Effects of Spirulina on the functions and redox status of auditory system in senescence-accelerated prone-8 mice

C-Phycocyanin Attenuates Noise-Induced Cochlear Synaptopathy via the Inhibition of Oxidative Stress and Intercellular Adhesion Molecule-1 in the Cochlea

The synapses between inner hair cells (IHCs) and spiral ganglion neurons (SGNs) are the most vulnerable structures in the noise-exposed cochlea. Cochlear synaptopathy results from the disruption of these synapses following noise exposure and is considered the main cause of poor speech understanding in noisy environments, even when audiogram results are normal. Cochlear synaptopathy leads to the degeneration of SGNs if damaged IHC-SGN synapses are not promptly recovered. Oxidative stress plays a central role in the pathogenesis of cochlear synaptopathy. C-Phycocyanin (C-PC) has antioxidant and anti-inflammatory activities and is widely utilized in the food and drug industry. However, the effect of the C-PC on noise-induced cochlear damage is unknown. We first investigated the therapeutic effect of C-PC on noise-induced cochlear synaptopathy. In vitro experiments revealed that C-PC reduced the H2O2-induced generation of reactive oxygen species in HEI-OC1 auditory cells. H2O2-induced cytotoxicity in HEI-OC1 cells was reduced with C-PC treatment. After white noise exposure for 3 h at a sound pressure of 118 dB, the guinea pigs intratympanically administered 5 μg/mL C-PC exhibited greater wave I amplitudes in the auditory brainstem response, more IHC synaptic ribbons and more IHC-SGN synapses according to microscopic analysis than the saline-treated guinea pigs. Furthermore, the group treated with C-PC had less intense 4-hydroxynonenal and intercellular adhesion molecule-1 staining in the cochlea compared with the saline group. Our results suggest that C-PC improves cochlear synaptopathy by inhibiting noise-induced oxidative stress and the inflammatory response in the cochlea.

The effects of resistance training and spirulina on the performance of the antioxidant system with emphasis on mir125b, mir146a and cognitive function in stanazolol-induced neurotoxicity in rats

Abuse of anabolic-androgenic steroids (AAS) is associated with neurological and cognitive problems in athletes. The Purpose of this study was to investigate the simultaneous effect of resistance training (RT) and spirulina supplementation (Sp) on the function of the antioxidant system with emphasis on mir125b, mir146a and cognitive function in Stanazolol (S)-induced neurotoxicity in rats. This experimental animal model study was performed with a post-test design with a control group. 45 male Sprague-Dawley rats were divided into six groups of 9 animals including (Althobaiti et al., 2022) [1]: sham (Sh/normal saline intake) (Havnes et al., 2019) [2], 25 mg/kg/wk of stanazolol (S) (Albano et al., 2021) [3], S + 100 mg/kg of Sp + (S + Sp) (Bjørnebekk et al., 2021) [4], RT (six weeks with an intensity of 50-100% of body weight) + S (S + RT) (Kanayama et al., 2013) [5] S + Sp + RT. Levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), total antioxidant capacity (TAC), malondialdehyde (MDA), percentage of healthy cells in the C1 and C3 regions of hippocampus, miR125b, miR146a, step-through latency (STL), time spent in dark compartment (TDC), repeated entry in dark compartment (RDC) and percentage of alternation (PA%) were measured in the post-test. Results showed that the Sp, RT and SP + RT increased levels of SOD, GPx and percentage of healthy cells in C1 region, decreased MDA, mir125b, mir146a in hippocampal tissue and decreased TDC levels in S-exposed rats (P ≤ 0.05). Sp + RT decreased RDC and increased SOD levels; on the other hand, RT decreased RDC levels in S-exposed rats (P ≤ 0.05). Levels of TAC in the Sp groups were significantly higher than the S group (P ≤ 0.05). Also, the effect of Sp + RT in reducing miR125b, miR146a, and STL levels was much higher than the effect of Sp and RT alone (P ≤ 0.05). It seems that applying resistance training and spirulina supplementation both separately and interactively is effective in improving the antioxidant system as well as memory and learning in cognitive impairment caused by stanazolol. However, more studies on microRNAs are needed.

Coffeeberry Activates the CaMKII/CREB/BDNF Pathway, Normalizes Autophagy and Apoptosis Signaling in Nonalcoholic Fatty Liver Rodent Model

Nonalcoholic fatty liver disease (NAFLD) shows extensive liver cell destruction with lipid accumulation, which is frequently accompanied by metabolic comorbidities and increases mortality. This study aimed to investigate the effects of coffeeberry (CB) on regulating the redox status, the CaMKII/CREB/BDNF pathway, autophagy, and apoptosis signaling by a NAFLD rodent model senescence-accelerated mice prone 8 (SAMP8). Three-month-old male SAMP8 mice were divided into a control group and three CB groups (50, 100, and 200 mg/kg BW), and fed for 12 weeks. The results show that CB reduced hepatic malondialdehyde and carbonyl protein levels. CB significantly enhanced Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) and brain-derived neurotrophic factor (BDNF) and reduced the phospho-cAMP response element-binding protein (p-CREB)/CREB ratio. In addition, CB increased the silent information regulator T1 level, promoted Beclin 1 and microtubule-associated protein light chain 3 II expressions, and reduced phosphorylated mammalian target of rapamycin and its downstream p-p70s6k levels. CB also inhibited the expressions of apoptosis-related factors poly (ADP-ribose) polymerase-1 and the apoptosis-inducing factor. In conclusion, CB might protect the liver by reducing oxidative stress, activating the CaMKII/CREB/BDNF pathway, and improving autophagic and apoptotic expressions in a dose-dependent manner.

Spirulina Microalgae and Brain Health: A Scoping Review of Experimental and Clinical Evidence

Spirulina microalgae contain a plethora of nutrient and non-nutrient molecules providing brain health benefits. Numerous in vivo evidence has provided support for the brain health potential of spirulina, highlighting antioxidant, anti-inflammatory, and neuroprotective mechanisms. Preliminary clinical studies have also suggested that spirulina can help to reduce mental fatigue, protect the vascular wall of brain vessels from endothelial damage and regulate internal pressure, thus contributing to the prevention and/or mitigating of cerebrovascular conditions. Furthermore, the use of spirulina in malnourished children appears to ameliorate motor, language, and cognitive skills, suggesting a reinforcing role in developmental mechanisms. Evidence of the central effect of spirulina on appetite regulation has also been shown. This review aims to understand the applicative potential of spirulina microalgae in the prevention and mitigation of brain disorders, highlighting the nutritional value of this "superfood", and providing the current knowledge on relevant molecular mechanisms in the brain associated with its dietary introduction.

Association of Tinnitus and Other Cochlear Disorders With a History of Migraines

Importance

A headache is a symptom of a migraine, but not all patients with migraine have headaches. It is still unclear whether a migraine might increase the risk of cochlear disorders, even though a migraine does not occur concurrently with cochlear disorders.

Objective

To investigate the risk of cochlear disorders for patients with a history of migraines.

Design, Setting, and Participants

This study used claims data from the Taiwan Longitudinal Health Insurance Database 2005 to identify 1056 patients with migraines diagnosed between January 1, 1996, and December 31, 2012. A total of 4224 controls were also identified from the same database based on propensity score matching. Statistical analysis was performed from January 23, 1996, to December 28, 2012.

Main Outcomes and Measures

The incidence rate of cochlear disorders (tinnitus, sensorineural hearing impairment, and/or sudden deafness) was compared between the cohorts by use of the Kaplan-Meier method. The Cox proportional hazards regression model was also used to examine the association of cochlear disorders with migraines.

Results

Of the 1056 patients with migraines, 672 were women and 384 were men, and the mean (SD) age was 36.7 (15.3) years. Compared with the nonmigraine cohort, the crude hazard ratio for cochlear disorders in the migraine cohort was 2.83 (95% CI, 2.01-3.99), and the adjusted hazard ratio was 2.71 (95% CI, 1.86-3.93). The incidence rates of cochlear disorders were 81.4 (95% CI, 81.1-81.8) per 1 million person-years for the migraine cohort and 29.4 (95% CI, 29.2-29.7) per 1 million person-years for the nonmigraine cohort. The cumulative incidence of cochlear disorders in the migraine cohort (12.2%) was significantly higher than that in the matched nonmigraine cohort (5.5%). Subgroup analysis showed that, compared with the nonmigraine cohort, the adjusted hazard ratios in the migraine cohort were 3.30 (95% CI, 2.17-5.00) for tinnitus, 1.03 (95% CI, 0.17-6.41) for sensorineural hearing impairment, and 1.22 (95% CI, 0.53-2.83) for sudden deafness.

Conclusions and Relevance

In this population-based study, the risk of cochlear disorders, especially for tinnitus, was found to be significantly higher among patients with a history of migraines. This finding may support the presence and/or concept of "cochlear migraine."

Risks of tinnitus, sensorineural hearing impairment, and sudden deafness in patients with non-migraine headache

Tinnitus and hearing impairment are prevalent among headache patients. This study aims to investigate the risk of tinnitus, sensorineural hearing impairment, and sudden deafness in patients with non-migraine headache. Participants included 43 294 patients with non-migraine headache (non-migraine headache cohort) and 173 176 patients with no headache of any type (control cohort) frequency-matched with respect to 10-year age interval and sex from the Longitudinal Health Insurance Database 2005 of the Taiwan National Health Insurance Research Database. The mean age of the non-migraine headache cohort was 28.4 ± 14.9 years, and 58.5% of this cohort was male. The incidence rates of tinnitus, sensorineural hearing impairment, and sudden deafness were compared between cohorts using the Kaplan–Meier method with the log-rank test. A Cox proportional hazard model was used to examine the association of tinnitus, sensorineural hearing impairment, and sudden deafness with non-migraine headache, with adjustment for all covariates. The combined risk of either tinnitus, sensorineural hearing impairment, or sudden deafness was higher in the non-migraine headache cohort than in the control cohort (adjusted odds ratio [aHR], 2.73; 95% confidence interval [95% CI], 2.62–2.84; p < 0.0001). Subgroup analysis showed that patients in the non-migraine headache cohort were at significantly higher risk of developing tinnitus (aHR, 3.05; 95% CI, 2.91–3.19; p < 0.0001), sensorineural hearing impairment (aHR, 1.89; 95% CI, 1.74–2.05; p < 0.0001), and sudden deafness (aHR, 2.14; 95% CI, 1.77–2.59; p < 0.0001) than were controls. In this population-based study, the risks of tinnitus, sensorineural hearing impairment, and sudden deafness were found to be significantly higher in patients with non-migraine headache than in those without headache.

Correction: Effects of Spirulina on the functions and redox status of auditory system in senescence-accelerated prone-8 mice

[This corrects the article DOI: 10.1371/journal.pone.0178916.].