Candida albicans and Antifungal Peptides.

Candida albicans, a ubiquitous opportunistic fungal pathogen, plays a pivotal role in human health and disease. As a commensal organism, it normally resides harmlessly within the human microbiota. However, under certain conditions, C. albicans can transition into a pathogenic state, leading to various infections collectively known as candidiasis. With the increasing prevalence of immunocompromised individuals and the widespread use of invasive medical procedures, candidiasis has become a significant public health concern. The emergence of drug-resistant strains further complicates treatment options, highlighting the urgent need for alternative therapeutic strategies. Antifungal peptides (AFPs) have gained considerable attention as potential candidates for combating Candida spp. infections. These naturally occurring peptides possess broad-spectrum antimicrobial activity, including specific efficacy against C. albicans. AFPs exhibit several advantageous properties, such as rapid killing kinetics, low propensity for resistance development, and diverse mechanisms of action, making them promising alternatives to conventional antifungal agents. In recent years, extensive research has focused on discovering and developing novel AFPs with improved efficacy and selectivity against Candida species. Advances in biotechnology and synthetic peptide design have enabled the modification and optimization of natural peptides, enhancing their stability, bioavailability, and therapeutic potential. Nevertheless, several challenges must be addressed before AFPs can be widely implemented in clinical practice. These include optimizing peptide stability, enhancing delivery methods, overcoming potential toxicity concerns, and conducting comprehensive preclinical and clinical studies. This commentary presents a short overview of candidemia and AFP; articles and reviews published in the last 10 years were searched on The National Library of Medicine (National Center for Biotechnology Information-NIH-PubMed). The terms used were C. albicans infections, antimicrobial peptides, antifungal peptides, antifungal peptides mechanisms of action, candidemia treatments and guidelines, synthetic peptides and their challenges, and antimicrobial peptides in clinical trials as the main ones. Older publications were cited if they brought some relevant concept or helped to bring a perspective into our narrative. Articles older than 20 years and those that appeared in PubMed but did not match our goal to bring updated information about using antifungal peptides as an alternative to C. albicans infections were not considered.

An Immunomodulatory Peptide Confers Protection in an Experimental Candidemia Murine Model.

Fungal Candida species are commensals present in the mammalian skin and mucous membranes. Candida spp. are capable of breaching the epithelial barrier of immunocompromised patients with neutrophil and cell-mediated immune dysfunctions and can also disseminate to multiple organs through the bloodstream. Here we examined the action of innate defense regulator 1018 (IDR-1018), a 12-amino-acid-residue peptide derived from bovine bactenecin (Bac2A): IDR-1018 showed weak antifungal and antibiofilm activity against a Candida albicans laboratory strain (ATCC 10231) and a clinical isolate (CI) (MICs of 32 and 64 µg · ml-1, respectively), while 8-fold lower concentrations led to dissolution of the fungal cells from preformed biofilms. IDR-1018 at 128 µg · ml-1 was not hemolytic when tested against murine red blood cells and also has not shown a cytotoxic effect on murine monocyte RAW 264.7 and primary murine macrophage cells at the tested concentrations. IDR-1018 modulated the cytokine profile during challenge of murine bone marrow-derived macrophages with heat-killed C. albicans (HKCA) antigens by increasing monocyte chemoattractant protein 1 (MCP-1) and interleukin-10 (IL-10) levels, while suppressing tumor necrosis factor alpha (TNF-α), IL-1ß, IL-6, and IL-12 levels. Mice treated with IDR-1018 at 10 mg · kg-1 of body weight had an increased survival rate in the candidemia model compared with phosphate-buffered saline (PBS)-treated mice, together with a diminished kidney fungal burden. Thus, IDR-1018 was able to protect against murine experimental candidemia and has the potential as an adjunctive therapy.

Monitoring Salivary Immunoglobulin A Responses to Official and Simulated Matches In Elite Young Soccer Players.

The purpose of the present study was to examine SIgA responses (concentration [SIgAabs] and a secretion rate [SIgArate]) to official and simulated competitive matches in young soccer players. The sample was composed of 26 male soccer players (age 15.6 ± 1.1 yrs, stature 177.0 ± 6.1 cm, body mass 70.5 ± 5.7 kg). Four soccer matches (two simulated matches [SM] and two official matches [OM]) were conducted. The matches consisted of two halves of 35 min with a 10 min rest interval. Each assessed player participated in only one SM and one OM. All matches were performed in the same week, during the competitive season, and at the same time of the day (9:00 am), separated by 48 h. Saliva samples were collected before and after every match. The session rating of perceived exertion was reported 30 min after each match in order to determine the internal training load (ITL). A significant decrease in SIgAabs and SIgArate after OM was observed when compared to the pre-match value. In addition, the SIgArate was higher at pre-OM when compared to pre-SM. A higher ITL for OM was observed compared to SM. The current findings indicate that OM may lead to a decrease in the main mucosal immunity function parameter of young soccer players that could increase the risk of URTI. Coaches should be aware of it in order to plan appropriate training loads and recovery procedures to avoid or minimize the likelihood of upper respiratory tract infection occurrences.

Playing match venue does not affect resting salivary steroids in elite Futsal players.

This study examined the influence of competition playing venue on the hormonal responses in elite Futsal players. Twenty-one males (age, 19.3 ± 0.7 years; height, 174.2 ± 4.1cm; body mass, 71.8 ± 7.9 kg) from two Futsal teams were monitored during two competitive matches that were played against each other on a home and away basis. Saliva sampling was conducted before (pre) and after (post) each match. The concentration of salivary steroids (testosterone [T] and cortisol [C]) was assessed by ELISA. Resting concentration of salivary steroid (T and C) hormones was not affected by playing venue (home and away). Both Futsal matches promoted a significant increase in T and C from pre--to post-matches (p<0.05), with a higher post-C concentration for playing at home (p<0.05). No effect of playing venue on T was observed. In conclusion, the findings of this study indicate that the playing venue did not elicit a significant change in resting concentration of salivary steroid hormones. However, playing home induced a greater post-match C response, suggesting that the pressure for positive results in front of supporters, families and friends may impose a higher level of stress on the players at their own facility.

Testosterone Concentration and Lower Limb Power Over an Entire Competitive Season in Elite Young Soccer Players.

The aim of this study was to investigate salivary T changes and its relationship with power performance over a 1-year competitive season in elite under 15 (U15) and under 17 (U17) soccer players. Soccer players were recruited from 1 soccer club that has been participated in the main state and national leagues for these age groups. The soccer players were divided into 2 age categories (U15, n = 16 and U17, n = 23). A resting saliva sample was taken to determine T level, and power was assessed using the countermovement jump test with a bar of 30% of body mass on the athletes' shoulders on 3 occasions (T1: beginning of the competitive season, T2: end of the regular season, and T3: end of the playoffs). There was a decrease in T concentration at the end of the competitive season (T3) as compared with the beginning of the season (T1) for both age categories (p ≤ 0.05). Conversely, power performance parameters were increased for both age groups (U15: mean power and relative mean power and U17: peak power, mean power, relative peak power, and relative mean power; p ≤ 0.05). No significant correlation was identified between the relative changes in T concentration and power performance in both groups. The findings of this study suggest that T changes and power changes are not related.

Does Testosterone Modulate Mood States and Physical Performance in Young Basketball Players?

This study aimed to examine and compare mood states profile and physical performance during different training phases between 2 groups of adolescent basketball players that were differentiated according to baseline testosterone concentration (T). The basketball players were submitted to an intensified training period (OVL) followed by a tapering period (TP). Twenty-three young male basketball players initiated the study. Experimental criteria data were used to stratify 16 players into high-testosterone (HTC) or low-testosterone (LTC) concentration groups. All the 16 athletes undertook 5 weeks of OVL followed by a 3-week TP. Saliva sampling, Yo-Yo intermittent recovery level 1 (Yo-Yo IRL1) test and the T-test were conducted at the beginning (T1), after OVL (T2), and after TP (T3). A similar increase in internal training load was observed during OVL when compared with TP in both groups (p < 0.05). No difference in mood states was observed between groups (p > 0.05); however, LTC displayed a higher score for fatigue (p < 0.05) and a lower score for energy index (p < 0.05) in OVL, compared with TP. A significant improvement in the Yo-Yo IRL1 test and the T-test was observed (T1 to T3) (p < 0.05), with no difference between groups (p > 0.05). In conclusion, these results suggest that LTC athletes may be more susceptible to changes in mood states during intensified training periods. In addition, data indicate that a periodized training program successfully improved the physical performance (endurance and agility) of young basketball players; however, this improvement was not affected by testosterone level.

Antifungal nanofibers made by controlled release of sea animal derived peptide.

Candida albicans is a common human-pathogenic fungal species with the ability to cause several diseases including surface infections. Despite the clear difficulties of Candida control, antimicrobial peptides (AMPs) have emerged as an alternative strategy for fungal control. In this report, different concentrations of antifungal Cm-p1 (Cencritchis muricatus peptide 1) were electrospun into nanofibers for drug delivery. The nanofibers were characterized by mass spectrometry confirming the presence of the peptide on the scaffold. Atomic force microscopy and scanning electronic microscopy were used to measure the diameters, showing that Cm-p1 affects fiber morphology as well as the diameter and scaffold thickness. The Cm-p1 release behavior from the nanofibers demonstrated peptide release from 30 min to three days, leading to effective yeast control in the first 24 hours. Moreover, the biocompatibility of the fibers were evaluated through a MTS assay as well as ROS production by using a HUVEC model, showing that the fibers do not affect cell viability and only nanofibers containing 10% Cm-p1-PVA improved ROS generation. In addition, the secretion of pro-inflammatory cytokines IL-6 and TNF-α by the HUVECs was also slightly modified by the 10% Cm-p1-PVA nanofibers. In conclusion, the electrospinning technique applied here allowed for the manufacture of biodegradable biomimetic nanofibrous extracellular membranes with the ability to control fungal infection.

Psychophysiological responses to overloading and tapering phases in elite young soccer players.

This study investigated the effect of a 2-week overloading training phase followed by a 2-week tapering phase on internal training load (ITL), salivary cortisol, stress tolerance, and upper respiratory tract infections symptoms (URTI) in 11 male young soccer players (16.0 ± 0.5 yrs). Ratings of perceived exertion (session- RPE) were taken after each training session (N = 194) to determine ITL. Saliva sampling was conducted at the end of each week and cortisol concentration assessed by ELISA. DALDA and WURSS-21 questionnaires were administered every week to evaluate stress tolerance and severity of URTI respectively. The number of athletes reporting URTI symptoms was recorded. The overloading phase promoted greater ITL and a higher resting cortisol concentration than the tapering phase (P < .05). While no significant changes in stress tolerance or URTI severity were observed, the number of athletes reporting URTI symptoms was higher during the overloading phase. A significant correlation was observed between symptoms of stress and severity of URTI (rs=-.71; P = .01). The results indicate that an integrated approach using psychological measures (session-RPE and DALDA), self-reports of URTI symptoms, and endocrine responses (cortisol) to training are pertinent for monitoring young soccer players.

Influence of competition playing venue on the hormonal responses, state anxiety and perception of effort in elite basketball athletes.

This study examined the influence of competition playing venue on the hormonal responses, state anxiety and perception of effort in elite basketball players. Eighteen males from two basketball teams were monitored during two competitive matches that were played against each other on a home and away basis. Salivary testosterone (T) and cortisol (C) concentrations were measured before and after each match. The Competitive State Anxiety Inventory-2 (CSAI-2) test was also administrated prior to each match and session ratings of perceived exertion (RPE) were taken post-game. Playing at home was accompanied by elevated pre-match T concentration, as compared to playing away (p<0.05). The matches played at home were also won. Salivary T and C concentrations were similarly elevated across the matches (percent changes from pre to post) played either at home or away. No significant differences in state anxiety and perception of effort were identified between the playing venues. Pre-match T and C concentrations and the percent changes in these hormones were significantly related to somatic anxiety, especially when playing at home (p<0.05). In conclusion, the competition playing venue appeared to influence athlete salivary hormonal responses prior to elite basketball matches. These hormonal responses were associated with player's anxiety state, which might contribute to performance and the eventual match outcomes.

Salivary IgA response and upper respiratory tract infection symptoms during a 21-week competitive season in young soccer players.

Sports training and competition are significant sources of stress, especially for young athletes. It is well known that physiological and psychological stressors induce neuroendocrine responses that could modulate immune system function. However, to date, little is known about the immune responses of young soccer players during a competitive season. Therefore, this study examined the effects of a 21-week competitive season divided into preseason, competitive season, and detraining on salivary immunoglobulin A (SIgA), upper respiratory tract infection (URTI) symptoms, and salivary cortisol in preadolescent male soccer players. Thirty-four young soccer players agreed to participate, and 26 (12.9 ± 0.2 years) completed the entire study. The investigation period was structured as follows: a 12-week preparatory training phase (preseason training), a 7-week competitive and a 2-week detraining phase. Resting saliva samples were taken to determine cortisol and SIgA responses. The players were required to complete a weekly log during the entire investigation reporting every sign or symptoms consistent with URTI. A significant increase in SIgA secretion rate and a decrease in URTI symptoms were observed after the 2-week detraining period (p < 0.05). No change was observed for cortisol during the study. These results indicate that training and competition demands affect the mucosal immune responses of young athletes. In addition, a short-prophylactic period (2-week detraining period) after a competitive period may attenuate mucosal immunosuppression related to URTI symptoms. Sport coaches should monitor markers of mucosal immune function to minimize illness that ultimately might lead to a decrease in performance.

Effect of match importance on salivary cortisol and immunoglobulin A responses in elite young volleyball players.

The purpose of this study was to compare the session ratings of perceived exertion (Session-RPE) responses and the salivary cortisol (sC) and immunoglobulin A (SIgA) levels between a regular season match (RM) and the final championship match (FM) in elite male volleyball players against the same opponent team. Higher importance was assumed for FM because this match would define the championship team. Session-RPE was obtained after 30 minutes of each match using the CR-10 scale. Saliva samples were collected before and after each match and during a rest day (baseline) at the same period of the matches. The SIgA and sC concentrations were measured by enzyme-linked immunosorbent assay. Greater Session-RPE was observed for FM as compared with RM (p < 0.01). The analysis of variance showed greater sC concentrations to FM as compared with RM for both prevalues and postvalues and compared with baseline (p < 0.05). Significant lower SIgA prevalues were noted for FM. In conclusion, the results showed that match intensity, cortisol concentration, and SIgA prelevel were affected by the match importance. These results indicate that monitoring session-RPE, sC, and SIgA responses, in conjunction, during training and competition, would provide valuable informations regarding how athletes cope with sports induced stress. This study provided knowledge about the effect of match importance on salivary markers related to stress that may help coaches to avoid excessive training loads reducing the likelihood to decrements on mucosal immunity and its consequent risk to upper respiratory tract infections, which in turn might affect the performance.

Monitoring internal load parameters during simulated and official basketball matches.

The purpose of this study was to compare the internal load responses (session rating of perceived exertion [RPE] and salivary cortisol) between simulated and official matches (SM and OM). Ten professional basketball players participated in 2 OMs and 2 SMs during the competition season. Subjects provided saliva samples 30 minutes before the prematch warm-up (PRE) and 10 minutes after the end of the match. Session RPE (CR-10 scale) was assessed 30 minutes after each match. The results from the 2-way analysis of variance showed significant differences for post-OM salivary cortisol as compared with pre-OM values (p < 0.05). No changes were observed for cortisol during the SM. Before the OM, a significant difference in salivary cortisol was observed as compared with pre-SM values (p < 0.05). Moreover, the OM session RPE was significantly greater than that of SM. There was a significant correlation between session RPE and cortisol changes (r = 0.75). In summary, the results of this study showed a greater magnitude of cortisol and session RPE responses after OM as compared with that after SM confirming the hypothesis that a real competition generates a greater stress response than a simulated condition does. The anticipatory effect was also observed in the OM. In addition, the results indicate that session RPE seems to be a viable tool in monitoring internal loads, and the results are useful in providing a better understanding of internal loads imposed by basketball training and competitions. The precise monitoring of these responses might help the coaches to plan appropriate loads maximizing recovery and performance.