Extraction optimization of bioactive compounds from ora-pro-nobis (Pereskia aculeata Miller) leaves and their in vitro antioxidant and antihemolytic activities

High-throughput synchronous erythrocyte cellular antioxidant activity and protection screening of phenolic-rich extracts: Protocol validation and applications

Oxidative/nitrosative damage takes part in chronic disease development, which generates an urgent need for intervention and better therapies to manage them. The scientific community has demanded easy-to-run, cheap, and reliable methods for cellular antioxidant activity assays. This work standardised and validated an erythrocyte cellular antioxidant activity and membrane protection/injury (HERYCA-P) protocol to study food-derive extracts. The method measures intracellular reactive oxygen species (ROS) generation, lipoperoxidation, and haemolysis induced by 2,2'-azobis(2-amidinopropane) dihydrochloride. Quercetin decreased ROS generation by 50.4% and haemolysis by 2.2%, while ascorbic acid inhibited lipid peroxidation by 40.1%. Total phenolic contents of teas were correlated with decreased ROS generation (r = -0.924), lipoperoxidation (r = -0.951), and haemolysis (r = -0.869). The erythrocyte ROS generation and lipoperoxidation were also associated with CUPRAC (r = -0.925; r = -0.951) and hydroxyl radical scavenging activity (r = -0.936; r = -0.949). The precision rates of antioxidant standards and tea samples were below 15%. HERYCA-P is feasible as a complementary antioxidant assay for food matrices.

Macroporous resin purification of phenolics from Irish apple pomace: Chemical characterization, and cellular antioxidant and anti-inflammatory activities

Apple pomace (AP) is a highly prevalent waste product worldwide in the fruit processing sector. This study compared the chemical profile, antioxidant, and anti-inflammatory activities of crude (CE) and an extract purified using XAD-7 resin (PE). The purification process increased the total phenolic content, flavonoids, and tannins by 3.35, 40.31, and 8.87-fold, respectively. The main phenolic compounds identified in PE were phlorizin (20.54 mg/g), chlorogenic acid (10.01 mg/g), and hyperoside (2.77 mg/g). No difference was found between CE and PE in protecting human plasma against oxidation. In human erythrocytes, both CE and PE decreased the reactive oxygen species (ROS) generation and decreased lipoperoxidation. However, PE had stronger anti-inflammatory effects than CE by promoting HO-1 gene expression, suppressing NO production, and inhibiting IL-1β, IL-6, and IL-10 mRNA expression in lipopolysaccharide-challenged RAW.264.7 macrophages. Therefore, purifying apple pomace crude extract is a promising approach to boosting valuable antioxidants and anti-inflammatory phenolics.

Technology Prospection of Ora-pro-Nóbis (Pereskia aculeata Mill.): A Non-conventional Food Plant

BACKGROUND

The ora-pro-nóbis (Pereskia aculeata Mill.) is a plant from Brazilian biodiversity used for food and medicinal purposes. It has ample technological potential, however, it is still underutilized, being classified as a Non-Conventional Food Plant (PANC). Prospective studies in intellectual property banks make it possible to expand perspectives for scientific research, enhancing the generation of new products.

OBJECTIVE

Evaluate the patents of products containing Pereskia aculeata Mill. for the areas of food and health in intellectual property databases.

METHODS

The study was conducted through structured prospective investigation (collection, processing and analysis) in 4 patent databases: National Institute of Intellectual Property (INPI) - Brazil, United States Patent and Trademark Office, World Trade Organization Intellectual Property (WIPO) and Espacenet.

RESULTS

The evaluation showed a reduced number of registered patents. In general, 8 patent applications were examined, of which 7 are directly associated with the species (and its derivatives) and 1 is related to a device specially designed for harvesting leaves/fruits and removing thorns. The focus of the patents was the use of the species in the food, pharmaceutical and biotechnological areas, with emphasis on the use of the leaves in the extraction of mucilage and proteins.

CONCLUSION

This study showed that Pereskia aculeata Mill. is a technologically promising plant, because of its nutritional and medicinal composition, and it is important to encourage innovation and the development of new products with the species.

A Critical Appraisal of the Most Recent Investigations on Ora-Pro-Nobis (Pereskia sp.): Economical, Botanical, Phytochemical, Nutritional, and Ethnopharmacological Aspects

Pereskia aculeata Miller and Pereskia grandfolia Haw, known as 'ora-pro-nobis', are unconventional vegetables belonging to the Cactaceae family, native to the Americas and common in the northeast and southeast regions of Brazil. This review attempts to present a balanced account of both the methods used for obtaining extracts from the diverse parts of the plants and the results that were obtained in terms of their applicability to foods and other products with biological activities. Attention will also be devoted to the properties of their bioactives and their applications to real food products. Methods for obtaining extracts from the diverse parts of the plants will be analyzed, as well as the chemical nature of the bioactives that were hitherto identified. Next, the applicability of ora-pro-nobis in either its integral form or in the form of extracts or other products (mucilages) to the production of food and dietary supplements will be analyzed. The species have been extensively investigated during the last few decades. But, the determination of chemical structures is frequently incomplete and there is a need for new studies on texture determination and color evaluation. Further studies exploring the fruit and flowers of P. aculeata are also required.

Optimization of the Green Chemistry-like Extraction of Phenolic Compounds from Grape (Vitis labrusca L.) and Blackberry (Rubus fruticosus L.) Seeds with Concomitant Biological and Antioxidant Activity Assessments

The objective of this work was to determine the phenolic composition, chemical and cellular antioxidant activity, cytotoxicity in human cells, and peroxidative inhibition of the defatted fraction of grape (Vitis labrusca) and blackberry (Rubus fruticosus) seeds. Soxhlet extraction (Sox) was used to extract the fat and obtain the degreased material. A statistical optimization study was developed to maximize the extraction of bioactive compounds and antioxidant activity from defatted grape and blackberry seeds. Simultaneous optimization was applied with a combination of 35.9 min of extraction and a solid-to-solvent ratio of 1 g of defatted grape seed to 61.28 mL of an extracting solvent (60% ethanol) and 62.1 min of extraction and a solid-to-solvent ratio of 1 g of defatted blackberry seed to 64.1 mL of an extracting solvent (60% ethanol). In the cell viability assay, HepG2 cancer cells seemed more sensitive to grape and blackberry extracts, while Ea.hy926 hybrid cells showed more resistance to their effects. In general, the extracts presented low/no cytotoxicity, exhibited a protective effect against H₂O₂-induced ROS production, and demonstrated antioxidant activity and a protective effect on the erythrocytes when subjected to hypotonic and isotonic conditions not presenting hemolytic behavior (5.0 to 10.0 μg GAE/mL). Thus, the results provided a broad assessment of the bioactivity of the extracts obtained using a simple and low-cost process developed by employing non-toxic solvents and with the potential to be used in technological applications.

Elaboration and Characterization of Pereskia aculeate Miller Extracts Obtained from Multiple Ultrasound-Assisted Extraction Conditions

Pereskia aculeata Miller, is an unconventional food plant native to South America. This study aimed to investigate the influence of different ultrasonic extraction times (10, 20, 30, and 40 min) on the phytochemical profile, antioxidant and antibacterial activities of ethanolic extracts obtained from lyophilized Pereskia aculeate Miller (ora-pro-nobis) leaves, an under-researched plant. Morphological structure and chemical group evaluations were also conducted for the lyophilized P. aculeate leaves. The different extraction times resulted in distinct phenolic content and Antioxidant Activity (ATT) values. Different extraction time conditions resulted in phenolic compound contents ranging from 2.07 to 2.60 mg EAG.g^-1 of extract and different ATT values. The ATT evaluated by DPPH was significantly higher (from 61.20 to 70.20 μM of TE.g^-1 of extract) in extraction times of 30 and 40 min, respectively. For ABTS, it varied between 6.38 and 10.24 μM of TE.g^-1 of extract and 24.34 and 32.12 μM ferrous sulp.g^-1 of extract. All of the obtained extracts inhibited the growth of Staphylococcus aureus, particularly the treatment employing 20 min of extraction at the highest dilution (1.56 mg.mL^-1). Although liquid chromatography analyses showed that chlorogenic acid was the primary compound detected for all extracts, Paper Spray Mass Spectrometry (PS-MS) suggested the extracts contained 53 substances, such as organic, fatty, and phenolic acids, sugars, flavonoids, terpenes, phytosterols, and other components. The PS-MS proved to be a valuable technique to obtain the P. aculeate leaves extract chemical profile. It was observed that the freeze-drying process enhanced the conservation of morphological structures of P. aculeate leaves, as evidenced by scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FTIR) identified carboxyl functional groups and proteins between the 1000 and 1500 cm^-1 bands in the P. aculeate leaves, thus favoring water interaction and contributing to gel formation. To the best of our knowledge, this is the first study to evaluate different times (10, 20, 30 and 40 min) for ultrasound extraction of P. aculeate leaves. The polyphenols improved extraction, and high antioxidant activity demonstrates the potential for applying P. aculeate leaves and their extract as functional ingredients or additives in the food and pharmaceutical industries.

Pereskia aculeata Miller as a Novel Food Source: A Review

Pereskia aculeata Miller is an edible plant species belonging to the Cactaceae family. It has the potential to be used in the food and pharmaceutical industries due to its nutritional characteristics, bioactive compounds, and mucilage content. Pereskia aculeata Miller is native to the Neotropical region, where it is traditionally employed as food in rural communities, being popularly known as 'ora-pro-nobis' (OPN) or the Barbados gooseberry. The leaves of OPN are distinguished by their nontoxicity and nutritional richness, including, on a dry basis, 23% proteins, 31% carbohydrates, 14% minerals, 8% lipids, and 4% soluble dietary fibers, besides vitamins A, C, and E, and phenolic, carotenoid, and flavonoid compounds. The OPN leaves and fruits also contain mucilage composed of arabinogalactan biopolymer that presents technofunctional properties such as thickener, gelling, and emulsifier agent. Moreover, OPN is generally used for pharmacological purposes in Brazilian folk medicine, which has been attributed to its bioactive molecules with metabolic, anti-inflammatory, antioxidant, and antimicrobial properties. Therefore, in the face of the growing research and industrial interests in OPN as a novel food source, the present work reviews its botanical, nutritional, bioactive, and technofunctional properties, which are relevant for the development of healthy and innovative food products and ingredients.

Sustainable and effective approach to recover antioxidant compounds from purple tea (Camellia sinensis var. assamica cv. Zijuan) leaves

Camellia sinensis var. assamica cv. Zijuan (purple tea) is known for its content of anthocyanins, flavan-3-ols, and bioactivities. This study aimed to verify the influence of solvent polarity, in a solid-liquid extraction, on the content of phenolic compounds and chlorophylls, instrumental color, and antioxidant activity. Different proportions of water and ethanol (0:100, 25:75, 50:50, 75:25, and 100:0 v/v) were used for extraction. The results showed that the hydroalcoholic extract (75 % ethanol + 25 % water) had the highest contents of total flavonoids, total anthocyanins, chlorophyll A, and total carotenoids, as well as presenting the highest color intensity, proportion of yellow pigments, and antioxidant activity (total reducing capacity and scavenging of the DPPH free radical). Twenty-two compounds were identified, with chlorogenic acid, hesperidin, (-)-epicatechin, (-)-epigallocatechin gallate, and isoquercitrin being the main phenolics. This phenolic-rich extract inhibited lipoperoxidation induced in egg yolk homogenate (IC₅₀ = 455 mg/L), showed no hemolytic behavior when human erythrocytes were subjected to osmotic stress, and exerted in vitro cytotoxic effects against cancer and hybrid cells. The extract obtained with the mixture of non-toxic solvents presented critical bioactivities, as well as a comprehensive identification of phenolic compounds in the cultivar, and has potential to be used in technological applications.

Influence of Harvest Time on the Chemical Profile of Pereskia aculeate Mill. Using Paper Spray Mass Spectrometry

This study evaluated the physicochemical characteristics and the production of bioactive compounds of Pereskia aculeata Mill. at different harvest times. Here, we performed a qualitative evaluation of the chemical profile by paper spray mass spectrometry (PSMS), the phenolic acid and flavonoid profile by high-performance liquid chromatography (HPLC), antioxidant activity, total carotenoids, total phenolic compounds, total flavonoids, total anthocyanins, color characteristics, total soluble solids (TSS), total solids (TS), pH, and total titratable acidity (TTA). The chemical profile was not affected, with the exception of 4,5-dimethyl-2,6-octadiene and azelaic acid, which was only identified in the leaves harvested during the winter. The content of four phenolic acids and three flavonoids were analyzed; out of these, no significant amounts of ellagic acid and quercetin were detected. There was no difference in production of bioactive compounds between seasons, reflecting the antioxidant activity, which also did not differ. Brightness, chroma, and leaf pH were the only physicochemical characteristics that did not vary between seasons.

Encapsulation and dispersion of Lactobacillus acidophilus in a chocolate coating as a strategy for maintaining cell viability in cereal bars

Flour from Pereskia aculeata leaf and green banana were used as ingredients in the formulation of a cereal bar with added Lactobacillus acidophilus LA02-ID-1688. Encapsulation in a calcium-alginate hydrogel reinforced with magnesium hydroxide was used as a strategy to protect the probiotic cells under gastrointestinal conditions and to prolong shelf-life. The results are relevant especially for maintaining cell viability during shelf-life; a challenge for the food industry in relation to dry probiotic products. Encapsulation promoted the protection of probiotic cells in simulated gastric and intestinal conditions, allowing the maintenance of high viable cell counts (> 10 log CFU, colony forming unit). Encapsulation also contributed to cellular protection under extreme temperature conditions, with reductions of cell viability of < 1 logarithmic cycle when the capsules were subjected to 55ºC/10 min. Even at 75ºC/10 min, encapsulation protected the probiotic cells 3-times greater than the free-cells. The food bar proved to be rich in dietary fiber (19 g 100 g-1), lipids (12.63 g 100 g-1) and showed an appreciable protein content (5.44 g 100 g-1). A high viable probiotic cell count on storage over 120 days (12.54 log CFU) was observed, maintaining a probiotic survival rate > 90% and viability levels sufficient to promote health benefits.