The main objective of this study was to investigate if natural honey can be used as a cryoprotecting agent (CP) in vitrification medium to improve the viability of vitrified-warmed bovine oocytes. The first study was conducted to investigate the dehydration capability of natural honey compared with sucrose, and to determine the proper concentration of honey-based medium and the optimum time for sufficiently safe dehydration of bovine oocytes. Matured cumulus-oocyte complexs (COCs) were denuded and introduced individually into different concentrations (0.25, 0.5, 1.0, 1.5 or 2.0 M) of honey and sucrose-based medium followed by rehydration in control media (TCM). Video images were recorded during dehydration and rehydration, and oocyte images were captured at 12 time intervals to calculate oocyte-volume changes during dehydration and rehydration. Results demonstrated that, in honey-based media, the maximum oocyte shrinkage was achieved after 60 sec exposure in 0.25M, 0.5M and 1.0M concentrations; while at higher concentrations 1.5M and 2.0M, the maximum dehydration occurred at 30 and 20 seconds respectively. In sucrose-based medium, the maximum oocyte shrinkage was achieved after 60 sec exposure in 0.25 or 0.5M concentrations. However, at higher concentrations (1M, 1.5M or 2M), the maximum dehydration occurred at 30, 20 and 10 sec. For rehydration, oocytes dehydrated in honey or sucrose-based medium were able to regain their original volume within 60-120 sec. However, oocytes dehydrated in higher concentrations (2M honey, and 1.5M and 2M sucrose) were rehydrated back to their original volume within 20 sec. This study concluded that natural honey and sucrose caused similar cell dehydration. Only oocytes dehydrated in 1M honey-based media reached maximal dehydration after 60 sec and equally regained original volume. Therefore, 1M of honey-based medium is suggested for sufficient and safe oocyte dehydration during vitrification. The second study was conducted to determine in vitro maturation (IVM), in vitro fertilization (IVF) and embryonic development of bovine oocytes vitrified in honey-based vitrifcation media. In Experiment 1, bovine COCs were randomly distributed in control group (non-vitrified; G1), 0.5M sucrose group (second control; G2), and 0.5M, 1M and 1.5M honey groups (G3, G4 and G5 respectively). The COCs were exposed to equilibration solution 1 (VS1) at ~ 22 oC for 5 min and to vitrification solution 2 (VS2) for 1 min, mounted on Cryotops and plunged into LN2. COCs were warmed in TCM and honey/sucrose medium at 38.5oC for 1 min, washed, matured in vitro (IVM), denuded, and immunostained to evaluate maturation. Maturation rate was significantly higher (80.7%) in control group (G1) than in vitrified groups (56, 52, 55 and 51% in G2, G3, G4 and G5, respectively) (P<.0001), whereas there was no significant difference among the vitrified groups (P>0.05). In Experiment 2, bovine COCs distributed in control (not vitrified, G1) and vitrified groups using 1M honey and 0.5M sucrose (G2 and G3 respectively), underwent for IVM, IVF and in vitro culture (IVC) for 9 days. Cleavage rate was significantly higher (P<.0001) in the control group (74%, G1, n=183) than rates of vitrified groups (51% in G2, n=137; and 42% in G3, n=131), whereas no differences among vitrified groups (P=0.0723). Rate of blastocyst formation was significantly higher (34%) in G1 than in the vitrified groups (P<.0001); however, blastocyst formation rates in the honey group were significantly higher (P=0.0026) than in the sucrose group (13% and 3% respectively). Addition of natural honey (1.0M; or 21.7%w/v) in vitrification medium can safely and sufficiently dehydrate bovine oocytes during vitrification procedure. The vitrification of bovine oocytes in 1M honey improved their post-warming maturation abtility and embryonic development.

Honey is a naturally sweet substance produced by honeybees from water, pollen, and nectar. Due to its unique nutritional and therapeutic benefits, which are ascribed to the interaction of the various chemical groups it contains, natural honey is one of the most popular consumed products. Modern-day individuals consume a lot of refined granulated sugar, either directly through foods or indirectly from other sources. The consumption of large amounts of refined granulated sugar alters hematological and physiological changes in the body. According to several scientific studies, honey can be a healthier alternative to refined granulated sugar because it does not threaten human health. Consuming natural honey raises serum iron levels and red blood cell counts since it is known that the iron in honey serves as a precursor to hemoglobin. Overconsumption of refined granulated sugar has been identified as a risk factor for metabolic disorders such as obesity, cardiovascular disease, type 2 diabetes, and non-alcoholic fatty liver disease. This study, therefore, investigated the effect of the golden liquid from honeybees (natural honey) and refined granulated sugar on the blood glucose and serum iron levels of 25 Wistar albino rats. The experimental animals used in this study were grouped into five treatments based on the dose of natural honey and refined granulated sugar administered namely: T1 (1.02 g of honey /kg BW), T2 (1.40g of honey /kg BW), T3 (1.02 g of refined granulated sugar /kg BW), T4 (1.40g of refined granulated sugar /kg BW), rats in T5 were not administered honey, and refined granulated sugar served as the control. The blood glucose concentration of the albino rats was measured using the glucose strips with a glucometer while the serum iron analysis was conducted using Atomic Absorption Spectrophotometer. The result revealed that the mean blood glucose level of the rats was highest in T3 (112.95mg/dl), followed by T5 (92.20mg/dl) while the least value was recorded in T2 (74.86mg/dl). There was a significant difference in the blood glucose levels of albino rats orally administered natural honey and refined granulated sugar at varying levels (P0.05) among treatments. It was found that the highest serum iron level was recorded in T5 (1.31±0.395 ppm) followed by T2 (1.22± 0.115 ppm), while the least serum iron level was recorded in T1 (0.88±1.319ppm). It was observed that there were no significant differences in the serum iron levels of the albino rats (p>0.05) among treatments The use of natural honey is recommended since albino rats orally administered honey at varying doses had lower blood glucose levels than those given refined granulated sugar. This work will be a useful tool for understanding the role of honey over granulated sugars, especially among prediabetic and diabetic patients in order to control their sugar levels using diet as a source. This implies that the consumption of natural honey did not significantly increase blood glucose levels. It was therefore recommended that physicians and dietitians should advocate for natural honey use over refined granulated sugar which could be safe for consumption by diabetic patients.

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / A pesquisa objetivou investigar o processo de cointegraÃÃo espacial entre os principais mercados brasileiros exportadores de mel natural: Rio Grande do Sul, Santa Catarina, PiauÃ, Cearà e SÃo Paulo. Foram utilizados dados secundÃrios obtidos diretamente da base de dados do MinistÃrio de Desenvolvimento, IndÃstria e ComÃrcio Exterior, compreendendo a sÃrie de tempo entre janeiro de 2002 a julho de 2011. Para investigar as relaÃÃes entre os mercados supracitados, fez-se uso de metodologia baseada nas premissas da Lei do PreÃo Ãnico â LPU e modelagem que considera a presenÃa de custos de transaÃÃo. Os resultados indicam que, apesar da confirmaÃÃo da existÃncia de cointegraÃÃo entre os mercados brasileiros exportadores de mel natural, a LPU nÃo foi totalmente confirmada, uma vez que se rejeitou a hipÃtese nula de perfeita integraÃÃo espacial entre os mercados. O teste de exogeneidade fraca indica que o mercado de mel natural do Rio Grande do Sul atua como mercado central na formaÃÃo de preÃos. Hà a presenÃa de custos de transaÃÃo entre quase todos os mercados espacialmente separados, pois, segundo os resultados oriundos da modelagem threshold, rejeitou-se a hipÃtese nula de ajuste linear e simÃtrico entre os mercados investigados. / This study investigated the process of cointegration space between the main markets Brazilian exporters of natural honey Rio Grande do Sul, Santa Catarina, PiauÃ, Cearà and SÃo Paulo. Secondary data obtained directly from the database of the MinistÃrio de Desenvolvimento, IndÃstria e ComÃrcio Exterior, comprising the time series between January 2002 and July 2011. To investigate the relationship between the markets mentioned above, was made use of a methodology based on the premises of the Law of One Price- LPU and modeling that considers the presence of transaction costs. The results indicate that despite the confirmation of the existence of markets cointegration Brazilian exporting natural honey, the LPU has not been fully confirmed, since it is rejecting the null hypothesis of perfect integration space between the markets. The weak exogeneity test indicates that the market for natural honey of Rio Grande do Sul acts asthe central market pricing. There is the presence of transaction costs between almost allspatially separated markets, because, according to the results from the modelingthreshold, rejected the null hypothesis of linear and symmetric adjustment between markets investigated.