Cryopreserved semen is widely used in assisted reproductive techniques. Post-thawing spermatozoa endure oxidative stress due to the high levels of reactive oxygen and nitrogen species, which are produced during the freezing/thawing process, and the depletion of antioxidants. To counteract this depletion, supplementation of sperm preparation medium with antioxidants has been widely applied. Melatonin is a hormone with diverse biological roles and a potent antioxidant, with an ameliorative effect on spermatozoa. In the present study, we assessed the effect of melatonin on thawed bovine spermatozoa during their handling. Cryopreserved bovine spermatozoa were thawed and incubated for 60 min in the presence or absence of 100 μΜ melatonin. Also, the effect of melatonin was assessed on spermatozoa further challenged by the addition of 100 μΜ hydrogen peroxide. Spermatozoa were evaluated in terms of kinematic parameters (CASA), viability (trypan blue staining) and antioxidant capacity (glutathione and NBT assay, determination of iNOS levels by Western blot analysis). In the presence of melatonin, spermatozoa presented better kinematic parameters, as the percentage of motile and rapid spermatozoa was higher in the melatonin group. They also presented higher viability and antioxidant status, as determined by the increased cellular glutathione levels and the decreased iNOS protein levels.
Alzheimer’s disease (AD) is the neurodegenerative condition with the outmost future challenges, with timely diagnosis and treatment being the most urgent. Discovery of more and more biomarkers is widely attempted; however, current diagnostic methods often lack sensitivity, specificity, and accessibility. Nucleotide aptamers—short, highly specific oligonucleotide or ligands—are now recognized as highly promising molecular agents for both measuring and targeting key AD biomarkers, with the most notorious being amyloid-beta (Aβ), tau protein, and disease-associated microRNAs (miRNAs). This review provides a comprehensive analysis of nucleotide aptamers related to AD, detailing their mechanisms of selection, recent advances in biosensing applications, and therapeutic potential. Aptamers, targeting the most significant biomarkers of AD, are mainly discussed, as well as ones interacting with novel, promising biomarkers, with a special aim on miRNAs. Additionally, aptamers are compared with conventional antibody-based approaches, highlighting their advantages in terms of stability, cost-effectiveness, and ease of modification. By elucidating the role of aptamers in AD diagnosis and treatment, this review underscores their promise as next-generation tools for precision medicine and neurodegenerative disease management.
Reactive Oxygen Species (ROS), primarily produced by cellular metabolism, are highly reactive molecules that modify cellular compounds. During sperm preparation in Assisted Reproductive Techniques (ARTs), intrinsic and extrinsic sources of ROS can impact spermatozoa’s oxidative status. The modification of the media with compounds that enhance sperm quality characteristics is of great significance. The current study investigated the effect of pterostilbene, a phenolic compound, on bovine sperm quality. Cryopreserved spermatozoa from six bulls were thawed, supplemented with pterostilbene (0, 10 μΜ, 25 μΜ) and incubated for 60 min and 240 min. Spermatozoa were analyzed in terms of motility, viability, acrosomal status and intracellular concentration of superoxide anion in each time point. The incubation of spermatozoa with 25 μΜ pterostilbene resulted in the preservation of quality parameters through superoxide anion mitigation, while its presence in capacitating conditions resulted in higher percentage of acrosome-reacted spermatozoa. The results of the present study indicate that the addition of pterostilbene prevents oxidative insult to spermatozoa and preserves the sperm quality parameters.
The supplementation of freezing medium with crocin results in an amelioration of post-thawing sperm quality, as determined by motility and viability. This study aimed to examine the molecular mechanisms underlying the ameliorative effect of crocin. Bovine spermatozoa were cryopreserved in a freezing medium supplemented with 0, 0.5, or 1 mM of crocin. Sperm lysates were evaluated for their redox status and the expression of proteins implicated in the heat stress response (HSR) and apoptosis. Crocin protected spermatozoa from the accumulation of superoxide anion and ameliorated their post-thawing antioxidant capacity in terms of ROS scavenging activity and glutathione content. Moreover, crocin decreased the levels of inducible nitric oxide synthase (iNOS), while it increased superoxide dimsutase-1 (SOD-1) levels. These effects were associated with an inhibition of apoptosis, as evidenced by a decreased Bax/Bcl-2 protein ratio and decreased levels of caspase-cleaved substrates. Finally, crocin affected the heat shock response of spermatozoa, since it upregulated the levels of heat shock proteins (Hsp) 60, 70, and 90. In conclusion, the addition of crocin to the freezing medium ensured controlled amounts of ROS, enhanced the antioxidant capacity of spermatozoa, and upregulated the anti-apoptotic proteins and Hsps, thus contributing to the maintenance of cellular homeostasis.
Alzheimer’s disease (AD) remains a significant global health challenge with limited FDA-approved treatments, necessitating the search for novel preventive strategies. Antioxidants that are present in fruits and vegetables have garnered attention due to their potential neuroprotective effects. Among these, pomegranate (Punica granatum L.) has emerged as a promising source of neuroprotective antioxidants as it is rich in polyphenols, flavonoids, and hydrolysable tannins. Pomegranate seed oil (PSO) is a source of bioactive compounds that may modulate key pathological processes of AD. This study investigated the therapeutic potential of PSO in murine neuroblastoma N2a cells treated with lipopolysaccharide (LPS) to simulate AD-like inflammation. The effects of PSO on inflammation and oxidative stress markers, including TNF-α, iNOS, SOD1, and IL1β, were evaluated, along with changes in AD-related biomarkers Aβ42, Aβ40, and p-tau181. Additionally, the study extended its findings to clinical settings by assessing the impact of supervised PSO consumption for 12 months on similar biomarkers in patients with mild cognitive impairment. Results from this integrative approach demonstrated the anti-inflammatory and antioxidant potential of PSO, supporting its role in modulating AD-associated pathophysiology. These findings suggest that PSO may serve as an early-stage intervention to delay or mitigate AD progression, highlighting its therapeutic potential in preclinical and clinical contexts.