Inhibition of rat microsomal lipid peroxidation by the oral administration of D002

The effect of D002, a defined mixture of higher primary alcohols purified from bee wax, on in vivo and in vitro lipid peroxidation was studied. The extent of lipid peroxidation was measured on the basis of the levels of thiobarbituric acid reactive substances (TBARS). When D002 (5-100 mg/kg body weight) was administered orally to rats for two weeks, a partial inhibition of the in vitro enzymatic and non-enzymatic lipid peroxidation was observed in liver and brain microsomes. Maximal protection (46%) occurred at a dose of 25 mg/kg. D002 behaved differently depending on both the presence of NADPH and the integrity of liver microsomes, which suggests that under conditions where microsomal metabolism was favored the protective effect of D002 was increased. D002 (25 mg/kg) also completely inhibited carbon tetrachloride- and toluene-induced in vivo lipid peroxidation in liver and brain. Also, D002 significantly lowered in a dose-dependent manner the basal level of TBARS in liver (19-40%) and brain (28-44%) microsomes. We conclude that the oral administration of D002 (5, 25 and 100 mg/kg) for two weeks protected rat liver and brain microsomes against microsomal lipid peroxidation in vitro and in vivo. Thus, D002 could be useful as a dietary natural antioxidant supplement. More studies are required before these data can be extrapolated to the recommendation for the use of D002 as a dietary antioxidant supplement for humans.

Insect juvenile hormone: from "status quo" to high society

Juvenile hormone (JH) exerts pleiotropic functions during insect life cycles. The regulation of JH biosynthesis by neuropeptides and biogenic amines, as well as the transport of JH by specific binding proteins is now well understood. In contrast, comprehending its mode of action on target organs is still hampered by the difficulties in isolating specific receptors. In concert with ecdysteroids, JH orchestrates molting and metamorphosis, and its modulatory function in molting processes has gained it the attribute "status quo" hormone. Whereas the metamorphic role of JH appears to have been widely conserved, its role in reproduction has been subject to many modifications. In many species, JH stimulates vitellogenin synthesis and uptake. In mosquitoes, however, this function has been transferred to ecdysteroids, and JH primes the ecdysteroid response of developing follicles. As reproduction includes a variety of specific behaviors, including migration and diapause, JH has come to function as a master regulator in insect reproduction. The peak of pleiotropy was definitely reached in insects exhibiting facultative polymorphisms. In wing-dimorphic crickets, differential activation of JH esterase determines wing length. The evolution of sociality in Isoptera and Hymenoptera has also extensively relied on JH. In primitively social wasps and bumble bees, JH integrates dominance position with reproductive status. In highly social insects, such as the honey bee, JH has lost its gonadotropic role and now regulates division of labor in the worker caste. Its metamorphic role has been extensively explored in the morphological differentiation of queens and workers, and in the generation of worker polymorphism, such as observed in ants.

Anti-inflammatory and antispasmodic activity of Ipomoea imperati (Vahl) Griseb (Convolvulaceae)

Ipomoea imperati (Convolvulaceae) lives on the sandy shores of the Brazilian coast and in other areas of the world. The anti-inflammatory activity of a methanol-water extract of the leaves of I. imperati was investigated in experimental models of acute and subchronic inflammation. Topical application of the extract (10 mg/ear) inhibited mouse ear edema induced by croton oil (89.0 ± 1.3% by the lipid fraction with an IC50 of 3.97 mg/ear and 57.0 ± 1.3% by the aqueous fraction with an IC50 of 3.5 mg/ear) and arachidonic acid (42.0 ± 2.0% with an IC50 of 4.98 mg/ear and 31.0 ± 2.0% with an IC50 of 4.72 mg/ear). Phospholipase A2, purified from Apis mellifera bee venom, was also inhibited by the extract (5.0 mg/ml lipid and aqueous fraction) in vitro in a dose-dependent manner (85% by the lipid fraction with an IC50 of 3.22 mg/ml and 25% by the aqueous fraction with an IC50 of 3.43 mg/ml). The methanol-water extract of I. imperati (1000 mg/kg) administered by the oral route also inhibited the formation of cotton pellet-induced granulomas (73.2 ± 1.2% by the lipid fraction and 56.14 ± 2.7% by the aqueous fraction) and did not cause gastric mucosal lesions. I. imperati extracts (10 mg/ml) also inhibited in a dose-dependent manner the muscle contractions of guinea pig ileum induced by acetylcholine and histamine (IC50 of 1.60 mg/ml for the lipid fraction and 4.12 mg/ml for the aqueous fraction). These results suggest the use of I. imperati as an anti-inflammatory and antispasmodic agent in traditional medicine.

A protein with amino acid sequence homology to bovine insulin is present in the legume Vigna unguiculata (cowpea)

Since the discovery of bovine insulin in plants, much effort has been devoted to the characterization of these proteins and elucidation of their functions. We report here the isolation of a protein with similar molecular mass and same amino acid sequence to bovine insulin from developing fruits of cowpea (Vigna unguiculata) genotype Epace 10. Insulin was measured by ELISA using an anti-human insulin antibody and was detected both in empty pods and seed coats but not in the embryo. The highest concentrations (about 0.5 ng/µg of protein) of the protein were detected in seed coats at 16 and 18 days after pollination, and the values were 1.6 to 4.0 times higher than those found for isolated pods tested on any day. N-terminal amino acid sequencing of insulin was performed on the protein purified by C4-HPLC. The significance of the presence of insulin in these plant tissues is not fully understood but we speculate that it may be involved in the transport of carbohydrate to the fruit.

Physicochemical analyses indicated to the quality control of royal jelly with honey

Royal jelly (RJ) is used as a revitalizing tonic. In order to avoid rejection to its acid taste, it is added to honey. There are regulations for honey and for royal jelly separately but not for the mixture. The objective of this work is, therefore, to verify if the same methods used for pure honey quality control can be used for honey mixed with royal jelly and also the presence of RJ through 10-HDA determination. The methods used were: moisture, reducing sugars, apparent sucrose, ash, hydroxymethylfurfural, insoluble solids, diastase activity, acidity and 10-HDA. Samples were prepared by adding 0-100% of RJ in honey. The results showed that the ash method was the only suitable one to all the samples. The acidity analysis (direct titration) was suitable to 0-30%RJ samples; the reducing sugar analysis was suitable to 0-20% RJ samples. Concerning moisture analysis the refractometric method is suitable to 0-10% RJ and the Infra Red method is suggested to be used for samples with more than 10% RJ. The methods for diastase activity, HMF, apparent sucrose and insoluble solids were inadequate for all samples with RJ. The presence of RJ in the samples was confirmed by the 10-HDA analyses.

Quality of propolis commercialized in the informal market

The purpose of this research was to evaluate the quality of propolis produced and commercialized informally in São Paulo State through physicochemical analyses of ethanolic extracts of propolis (EEP). Thus, 40 samples of in nature propolis, provided by beekeepers from 32 towns, were analyzed. The EEP were prepared in a proportion of 30% (w/v), and the physicochemical tests were performed according to the Technical Regulation of Propolis Identity and Quality. The pH of each EEP sample was also evaluated. Regarding the dry extract, it was observed that 80% of the samples meet the minimum requirements established by the Brazilian legislation. With regard to the oxidizing property, 67.5% of EEP were below the maximum time allowed for oxidation. With regard to the solubility in lead acetate, 97.5% of the samples showed positive results, whereas no sample produced a negative result in terms of solubility in sodium hydroxide. Regarding the concentration of flavonoids, 95% of the samples produced results consistent with the minimum value allowed, and regarding the phenolic compounds, all samples were in accordance with the legislation. The EEP pH was slightly acidic. Therefore, it can be concluded that most EEP is consistently in accordance with the Brazilian legislation, which suggests that good quality propolis is produced by those beekeepers.

Quality of royal jelly produced by Africanized honeybees fed a supplemented diet

This study was carried out to evaluate the effect of artificial supplements prepared with soybean protein isolate, brewer's yeast, mixture of soybean protein isolate with brewer's yeast, linseed oil, palm oil, and a mixture of linseed oil with palm oil on the physicochemical and microbiological composition of royal jelly produced by Africanized honey bee colonies. Considering these results, providing supplements for Africanized honeybee colonies subjected to royal jelly production can help and strengthen the technological development of the Brazilian beekeeping industry increasing its consumption in the national market. This research presents values of royal jelly a little different from those established by the Brazilian legislation. This fact shows that is important to discuss or change the official method for royal jelly analysis. The characterization of physicochemical and microbiological parameters is important in order to standardize fresh, frozen, and lyophilized royal jelly produced by Africanized honeybees.

Extraction of DNA from honey and its amplification by PCR for botanical identification

The physiochemical and biological properties of honey are directly associated to its floral origin. Some current commonly used methods for identification of botanical origin of honey involve palynological analysis, chromatographic methods, or direct observation of the bee behavior. However, these methods can be less sensitive and time consuming. DNA-based methods have become popular due to their simplicity, quickness, and reliability. The main objective of this research is to introduce a protocol for the extraction of DNA from honey and demonstrate that the molecular analysis of the extracted DNA can be used for its botanical identification. The original CTAB-based protocol for the extraction of DNA from plants was modified and used in the DNA extraction from honey. DNA extraction was carried out from different honey samples with similar results in each replication. The extracted DNA was amplified by PCR using plant specific primers, confirming that the DNA extracted using the modified protocol is of plant origin and has good quality for analysis of PCR products and that it can be used for botanical identification of honey.

Genetic purity certificate in seeds of hybrid maize using molecular markers

One of the main features that confer high quality to the seed is its genetic purity, in which one of the major causes of contamination is the self-pollination of the female parent. Up to date, there is no accurate and fast methods for detecting such contamination. Thus, this work was carried out to certify the genetic purity in seeds of hybrid maize using different biochemical and DNA-based markers. Two single-cross hybrids and their parental lines derived from the maize breeding program at UFLA were evaluated by isoenzymatic pattern of alcohol dehydrogenase (ADH), esterase (EST), acid phosphatase (ACP), glutamate-oxaloacetate transaminase (GOT), malate dehydrogenase (MDH), isocitrate dehydrogenase (IDH), phosphoglucomutase (PGM), 6-phosphoglucomate dehydrogenase (PGDH), catalase (CAT) and ß-glucosidade (ßGLU) and by microsatellites markers. The enzymatic systems that were able to distinguish the hybrids from their parental line were the catalase, the isocitrate dehydrogenase and the esterase. The esterase showed a Mendelian segregation pattern for UFLA 8/3 hybrid, that enables a safer genetic purity certificate. Microsatellites were able to differentiate the hybrid lines and the respective parental lines. Moreover, this technique was fast, precise and without environment effects. For microsatellites, the amplification pattern was identical when young leaves or seeds were used as DNA source. The possibility of using seeds as DNA source would accelerate and facilitate the role process of the genetic purity analysis.

Physiological maturity of eggplant seeds

Determination of seed physiological maturity and ideal moment for harvesting fruits to extract their seeds are important aspects to produce seeds with high quality. To identify the best period for harvesting eggplant fruits, associated with ideal resting period of the fruit for extracting seeds, an eggplant production field was installed in municipality of Ijaci, in the State of Minas Gerais, Southwestern Brazil. The fruits were harvested at periods of 49, 56, 63, 70, and 77 days after pollination (DAP). The seeds of fruits harvested in each period were manually extracted immediately after harvest or after a post-harvest resting period of seven days, under a shed. The physiological quality of seeds was assessed by tests of: germination percentage; germination and emergence speed indexes; and electrical conductivity; which were carried out in the Central Seed Laboratory, Federal University of Lavras. Electrophoretic analyses of isoenzymes: catalase (CAT); esterase (EST); superoxide dismutase (SOD); and peroxidase (PO), were also therein performed. Results of germination and vigor of seeds have showed that the best period for harvesting the fruit is around 70 DAP; and that seeds should be extracted immediately after harvest. Electrophoretic analysis of enzymes has showed immaturity for eggplant seeds, harvested after 49 DAP.