Identification of bioactive peptides from a Brazilian kefir sample, and their anti-Alzheimer potential in Drosophila melanogaster.

Alzheimer's disease (AD) is the most common form of dementia in the elderly, affecting cognitive, intellectual, and motor functions. Different hypotheses explain AD's mechanism, such as the amyloidogenic hypothesis. Moreover, this disease is multifactorial, and several studies have shown that gut dysbiosis and oxidative stress influence its pathogenesis. Knowing that kefir is a probiotic used in therapies to restore dysbiosis and that the bioactive peptides present in it have antioxidant properties, we explored its biotechnological potential as a source of molecules capable of modulating the amyloidogenic pathway and reducing oxidative stress, contributing to the treatment of AD. For that, we used Drosophila melanogaster model for AD (AD-like flies). Identification of bioactive peptides in the kefir sample was made by proteomic and peptidomic analyses, followed by in vitro evaluation of antioxidant and acetylcholinesterase inhibition potential. Flies were treated and their motor performance, brain morphology, and oxidative stress evaluated. Finally, we performed molecular docking between the peptides found and the main pathology-related proteins in the flies. The results showed that the fraction with the higher peptide concentration was positive for the parameters evaluated. In conclusion, these results revealed these kefir peptide-rich fractions have therapeutic potential for AD.

Antioxidant compounds of Kielmeyera coriacea Mart. with α-amylase, lipase and advanced glycation end-product inhibitory activities.

Chronic hyperglycemia and hyperlipidemia are associated with excessive formation of reactive oxygen species and advanced glycation end-products. The present study aimed to evaluate the potential in vitro antidiabetic properties of Kielmeyera coriacea inner bark. The main phytochemical compounds were identified by UHPLC-ESI/MSn and the ethanol extract and its fractions were used to evaluate their antioxidant and anti-glycation capacities, as well as their inhibitory potential against glycoside and lipid hydrolases activities. The polar fractions, especially the n-butanol fraction, had free radical scavenging and quenching properties (ORAC and FRAP values>1800 and 1000 µmol trolox eq/g, respectively, and DPPH IC50<4 µg/mL), and inhibited ROS production (p < 0.01), lipid peroxidation (p < 0.001), glycation (IC50 ~ 10 µg/mL in the BSA-fructose assay; IC50 ~ 200 µg/mL in the BSA-methylglyoxal and arginine-methylglyoxal assays), α-amylase (IC50<0.1 µg/mL) and lipase (IC50<5 µg/mL), with no cytotoxicity. Biomolecules well-known as potent antioxidants were identified for the first time in the inner bark of K. coriacea, such as protocatechuic acid, epicatechin and procyanidins A, B and C. Together, our results support the antioxidant, anti-glycation and glycoside and lipid hydrolases inhibitory properties of the inner bark of K. coriacea, a species found in the Brazilian savanna, which makes it especially useful to combat oxidative stress and hyperglycemia and hyperlipidemia.

Pharmacological investigation of antioxidant and anti-inflammatory activities of leaves and branches extracts from Plinia cauliflora (Jaboticaba).

ETHNOPHARMACOLOGICAL RELEVANCE: Among all native Brazilian plant species, Plinia cauliflora (DC.) Kausel (Jaboticaba), is well known for producing "superfruits", due to their high phenolic content and antioxidant property. The fruit has astringent characteristics, and it is popularly known for the treatment of diarrhea, rash, and intestinal inflammation. However, there are only a few studies on the use of leaves and branches of this species in the literature, mainly to treat oxidative stress and inflammation. AIM OF THE STUDY: The present study aimed to investigate the antioxidant and anti-inflammatory potential of leaves and branches extracts from P. cauliflora. MATERIAL AND METHODS: The phytochemical analysis of P. cauliflora extracts was performed by the total phenolic, flavonoid, and tannin dosage method. Moreover, the compounds were identified by HPLC-MS-Q-TOF. Antioxidant capacity was determined by DPPH, ß-carotene/linoleic acid system, MDA formation, and phosphomolybdenum assays. In vitro and in vivo anti-inflammatory activities of P. cauliflora were evaluated by the reduction of nitric oxide in the J774A.1 cell line and inhibition of ear edema in mice, respectively. RESULTS: The ethanolic extract of the leaves exhibited greater flavonoid content whereas the ethanolic extract of the branches showed higher tannins content. Twenty-two and seventeen compounds were identified by HPLC-MS-Q-TOF in the leaves and branches, respectively, being tellimagrandin I, castalagin, and valoneic acid dilactone reported for the first time in P. cauliflora. The antioxidant potential of extracts was confirmed through different oxidation pathways from oxidizing radicals, which might be related to the presence of phenolic compounds. For the anti-inflammatory assay, the leaves and branches extracts showed promising results, with a reduction of nitric oxide ear edema inhibition around 95% and 80%, respectively. CONCLUSIONS: Herein, the great biological potential of leaves and branches extracts from P. cauliflora was highlighted. These parts of the plant are underused and poorly reported in the literature, especially for the antioxidant and anti-inflammatory activities.

Cell-free DNA promotes malignant transformation in non-tumor cells.

Cell-free DNA is present in different biological fluids and when released by tumor cells may contribute to pro-tumor events such as malignant transformation of cells adjacent to the tumor and metastasis. Thus, this study analyzed the effect of tumor cell-free DNA, isolated from the blood of prostate cancer patients, on non-tumor prostate cell lines (RWPE-1 and PNT-2). To achieve this, we performed cell-free DNA quantification and characterization assays, evaluation of gene and miRNA expression profiling focused on cancer progression and EMT, and metabolomics by mass spectrometry and cellular migration. The results showed that tumor-free cell DNA was able to alter the gene expression of MMP9 and CD44, alter the expression profile of nine miRNAs, and increased the tryptophan consumption and cell migration rates in non-tumor cells. Therefore, tumor cell-free DNA was capable of altering the receptor cell phenotype, triggering events related to malignant transformation in these cells, and can thus be considered a potential target for cancer diagnosis and therapy.

Antidiabetic potential of Bauhinia forficata Link leaves: a non-cytotoxic source of lipase and glycoside hydrolases inhibitors and molecules with antioxidant and antiglycation properties.

Bauhinia forficata Link., a cerrado native plant, is used as a complementary treatment for Type 2 Diabetes Mellitus (T2DM). Several studies involving this plant have shown that it has prominent potential to combat hyperglycemia and oxidative stress. Our objective was suggest the phytochemical constitution of fractions of ethanol extract of B. forficata leaves using HPLC-ESI-MS/MS, and evaluates their activities in enzymatic assays to evaluate their inhibitory potential against α-amylase, α-glucosidase and lipase, as well as their antioxidant and anti-glycation capacities. In addition, we evaluated the cytotoxic effects of these fractions using rodents macrophages and erythrocytes. The ETOAC e ButOH fractions showed high polyphenols concentrations, having been determined 11 flavonoids, including the kaempferitrin, the phytomarker of B. forficata Link. In addition, all fractions presented higher antioxidant and antiglycation activities and prominent capacities to digestive enzymes inhibition. On the other hand, in the cellular assays, none fractions showed cytotoxic and hemolytic effects, able to combat the ROS production in macrophages. Thus, this study presented new results on the biological activities of this plant, contributing to the understanding of the action and effectiveness of its use in the management of diabetes mellitus and its complications.

Annona muricata Linn. leaf as a source of antioxidant compounds with in vitro antidiabetic and inhibitory potential against α-amylase, α-glucosidase, lipase, non-enzymatic glycation and lipid peroxidation.

Annona muricata leaves are used in traditional medicine to manage diabetes mellitus and its complications. The aim of this study was to evaluate the potential in vitro antidiabetic properties of Annona muricata leaf by identifying its main phytochemical constituents and characterizing the phenolic-enriched fractions for their in vitro antioxidant capacity and inhibitory activities against glycoside and lipid hydrolases, advanced glycation end-product formation and lipid peroxidation. Ethanol extract of A. muricata leaf was subjected to a liquid-liquid partitioning and its fractions were used in enzymatic assays to evaluate their inhibitory potential against α-amylase, α-glucosidase and lipase, as well as their antioxidant (DPPH, ORAC, FRAP and Fe2+-ascorbate-induced lipid peroxidation assays) and anti-glycation (BSA-fructose, BSA-methylglyoxal and arginine-methylglyoxal models) capacities. In addition, identification of the main bioactive compounds of A. muricata leaf by HPLC-ESI-MS/MS analysis was carried out. Ethyl acetate (EtOAc) and n-butanol (BuOH) fractions showed, respectively, antioxidant properties (ORAC 3964 ±â€¯53 and 2707 ±â€¯519 µmol trolox eq g-1, FRAP 705 ±â€¯35 and 289 ±â€¯18 µmol trolox eq g-1, and DPPH IC50 4.3 ±â€¯0.7 and 9.3 ±â€¯0.8 µg mL-1) and capacity to reduce liver lipid peroxidation (p < .01). Also, EtOAc and BuOH, respectively, inhibited glycation in BSA-fructose (IC50 45.7 ±â€¯13.5 and 61.9 ±â€¯18.2 µg mL-1), BSA-methylglyoxal (IC50 166.1 ±â€¯21.6 and 413.2 ±â€¯49.5 µg mL-1) and arginine-methylglyoxal (IC50 437.9 ±â€¯89.0 and 1191.0 ±â€¯199.0 µg mL-1) assays, α-amylase (IC50 9.2 ±â€¯2.3 and 6.1 ±â€¯1.6 µg mL-1), α-glucosidase (IC50 413.1 ±â€¯121.1 and 817.4 ±â€¯87.9 µg mL-1) and lipase (IC50 74.2 ±â€¯30.1 and 120.3 ±â€¯50.5 µg.mL-1), and presented lower cytotoxicity, when compared to the other fractions and crude extract. Various biomolecules known as potent antioxidants were identified in these fractions, such as chlorogenic and caffeic acids, procyanidins B2 and C1, (epi)catechin, quercetin, quercetin-hexosides and kaempferol. This study presents new biological activities not yet described for A. muricata, which contributes to the understanding of the potential effectiveness in the use of the A. muricata leaf, especially its polyphenols-enriched fractions, for the management of diabetes mellitus and its complications.