Antiproliferative and cytotoxic effects of purple pitanga (Eugenia unifloraL.) extract on activated hepatic stellate cells

Amazonian Fruits for Treatment of Non-Communicable Diseases

PURPOSE OF REVIEW

The Amazon region has a high biodiversity of flora, with an elevated variety of fruits, such as Camu-Camu (Myrciaria dúbia), Açaí (Euterpe oleracea Mart.), Tucumã (Astrocaryum aculeatum and Astrocaryum vulgare), Fruta-do-conde (Annona squamosa L.), Cupuaçu (Theobroma grandiflorum), Graviola (Annona muricata L.), Guarana (Paullinia cupana Kunth var. sorbilis), and Pitanga (Eugenia uniflora), among many others, that are rich in phytochemicals, minerals and vitamins with prominent antioxidant and anti-inflammatory potential.

RECENT FINDINGS

Studies evaluating the chemical composition of these fruits have observed a high content of nutrients and bioactive compounds. Such components are associated with significant biological effects in treating various non-communicable diseases (NCDs) and related complications. Regular intake of these fruits from Amazonas emerges as a potential therapeutic approach to preventing and treating NCDs as a nutritional strategy to reduce the incidence or mitigate common complications in these patients, which are the leading global causes of death. As studies remain largely unexplored, this narrative review discusses the possible health-beneficial effects for patients with NCDs.

Antiproliferative Cancer Cell and Fungicidal Effects of Yellow and Red Araçá (Psidium cattleianum Sabine) Fruit Extract

Araçá is a native Brazil fruit, and has two morphological types, yellow and red; however, it is still little consumed by the population. Although there are few studies on the araçá fruit, some phytochemical propriety benefits have been described for this plant, such as antioxidant effects. To explore the benefits of araçá fruit, the physicochemical characteristics and in vitro toxicological effects of red and yellow araçá fruit were evaluated. In this work, the toxicity of araçá extracts in NIH/3T3 cell lines, the antiproliferative effects in cancer cell lines (C6, HT-29, and DU149), and the overall antifungal effects were evaluated. The irritant potential of araçá extracts was assessed by the HET-CAM test. The results demonstrated that the fruits are rich in fiber content and showed high phenols content. In addition, the araçá extracts had no present toxicity effects in cell lines; however, the red araçá extracts showed antiproliferative effects in HT-29 cancer cells at 50 mg/mL. The antifungal effects of araçá extract were promising in 23 isolates of Candida spp., and both araçá extracts showed no irritant effects. Therefore, this study demonstrated that red and yellow araçá fruit extract has promising biological and pharmacological effects that should be further explored.

Eugenia uniflora L. seed and pulp extracts: phytochemical profile, cytotoxic potential, antitumoral activity, and α-amylase and α-glucosidase inhibition capacity

In this study, phytochemical profiling, cytotoxic potential, antitumoral activity, and α-amylase and α-glucosidase inhibition capacity of extracts of seed and pulp of Eugenia uniflora L. fruits were investigated. The extracts were obtained using a cellulase complex and the phenolic compounds were quantified. The cytotoxic potential and antitumoral activity were evaluated using peripheral blood mononuclear cells and melanoma-type tumor cells, respectively. The α-amylase and α-glucosidase inhibition capacity was determined. For all extracts, the compounds identified and quantified were salicylic acid, protocatechuic acid, gallic acid and, myricitrin. For extract of pulp, ellagic and p-coumaric acids were also identified and quantified. The extracts do not show cytotoxicity in peripheral blood mononuclear cells. Extract of seed was able to decrease cell viability in melanoma-type tumor cells within 24 h of exposure. The concentration 5 µg mL-1 of extracts inhibited 7.73% of α-amylase and 15.34% of α-glucosidase. The Pitanga extracts presents substances with biological activities.

Synthesis and Characterization of Eugenia uniflora L. Silver Nanoparticles and L-Cysteine Sensor Application

L-Cysteine (Cys) is a non-essential sulfur-containing amino acid, crucial for protein synthesis, detoxification, and several metabolic functions. Cys is widely used in the agricultural, food, cosmetic, and pharmaceutical industries. So, a suitable sensitive and selective sensing approach is of great interest, and a low-cost sensor would be necessary. This article presents silver nanoparticles (EuAgNPs) synthesized by a green synthesis method using Eugenia uniflora L. extracts and photoreduction. The nanoparticles were characterized by UV/VIS, transmission electron microscopy, high-performance liquid chromatography (HPLC), FTIR, and Zeta potential. With the addition of Cys in the EuAgNPs solution, the terminal thiol part of L-cysteine binds on the surface of nanoparticles through Ag-S bond. The EuAgNPs and CysAgNPs coexist until flavonoids bound the amino group of Cys, enhancing the red color of solutions. The EuAgNPs provided selectivity to detect Cys among other amino acids, and its detection limit was found to be 3.8 nM. The sensor has the advantages of low-cost synthesis, fast response, high selectivity, and sensitivity.

Eugenunilones A–H: rearranged sesquiterpenoids from Eugenia uniflora

Six rearranged sesquiterpenoids (1–6) with four types of new polycyclic caged skeletons were isolated from Eugenia uniflora.

Lipid reducing potential of liposomes loaded with ethanolic extract of purple pitanga (Eugenia uniflora) administered to Caenorhabditis elegans

The ethanolic extract obtained from purple pitanga fruit (Eugenia uniflora - PPE) has been previously described by its potential to reduce lipid accumulation in vitro. In this study, we aimed to study this potential in vivo using Caenorhabditis elegans as animal model. Considering the low pH of the extract, its hydrophilic characteristic, its absorption by the medium where the worms are cultivated and the need of a chronic exposure in the worms solid medium, we have loaded liposomes with PPE and investigated its potential for oral administration. Following 48 h exposure to the PPE-loaded liposomes on worms nematode growth medium, we did not observe any toxic effects of the formulation. Under high cholesterol diet, which increased worms total lipid and also triacylglycerides levels, liposomes containing PPE were able to significantly attenuate these alterations, which could not be observed when worms were treated with free PPE. Furthermore, we could evidence that liposomes were ingested by worms through their labelling to uranin fluorescence dye. Through total phenolic compounds quantification, we estimated an entrapment efficacy of PPE into liposomes of 87.7%. The high levels of phenolic compounds present in PPE, as previously described by our group, indicate that these antioxidants may interfere in worms lipid metabolism, which may occur through many and intricated mechanisms. Although the use of conventional liposomes for human consumption may not be pragmatic, its application for oral delivery of a hydrophilic substance in C. elegans was absolutely critical for our experimental design and has proven to be efficient.

Autophagy induced by purple pitanga (Eugenia uniflora L.) extract triggered a cooperative effect on inducing the hepatic stellate cell death

Activated hepatic stellate cells (HSC) are the major source of collagen I in liver fibrosis. Eugenia uniflora L. is a tree species that is widely distributed in South America. E. uniflora L. fruit-popularly known as pitanga-has been shown to exert beneficial properties. Autophagy contributes to the maintenance of cellular homeostasis and survival under stress situation, but it has also been suggested to be an alternative cell death pathway. Mitochondria play a pivotal role on signaling cell death. Mitophagy of damaged mitochondria is an important cell defense mechanism against organelle-mediated cell death signaling. We previously found that purple pitanga extract induced mitochondrial dysfunction, cell cycle arrest, and death by apoptosis and necrosis in GRX cells, a well-established activated HSC line. We evaluated the effects of 72-h treatment with crescent concentrations of purple pitanga extract (5 to 100 μg/mL) on triggering autophagy in GRX cells, as this is an important mechanism to cells under cytotoxic conditions. We found that all treated cells presented an increase in the mRNA expression of autophagy-related protein 7 (ATG7). Concomitantly, flow cytometry and ultrastructural analysis of treated cells revealed an increase of autophagosomes/autolysosomes that consequentially led to an increased mitophagy. As purple pitanga extract was previously found to be broadly cytotoxic to GRX cells, we postulated that autophagy contributes to this scenario, where cell death seems to be an inevitable fate. Altogether, the effectiveness on inducing activated HSC death can make purple pitanga extract a good candidate on treating liver fibrosis.