Sustainable biosynthesis of squalene from waste cooking oil by the yeast Yarrowia lipolytica.

Squalene is a highly sought-after triterpene compound in growing demand, and its production offers a promising avenue for circular economy practices. In this study, we applied metabolic engineering principles to enhance squalene production in the nonconventional yeast Yarrowia lipolytica, using waste cooking oil as a substrate. By overexpressing key enzymes in the mevalonate pathway - specifically ERG9 encoding squalene synthase, ERG20 encoding farnesyl diphosphate synthase, and HMGR encoding hydroxy-methyl-glutaryl-CoA reductase - we achieved a yield of 779.9 mg/L of squalene. Further co-overexpression of DGA1, encoding diacylglycerol acyltransferase, and CAT2, encoding carnitine acetyltransferase, in combination with prior metabolic enhancements, boosted squalene production to 1381.4 mg/L in the engineered strain Po1g17. To enhance the supply of the precursor acetyl-CoA and inhibit downstream squalene conversion, we supplemented with 6 g/L pyruvic acid and 0.7 mg/L terbinafine, resulting in an overall squalene titer of 2594.1 mg/L. These advancements underscore the potential for sustainable, large-scale squalene production using Y. lipolytica cell factories, contributing to circular economy initiatives by valorizing waste materials.

The influence of neighborhood built environment on school-age children's outdoor leisure activities and obesity: a case study of Shanghai central city in China.

Objective: The aim of this study was to examine the influencing pathways of the neighborhood built environment on children's outdoor leisure activities and obesity. Methods: A total of 378 elementary school students from 10 schools in central Shanghai were selected by a convenient sampling method for questionnaire survey and accelerometer tracking. Results: 1) The neighborhood built environment could affect children's obesity not only through direct effect (ß = 0.15, p < 0.05), but also through the mediating effect of outdoor leisure activities (ß = 0.19, p < 0.05). 2) For boys, the neighborhood built environment could affect children's obesity not only through direct effect (ß = 0.17, p < 0.05), but also through the mediating effect of outdoor leisure activities (ß = 0.26, p < 0.05). For girls, the neighborhood built environment could affect children's obesity only through the mediating effect of outdoor leisure activities (ß = 0.13, p < 0.05). Conclusion: The neighborhood built environment and outdoor leisure activities are important influencing factors in children's obesity. The neighborhood built environment and outdoor leisure activities could have direct and indirect effects on children's obesity, while there are gender differences in the influencing pathways of the neighborhood built environment on children's obesity. This study suggests that improving the neighborhood built environment and promoting outdoor leisure activities in children have important value for influencing children's obesity.

Inhibition of pancreatic lipase, α-glucosidase, α-amylase, and hypolipidemic effects of the total flavonoids from Nelumbo nucifera leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Nelumbo nucifera Gaertn. leaves have been used as medicinal herbs in the past 1300 years, specifically utilized to cure hyperlipidemia, hyperglycemia, and obesity. It has been recorded in the most famous medicinal book in China for more than 400 years. The present study aims to identify the potential therapeutic activities of the flavonoids isolated from Nelumbo nucifera leaves. MATERIALS AND METHODS: Nelumbo nucifera leaf flavonoids (NLF) were tested for the inhibition of lipase, α-glucosidase, and α-amylase activities in vitro. A single dose of NLF was administered by oral gavage in mice for acute toxicity. Wistar rats with high-fat diet-induced hyperlipidemia and two other animal models were used to evaluate the hypolipidemic effects of NLF. RESULTS: Our in vitro biochemistry tests revealed that the NLF showed high inhibitory activity against porcine pancreatic lipase, α-amylase, and α-glucosidase with IC50 values of 0.38 ± 0.022, 2.20 ± 0.18, and 1.86 ± 0.018 mg/mL, respectively. Furthermore, the NLF significantly lowered the lipid components, such as the total cholesterol, triglycerides, low-density lipoprotein cholesterol, and malondialdehyde, in various established in vivo systems and raised the high-density lipoprotein cholesterol. Moreover, the NLF alleviated high-fat diet-induced lipid accumulation in the liver. CONCLUSIONS: The results demonstrate that NLFs can effectively ameliorate hyperlipidemia and inhibit the key enzymes related to type 2 diabetes mellitus. Our findings may provide new pharmacological basis for the treatment of hyperlipidemia, hyperglycemia, and obesity using NLFs.

Reaction temperature alters chorzoxazone metabolism in carp (Cyprinus carpio) hepatic microsomes.

The study aimed to study the influence of different reaction temperatures on the carp (Cyprinus carpio) hepatic CYPs activity. Six groups of carp hepatic microsomes were incubated with probe drug (chorzoxazone) at 5, 10, 15, 20, 25 and 30°C separately. According to the principle of enzyme kinetics theory, the Michaelis constant (K (m)) value and maximum reaction velocity (V (max)) of CYPs (with CZX as probe) were obtained. The CYPs activity at different reaction temperatures was compared. In results, the K (m) values were separately 44.62, 31.35, 26.59, 21.75, 16.39, 29.69 µM, and the V (max) were separately 0.231, 0.234, 0.265, 0.294, 0.315, 0.239 nmol min(-1)mg(-1) at 5, 10, 15, 20, 25, 30°C. Results indicated that the enzyme CYPs activity was much higher at 25°C. It was also demonstrated that reaction temperature could affect the CYPs activity significantly. Therefore, this experiment builded a theoretical basis for the variations of fish pharmacokinetic parameters at different water temperatures and contributed to further research on the influence of water temperature on fish drug metabolism.

Determination of atractylenolide II in rat plasma by reversed-phase high-performance liquid chromatography.

A method for quantitative determination of atractylenolide II in rat plasma using reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with UV spectrometry was established. From a variety of compounds and solvents tested, atractylenolide III was selected as the internal standard (IS) and ethyl acetate was found to be the best solvent for extracting atractylenolide II from plasma samples. RP-HPLC analysis of the extracts was performed on an analytical column (DIKMA ODS, 150 x 4.6 mm; i.d., 5 microm) equipped with a security guard pre-column system. There was good linearity over the range 0.05-5.0 microg/mL (r > 0.99). The recoveries were more than 90.0% in plasma, and the intra- and inter-day coefficients of variation were less than 10.0% in all cases. The limit of detection (LOD) was 0.025 microg/mL and the lower limit of quantification (LLOQ) was 0.05 microg/mL. The RP-HPLC method was applied to quantitate atractylenolide II in rat plasma within 24 h in a pharmacokinetics study where experimental rats received a single dose of atractylenolide II (60 mg/kg).