Phytochemicals and Their Usefulness in the Maintenance of Health.

Inflammation is the immune system's first biological response to infection, injury, or irritation. Evidence suggests that the anti-inflammatory effect is mediated by the regulation of various inflammatory cytokines, such as nitric oxide, interleukins, tumor necrosis factor alpha-α, interferon gamma-γ, as well as the non-cytokine mediator, prostaglandin E2. Currently, the mechanism of action and clinical usefulness of phytochemicals is known; their action on the activity of cytokines, free radicals, and oxidative stress. The latter are of great relevance in the development of diseases, such that the evidence collected demonstrates the beneficial effects of phytochemicals in maintaining health. Epidemiological evidence indicates that regular consumption of fruits and vegetables is related to a low risk of developing cancer and other chronic diseases.

Polyamines modulate mouse sperm motility.

Polyamines are polycationic molecules which contains two or more amino groups (-NH3+) highly charged at physiological pH, and among them we found spermine, spermidine, putrescine, and cadaverine. They interact with proteins, nucleic acids, modulate Ca2+, K+, and Na+ channels, and protect sperm from oxidative stress. In this work, we evaluate the effect of spermine, spermidine, and putrescine on the total, progressive and kinematic parameters of motility, capacitation, acrosome reaction, also in presence and absence of the dbcAMP, an analogue of the cAMP, and the IBMX, a phosphodiesterase inhibitor. In addition, we evaluated the intracellular concentrations of cAMP [cAMP]i, and performed an in silico analysis between polyamines and the sAC from mouse to predict the possible interaction among them. Our results showed that all polyamines decrease drastically the total, progressive and the kinetic parameters of sperm motility, decrease the capacitation, and only spermidine and putrescine impeded the acquisition of acrosome reaction. Moreover, the effect of polyamines was attenuated but not countered by the addition of db-cAMP and IBMX, suggesting a possible inhibition of the sAC. Also, the presence of polyamines induced a decrease of the [cAMP]i, and the in silico analysis predicted a strong interaction among polyamines and the sAC. Overall, the evidence suggests that probably the polyamines interact and inhibit the activity of the sAC.

Chiranthodendron pentadactylon Larreat (Sterculiaceae), a Potential Nephroprotector against Oxidative Damage Provoked by STZ-Induced Hyperglycemia in Rats.

BACKGROUND: Chiranthodendron pentadactylon, known in Mexico as the "tree of the little hands", flower's infusion is used to treat kidney failure associated with diseases such as diabetes. The aim of this work is to evaluate the antioxidant effect of the methanolic extract of its flowers on oxidative damage in kidneys caused by streptozotocin in rats. METHODS: The extract phytochemical profile was performed with HPLC. Antioxidant potential in vitro was determined with DPPH and total phenolic tests; antioxidant evaluation in vivo was performed in diabetic rats administered daily via the intragastric route (100 and 200 mg/kg) for 6 weeks; serum glucose/creatinine, food/water consumption, and urinary volume were measured. Relative weight, protein/DNA ratios and oxidative stress were measured in renal tissue. RESULTS: The extract showed 20.53% of total phenolic content and IC50 of 18.05 µg/mL in DPPH, and this was associated with ferulic acid, phloretin and α-amyrin. Both doses showed a moderate decrease in the protein/DNA ratio in renal tissue, and the same behavior was observed for total urinary protein loss and serum creatinine, while the best antioxidant effect was exerted by a lower dose, which increased catalase activity and decreased lipid peroxidation in the kidneys. CONCLUSIONS: Results demonstrated that C. pentadactylon methanolic flower's extract improves renal function through antioxidant mechanisms during experimental diabetes.

Developmental Toxicity Study of DL-4-Hydroxy-4-Phenylhexanamide (DL-HEPB) in Rats.

Antiepileptic drugs affect embryonic development when administered during pregnancy, generating severe alterations, such as as cleft lip, spina bifida, heart abnormalities, or neuronal alterations. The compound DL-4-hydroxy-4-phenylhexanamide (DL-HEPB), a phenyl alcohol amide structurally different from known anticonvulsants, has shown good anticonvulsant effects in previous studies. However, its effects on intrauterine development are unknown. So, the purpose of this study was to determine the potential of DL-HEPB to produce alterations in conceptus. Pregnant Wistar rats were orally exposed to 0, 50, 100, and 200 mg/kg of DL-HEPB during organogenesis, and their food consumption and weight gain were measured. On gestation day 21, pregnant females were euthanized to analyze the fetuses for external, visceral, and skeletal malformations. A significant decrease in food consumption and body weight was observed in mothers, without any other manifestation of toxicity. In fetuses, no external malformations, visceral, or skeletal abnormalities, were observed under the dose of 100 mg/kg, while the dose of 200 mg/kg caused malformations in low frequency in brain and kidneys. In view of the results obtained, DL-HEPB could be a good starting point for the design of new highly effective anticonvulsant agents, with much lower developmental toxicity than that shown by commercial anticonvulsants.

Spirulina (Arthrospira maxima) mitigates the toxicity induced by a mixture of metal and NSAID in Xenopus laevis.

Cadmium (Cd) is often detected in the environment due to its wide use in industry; also, NSAIDs are one of the most consumed pharmaceuticals, particularly diclofenac (DCF). Several studies have reported the presence of both contaminants in water bodies at concentrations ranging from ng L-1 to µg L-1; in addition, they have shown that they can induce oxidative stress in aquatic species and disturb signal transduction, cell proliferation, and intercellular communication, which could lead to teratogenesis. Spirulina has been consumed as a dietary supplement; its antioxidant, anti-inflammatory, neuroprotective, and nutritional properties are well documented. This work aimed to evaluate if Spirulina reduces the damage induced by Cd and DCF mixture in Xenopus laevis at early life stages. FETAX assay was carried out: 20 fertilized oocytes were exposed to seven different treatments on triplicate, control, Cd (24.5 µg L-1), DCF (149 µg L-1), Cd + DCF, Cd+DCF+Spirulina (2 mg L-1), Cd+DCF+Spirulina (4 mg L-1), Cd+DCF+Spirulina (10 mg L-1), malformations, mortality, and growth were evaluated after 96 h, also lipid peroxidation, superoxide dismutase and catalase activity were determined after 192 h. Cd increased DCF mortality, Cd and DCF mixture increased the incidence of malformations as well as oxidative damage; on the other hand, the results obtained show that Spirulina can be used to reduce the damage caused by the mixture of Cd and DCF since it promotes growth, reduce mortality, malformations, and oxidative stress in X. laevis.

Protective Effect of the Phycobiliproteins from Arthrospira maxima on Indomethacin-Induced Gastric Ulcer in a Rat Model.

Gastric ulcers (GU) constitute a disease with a global prevalence ≈ 8.09 million. Of their causes, non-steroidal anti-inflammatory drugs (NSAIDs) such as indomethacin (IND) rank as the second most frequent etiologic agent. The pathogenic process of gastric lesions is given by the overproduction of oxidative stress, promotion of inflammatory processes, and inhibition of prostaglandin synthesis. Spirulina Arthrospira maxima (SP) is a cyanobacterium with a wide variety of substances with high nutritional and health values such as phycobiliproteins (PBPs) that have outstanding antioxidant activity, anti-inflammatories effects, and accelerate the wound healing process. This study aimed to determine the protective effect of PBPs in GU induced by IND 40 mg/kg. Our results show that the PBPs protected against IND-induced damage with a dose-dependent effect. At a dose of 400 mg/kg, a marked decrease in the number of lesions is observed, as well as the recovery of the main markers of oxidative stress damage (MDA) and antioxidant species (SOD, CAT, GPx) at close to baseline levels. The evidence derived from the present investigation suggests that the antioxidant effect of PBPs, together with their reported anti-inflammatory effects to accelerate the wound healing process, is the most reliable cause of their antiulcerogenic activity in this GU model.

Effects of Spirulina maxima on a Model of Sexual Dysfunction in Streptozotocin-Induced Diabetic Male Rats.

Arthrospira (Spirulina) maxima (SM) is a cyanobacterium that has a long history of being used as human food. In recent years, several investigations have shown its beneficial biological effects, among which its antioxidant capacity has been highlighted. The purpose of this study was to evaluate the effects of SM on body weight, glycemia, sexual behavior, sperm quality, testosterone levels, sex organ weights, and the activity of antioxidant enzymes in diabetic male rats (a disease characterized by an increase in reactive oxygen species). The experiment consisted of six groups of sexually expert adult males (n = 6): (1) control (vehicle); (2) streptozotocin (STZ)-65 mg/kg; (3) SM-400 mg/kg; (4) STZ + SM-100 mg/kg; (5) STZ + SM-200 mg/kg; and (6) STZ + SM-400 mg/kg. Sexual behavior tests were performed during the first 3 h of the dark period under dim red illumination. Our results showed that SM significantly improved sexual behavior and sperm quality vs. diabetic animals. Likewise, while the enzymatic activities of SOD and GPx increased, TBARS lipoperoxidation decreased and testosterone levels increased. In view of the findings, it is suggested that SM may potentially be used as a nutraceutical for the treatment of diabetic male sexual dysfunction due to its antioxidant property.

Participation of signaling proteins in sperm hyperactivation.

Sperm hyperactivation is described as a fast whip movement of the flagellum, an irregular trajectory, and an asymmetrically flagellum bend. This motility pattern is achieved during the passage of the sperm along the female genital tract. It helps the spermatozoa to cross through different viscous ambient fluids to finally reach the oocyte. Important signaling proteins are located in the sperm head and flagellum, and they all play an important role in the cascade that controls the sperm hyperactivation. The presence of HCO3- modulates the activity of the soluble adenylyl cyclase (sAC), leading to the production of cAMP. In turn, cAMP modulates the sperm-specific Na+/H+ exchanger (sNHE) and the t-complex protein 11 (TCP11) which play an essential role on the signaling pathway (cAMP/PKA and tyrosine phosphorylation) and sperm hypermotility. sNHE, cystic fibrosis transmembrane conductance regulator (CFTR), and voltage-gated proton channel (Hv) mainly contribute to the regulation of the intracellular pH (pHi) during capacitation. HCO3- entrance and the removal of H+ from the cytoplasm induces the alkalization of pHi, and this change will contribute to the activation of the cation channel of sperm (CatSper). Recently, it was described the participation on sperm motility and the regulation of calcium channels of an autophagy-related protein, the microtubule-associated protein light chain 3 (LC3). This review gathers important literature about the essential roles of sAC, sNHE, CFTR, Hv, and CatSper in the acquisition of sperm hyperactivation, and provides an integrated overview of recently described roles of TCP11 and LC3 on the sperm signaling pathway. Additionally, we provide insight into the infertility induced by the dysfunction of these critical proteins.

A Complete Review of Mexican Plants with Teratogenic Effects.

In Mexico, the use of medicinal plants is the first alternative to treat the diseases of the most economically vulnerable population. Therefore, this review offers a list of Mexican plants (native and introduced) with teratogenic effects and describes their main alterations, teratogenic compounds, and the models and doses used. Our results identified 63 species with teratogenic effects (19 native) and the main alterations that were found in the nervous system and axial skeleton, induced by compounds such as alkaloids, terpenes, and flavonoids. Additionally, a group of hallucinogenic plants rich in alkaloids employed by indigenous groups without teratogenic studies were identified. Our conclusion shows that several of the identified species are employed in Mexican traditional medicine and that the teratogenic species most distributed in Mexico are Astragalus mollissimus, Astragalus lentiginosus, and Lupinus formosus. Considering the total number of plants in Mexico (≈29,000 total vascular plants), to date, existing research in the area shows that Mexican plants with teratogenic effects represent ≈0.22% of the total species of these in the country. This indicates a clear need to intensify the evaluation of the teratogenic effect of Mexican plants.

Antifungal Activity of Fibrate-Based Compounds and Substituted Pyrroles That Inhibit the Enzyme 3-Hydroxy-methyl-glutaryl-CoA Reductase of Candida glabrata (CgHMGR), Thus Decreasing Yeast Viability and Ergosterol Synthesis.

Due to the emergence of multidrug-resistant strains of yeasts belonging to the Candida genus, there is an urgent need to discover antifungal agents directed at alternative molecular targets. The aim of the current study was to evaluate the capacity of three different series of synthetic compounds to inhibit the Candida glabrata enzyme denominated 3-hydroxy-methyl-glutaryl-CoA reductase and thus affect ergosterol synthesis and yeast viability. Compounds 1c (α-asarone-related) and 5b (with a pyrrolic core) were selected as the best antifungal candidates among over 20 synthetic compounds studied. Both inhibited the growth of fluconazole-resistant and fluconazole-susceptible C. glabrata strains. A yeast growth rescue experiment based on the addition of exogenous ergosterol showed that the compounds act by inhibiting the mevalonate synthesis pathway. A greater recovery of yeast growth occurred for the C. glabrata 43 fluconazole-resistant (versus fluconazole-susceptible) strain and after treatment with 1c (versus 5b). Given that the compounds decreased the concentration of ergosterol in the yeast strains, they probably target ergosterol synthesis. According to the docking analysis, the inhibitory effect of 1c and 5b could possibly be mediated by their interaction with the amino acid residues of the catalytic site of the enzyme. Since 1c displayed higher binding energy than α-asarone and 5b, it is the best candidate for further research, which should include structural modifications to increase its specificity and potency. The derivatives could then be examined with in vivo animal models using a therapeutic dose. IMPORTANCE Within the context of the COVID-19 pandemic, there is currently an epidemiological alert in health care services due to outbreaks of Candida auris, Candida glabrata, and other fungal species multiresistant to conventional antifungals. Therefore, it is important to propose alternative molecular targets, as well as new antifungals. The three series of synthetic compounds herein designed and synthesized are inhibitors of ergosterol synthesis in yeasts. Of the more than 20 compounds studied, two were selected as the best antifungal candidates. These compounds were able to inhibit the growth and synthesis of ergosterol in C. glabrata strains, whether susceptible or resistant to fluconazole. The rational design of antifungal compounds derived from clinical drugs (statins, fibrates, etc.) has many advantages. Future studies are needed to modify the structure of the two present test compounds to obtain safer and less toxic antifungals. Moreover, it is important to carry out a more in-depth mechanistic approach.

Development, Characterization, Optimization, and In Vivo Evaluation of Methacrylic Acid-Ethyl Acrylate Copolymer Nanoparticles Loaded with Glibenclamide in Diabetic Rats for Oral Administration.

The methacrylic acid-ethyl acrylate copolymer nanoparticles were prepared using the solvent displacement method. The independent variables were the drug/polymer ratio, surfactant concentration, Polioxyl 40 hydrogenated castor oil, the added water volume, time, and stirring speed, while size, PDI, zeta potential, and encapsulation efficiency were the response variables analyzed. A design of screening experiments was carried out to subsequently perform the optimization of the nanoparticle preparation process. The optimal formulation was characterized through the dependent variables size, PDI, zeta potential, encapsulation efficiency and drug release profiles. In vivo tests were performed in Wistar rats previously induced with diabetes by administration of streptozotocin. Once hyperglycemia was determined in rats, a suspension of nanoparticles loaded with glibenclamide was administered to them while the other group was administered with tablets of glibenclamide. The optimal nanoparticle formulation obtained a size of 18.98 +/- 9.14 nm with a PDI of 0.37085 +/- 0.014 and a zeta potential of -13.7125 +/- 1.82 mV; the encapsulation efficiency was of 44.5%. The in vivo model demonstrated a significant effect (p < 0.05) between the group administered with nanoparticles loaded with glibenclamide and the group administered with tablets compared to the group of untreated individuals.

Oxidative Stress, Mitochondrial Function and Adaptation to Exercise: New Perspectives in Nutrition.

Cells have the ability to adapt to stressful environments as a part of their evolution. Physical exercise induces an increase of a demand for energy that must be met by mitochondria as the main (ATP) provider. However, this process leads to the increase of free radicals and the so-called reactive oxygen species (ROS), which are necessary for the maintenance of cell signaling and homeostasis. In addition, mitochondrial biogenesis is influenced by exercise in continuous crosstalk between the mitochondria and the nuclear genome. Excessive workloads may induce severe mitochondrial stress, resulting in oxidative damage. In this regard, the objective of this work was to provide a general overview of the molecular mechanisms involved in mitochondrial adaptation during exercise and to understand if some nutrients such as antioxidants may be implicated in blunt adaptation and/or an impact on the performance of exercise by different means.

Phycobiliproteins Ameliorate Gonadal Toxicity in Male Mice Treated with Cyclophosphamide.

Cyclophosphamide (CP)-which is used to treat autoimmune diseases and cancer-is related to gonadotoxicity attributed to oxidative stress. As phycobiliproteins (PBPs) are strong antioxidants that are unexplored as protective agents against male gonadotoxicity, our work aimed to investigate the effects of PBP crude extract on testicular damage and sperm parameter alterations caused by CP in mice. Three doses of PBP (50, 100, and 200 mg/kg) were tested in the experimental groups (n = 8 per group), administered concomitantly with 100 mg/kg CP. After 42 days receiving PBP daily and CP weekly, body and relative testicular weights, serum testosterone levels, testicular lipoperoxidation and antioxidant enzyme activity levels, and testicular histology and sperm parameter alterations were assessed. The results showed that PBP crude extract at 200 mg/kg prevented testosterone serum reduction, body weight loss, lipoperoxidation and enzyme activity increments, and sperm parameter alterations and partially ameliorated relative testicular weight reductions and histological damage in CP-treated mice. In conclusion, we showed that PBP crude extract (200 mg/kg) mitigated oxidative damage in the testes and ameliorated alterations in sperm parameters in mice treated with CP (100 mg/kg); therefore, PBP extract could be considered as a potential protective agent against CP toxicity.

Protective effects of Spirulina (Arthrospira maxima) against toxicity induced by cadmium in Xenopus laevis.

Spirulina (Arthrospira maxima) has been recognized as a superfood and nutraceutical by its high nutritional value and the benefits of its consumption; it is an important source of lipids, proteins, vitamins, minerals, and antioxidants. It is known that spirulina has positive effects on the toxicity induced by pharmaceuticals and metals. Heavy metals such as cadmium, frequently used in industrial activities, are continuously detected in water bodies and can generate adverse effects on aquatic organisms even at low concentrations. This study aimed to evaluate the protective effect of spirulina (Arthrospira maxima) against the toxic effects induced by cadmium in the early life stages of Xenopus laevis. Twenty Xenopus laevis embryos were exposed to five different treatments on triplicate, control, cadmium (CdCl2 24.5 µg L-1) and three spirulina mixtures Cd + S 1 (24.5 µg L-1 CdCl2 + 2 mg L-1 spirulina), Cd + S 2 (24.5 µg L-1 CdCl2 + 2 mg L-1 spirulina), Cd + S 3 (24.5 µg L-1 CdCl2 + 10 mg L-1 spirulina); after 96 h of exposure: Malformations, mortality and length were evaluated; also, after 192 h, lipid peroxidation (LPX), superoxide dismutase (SOD) and catalase (CAT) were determined. All spirulina treatments decreased mortality from 34 to 50% and reduced malformations on incidence from 36 to 68%. Treatment Cd + S 3 decreased growth inhibition significantly. Spirulina treatment Cd + S 2 decreased lipidic peroxidation and antioxidant activity; these results suggest that spirulina (Arthrospira maxima) can decrease the mortality, frequency of malformations, the severity of malformations, growth inhibition, and oxidative damage induced by cadmium in Xenopus laevis embryos.

Evidence of Some Natural Products with Antigenotoxic Effects. Part 2: Plants, Vegetables, and Natural Resin.

Cancer is one of the leading causes of death worldwide. The agents capable of causing damage to genetic material are known as genotoxins and, according to their mode of action, are classified into mutagens, carcinogens, or teratogens. Genotoxins are also involved in the pathogenesis of several chronic degenerative diseases, including hepatic, neurodegenerative, and cardiovascular disorders; diabetes; arthritis; cancer; chronic inflammation; and ageing. In recent decades, researchers have found novel bioactive phytocompounds able to counteract the effects of physical and chemical mutagens. Several studies have shown the antigenotoxic potential of different fruits and plants (Part 1). In this review (Part 2), we present a research overview conducted on some plants and vegetables (spirulina, broccoli, chamomile, cocoa, ginger, laurel, marigold, roselle, and rosemary), which are frequently consumed by humans. In addition, an analysis of some phytochemicals extracted from those vegetables and the analysis of a resin (propolis),whose antigenotoxic power has been demonstrated in various tests, including the Ames assay, sister chromatid exchange, chromosomal aberrations, micronucleus, and comet assay, was also performed.

Beneficial effects of phycobiliproteins from Spirulina maxima in a preeclampsia model.

AIMS: Considering phycobiliproteins of Spirulina maxima has shown a wide margin of security in pregnant and non-pregnant animals as well as antioxidant properties, present study aimed to investigate if the cardiovascular and metabolic effects of an experimental model of preeclampsia can be prevented by the administration of this compound. MAIN METHODS: Subrenal aortic coarctation (SRAC) practiced to female Wistar rats of 8 weeks of age. Animals were divided randomly to conform non-pregnant and pregnant groups and pregnant with SRAC showed fetoplacental ischemia and were considered preeclamptic (PE). Groups were treated with saline solution (control group) or phycobiliproteins solution (100 mg/kg/day ig) for the last 7, 14 or 20 days of pregnancy. KEY FINDINGS: PE animals showed increased systolic blood pressure, weight gain, glucose and GTT as well as vascular contractility. Also, PE animals showed decreased SOD, GPx activities while MDA was increased. Phycobiliproteins oral treatment for 3 weeks significantly decreased systolic blood pressure and reestablished glucose, weight gain and vascular contractility as well as enzyme activities of PE rats to those of normal pregnant animals. SIGNIFICANCE: Our results show that phycobiliproteins can prevent the damage produced by fetoplacental ischemia and provides evidence of free radical species contribution to the physiopathology of the disease. Also, we conclude phycobiliproteins can be an alternative to reduce preeclampsia manifestations, however, more studies are recommended.

Amelioration of Ethanol-Induced Gastric Ulcers in Rats Pretreated with Phycobiliproteins of Arthrospira (Spirulina) Maxima.

Phycobiliproteins of Arthrospira (Spirulina) maxima have attracted attention because of their potential therapeutic antioxidant properties. The aim of this study was to assess the possible antiulcerogenic activity of these phycobiliproteins (ExPhy) against ethanol-induced gastric ulcers in rats. To explore the possible mechanisms of action, we examined antioxidant defense enzymes (e.g., catalase, superoxide dismutase, and glutathione peroxidase), as well as the level of lipid peroxidation (MDA) and the histopathological changes in the gastric mucosa. Intragastric administration of ExPhy (100, 200, and 400 mg/kg body weight) significantly lowered the ulcer index value compared to the ulcer control group (p < 0.05). The greatest protection was provided by the concentration of 400 mg/kg. The histological study supported the observed gastroprotective activity of ExPhy, showing a reduced inflammatory response. Moreover, the alcohol-induced decrease in stomach antioxidant enzyme activity found in the ulcer control group was prevented by ExPhy pretreatment. Furthermore, ExPhy reversed the ethanol-induced increase in lipid peroxidation. In summary, the antiulcerogenic potential of ExPhy may be due, at least in part, to its anti-oxidant and anti-inflammatory effects.

Morphological and biochemical effects of weekend alcohol consumption in rats: Role of concentration and gender.

AIM: To examine the association between weekend alcohol consumption and the biochemical and histological alterations at two different concentrations of alcohol in both genders in rats. METHODS: Wistar rats weighing 170-200 g were divided into groups as follows: (1) Control groups; and (2) weekend alcohol-consumption group: 2 d/weekly per 12 wk, at two different concentrations: (1) Group of males or females with a consumption of a solution of alcohol at 40%; and (2) group of males or females with a consumption of a solution of alcohol at 5%. At the end of the experiment, serum and liver samples were obtained. The following enzymes and metabolites were determined in serum: Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), Lactate Dehydrogenase, and Gamma-Glutamyltransferase, and glucose, triglycerides, cholesterol, bilirubin, and albumin. Liver samples from each group were employed to analyze morphological abnormalities by light microscopy. RESULTS: In all of the weekend alcohol-consumption groups, AST activity presented a significant, 10-fold rise. Regarding ALT activity, the groups with weekend alcohol consumption presented a significant increase that was six times greater. Bilirubin levels increased significantly in both groups of females. We observed a significant increase in the parameters of fatty change and inflammation due to weekend alcohol consumption. Only the group of females that consumed alcohol at 40% presented slight hepatocellular disorganization. CONCLUSION: The results obtained herein provide solid evidence that weekend alcohol consumption gives rise to liver damage, demonstrated by biochemical and histological alterations, first manifested acutely, and prolonged weekend alcohol consumption can cause greater, irreversible damage.

Analgesic and anxiolytic effects of [Leu31,Pro34]-neuropeptide Y microinjected into the periaqueductal gray in rats.

Several reports have demonstrated that neuropeptide Y (NPY) is involved in food intake, epilepsy, circadian rhythms, drug seeking, pain and anxiety, and other physiological or pathological conditions. On the other hand, periaqueductal gray (PAG) is a key brain center for modulating pain, anxiety and fear. It is the main structure implicated in integrated defensive behaviors. One such behavior, tonic immobility (TI), resembles fear and is able to induce analgesia. After microinjection of [Leu31,Pro34]-Neuropeptide Y ([Leu31,Pro34]-NPY) into the PAG dorsal (D) or ventrolateral (VL) of adult male Wistar rats, the following parameters were assessed: i) the analgesic effect by means of the tail-flick test (TF), ii) the duration of TI as a passive defensive behavioral response and as an anxiety/fear model (considering both TF and TI as single behaviors), iii) TI-induced analgesia by the combination of TF/TI, and iv) the anxious-like state through the elevated plus maze (EPM), and defensive burying behavior (DBB). The results show that the microinjection of [Leu31,Pro34]-NPY into the PAG produced an analgesic effect (increasing the TF latency); overall decreased the TI duration, which might represent an important anti-fear effect. Moreover, [Leu31,Pro34]-NPY microinjected into the PAG allows for a TI-induced analgesic effect, as well as, a substantial anxiolytic effect (evidenced by the EPM and DBB models). Hence, [Leu31,Pro34]-NPY microinjected into the PAG, especially at 0.47nmol/0.5µL produces both analgesic and anxiolytic effects, in a higher magnitude within ventrolateral area.

Structural and Physicochemical Characterization of Spirulina (Arthrospira maxima) Nanoparticles by High-Resolution Electron Microscopic Techniques.

The objective of this work was to obtain Spirulina (Arthrospira maxima) nanoparticles (SNPs) by using high-impact mechanical milling and to characterize them by electron microscopy and spectroscopy techniques. The milling products were analyzed after various processing times (1-4 h), and particle size distribution and number mean size (NMS) were determined by analysis of high-resolution scanning electron microscopic images. The smallest particles are synthesized after 3 h of milling, had an NMS of 55.6±3.6 nm, with 95% of the particles being smaller than 100 nm. High-resolution transmission electron microscopy showed lattice spacing of ~0.27±0.015 nm for SNPs. The corresponding chemical composition was obtained by energy-dispersive X-ray spectroscopy, and showed the presence of Ca, Fe, K, Mg, Na, and Zn. The powder flow properties showed that the powder density was higher when the average nanoparticle size is smaller. They showed free flowability and an increase in their specific surface area (6.89±0.23 m2/g) up to 12-14 times larger than the original material (0.45±0.02 m2/g). Fourier transform infrared spectroscopy suggested that chemical damage related to the milling is not significant.