ABSTRACT
Antimicrobial peptides (AMPs), commonly referred to as host defense peptides, are found in a wide range of organisms, including bacteria, plants, and both vertebrate and invertebrate animals. They function as an initial defense mechanism against pathogenic microorganisms, modulate immune responses, and in specific instances, confer protection against the onset of cancer. Pleurocidin (Ple) is a linear antimicrobial peptide with amphipathic α-helical conformation, isolated originally from the winter flounder (Pleuronectes americanus), notable for its wide-ranging effectiveness against both bacteria and fungi. While the majority of research on pleurocidin's biological characteristics has primarily focused on deciphering its mechanisms of interaction with the biological membranes of pathogenic bacteria and host cells, as well as investigating its modes of killing activities, there is a growing body of evidence suggesting that pleurocidin and pleurocidin-derived analogs might be effectively employed as anti-cancer agents against breast carcinoma and leukemia due to their potent cytotoxic properties and selectivity towards cancer cells. Notably, some characteristics of pleurocidin observed in microbiological investigations of this compound could be effectively applied in examining the anti-cancer capabilities of Ple-like derivatives. This review provides a comprehensive overview of the literature on the biological activities of pleurocidin, pleurocidin-derived peptides, pleurocidin-containing hybrid peptides, and nanosystems. The primary emphasis is on elucidating the range of activities exhibited by these compounds, evaluating their potential therapeutic applications, assessing their safety profile, and identifying any limits observed thus far. This paper will also discuss potential areas for further investigation into the anti-cancer effects of Ple and its derivatives, drawing insights from microbiological research.
ABSTRACT
BACKGROUND: Sleep disorders are highly prevalent among patients with Parkinson's disease (PD). Chronic medication with L-dopa may be one of the factors that contributes to poor sleep quality. The aim of this study was to assess the effects of long term use of L-dopa on objective and subjective measures of sleep quality in PD patients. METHODS: Twenty-seven PD patients (mean age 62.5 ± 8.6 years, mean disease duration 7.3 ± 5.9 years, 11 females) underwent nocturnal polysomnography. Their sleep was rated subjectively using the Parkinson's disease sleep scale (PDSS), and their disease severity was assessed using the unified Parkinson's disease severity scale (UPDRS) standard questionnaire. Doses of L-dopa and other medications were correlated with parameters of sleep quality. The polysomnographic recordings were compared with those from 24 age- and gender-matched normal controls. RESULTS: The patients showed decreased total sleep time (TST) and sleep efficiency (SE), prolonged sleep onset and REM sleep latency and wake after sleep onset (WASO). Parts I-III of the UPDRS scores correlated with TST, SE and WASO but not with PDSS scores. L-dopa dosage and part IV of the UPDRS correlated with PDSS scores but not with polysomnographic parameters. CONCLUSIONS: Higher doses of chronically administered L-dopa correlated with lower sleep quality according to the subjective measures but not according to the polysomnographic parameters, which were related to the severity of PD symptoms. The low sleep quality according to the subjective measurements may result from complications of therapy at high doses of L-dopa.
