properties might account for the difference between the two compounds. In agreement with previous information, a much lower increase in hippocampal 5-HT was observed in response to systemic fluoxetine. This difference in the magnitude of the response after MTA or MMAI and fluoxetine indicates that different mechanisms of action are operating. Based on evidence showing that an acute enhancement of 5-HT neurotransmission might result in the rapid appearance of therapeutic effects of serotonergic antidepressants, we suggest that MTA and MMAI might serve as leads for a novel family of compounds with a short onset of action useful for treating depression.

Effects of the D3 preferring dopamine agonist pramipexole on sleep and waking, locomotor activity and striatal dopamine release in rats

Quantitation of 2 h sessions after administration of the D3 preferring dopamine (DA) agonist pramipexole (10-500 microg/kg) showed dose-related effects on wakefulness (W), slow wave sleep (SWS) and REM sleep in rats. The 30 microg/kg dose of the DA agonist increased SWS and REM sleep and reduced W during the first recording hour, while the 500 microg/kg dose augmented W. On the other hand, W was increased while SWS and REMS were decreased after the 500 microg/kg dose during the second recording hour. The mixed D2- and D3 receptor antagonist YM-09151-2 (30-500 microg/kg), which per se affected sleep variables prevented the increase of REMS induced by pramipexole. Furthermore, the highest doses (500-1000 microg/kg) of the DA antagonist effectively antagonized the increase of W and reduction of SWS induced by the 500 microg/kg dose of the DA agonist. Pramipexole (30-100 microg/kg) induced a decrease of locomotor activity during the 2 h recording period. In addition, the 500 microg/kg dose gave rise to an initial reduction of motor behavior which was reverted 2 h later. Pramipexole (30 and 500 microg/kg) did not significantly affect striatal DA release during the first two hours following drug administration, as measured by microdialysis. It is tentatively suggested that D3 receptor could be involved in the pramipexole-induced increase of sleep and reduction of locomotor activity. On the other hand, the increase of W and of motor behavior after relatively high doses could be related to activation of postsynaptic D2 receptor.

(+/-)-1-(2,5-Dimethoxy-4-ethylthiophenyl)-2-aminopropane (ALEPH-2), a novel putative anxiolytic agent lacking affinity for benzodiazepine sites and serotonin-1A receptors

Serotonergic behavioral responses, effects on motor activity and core temperature, and binding properties of the novel putative anxiolytic amphetamine derivative (+/-)1-(2,5-dimethoxy-4-ethylthio-phenyl)-2-aminopropane (ALEPH-2), were examined in rodents in order to elucidate the mechanism underlying its anxiolytic-like effect. After peripheral administration in rats, ALEPH-2 induced some symptoms of the serotonergic syndrome, e.g. forepaw treading and flat body posture. Additionally, a decrease in motor activity was observed. No significant effects on the number of head shakes were observed after injection, although high inter-subject variability was noted. Higher doses of ALEPH-2, in the range exhibiting anxiolytic properties (4mg/kg), elicited significant hypothermia in mice. The affinity of the drug for 5-HT2A/2C receptors ([3H]ketanserin sites) was in the nanomolar range (Ki = 173 nM), whereas for 5-HT1A, benzodiazepine sites, and GABAA receptors, the affinity was micromolar of lower. Based on these results the mechanism of action and the anxiolytic-like properties of ALEPH-2 are discussed.

Sleep and waking in 5,7-DHT-lesioned or (-)-pindolol-pretreated rats after administration of buspirone, ipsapirone, or gepirone

The effects of partial 5-HT1A receptor agonists buspirone (0.010-4.0 mg/kg), ipsapirone (0.010-6.0 mg/kg), and gepirone (0.025-4.0 mg/kg) on sleep and waking were studied in vehicle-treated and 5,7-dihydroxytryptamine (5,7-DHT)-injected rats. 5,7-DHT-treated animals showed a marked and significant serotonin and 5-HIAA depletion in the raphe regions of the pons and upper brain stem, cerebral cortex, hippocampus, and striatum. Subcutaneous administration of the partial agonists to both the vehicle-infused and the 5,7-DHT-treated animals significantly increased waking (W) and reduced light sleep (LS), slow-wave sleep (SWS), and REM sleep (REMS). Pretreatment with (-)pindolol (2.0 mg/kg) reversed the effects of buspirone and gepirone on W and non-REM sleep (LS + SWS) whereas REMS remained suppressed. (-)-Pindolol failed to reverse the effects of ipsapirone on sleep and W. The present results tend to indicate that increased W after acute administration of buspirone, ipsapirone, or gepirone depends upon the activation of postsynaptic 5-HT1A receptors. The well-known anxiolytic action observed after chronic administration of the azapirones seems to be related to mechanisms other that these involved in their stimulant effect.

Depletion of brain serotonin by 5,7-DHT: effects on the 8-OH-DPAT-induced changes of sleep and waking in the rat

The effect of 5-HT1A receptor agonist 8-OH-DPAT on sleep and wakefulness was studied in rats with selective serotonin depletion after ICV administration of the neurotoxin 5,7-dihydroxytryptamine (5,7-DHT). Injection of 8-OH-DPAT to vehicle-treated animals induced biphasic effects, such that low doses (0.010 mg/kg) which act perferentially on the somatodendritic autoreceptor decreased wakefulness (W) and increased slow wave sleep (SWS), while higher doses (0.375 mg/kg) which stimulate postsynaptic receptors caused opposite effects. REM sleep was suppressed irrespective of the dosage given. Injection of the 0.010 mg/kg dose in the 5,7-DHT-treated rats did not result in significant changes in sleep or W. On the other hand, the 0.375 mg/kg dose produced changes in sleep variables which were similar to those described in the vehicle-treated animals. Our findings tend to indicate that increased SWS after low doses of 8-OH-DPAT depends upon the activation of inhibitory somatodendritic 5-HT1A receptors, while increased W after higher doses of the compound is related to stimulation of postsynaptic receptors.

Ultrastructural characteristics of different stages of human chagasic myocarditis

Myocardial damage was analyzed in the different stages of Chagas' disease. Myocardial biopsies from chagasic patients, whose clinical histories were initially unknown to the examiner, were examined and evaluated by electron microscopy using a table in which 244 characteristics were considered. When the ultrastructural results were associated with their respective clinical reports, it was found that Chagas' disease stages showed significant myocardium damage between stages IA and II: IA (normal EKG and cineventriculogram), 13.0%; IB (early left ventricular damage with normal EKG), 14.5%; II (advanced left ventricular damage, abnormal EKG), 25.5%; stage III (congestive heart failure) showed a decrement to 22.5% if compared with stage II. The acute stage of the illness was characterized by the presence of the parasites within the myocytes which were surrounded by inflammatory cell infiltrate. During Chagas' disease evolution the most affected organelle was the sarcoplasmic reticulum.

Comparative non-blind trial of ceftriaxone and gentamicin in the treatment of complicated urinary tract infections

Forty hospitalized patients with complicated urinary tract infections were treated with gentamicin 240 mg die i.m. or ceftriaxone, a new parenteral cephalosporin, 2 g die i.v. for 7 days. Ceftriaxone gave good clinical and bacteriological results which were better than those obtained with gentamicin, showing also an appreciable activity in cases of infection due to problematic organisms.