N-(levodopa) chitosan derivative based on click chemistry shows biological functionality in brain cells.

OBJECTIVE: To develop N-(levodopa) chitosan derivatives through click chemistry to study their effect in brain cells.Significance: This study presents a proof-of-concept that macromolecules such as N-(Levodopa) chitosan derivatives traverse brain cell membranes and induce biomedical functionalities. METHODS: Through click chemistry, we developed N-(levodopa) chitosan derivatives. They were physically and chemically characterized by FT-IR, 1H-NMR, TGA and Dynamic Light Scattering analyses. Solution and nanoparticles of N-(levodopa) chitosan derivatives were tested in primary cell cultures from the postnatal rat olfactory bulb, substantia nigra and corpus callosum. Ca2+ imaging and UPLC experiments were used to investigate if the biomaterial modulated the brain cell physiology. RESULTS: N-(levodopa) chitosan derivatives induced intracellular Ca2+ responses in primary cell cultures of the rat brain. UPLC experiments indicated that levodopa attached to chitosan was converted into dopamine by brain cells. CONCLUSION: The present study shows that N-(levodopa) chitosan may be useful to develop new treatment strategies, which could serve as molecular reservoirs of biomedical drugs to treat degenerative disorders of the nervous system.

Revisiting the high-fat diet/low streptozotocin prediabetic rat model: A bioanalytical adjustment.

Insulin resistance (IR) is the main feature of prediabetes (PD), which ultimately leads to diabetes. High-dose streptozotocin-treated rodents often show irreversible ß-cell mass loss and function, leaving the premorbid diabetic state (PD/IR) unnoticed. This study aimed to re-evaluate the synergistic/independent effect of a sub-chronic consumption (1-5 weeks) of a high-fat diet (60% gross energy from fat, 3.8 kcal.g-1) with [PD/IR-2 (week 2) to PD/IR-5 week five)] or without [HFD-5 (week five)] a single intraperitoneal dose (35 mg.kg-1) of streptozotocin in Wistar rats. Bioassay performance and clinical/histological features suggesting PD/IR or diabetes, were documented weekly and compared to standard chow-fed (3.5 kcal.g-1) rats (healthy controls, HC). PD/IR1-5 (fed with HFD for 1 to 5 weeks plus a single dose of streptozotocin) and HFD-5 (just fed with HFD for 5 weeks) groups reduced their food intake yet gained more body weight than HC. Groups exhibited hyperglycemia, dyslipidemia, and impaired glucose tolerance in decreasing order as follows: PD/IR-5, PD/IR-4, HFD-5, PD/IR-2-3, and HC. Histological disturbances in the pancreas, Soleus muscle, and liver were mostly observed in HFD-5 and PD/IR4-5 groups. HFD administration for 4 weeks white a single moderate dose of streptozotocin four days before sacrifice, leads to a convenient PD/IR rat model.

Lesser-Consumed Tropical Fruits and Their by-Products: Phytochemical Content and Their Antioxidant and Anti-Inflammatory Potential.

Açaí, lychee, mamey, passion fruit and jackfruit are some lesser-consumed tropical fruits due to their low commercial production. In 2018, approximately 6.8 million tons of these fruits were harvested, representing about 6.35% of the total world production of tropical fruits. The present work reviews the nutritional content, profile of bioactive compounds, antioxidant and anti-inflammatory capacity of these fruits and their by-products, and their ability to modulate oxidative stress due to the content of phenolic compounds, carotenoids and dietary fiber. Açaí pulp is an excellent source of anthocyanins (587 mg cyanidin-3-glucoside equivalents/100 g dry weight, dw), mamey pulp is rich in carotenoids (36.12 mg ß-carotene/100 g fresh weight, fw), passion fruit peel is rich in dietary fiber (61.16 g/100 dw). At the same time, jackfruit contains unique compounds such as moracin C, artocarpesin, norartocarpetin and oxyresveratrol. These molecules play an important role in the regulation of inflammation via activation of mitogen-activated protein kinases (including p38, ERK and JNK) and nuclear factor κB pathways. The properties of the bioactive compounds found in these fruits make them a good source for use as food ingredients for nutritional purposes or alternative therapies. Research is needed to confirm their health benefits that can increase their marketability, which can benefit the primary producers, processing industries (particularly smaller ones) and the final consumer, while an integral use of their by-products will allow their incorporation into the circular bioeconomy.

Mango "Ataulfo" Peel Extract Improves Metabolic Dysregulation in Prediabetic Wistar Rats.

The hypoglycemic effect of functional phytochemicals has been evaluated in diabetic rodents but scarcely in its premorbid condition (prediabetes; PD). This study aimed to evaluate a mango (cv. Ataulfo) peel hydroethanolic (20:80) extract (MPE) for in vivo glycemic/lipidemic-normalizing effect and in vitro enzyme inhibitory (α-amylase/α-glucosidase) activity. The polyphenolic MPE (138 mg EAG.g−1, mainly gallic acid and mangiferin) with antioxidant capacity (DPPH• 34 mgTE.g−1) was fed to PD rats (induction: high-fat diet (60% energy) + single dose streptozotocin (35 mg·kg−1), 4 weeks). At the 8th week, fasting glycemia (FG), oral glucose tolerance test, and insulin sensitivity indexes (HOMA-IR, HOMA-ß) > blood lipid-normalizing effect were documented as healthy controls > MPE > disease (PD) controls, which was possibly related to the extract's concentration−response in vitro enzyme inhibitory activity (IC50 ≈ 0.085 mg·mL−1). MPE is a rich source of glucose-lowering phytochemicals for the primary prevention of type 2 diabetes.

Formulation and characterization of an optimized functional beverage from hibiscus (Hibiscus sabdariffa L.) and green tea (Camellia sinensis L.).

Hibiscus sabdariffa and Camellia sinensis are traditionally consumed as beverages and are good sources of health-promoting phenolic compounds. The objective of this work was to use response surface methodology to develop an optimized functional beverage with high total phenolic content, antioxidant capacity, and acceptable for potential consumers. Optimum infusion conditions were 4.9 g of hibiscus calyces or C. sinensis leaves/100 ml of water at 26 ℃ for 291 min. These conditions yielded a total phenolic content of 14.80 ± 1.4 and 33.02 ± 0.34 mg gallic acid equivalents/100 ml for hibiscus and green tea, respectively. The optimized beverages were combined in a 7:3 (hibiscus:green tea, v/v) ratio; a consumer preference test showed that this combination had an acceptable taste according to untrained panelists. A chromatographic analysis showed that this formulation contained flavonoids, phenolic acids, and anthocyanins as its main components. Our data suggested that hibiscus and green tea phenolic compounds were efficiently extracted using near-ambient temperature water for prolonged times, contrary to routine methods (high temperature, short time). Our method also preserved antioxidant capacity, possibly by avoiding chemical changes/degradation due to high temperatures. This process can be used to produce organoleptically acceptable functional beverages that deliver a varied phenolic compound profile to the consumer.