The phenomenon of drug resistance in micro-organisms necessitates the search for new compounds capable of combating them. Fungi emerge as a promising source of such compounds as they produce a wide range of secondary metabolites with bacteriostatic or fungistatic activity. These compounds can serve as alternatives for commonly used antibiotics. Furthermore, fungi also accumulate compounds with antiviral activity. This review focuses on filamentous fungi and macrofungi as sources of antimicrobial compounds. The article describes both individual isolated compounds and extracts that exhibit antibacterial, antifungal, and antiviral activity. These compounds are produced by the fruiting bodies and mycelium, as well as the biomass of mycelial cultures. Additionally, this review characterizes the chemical compounds extracted from mushrooms used in the realm of cosmetology; specifically, their antimicrobial activity.
17 August 2013 in Current Neurology and Neuroscience Reports
Every year, more cases of sepsis appear in intensive care units. The most frequent complication of sepsis is septic encephalopathy (SE), which is also the essential determinant of mortality. Despite many years of research, it still is not known at which stage of sepsis the first signs of SE appear; however, it is considered the most frequent form of encephalopathy. Patients have dysfunction of cognitive abilities and consciousness, and sometimes even epileptic seizures. Despite intensive treatment, the effects of SE remain for many years and constitute an important social problem. Numerous studies indicate that changes in the brain involve free radicals, nitric oxide, increased synthesis of inflammatory factors, disturbances in cerebral circulation, microthromboses, and ischemia, which cause considerable neuronal destruction in different areas of the brain. To determine at what point during sepsis the first signs of SE appear, different experimental models are needed to detect the aforementioned changes and to select the proper therapy for this syndrome.
Dietary interventions for people suffering from major depressive disorder (MDD) are an ongoing field of research. In this article, we present a comprehensive background for understanding the possibility of using edible medicinal mushrooms as an adjunctive treatment for MDD. We start with a brief history of MDD, its diagnosis, epidemiology and treatment, and the effects of diet on depression symptoms, followed by a review of neurobiological, behavioral, and clinical studies of medicinal mushrooms. We specifically highlight the results of preclinical and clinical studies on dietary supplementation with three selected mushroom species: Lion’s mane (Hericium erinaceus), Caterpillar mushroom (Cordyceps militaris), and Lingzhi/Reishi (Ganoderma lucidum). Preliminary small-sample clinical studies suggest that Lion’s mane can influence well-being of humans. In the case of Reishi, the results of clinical studies are equivocal, while in the case of Caterpillar Mushroom, such studies are underway. Edible mushrooms contain 5-hydroxy-L-tryptophan (5-HTP), which is a direct precursor of serotonin—a neurotransmitter targeted in pharmacotherapy of MDD. Therefore, in light of the well-recognized role of stress as a pathogenic factor of MDD, we also describe the neurobiological mechanisms of the interaction between stress and serotonergic neurotransmission; and summarize the current state of knowledge on dietary supplementation with 5-HTP in MDD.
Traumatic brain injury (TBI) induces inflammatory reactions, and one of the essential mediators of this reaction is nitric oxide (NO). The action of this compound is still under study because no clear consensus has been reached about its exact action in the central nervous system. Further, it is unknown if, in the damaged brain, its neuroprotective activity outweighs its putative neurodegenerative properties. Using ferrous-diethyldithiocarbamate chelate, a lipophilic spin trap for NO detection by electron paramagnetic resonance (EPR) spectroscopy, we followed NO production in injured brain of mature Wistar rats. To relate changes in the amount of NO in the lesioned brain to the activity of NO synthase (NOS), this study also used NADPH-diaphorase staining. Our data show a rapid drop of NO concentration in the damaged brain below control values. This phenomenon persisted over several hours postinjury and varied with brain region. This decrease in NO concentration was accompanied by a simultaneous increase in the number of NADPH-diaphorase-positive cells, perhaps indicative of increased NOS activity. It is therefore assumed that, in the lesioned brain, a very rapid removal of NO occurs via its transformation to other reactive species such as peroxynitrite, which further adversely influence the damaged tissue.
The circadian clock controls various physiological processes, including synaptic function and neuronal activity, affecting the functioning of the entire organism. Light is an important external factor regulating the day–night cycle. This study examined the effects of the circadian clock and light on synaptic plasticity, and explored how locomotor activity contributes to these processes. We analyzed synaptic protein expression and excitatory synapse density in the somatosensory cortex of mice from four groups exposed to different lighting conditions (LD 12:12, DD, LD 16:8, and LL). Locomotor activity was assessed through individual wheel-running monitoring. To explore daily and circadian changes in synaptic proteins, we performed double-immunofluorescence labeling and laser scanning confocal microscopy imaging, targeting three pairs of presynaptic and postsynaptic proteins (Synaptophysin 1/PSD95, Piccolo/Homer 1, Neurexins/PICK1). Excitatory synapse density was evaluated by co-labeling presynaptic and postsynaptic markers. Our results demonstrated that all the analyzed synaptic proteins exhibited circadian regulation modulated by light. Under constant light conditions, only Piccolo and Homer 1 showed rhythmicity. Locomotor activity was also associated with the circadian clock’s effects on synaptic proteins, showing a stronger connection to changes in postsynaptic protein levels. Excitatory synapse density peaked during the day/subjective day and exhibited an inverse relationship with locomotor activity. Continued light exposure disrupted cyclic changes in synapse density but kept it consistently elevated. These findings underscore the crucial roles of light and locomotor activity in regulating synaptic plasticity.