Pitanga (Eugenia uniflora L.) as a source of bioactive compounds for health benefits: A review

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.

Microencapsulation to Harness the Antimicrobial Potential of Essential Oils and Their Applicability in Dairy Products: A Comprehensive Review of the Literature

This literature review explores cutting-edge microencapsulation techniques designed to enhance the antimicrobial efficacy of essential oils in dairy products. As consumer demand for natural preservatives rises, understanding the latest advancements in microencapsulation becomes crucial for improving the shelf life and safety of these products. The bibliometric analysis utilized in this review highlighted a large number of documents published on this topic in relation to the following keywords: essential oils, AND antimicrobials, AND dairy products, OR microencapsulation. The documents published in the last 11 years, between 2013 and 2023, showed a diversity of authors and countries researching this topic and the keywords commonly used. However, in the literature consulted, no study was identified that was based on bibliometric analysis and that critically evaluated the microencapsulation of essential oils and their antimicrobial potential in dairy products. This review synthesizes findings from diverse studies, shedding light on the various encapsulation methods employed and their impact on preserving the quality of dairy goods. Additionally, it discusses the potential applications and challenges associated with implementation in the dairy industry. This comprehensive analysis aims to provide valuable insights for researchers, food scientists, and industry professionals seeking to optimize the use of essential oils with antimicrobial properties in dairy formulations.

ESI(-)FT-ICR MS for the determination of best conditions for producing extract abundant in phenolic compounds from leaves of E. uniflora and FTIR-PCA as a sample screening method

E. uniflora leaves are a rich source of phenolic compounds with biological activities, including myricitrin. In this study, the chemical profile of nine extracts prepared with leaves collected in three regions (mountain, beach, and mangrove) and at three different times of the day (8 am, 1 pm, and 6 pm) was evaluated from spectra originating from ultra-high resolution mass spectrometry (Fourier transform ion cyclotron resonance, FT-ICR) coupled to electrospray ionisation (ESI). The best time of the day and location for collecting the leaves of E. uniflora used as raw materials for producing extracts and the best ethanol concentration for obtaining an extract more abundant in compounds of interest were verified. Several flavonoids and phenolic acids were detected in their deprotonated form in the regions from m/z 200 to 1200. Myricitrin ([C21H20O12-H]-, m/ztheo 463.08820), its chloride adduct ([C21H20O12+Cl]-, m/ztheo 499.06488), other myricitrin derivatives, and some tannins were the main compounds detected. Considering obtaining an extract rich in phenolic compounds, including myricitrin, the best place and time of the day to collect E. uniflora leaves is in the beach region at 1 pm. In contrast, the best ethanol concentration for extract production is 70 wt%. Therefore, extraction at 96 wt% ethanol is better for obtaining an extract more abundant in phenolic acids, although 70 wt% ethanol also extracted these compounds. FTIR-PCA models were used to check for possible similarities in the data according to collection time of the day and location. These models demonstrated an excellent solution for sample screening.

Improving the Properties of Gelatin-Based Films by Incorporation of "Pitanga" Leaf Extract and Crystalline Nanocellulose

Biopolymer-based films can be activated by the incorporation of active compounds into their matrix. Plant extracts are rich in phenolic compounds, which have antimicrobial and/or antioxidant properties. The aim of this study was to produce gelatin-based active films and nanocomposite films incorporated with "pitanga" (Eugenia uniflora L.) leaf extract (PLE) and/or crystalline nanocellulose extracted from soybean straw (CN), and to study the physicochemical, functional, microstructural, thermal, UV/Vis light barrier, and antioxidant properties of these materials. PLE enhanced some film properties, such as tensile strength (from 30.2 MPa to 40.6 MPa), elastic modulus (from 9.3 MPa to 11.3 MPa), the UV/Vis light barrier, and antioxidant activity, in addition to affecting the microstructural, surface, and color properties. These improvements were even more significant in nanocomposites simultaneously containing PLE and CN (59.5 MPa for tensile strength and 15.1 MPa for elastic modulus), and these composites also had lower moisture content (12.2% compared to 13.5-14.4% for other treatments) and solubility in water (from 48.9% to 44.1%). These improvements may be the result of interactions that occur between PLE's polyphenols and gelatin, mainly in the presence of CN, probably due to the formation of a stable PLE-CN-gelatin complex. These results are relevant for the food packaging sector, as the activated nanocomposite films exhibited enhanced active, barrier, and mechanical properties due to the presence of PLE and CN, in addition to being entirely produced with sustainable components from natural and renewable sources.

Biocultural heritage of the Caatinga: a systematic review of Myrtaceae and its multiple uses

The Caatinga, an exclusively Brazilian biome, stands as a reservoir of remarkable biodiversity. Its significance transcends ecological dimensions, given the direct reliance of the local population on its resources for sustenance and healthcare. While Myrtaceae, a pivotal botanical family within the Brazilian flora, has been extensively explored for its medicinal and nutritional attributes, scant attention has been directed towards its contextual relevance within the Caatinga's local communities. Consequently, this inaugural systematic review addresses the ethnobotanical roles of Myrtaceae within the Caatinga, meticulously anchored in the PRISMA 2020 guidelines. We searched Scopus, MEDLINE/Pubmed, Scielo, and LILIACS. No date-range filter was applied. An initial pool of 203 articles was carefully scrutinized, ultimately yielding 31 pertinent ethnobotanical studies elucidating the utility of Myrtaceae amongst the Caatinga's indigenous populations. Collectively, they revealed seven distinct utilization categories spanning ~54 species and 11 genera. Psidium and Eugenia were the genera with the most applications. The most cited categories of use were food (27 species) and medicinal (22 species). The importance of accurate species identification was highlighted, as many studies did not provide enough information for reliable identification. Additionally, the potential contribution of Myrtaceae fruits to food security and human health was explored. The diversity of uses demonstrates how this family is a valuable resource for local communities, providing sources of food, medicine, energy, and construction materials. This systematic review also highlights the need for more ethnobotanical studies to understand fully the relevance of Myrtaceae species in the Caatinga, promoting biodiversity conservation, as well as support for local populations.

Purple pitanga extract (Eugenia uniflora) attenuates oxidative stress induced by MPTP

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been widely used due to its specific and reproducible neurotoxic effect on the nigrostriatal system, being considered a convenient model of dopaminergic neurodegeneration to study interventions therapeutics. The purple pitanga (Eugenia uniflora) is a polyphenol-rich fruit with antioxidant and antidepressant properties, among others. Therefore, this study investigated the effect of purple pitanga extract (PPE) on acute early oxidative stress induced by intranasal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration in rats. Male Wistar rats were pre-treated orally with PPE (1000 mg/kg) or vehicle. After 24 h, MPTP (0.1 mg/10µL/nostril) or vehicle was administered bilaterally into the animal's nostrils, and 6 h later, the olfactory bulb (OB), striatum (ST), and substantia nigra (SN) were collected to evaluate the oxidative stress parameters. Our findings revealed that OB and SN were the most affected areas after 6 h of MPTP infusion; an early increase in reactive oxygen species (ROS) levels was observed, while pretreatment with a single dose of PPE prevented this increment. No differences in thiobarbituric acid reactive species (TBARS) and 3-nitrotyrosine (3-NT) formation were observed, although 4-hydroxy-2-nonenal (4-HNE) levels increased, which is the most toxic form of lipid peroxidation, in the MPTP group. The PPE pretreatment could prevent this increase by increasing the NPSH levels previously decreased by MPTP. Furthermore, PPE prevents the Na+/K + ATPase strongly inhibited by MPTP, showing the neuroprotective capacity of the PPE by inhibiting the MPTP-generated oxidation. Thus, we demonstrated for the first time the antioxidant and neuroprotective effects of PPE against the early MPTP neurotoxicity.

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.

Neuroprotective effect of Eugenia uniflora against intranasal MPTP-induced memory impairments in rats: The involvement of pro-BDNF/p75NTR pathway

Parkinson's disease is a multisystemic neurodegenerative disorder that includes motor and non-motor symptoms, and common symptoms include memory loss and learning difficulties. Thus, we investigated the neuroprotective potential of a hydroalcoholic extract of Brazilian purple cherry (Eugenia uniflora) (HAE-BC) on memory impairments induced by intranasal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration in rats and the involvement of hippocampal BDNF/TrkB/p75^NTR pathway in its effects. Adult male Wistar rats were exposed to MPTP (1 mg/nostril) or vehicle. Twenty-four hours later, the HAE-BC treatments began at doses of 300 or 2000 mg/kg/day or vehicle for 14 days. From 7 days after the MPTP induction, the animals were subjected to behavioral tests to evaluate several cognitive paradigms. HAE-BC treatments, at both doses, blocked the MPTP-caused disruption in the social recognition memory, short- and long-term object recognition memories, and working memory. Furthermore, MPTP-induced motor deficit linked to striatal tyrosine hydroxylase levels decreased, which was blocked by HAE-BC. Our findings demonstrated that HAE-BC blocked the MPTP-induced increase in the hippocampal pro-BDNF, TrkB.t1, and p75^NTR levels. The pro-BDNF/p75^NTR interaction negatively regulates synaptic transmission and plasticity, and the neuroprotective effect of HAE-BC was related, at least partly, to the modulation of this hippocampal signaling pathway. Thus, our study reports the first evidence of the potential therapeutic of E. uniflora in a Parkinson's disease model in rodents.

Safety Investigations of Two Formulations for Vaginal Use Obtained from Eugenia uniflora L. Leaves in Female Rats

Medicinal plants have great prominence in research into the development of new medicines. Eugenia uniflora L. (Myrtaceae) is an edible and medicinal plant with economic value in the northeast region of Brazil. Several preparations from E. uniflora leaves and its fruits are employed as a source of nutrients and bioactive compounds. In this study we evaluated the preclinical toxicology of crude extract and vaginal gel obtained from the leaves of E. uniflora (5%, 10%, and 15%) aiming to provide safety for its use in the treatment of vulvovaginitis. Both formulations were applied to the vaginal cavity for 14 days. Detailed observations of the vaginal region, including pruritus, swelling, irritation, burning, pain, and vaginal secretion, as well as the estrous cycle were evaluated. On the fifth day, blood samples were obtained from the supraorbital plexus for biochemical and hematological analyses. The animals were subsequently euthanized. All animals underwent necropsy and macroscopic examination of the vaginal mucosa and reproductive system. A histological examination was also performed. No clinically significant changes were detected during the entire experimental period. All biochemical, hematological, or histopathological parameters were within the normal range for the species. The data obtained allow us to suggest that the E. uniflora vaginal formulations are safe in this experimental model.

Safety evaluation of aqueous extract from Eugenia uniflora leaves: Acute and subacute toxicity and genotoxicity in vivo assays

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia uniflora Linn (Myrtaceae) is the native species of Brazil. The leaves of this species are used in folk medicine to treat different inflammatory and gastrointestinal disorders. However, research on the safety of using E. uniflora leaves has been poorly explored.

AIM OF THE STUDY

This approach aims to investigate the phytochemical composition as well as the acute, subacute toxicity, and in vivo genotoxic profile of the aqueous extract of E. uniflora leaves.

MATERIALS AND METHODS

The chemical composition of E. uniflora leaf extract was determined by Fingerprint by High-Performance Thin Layer and High-Performance Liquid Chromatography. The acute toxicity in vivo was evaluated for 14 days after the administration of E. uniflora leaves extract (2000 mg/kg). For the evaluation of subacute toxicity, mice were daily treated for 28 days with E. uniflora extract (250, 500, or 1000 mg/kg). Signs of behavioral toxicity and biochemical and hematological alterations, including the multiple organ toxicities were investigated. In addition, the micronucleus assay was used to evaluate the in vivo genotoxicity of the leaves extract in murine erythrocytes.

RESULTS

The phytochemical analysis showed the majority presence of phenolic compounds (gallic acid, ellagic acid, and myricitrin). Single or repeated doses of the aqueous extract of E. uniflora leaves did not reveal any signs of in vivo toxicity. Daily doses of the extract for 28 days induced a slight reduction in cholesterol and triglyceride levels. Furthermore, E. uniflora leaves extract (1000-2000 mg/kg) showed no genetic damage in the micronucleus assay, indicating the absence of genotoxicity of the herbal species.

CONCLUSION

The aqueous extract of E. uniflora leaves showed a predominance of phenolic compounds, with non-toxic and non-genotoxic action in vivo. This approach sheds light on the chemical composition of the leaves of E. uniflora and suggests a high margin of safety in the popular use of the leaves of this plant species.