Characterization and evaluation of potential halotolerant phosphate solubilizing bacteria from Salicornia fruticosa rhizosphere.

Soil salinization is a significant abiotic factor threatening agricultural production, while the low availability of phosphorus (P) in plants is another worldwide limitation. Approximately 95-99% of the P in soil is unavailable to plants. Phosphate-solubilizing bacteria (PSB) transform insoluble phosphates into soluble forms that plants can utilize. The application of PSB can replace or partially reduce the use of P fertilizers. Therefore, selecting bacteria with high solubilization capacity from extreme environments, such as saline soils, becomes crucial. This study aimed to identify twenty-nine bacterial strains from the rhizosphere of Salicornia fruticosa by sequencing the 16S rDNA gene, evaluate their development in increasing concentrations of NaCl, classify them according to their salinity response, and determine their P solubilization capability. The bacteria were cultivated in nutrient agar medium with NaCl concentrations ranging from 0.5% to 30%. The phosphate solubilization capacity of the bacteria was evaluated in angar and broth National Botanical Research Institute (NBRIP) media supplemented with calcium phosphate (CaHPO4) and aluminum phosphate (AlPO4), and increased with 3% NaCl. All bacterial strains were classified as halotolerant and identified to the genera Bacillus, Enterobacter, Halomonas, Kushneria, Oceanobacillus, Pantoea, Pseudomonas, and Staphylococcus, with only one isolate was not identified. The isolates with the highest ability to solubilize phosphorus from CaHPO4 in the liquid medium were Kushneria sp. (SS102) and Enterobacter sp. (SS186), with 989.53 and 956.37 mg·Kg-1 P content and final pH of 4.1 and 3.9, respectively. For the solubilization of AlPO4, the most effective isolates were Bacillus sp. (SS89) and Oceanobacillus sp. (SS94), which raised soluble P by 61.10 and 45.82 mg·Kg-1 and final pH of 2.9 and 3.6, respectively. These bacteria demonstrated promising results in in vitro P solubilization and can present potential for the development of bioinput. Further analyses, involving different phosphate sources and the composition of produced organic acids, will be conducted to contribute to a comprehensive understanding of their applications in sustainable agriculture.

Benefits and risks associated with consumption of raw, cooked, and canned tuna (Thunnus spp.) based on the bioaccessibility of selenium and methylmercury.

The Se, Hg, and methylmercury (MeHg) levels in raw, cooked (boiled and grilled), and canned tuna (Thunnus spp.) were determined before and after an in vitro digestion, thereby enabling the calculation of the respective bioaccessibility percentages. A risk-benefit evaluation of raw and canned tuna on the basis of the Se and MeHg data was performed. Selenium bioaccessibility was high in tuna, though slightly lower in canned than in raw products. Mercury levels were high in raw and cooked tuna. Hg bioaccessibility percentages were low (39-48%) in the cooked tuna and even lower (<20%) in canned tuna. For the bioaccessible fraction, all molar Se:MeHg ratios were higher than one (between 10 and 74). A probabilistic assessment of MeHg risk vs Se benefit showed that while a weekly meal of canned tuna presents very low risk, raw, boiled, and grilled tuna consumption should not exceed a monthly meal, at least, for pregnant and nursing women.

Evaluation of the risk/benefit associated to the consumption of raw and cooked farmed meagre based on the bioaccessibility of selenium, eicosapentaenoic acid and docosahexaenoic acid, total mercury, and methylmercury determined by an in vitro digestion model.

The bioaccessibility of total lipids, EPA, DHA, Se, Hg, and MeHg in raw and cooked meagre (Argyrosomus regius) was studied by using an in vitro digestion method. A risk-benefit assessment of raw and cooked meagre on the basis of the bioaccessibility data was carried out. The bioaccessibility of total lipids was generally high in raw and cooked meagre with exception of grilled fish. For EPA and DHA, bioaccessibility percentages were low never surpassing the 50% in raw, boiled, and grilled meagre. The bioaccessibility percentage of Se was equal or higher than 82% (grilling treatment). Likewise, for Hg and MeHg, high bioaccessibility values were determined with exception of grilled meagre, displaying lower values of 54% and 64%, respectively. The risk-benefit probabilistic assessment brought about a recommendation of a maximum consumption of two weekly meals for boiled or roasted meagre and three weekly meals for grilled meagre.

Influence of oily vehicles on fetal testis and lipid profile of rats exposed to di-butyl phthalate.

It has been hypothesized that oils containing high levels of omega-3 polyunsaturated fatty acids, such as canola and fish oil, could counteract some of the adverse effects induced by phthalates. In the present study, the influence of different oily vehicles on di-butyl phthalate (DBP)-induced testicular toxicity and lipid profile was investigated. Pregnant Wistar rats were treated by oral gavage from gestation days 13 to 20 with DBP (500 mg/kg/day) diluted in three different vehicles: corn, canola or fish oil. Male fetuses were analyzed on gestation day 20. DBP exposure lowered intratesticular testosterone levels and anogenital distance, regardless of the vehicle used. The percentage of seminiferous cords containing multinucleated gonocytes and cord diameter was increased in DBP-exposed groups, compared with vehicle controls, with no difference between the three DBP-exposed groups. Clustering of Leydig cells was seen in all DBP groups. Lipid profile indicated that administration of canola and fish oil can increase the content of omega-3 fatty acids in rat testis. However, content of omega-3 was diminished in DBP-treated groups. Overall, our results indicate that different oily vehicles did not alter fetal rat testicular toxicity induced by a high DBP dose.

Tumor growth reduction is regulated at the gene level in Walker 256 tumor-bearing rats supplemented with fish oil rich in EPA and DHA.

We investigated the effect of fish oil (FO) supplementation on tumor growth, cyclooxygenase 2 (COX-2), peroxisome proliferator-activated receptor gamma (PPARγ), and RelA gene and protein expression in Walker 256 tumor-bearing rats. Male Wistar rats (70 days old) were fed with regular chow (group W) or chow supplemented with 1 g/kg body weight FO daily (group WFO) until they reached 100 days of age. Both groups were then inoculated with a suspension of Walker 256 ascitic tumor cells (3 × 10(7) cells/mL). After 14 days the rats were killed, total RNA was isolated from the tumor tissue, and relative mRNA expression was measured using the 2(-ΔΔCT) method. FO significantly decreased tumor growth (W=13.18 ± 1.58 vs WFO=5.40 ± 0.88 g, P<0.05). FO supplementation also resulted in a significant decrease in COX-2 (W=100.1 ± 1.62 vs WFO=59.39 ± 5.53, P<0.001) and PPARγ (W=100.4 ± 1.04 vs WFO=88.22 ± 1.46, P<0.05) protein expression. Relative mRNA expression was W=1.06 ± 0.022 vs WFO=0.31 ± 0.04 (P<0.001) for COX-2, W=1.08 ± 0.02 vs WFO=0.52 ± 0.08 (P<0.001) for PPARγ, and W=1.04 ± 0.02 vs WFO=0.82 ± 0.04 (P<0.05) for RelA. FO reduced tumor growth by attenuating inflammatory gene expression associated with carcinogenesis.

Tumor growth reduction is regulated at the gene level in Walker 256 tumor-bearing rats supplemented with fish oil rich in EPA and DHA

We investigated the effect of fish oil (FO) supplementation on tumor growth, cyclooxygenase 2 (COX-2), peroxisome proliferator-activated receptor gamma (PPARγ), and RelA gene and protein expression in Walker 256 tumor-bearing rats. Male Wistar rats (70 days old) were fed with regular chow (group W) or chow supplemented with 1 g/kg body weight FO daily (group WFO) until they reached 100 days of age. Both groups were then inoculated with a suspension of Walker 256 ascitic tumor cells (3×107 cells/mL). After 14 days the rats were killed, total RNA was isolated from the tumor tissue, and relative mRNA expression was measured using the 2-ΔΔCT method. FO significantly decreased tumor growth (W=13.18±1.58 vs WFO=5.40±0.88 g, P<0.05). FO supplementation also resulted in a significant decrease in COX-2 (W=100.1±1.62 vs WFO=59.39±5.53, P<0.001) and PPARγ (W=100.4±1.04 vs WFO=88.22±1.46, P<0.05) protein expression. Relative mRNA expression was W=1.06±0.022 vs WFO=0.31±0.04 (P<0.001) for COX-2, W=1.08±0.02 vs WFO=0.52±0.08 (P<0.001) for PPARγ, and W=1.04±0.02 vs WFO=0.82±0.04 (P<0.05) for RelA. FO reduced tumor growth by attenuating inflammatory gene expression associated with carcinogenesis.

In vitro and in vivo Leishmanicidal activity of 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone (lapachol).

This study aims to evaluate the in vitro and in vivo leishmanicidal activity of lapachol, a naphthoquinone found in the seeds and heartwood of certain tropical plants, and to compare its efficacy with a reference drug, sodium stibogluconate (Pentostam(R)). These compounds (0.0125-4.0 mg/mL) were evaluated in vitro against intracellular amastigotes of Leishmania (Viannia) braziliensis (LVb), then tested in an animal model (hamster) to try to reproduce the leishmanicidal activity. In vitro, lapachol exhibited an anti-amastigote effect, whereas in vivo it did not prevent the development of LVb-induced lesions at an oral dose of 300 mg/kg/day for 42 days. Pentostam(R) demonstrated a significant anti-amastigote effect in vitro for LVb and apparent clinical cure in vivo (60 mg/kg/day). However, it could not completely eradicate parasites from the tissues of infected animals. The observation that lapachol exerts leishmanicidal activity in vitro without offering significant protection against LVb-infected lesions in hamsters suggests that lapachol in vivo might possibly inhibit the microbicidal functioning of macrophages. Alternatively, it might be transformed into an inactive metabolite(s) or neutralized, losing its leishmanicidal activity. It is also possible that an optimal and sustained plasma level of the drug could not be achieved at the dose used in this study.