Bioactive compounds, antioxidant capacity and antitumoral activity of ethanolic extracts from fruits and seeds of Eugenia involucrata DC

Emerging berries from the Brazilian Amazon and Atlantic Forest biomes: new sources of bioactive compounds with potential health benefits

Brazil has a broad geographic biodiversity spread across its six different biomes. However, it has been suffering from the abusive exploitation of its resources, which poses a threat to the local fauna and flora. The Amazon and Atlantic Forest, for example, are birthplaces to rare and edible native species, such as bacaba (Oenocarpus bacaba, Arecaceae) and camu-camu (Myrciaria dubia, Myrtaceae), and cereja-do-Rio Grande (Eugenia involucrata, Myrtaceae) and grumixama (Eugenia brasiliensis, Myrtaceae), respectively. These plants produce fruits which are sources of macro and micronutrients, including sugars, dietary fibers, vitamins, minerals, and/or lipids. Nutritionally, their consumption have the ability to reach partially or totally the daily recommendations for adults of some nutrients. More recently, these fruits have also been exposed as interesting sources of minor bioactive compounds, such as carotenoids, terpenes, and/or polyphenols, the latter which include anthocyanins, phenolic acids, and tannins. Particularly, bacaba stands out for being a rich source of polyunsaturated fatty acids (around 22%, dry weight) and dietary fibers (6.5-21%, dry weight); camu-camu has very high contents of vitamin C (up to 5000 mg per 100 g of pulp, dry basis); and cereja-do-Rio-Grande and grumixama are abundant sources of anthocyanins. Although they are still underexplored, several in vitro and in vivo studies with different parts of the fruits, including the peel, seed, and pulp, indicate their health potential through anti-oxidative, anti-obesity, antihyperglycemic, antidyslipidemic, antimicrobial, and/or anticancer effects. All things considered, the focus of this research was to highlight the bioactive potential and health impact of native fruits from the Amazon and Atlantic Forest biomes.

Ripening stage impacts nutritional components, antiglycemic potential, digestibility and antioxidant properties of grumixama (Eugenia brasiliensis Lam.) fruit

This study aimed to determine the nutritional components (macronutrients ans minerals) and α-amylase inhibition capacity of freeze-dried grumixama (Eugenia brasiliensis Lam) seeds (S) and pulp/peel (P) portions, at ripe and mid-ripe stages. In vitro digestion was also performed on S and P from grumixama to assess the bioaccessibility of total phenolic compound (TPC), flavonoids (TFC), and anthocyanins (TAC), as well as to examine their impact on antioxidant activity (DPPH, ABTS, FRAP). The ripening process impacts the bioactive compounds and individual phenolics of S and P portions. The ripe S was source of myricetin and exhibited higher antioxidant activity, while mid-ripe S was high in flavonoids and cinnamic acid with higher antiglycemic potential. Ripe P showed higher soluble fiber, carbohydrate, TAC, and caffeic acid content, whereas mid-ripe P had increased mineral content (calcium, potassium, manganese), catechin, and TPC. After in vitro digestion, the P portion showed a bioaccessibility of total phenolic content (TPC) and total flavonoid content (TFC) exceeding 40% at intestinal phase. In contrast, the S portions had better release of TPC and TFC and antioxidant activity at gastric phase. Considering the outstanding nutritional and biological properties of grumixama fruit, freeze-dried S and P portions from both ripening stages possess could be explored as valuable sources of nutrients and antioxidant compounds.

Piranhea trifoliata extracts ameliorate muscular decline in Drosophila melanogaster exposed to Paraquat

In this study, we have demonstrated, for the first time, the muscular protective effects of Piranhea trifoliata bark extract against Paraquat (PQ)-induced oxidative stress in Drosophila melanogaster. Exposure of D. melanogaster (Canton Special) to PQ caused oxidative stress, as evidenced by protein carbonyl and elevated acetylcholinesterase (AChE) activity levels. However, a diet supplemented with the P. trifoliata extracts (0.1 mg/ml) for 10 days ameliorates protein carbonyl levels and enzymatic activities of AChE and citrate synthase to prevent PQ damage. Also, P. trifoliata bark extracts showed in phytochemical assays the presence of phenols, at 46.06 mg EAG/g extract of total phenolic compounds, and a 40% 2,2-diphenyl-1-picryl-hydrazyl scavenging effect. The study showed the muscular protective function of the P. trifoliata extracts in D. melanogaster exposed to PQ. On the basis of the results, we contemplate that the bark of P. trifoliata might prevent and ameliorate human diseases caused by oxidative stress. The muscular action of the P. trifoliata extract can be attributed to the antioxidant constituents, while the precise mechanism of its action needs further investigation.

Bioactive Activities of the Phenolic Extract from Sterile Bracts of Araucaria angustifolia

Sterile bracts can represent 80% of Araucaria angustifolia pinecone and are a rich source of phenolic compounds. This study aimed to optimize the extraction of the phenolic compounds from Araucaria angustifolia bracts using response surface methodology; the bioactivity properties were also investigated. The effects of the ethanol concentration, solute/solvent ratio, and temperature in relation to the phenolic composition and antioxidant activity were evaluated. The quantification and identification of the individual phenolic compounds (using high-performance liquid chromatography) and their bioactivity were evaluated. The optimized extraction conditions, which detected gallic acid, catechin, epicatechin, quercetin, and kaempferol, were obtained using 60% ethanol at a ratio of 1:38 (w/v) and a temperature of 80 °C. The extract showed high levels of phenolic classes and antioxidant activity. The extract also showed an inhibitory activity for pathogenic (approximately 80%, 10,000 µg/mL) and lactic acid (27.9%, 15,000 µg/mL) bacteria strains. The α-glucosidase inhibitory activity was approximately ten times greater than acarbose, demonstrating its high antiglycemic potential. No antioxidant and anti-inflammatory cellular activity were determined; however, a high cytotoxicity for non-tumor cells and the antiproliferative activity against the tumor cells were observed. Overall, the phenolic extract showed promising action in relation to the fight against the diseases related to oxidative stress and, hopefully, the application of the safe concentrations of the extract, based on bioavailability assays, can be verified.

Active Biomolecules from Vegetable Extracts with Antitumoral Activity against Pancreas Cancer: A Systematic Review (2011-2021)

The emergence of resistance to pancreatic cancer (PC) current treatment requires the development of new therapeutic strategies. In this context, bioactive molecules from plant extracts have shown excellent properties to improve classical therapy against this type of tumor. This systematic review aims to collect all the in vitro studies related to the antiproliferative activity of isolated plant molecules that support their applicability in PC. A total of 620 articles published in the last 10 years were identified, although only 28 were finally included to meet the inclusion criteria. Our results reflect the most important biomolecules from natural compounds that induce cell death in PC and their essential mechanism of cell death, including apoptosis, pathways activated by the KRAS mutation and cycle cell arrest, among others. These in vitro studies provide an excellent molecule guide showing applications against PC and that should be tested in vivo and in clinical trials to determine their usefulness to reduce PC incidence and to improve the prognosis of these patients. However, natural compounds are isolated in small amounts, which prevents comprehensive drug screening, being necessary the role of organic synthesis for the total synthesis of natural compounds or for the synthesis of their simplified and bioactive analogs.

Bioactive Compounds and Antioxidant Properties with Involved Mechanisms of Eugenia involucrata DC Fruits

In this study, the phytochemical profile and the antioxidative properties of Eugenia involucrata fruits were evaluated. Spectrophotometric assays indicated that these berries are a rich source of polyphenols with very high radical-scavenging and metal-reducing activities. High-performance liquid chromatography–Orbitrap analysis was able to carry out the annotation of 36 different compounds, mainly belonging to the flavonol, flavan-3-ol, and anthocyanin families. Antioxidant activity of the fruit extract was evaluated in a cell-based lipid peroxidation model. Obtained data showed that the extract, at very low concentration, was able to prevent oxidative damage in HepG2 cells exposed to oxidative stimuli. Moreover, the evaluation of the gene expression of the most important antioxidant enzymes suggested that the observed antioxidant protection in cells also involves an improvement in enzymatic antioxidant defenses. Finally, the collected data show that E. involucrata fruits are a good source of natural antioxidant molecules and provide evidence of their potential application in the nutraceutical field.

Neuroprotective Effects of Quercetin on Ischemic Stroke: A Literature Review

Ischemic stroke (IS) is characterized by high recurrence and disability; however, its therapies are very limited. As one of the effective methods of treating acute attacks of IS, intravenous thrombolysis has a clear time window. Quercetin, a flavonoid widely found in vegetables and fruits, inhibits immune cells from secreting inflammatory cytokines, thereby reducing platelet aggregation and limiting inflammatory thrombosis. In pre-clinical studies, it has been shown to exhibit neuroprotective effects in patients with ischemic brain injury. However, its specific mechanism of action remains unknown. Therefore, this review aims to use published data to elucidate the potential value of quercetin in patients with ischemic brain injury. This article also reviews the plant sources, pharmacological effects, and metabolic processes of quercetin in vivo, thus focusing on its mechanism in inhibiting immune cell activation and inflammatory thrombosis as well as promoting neuroprotection against ischemic brain injury.