Plant Extracts in the Bone Repair Process: A Systematic Review.

Bone lesions are an important public health problem, with high socioeconomic costs. Bone tissue repair is coordinated by an inflammatory dynamic process mediated by osteoprogenitor cells of the periosteum and endosteum, responsible for the formation of a new bone matrix. Studies using antioxidant products from plants for bone lesion treatment have been growing worldwide. We developed a systematic review to compile the results of works with animal models investigating the anti-inflammatory activity of plant extracts in the treatment of bone lesions and analyze the methodological quality of the studies on this subject. Studies were selected in the PubMed/MEDLINE, Scopus, and Web of Science databases according to the PRISMA statement. The research filters were constructed using three parameters: animal model, bone repair, and plant extracts. 31 full-text articles were recovered from 10 countries. Phytochemical prospecting was reported in 15 studies (48.39%). The most common secondary metabolites were flavonoids, cited in 32.26% studies (n = 10). Essential criteria to in vivo animal studies were frequently underreported, suggesting publication bias. The animals treated with plant extracts presented positive results in the osteoblastic proliferation, and consequently, this treatment accelerated osteogenic differentiation and bone callus formation, as well as bone fracture repair. Possibly, these results are associated with antioxidant, regenerative, and anti-inflammatory power of the extracts. The absence or incomplete characterization of the animal models, treatment protocols, and phytochemical and toxicity analyses impairs the internal validity of the evidence, making it difficult to determine the effectiveness and safety of plant-derived products in bone repair.

Applicability of Plant Extracts in Preclinical Studies of Melanoma: A Systematic Review.

Melanoma is the most aggressive form of skin cancer and arises from melanocyte gene mutation. This disease is multifactorial, but its main cause is the excessive exposure to ultraviolet radiation. Currently, available chemotherapy has shown little expressive results, which may justify the high use of natural products to treat this cancer. We performed a systematic review to compile the results of studies carried out in murine models and investigated the effect of plant extracts on melanoma treatment. Papers were selected in MEDLINE/Pubmed and Scopus according to the PRISM statement. Search filters were developed using three parameters: plant extract, melanoma, and animal model. The 35 identified studies were all submitted to the criteria described in the ARRIVE guidelines. The different extracts showed antiangiogenic, antimetastatic, antioxidant, and anti-inflammatory activity, and also proved to be effective in cell cycle modulation and apoptosis evasion. Bias analysis evidenced the absence of standardized experimental designs, as well as failures in statistical tests and in the presentation of results. The analysis of the studies suggests that the use of plant extracts is effective for the treatment of melanoma in murine models.

Testicular histomorphometric patterns and spermatogenesis dynamics of Oecomys bicolor tomes, 1860 (Rodentia: Cricetidae).

Although the order Rodentia does not present a high risk of extinction compared to mammals as a whole, several families demonstrate high levels of threat and/or data deficiency, therefore highlighting the need for targeted research and the application of ecological and reproductive data to the development of conservation actions. The order Rodentia, the largest among mammals, includes 9 families, and the family Cricetidae is the most diverse of the Brazilian rodents. In Brazil, 12 of the 16 genera of Oecomys are found. Oecomys bicolor is known in Brazil as the 'arboreal rat' and is, found in dry, deciduous and tropical forests. The mean body weight of Oecomys bicolor was 35.8 g and the gonadal, tubular and epithelial somatic indexes were, 0.53%, 0.47% and 0.37%, respectively. Seminiferous tubules volume density was 89.72% and the mitotic and meiotic indexes corresponded to 8.59 and 2.45 cells, respectively, and the yield of spermatogenesis was 23.83 cells. The intertubular compartment represented 10.28% of the testis parenchyma and around 5% of the interstitial space was occupied by Leydig cells, whose number per gram of testis was 11.10 × 107 cells. By evaluating the biometric and histomorphometric characteristics of the testis, there is evidence that this species has a high investment in reproduction. Due to the high contribution of the seminiferous epithelium and the intertubular compartment in this species, compared to the others of the same family, it is possible to infer that the species Oecomys bicolor has a promiscuous reproductive behaviour.

The relevance of the use of plant extracts on testicular cells: A systematic review.

This review aims to establish an association between traditional and scientific knowledge to allow the evaluation of the effectiveness of medicinal plants, as well as their risks based on the testicular microenvironment. A systematic search was performed using PRISMA guidelines. The descriptors were structured based on search filters built for three domains: Animals, Plants, and Testis. The filters on the PubMed/Medline platform were constructed using a hierarchical distribution of the MeSH Terms. Methodological quality assessments were performed using the SYRCLE risk bias tool. Data on testicular cells, hormones and biochemistry, sperm, and sexual behavior were evaluated and compared. The search came out with 2644 articles, and 36 articles met the inclusion criteria and were used in this review. The included studies analyzed testicular cells from murine models treated with crude plant extracts. Plant extracts act directly on the hypothalamic-pituitary axis and/or directly on testicular cells, inhibiting and stimulating the reproductive process, thus causing alterations in fertility rates. Apiaceae and the Cucurbitaceae families are the most used in male reproductive biology experiments, being Apiaceae described as sexual stimulants, while Cucurbitaceae are the main sources of deleterious effects on the male reproductive system.

Anatomy of the dura mater venous sinus of Alouatta belzebul.

The anatomy of the dura mater's venous sinuses is important in the veterinary clinical and surgical area, for cranial procedures and interventions of wild animals, in addition to assisting in the management of neurological diseases, which can prevent serious complications. The macroscopic anatomy of the venous sinuses of the dura mater of Alouatta belzebul was studied. Five adult specimens, males and females, were dissected and fixed in 10% formaldehyde solution. In the dura mater of the Alouatta belzebul, nine venous sinuses were observed, being them dorsal sagittal sinus, ventral sagittal sinus, transverse sinus, straight sinus, sigmoid sinus, temporal sinus, parietal sinus, basilar sinus and cavernous sinus, with morphological similarities in origin, path and destination of blood flow to the internal jugular vein, assisting in the venous drainage function of the brain in this species. These data are similar to those found in other species of non-human and human primates such as Saimiri sciureus, Sapajus libidinosus and Homo sapiens. Of the venous sinuses observed, the cavernous sinus was of considerable clinical and surgical importance in Alouatta belzebul due to its topographic arrangement next to the internal carotid artery and pituitary gland, data that corroborate Sapajus libidinosus, Macaca fascicularis, Macaca mulatta, Papio ursinus, Cercopithecus pygerithrus and Galago senegalensis. In this context, the knowledge of the macroscopic anatomy of the venous sinuses of the dura mater may contribute to the role of veterinarians in less invasive surgical procedures in non-human primates such as Alouatta belzebul and other mammals.

Cadmium Exposure and Testis Susceptibility: a Systematic Review in Murine Models.

It is known that cadmium induces damage to the testis. However, the significant cadmium impact on the testicular architecture and the mechanisms involved in this process are not clear. Besides, the relationship between dose, route, and time of exposure and injuries remains poorly understood. Thus, we aimed to assess whether cadmium exposure in any dose, route, and time of exposure causes significant alteration in the testicular tissue of murine models, as well as the main mechanisms involved. We performed a structured search on the Medline/PubMed and Scopus databases to retrieve studies published until September 2018. The results were organized into an Adverse Outcome Pathway (AOP) framework. Also, a bias analysis of included studies was performed. We included 37 studies, and most of them identified significant histopathologies in both tubule and intertubule regarding routes, in a dose- and time-dependent manner. The damages were observed after the first hours of exposure, mainly vascular damages suggesting that vasculature failure is the primary mechanism. The AOP showed that potential molecular initiating events may mimic and interfere with essential elements disrupting proteins (structural and antioxidants), change in the oxidative phosphorylation enzyme activities, and gene expression alteration, which lead to reproductive failure (adverse outcome). Analysis of methodological quality showed that the current evidence is at high risk of bias. Despite the high risk of bias, cadmium triggers significant lesions in the testis of murine models, regarding routes, in a dose- and time-dependent manner, mainly due to vascular changes. Therefore, cadmium is a risk factor for male reproductive health.

Descriptive morphometry and stereology in accessing the testis structure and function of the marsupial Philander frenatus (Olfers, 1818) (Didelphimorphia: Didelphidae).

Philander frenatus is an important marsupial for the maintenance and conservation of the Atlantic Rainforest, however, it has biological characteristics that are still little explored. The study of the reproductive biology is an important key to understand the species reproductive strategies and to improve the development of conservation and management activities. The present study aimed to conduct a histological and morphometric investigation of the testis structure and function of P. frenatus. The average body and testicular weight were 445 g and 0.74 g, respectively, with a gonadosomatic index of 0.17%. The seminiferous tubules occupying 64.95% of the organ, totalising 9.26 m per gram of testis. The tubulesomatic and epitheliumsomatic indexes were 0.10% and 0.07%, respectively. Philander frenatus showed cell loss of approximately 98% during the proliferative phase and the spermatogenic yield was 10.3 cells. The high loss during the mitotic phase contributed to the low spermatogenic yield. The testicular parenchyma was composed of 35% of intertubular components, one of the highest proportions observed in mammals. Leydig cells were responsible for approximately 25% of the testes, followed by lymphatic space (6.44%), blood vessels and connective tissue (4% together). The organisation of the intertubular components resembles the Fawcett III category. The volume and number of Leydig cell per gram of testis were 2,627.12 µm3 and 91.28 × 106 cells, respectively. High investment in the intertubular compartment, specifically number and volume of Leydig cells in P. frenatus is consistent with territorial behaviour and polygynic mating system, which have greater androgenic capacity.

Different Routes of Administration Lead to Different Oxidative Damage and Tissue Disorganization Levels on the Subacute Cadmium Toxicity in the Liver.

The toxic effects of cadmium (Cd) on hepatic parameters are widely described in the literature. Experimental models often make use of the intraperitoneal route (i.p.) because it is easier to apply, while in the oral route, Cd poisoning in humans is best represented by allowing the metal to pass through the digestive system and be absorbed into the bloodstream. Thus, this study investigated the Cd exposure impact on the liver, by comparing both i.p. and oral routes, both in single dose, in addition to the oral route in fractional doses. Swiss adult male mice received CdCl2 1.5 mg/kg i.p., 30 mg/kg oral single dose, and 4.28 mg/kg oral route in fractional doses for 7 consecutive days. Cd bioaccumulation was observed in all animals exposed to Cd. Hepatic concentrations of Ca and Fe increased only in the fractionated oral route. Liver activities of SOD and CAT increased only by oral single dose. GST decreased in all forms of oral administration, while MDA decreased only in i.p. route. Liver weight and HSI increased in the i.p. route, while organ volume increased in all forms of oral administration, and liver density increased in all animals exposed to Cd. In hepatic histomorphometry, the changes were more evident in oral administration, mainly in exposure to metal in a single dose. Thus, the subacute administration of Cd in different routes of administration leads to different changes in liver poisoning.

Testicular morphometry of rats with Walker 256 tumor supplemented with L-glutamine.

Glutamine is often used to treat metabolic changes associated with anorexia-cachexia syndrome in patients with malignant neoplasms. Walker 256 tumor is an excellent model for studying these changes associated with cancer in different organs, including injuries in testicular functions. However, the effects of supplementing glutamine on testicular morphometry in this model have not yet been investigated. Thus, the objective of this study was to evaluate the effect of L-glutamine supplementation on testicular morphometry in rats transplanted with Walker 256 tumor cells. Forty puberty Wistar rats were divided into four groups: control without L-glutamine (C); control supplemented with L-glutamine (CG); inoculated with Walker 256 tumor cells (WT) and inoculated with Walker 256 tumor cells and supplemented with L-glutamine (WTG). The testicles were removed, weighed, fixed in Bouin, and included in paraffin for histomorphometric analysis. Walker 256 tumor caused quantitative changes in the tubular and intertubular compartments and tunica albuginea, with reductions in the percentages of lumen and tunica albuginea, number of Sertoli cells per gram of testis; number of Leydig cells; percentage of blood vessels and connective tissue in intertubule. However, glutamine supplementation prevented part of these changes caused by the tumor, presenting mainly a protective effect on the tunica albuginea and percentage of blood and lymph vessels in the intertubule. These results indicate the potential of L-glutamine was able to recover for testicular dysfunction associated with cancer.

Pfaffia glomerata hydroalcoholic extract stimulates penile tissue in adult Swiss mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Roots of Pfaffia glomerata are used in traditional medicine as aphrodisiacs and sexual stimulants. AIM OF THE STUDY: The aim of this study was to evaluate the action of the hydroalcoholic extract from the roots of Pfaffia glomerata on the Leydig cells, cavernous bodies and other penile constituents, as well as on serum testosterone and 17ß-estradiol levels of adult mice. MATERIALS AND METHODS: Mature male Swiss mice were divided into 6 groups: control (water), sildenafil citrate, 3 groups receiving daily doses of P. glomerata extract (100, 200 and 400 mg/kg) and one group receiving intermittent doses of P. glomerata (200 mg/kg/3-3d). RESULTS: The proportions of blood vessels, lymphatic space and estradiol levels were increased. On the other hand, reduction of testosterone levels due to Leydig cells death was observed. As for penile parameters, volumetric proportions of cavernous bodies, collagen and nitric oxide were increased, while smooth muscle content was decreased. CONCLUSIONS: Despite that the long term intake of P. glomerata extract was related to a stimulant action, reduction on Leydig cell viability induced decreased testosterone production.

Cadmium-Induced Testicular Toxicity in Mice: Subacute and Subchronic Route-Dependent Effects.

This study aimed to compare Cd exposure by intraperitoneal (i.p.) and oral routes, evaluating the testicular subacute and subchronic effects. Adult male mice were separated into three groups subdivided according to the experimental period (7 and 42 days after Cd exposure: subacute and subchronic effects, respectively): one group received water and two groups received CdCl2 (1.2 mg/kg i.p. and 24 mg/kg oral). The testicular concentration of essential minerals and Cd, activity of antioxidant enzymes and markers of oxidative stress, histology, and testicular histomorphometry were evaluated. The subacute effect of oral Cd showed reduced Fe concentration, while Ca and Cu increased in this route. The subchronic effect promoted decreasing in Mg in i.p. and oral routes, whereas Zn decreased only in the oral, and the Fe concentration did not change. SOD activity decreased in the oral subacute evaluation and in both pathways, i.p. and oral routes, in the subchronic evaluation, while GST activity increased, and MDA concentration decreased. Labeling of apoptotic cells was increased in the subacute and subchronic evaluation. Seminiferous epithelium degeneration, death of germ cells, and Leydig cell damages occurred in i.p. and oral routes. However, these damages were more intense in the oral route, mainly evaluating the subchronic effects. The results confirm that the severity of Cd-induced testicular injury depends on the pathway, as well as the duration of exposure.

Euterpe oleracea (Martius) Oil Reverses Testicular Alterations Caused after Cadmium Administration.

Cadmium (Cd) is an environmental pollutant that induces reproductive toxicity by generating reactive oxygen species, which leads to oxidative stress. Euterpe oleracea fruits are known for being rich in oils containing triacylglycerol and phenolic compounds. They are considered as potent antioxidants to be used to counteract Cd effects within the testis. In the present study, adult males Swiss mice were treated with CdCl2 aqueous solution (4.28 mg/kg) by gavage for 7 days. The experimental groups were treated with Euterpe oleracea oil at the doses of 50, 100, and 150 mg/kg, for 42 days. The results showed that Cd intoxication led to increased tubular pathologies, such as reduction in epithelium height and area thus increasing both luminal diameter and tubule-epithelium ratio. Besides, Leydig cell's morphometry indicated reduction in nucleus and cytoplasm volumes of this cell type, which were recovered after E. oleracea oil intake. In addition, serum testosterone levels, testicular Mn and Zn concentrations, SOD and CAT activity, and germ cell viability increased after oil intake. Therefore, E. oleracea oil showed a regenerative effect in the testicular parenchyma negatively affected by Cd, mainly in the animals that received the highest oil concentration (150 mg/kg).

Hydroalcoholic extract of Pfaffia glomerata alters the organization of the seminiferous tubules by modulating the oxidative state and the microstructural reorganization of the mice testes.

ETHNOPHARMACOLOGICAL USAGES: Leaves and roots of Pfaffia glomerata areused as aphrodisiacs, tranquilizers and antirheumatics. Due to the lack of experimental scientific data, studies are necessary to identify its medicinal properties. AIMS: The present study aimed to evaluate the effect of hydroalcoholic root extract of P. glomerata (Brazilian ginseng extract - BGE) on testicular parenchyma, and evaluate possible harmful effects through testicular oxidative stress analysis. MATERIALS AND METHODS: Adult mice were divided into 6 groups: control (water), sildenafil citrate, BGE (100, 200 and 400 mg/kg/day), and BGE (200 mg/kg every three days). RESULTS: The treatment reduced the volumetric proportions of seminiferous tubules and epithelium, the number of Sertoli cells, and increased hydrogen peroxide levels, without affecting sperm production. It also caused cell death and changes in the frequency of stages of the seminiferous epithelium cycles. The 100 mg/kg dose responds in a similar way to sildenafil citrate, promoting changes in the gonadal structure, but with efficient response to contain the damage. CONCLUSIONS: Doses of 200 mg/kg, continuous or discontinuous, induced an increase in testicular nitric oxide, as well as sildenafil citrate, showing be efficient as aphrodisiac, but promotes cell death regardless of the form of administration.

Testicular characterization and spermatogenesis of the hematophagous bat Diphylla ecaudata.

Diphylla ecaudata is a hematophagous bat endemic of South America, with food preference for bird blood. Given the lack of information about the reproductive activity of this species, this study aimed to describe the testicular morphology and histomorphometry of D. ecaudata in order to understand its reproductive biology, specially spermatogenesis. The animals were collected in Lajes city, Rio Grande do Norte, Brazil. Following euthanasia, the testes were histologically processed for morphological, morphometric, ultrastructural and immunohistochemical analyses. Their average body weight was 24.64g, with a gonadosomatic index of 0.49%, tubulesomatic index of 0.47%, and a total of 32.20m of seminiferous tubules per gram of testis. The pre-meiotic, meiotic, and post-meiotic phases accounted for 56.20%, 9.30%, and 34.50% of the seminiferous epithelium cycle, respectively. The ultrastructure of spermiogenesis was similar to that described in other mammals and the perforatorium was not observed in the sperm. Androgen receptors were detected in Sertoli cell nuclei and Leydig cell cytoplasm, while aromatase enzyme was detected only in Sertoli cell nuclei. FGF2 and BCL-2 activities were detected in the cytoplasm of zygotene and pachytene primary spermatocytes, as well as round and elongated spermatids. D. ecaudata showed testicular pattern similar to other mammals and characteristics common to other bat species. This species stood out for its high efficiency of Sertoli cells, which presented high capacity to support germ cells, besides the highest sperm production rates among those already recorded. This study is the first step towards the knowledge of D. ecaudata reproduction and the first description of its spermatogenesis.

Flavonoids Effects on Hepatocellular Carcinoma in Murine Models: A Systematic Review.

The hepatocellular carcinoma (HCC) is the second most common cause of cancer deaths worldwide. It occurs primarily as manifestation of other pathological processes, such as viral hepatitis, cirrhosis, and toxin exposure that affect directly the cellular process. Studies were selected from PubMed and Scopus databases according to the PRISMA statement. The research filters were constructed using three parameters: flavonoids, hepatocellular carcinoma, and animal model. The bias analysis of the 34 selected works was done using the ARRIVE guidelines. The most widely used flavonoid in the studies was epigallocatechin gallate extracted from green tea. In general, the treatment with different flavonoids presented inhibition of tumor growth and antiangiogenic, antimetastatic, antioxidant, and anti-inflammatory activities. The bias analysis evidenced the absence of methodological processes in all studies, such as the age or weight of the animals, the method of flavonoids' extraction, or the experimental designs, analytical methods, and outcome measures. It has been known that flavonoids have a protective effect against HCC. However, the absence or incomplete characterization of the animal models, treatment protocols, and phytochemical and toxicity analyses impaired the internal validity of the individual studies, making it difficult to determine the effectiveness of plant-derived products in the treatment of HCC.

Descriptive morphometry and stereology of the tubular compartment in the wild rodent Hylaeamys megacephalus (Rodentia: Cricetidae) from Central Brazil.

Information on reproductive characteristics of wild rodents is scarce in the literature. This study aimed to assess the testis morphometry and stereology of Hylaeamys megacephalus. We used five animals in the study, captured in forest fragments in southwestern Goias State, between April and August 2009. The testes were fixed in Karnovsky solution, dehydrated, and embedded in methacrylate. Two-micrometer-thick sections from each sample were stained with toluidine blue/sodium borate 1%. Images of the testicular parenchyma were obtained from photomicroscope and morphometric and stereological analyses were carried out using the Image Pro-Plus software. The average body weight observed in the specimens of H. megacephalus in the study was 47.84 g, of which, 0.40% is allocated to the gonads (GSI) and 0.36% to the seminiferous tubules (TSI). These parameters suggest promiscuous reproductive behavior, of the polyandrous type, favoring males with higher sperm production and consequently, larger testes. The volume density of the seminiferous tubules was 94.46%, which represented a volume of 0.18 mL. The volume density and volume of the interstitium were 5.54% and 0.011 mL, respectively. The diameter of the seminiferous tubules was 206.5 µm and the height of seminiferous epithelium was 71.27 µm. H. megacephalus presents 5.06 m of seminiferous tubules and an average of 27.96 m of seminiferous tubules per gram of testis. The mitotic and meiotic indexes showed losses of 85 and 42%, respectively and an overall loss of 90% over the full spermatogenic process. The number of Sertoli cells per testis and per gram of testis was 7.8×10(6) and 95.28×10(6), respectively. Most of the morphometric parameters evaluated in H. megacephalus in this study are within the range of values described for most mammals.

Effects of catuaba cristal® on the testis of wistar rats

The aim of this study was to evaluate the possible beneficial effects of Catuaba Cristal® (CC), an alcoholic drink made from wine and Erythroxylum catuaba Ar. Cam on testis. Wistar rats either received CC solution (n=8) or water (n=9). Results showed significant body weight reduction within the CC group, although, no weight changes were observed for liver, kidney, testis, epididymis, seminal vesicle and prostate. The volumetric proportion and volume of interstitial tissue and lymphatic space were reduced in the treated group. In the CC group, although the nuclear volume of Leydig cells (LC) decreased, the number of LC per testis increased. These results suggested that CC had no beneficial effect on spermatogenesis of Wistar rats.

Conhecimento cronobiológico de acadêmicos do curso de educação física da Faculdade Assis Gurgacz e sua relação com a aprendizagem / The chronobiological knowledge of physical education students at the assis gurgacz college and its relation to learning

O ser humano possui períodos do dia em que se encontra mais ativo, com maior facilidade para o aprendizado. Se um indivíduo conhecer seu cronotipo e os horários pertinentes e mais adequados para estudar, poderá distribuir tarefas diárias em favor da produtividadee qualidade de vida. Este trabalho teve por objetivo verificar o perfil cronobiológico dos acadêmicos do 3° período matutino e noturno do curso de Educação Física da FAG e compará-los com suas médias aritméticas. Para identificação dos cronotipos, aplicou-se questionário proposto por HORNE e OSTBERG (1976), adaptado por CARDINALI (1992). Constatou-se que dos 25 acadêmicos do período matutino,8 (32 por cento) têm seu cronotipo classificado como moderadamente matutino, 12 (48 por cento) intermediário, 5 (20 por cento) moderadamente vespertino, ouseja, estes últimos têm seu cronotipo em desacordo com o horário de estudo. Dos 46 acadêmicos do período noturno, 22 (47,83 por cento) têm seu cronotipo classificado como intermediário, 8 (17,39 por cento) moderadamente vespertino, 16 (34,78 por cento) moderadamente matutino e estudam em desacordo ao seu cronotipo. Analisando-se as médias aritméticas dos 25 alunos do período matutino 5 (20 por cento) tinham notas abaixo da media, sendo 1 deles moderadamente matutino, 2 intermediários e 2 moderadamente vespertinos. Dos 46 acadêmicos do período noturno, 5 (10,86 por cento) apresentam notas abaixo da média, sendo 2 moderadamente matutino e 3 intermediários. Através dos dados, concluiu-se que os indivíduos que freqüentam as aulas em horários condizentes com o seu cronotipo podem apresentar uma maior produtividade, fato que contribuirá para uma melhor aprendizagem e qualidade de vida.

Human beings have periods in which they are more active and are prone to learn easily. If one knows its own chronotype and the suitable period to study, one could distribute the daily tasks in favor of productivity and life quality. This study aimed to verify thechronobiological profile of college students in the 3rd period of the Physical Education course at FAG and compare them to their arithmetic means. In order to identify the chronotype, a questionnaire proposed by HORNE and OSTBERG (1976) adapted by CARDINALI (1992) was used. It was evidenced that among the 25 students in the matutine period, 8 (32) percent had their chronotype classified as moderatelymatutine, 12 (48 percent) intermediate, 5 (20 percent) moderately vespertine, which means that the latter are in disagreement with their period of study.From the 46 students studying at night, 22 (47.83 percent) had their chronotype classified as intermediate, 8 (17.39) moderately vespertine, 16 (34.78) moderately matutine and they study in the least suitable period for their chronotype. Analyzing the arithmetic means of the 25 students of the matutine period, 5 (20 percent) had grades lower than the average: one was moderately matutine, 2 intermediate, and 2 moderately vespertine. Among the 46 students who studied at night, 5 (10.86 percent) had grades lower than the average: 2 moderately matutine and 3intermediate. Through the obtained data, it was possible to conclude that individuals attending classes in the period appropriated for theirchronotype may present higher productivity – what will contribute for better learning and life quality.