Probiotic Yogurt Supplemented with Lactococcus lactis R7 and Red Guava Extract: Bioaccessibility of Phenolic Compounds and Influence in Antioxidant Activity and Action of Alpha-amylase and Alpha-glucosidase Enzymes

The industry has increasingly explored the development of foods with functional properties, where supplementation with probiotics and bioactive compounds has gained prominence. In this context, the study aimed to evaluate the influence of in vitro biological digestion on the content of phenolic compounds, antioxidant activity, and inhibition of α-amylase and α-glucosidase activities of probiotic yogurt supplemented with the lactic acid bacteria Lactococcus lactis R7 and red guava extract (Psidium cattleianum). A yogurt containing L. lactis R7 (0.1%) and red guava extract (4%) was characterized for the content of phenolic compounds, antioxidant activity, and potential for inhibition of digestive enzymes after a simulated in vitro digestion process. After digestion, the caffeic and hydroxybenzoic acids remained, and sinapic acid only in the last digestive phase. Antioxidant activity decreased during digestion by 28.93, 53.60, and 27.97% for DPPH, nitric oxide and hydroxyl radicals, respectively, and the inhibition of the α-amylase enzyme decreased only 4.01% after the digestion process. α-glucosidase was more efficient in intestinal digestion, demonstrating an increase of almost 50% in probiotic yogurt with red guava extract before digestion. Possibly, the phenolics change their conformation during digestion, generating new compounds, reducing antioxidant activity, and increasing the inhibitory activity of α-glucosidase digestive enzymes. It was concluded that the probiotic yogurt formulation supplemented with red guava extract could interfere with the concentration of phenolic compounds and the formation of new compounds, suggesting a positive and effective inhibition of the digestive enzymes, even after the digestive process.

Corrigendum: Essential oils of Psidium cattleianum Sabine leaves and flowers: anti-inflammatory and cytotoxic activities

[This corrects the article DOI: 10.3389/fchem.2023.1120432.].

Essential oils of Psidium cattleianum Sabine leaves and flowers: Anti-inflammatory and cytotoxic activities

Introduction: Psidium cattleianum Sabine is a Brazilian native shrub cultivated for its edible fruit araçá (strawberry guava). P. cattleianum is recognized for health and food applications, although the essential oils (EOs) from the Egyptian inhabitant are not fully explored. The current study investigated the anti-inflammatory and cytotoxic activities of EOs from P. cattleianum leaves and flowers. Materials and methods: The EOs were obtained by three different methods viz; the conventional hydro-distillation, microwave assisted hydro-distillation, and supercritical fluid extraction, while their analysis was accomplished using GC/MS. The derived EOs were screened for their anti-inflammatory activity in the 5-lipoxygenase, COX-1, and COX-2 enzyme based assays, while the anticancer potential was deduced from MTT cytotoxic assay, cell cycle, and western blotting analysis. Results and discussion: Among other methods, supercritical fluid extraction offered the highest EO yield, 0.62% (leaves) and 1.4% (flowers). GC/MS identified β-caryophyllene and α-humulene in both organs with high but variable percentages. The leaves demonstrated strong activity in inhibiting the 5-lipoxygenase enzyme (IC50 2.38), while the flowers, in inhibiting COX-2 (IC50 2.575). Moreover, the leaves showed potent, selective cytotoxicity to MCF-7 cells (IC50 5.32) via apoptosis by modulating the p53/Bax/Bcl2 axis. The deduced activities are possible due to the synergism between the volatile components that endorses P. cattleianum leaves' EOs in the management of breast cancer and inflammatory disorders.

An Integrative Review on the Main Flavonoids Found in Some Species of the Myrtaceae Family: Phytochemical Characterization, Health Benefits and Development of Products

This integrative review aims to identify the main flavonoids present in some species of the Myrtaceae family. Studies published between 2016 and 2022 were selected, specifically those which were fully available and written in Portuguese, English, or Spanish, and which were related to the fruits araçá (Psidium cattleianum), cambuí (Myrciaria floribunda), gabiroba (Campomanesia xanthocarpa), jabuticaba (Plinia cauliflora), and jambolan (Syzygium cumini). Scientific studies were gathered and selected in Google Scholar, Scielo, and Science Direct indexed databases, out of which 14 were about araçá, 7 concerned cambuí, 4 were about gabiroba, 29 were related to jabuticaba, and 33 concerned jambolan, when we observed the pre-established inclusion criteria. Results showed that the anthocyanins, such as cyanidin, petunidin, malvidin, and delphinidin, were the mostly identified class of flavonoids in plants of the Myrtaceae family, mainly relating to the purple/reddish color of the evaluated fruits. Other compounds, such as catechin, epicatechin, quercetin, and rutin were also identified in different constituent fractions, such as leaves, peel, pulp, seeds, and in developed products, such as jams, desserts, wines, teas, and other beverages. It is also worth noting the positive health effects verified in these studies, such as anti-inflammatory qualities for jambolan, antidiabetic qualities for gabiroba, antioxidant qualities for araçá, and cardioprotective actions for jabuticaba, which are related to the presence of these phytochemicals. Therefore, it is possible to point out that flavonoids are important compounds in the chemical constitution of the studied plants of the Myrtaceae family, with promising potential in the development of new products by the food, chemical, and pharmaceutical industries due to their bioactive properties.

Antidepressant-like effect and phenolic profile of Brazilian native and exotic species from Psidium genus

Depression is one of the disorders involving mental health that most affects the population worldwide. Considering the available pharmacological therapies for the treatment of depression are ineffective in most patients, the search for new alternatives is crucial. In line with this, we investigated the phenolic profile, antidepressant-like, and antioxidant effects triggered by the administration of aqueous extracts from Psidium guajava L. (GUA), Psidium cattleianum Sw. (CAT), and Psidium guineense Sabine (GUI) leaves in mice. Our results show that quercetin is the major compound of GUA and GUI, and o-coumaric acid in CAT extracts. The acute and subchronic administrations of the three plant extracts exerted an antidepressant-like effect in mice exposed to the tail suspension test, without changes on locomotor performance evaluated by the open field test. Furthermore, the GUI and CAT decreased oxidative stress markers, mainly lipid peroxidation and nitrites in the hippocampus, prefrontal cortex, liver, and plasma. Notably, GUA and CAT increased non-protein thiols in all tissues. Therefore, the Psidium extracts demonstrated an antidepressant-like effect in mice, and the antioxidant capacity of the extracts seems to underlie the behavioral effect.

Aboveground carbon accumulation by second-growth forests after deforestation in Hawai'i

Successional processes ultimately determine and define carbon accumulations in forested ecosystems. Although primary succession on wholly new substrate occurs across the globe, secondary succession, often following storm events or anthropogenic disturbance, is more common and is capable of globally significant accumulations of carbon (C) at a time when offsets to anthropogenic carbon dioxide (CO₂ ) emissions are critically needed. In Hawai'i, prior studies have investigated ecosystem development during primary succession on lava flows, including estimates of C mass accumulation. Yet relatively little is known regarding secondary succession of Hawaii's native forests, particularly regarding C mass accumulation. Here we documented aboveground C mass accumulation by native- and nonnative-dominated second-growth forests following deforestation of mature native lowland rainforests in the Puna District of Hawai'i Island. We characterized species composition and stand structure of three distinct successional forest stand types: those dominated by the native tree, Metrosideros polymorpha ('Ōhi'a), and those dominated by invasive nonnative trees, Falcataria moluccana (albizia) and Psidium cattleianum (strawberry guava). We compared M. polymorpha-dominated and F. moluccana-dominated second-growth forests to adjacent mature M. polymorpha-dominated forests as well as young M. polymorpha-dominated forests undergoing initial stages of primary succession on 36-years-old lava fields. Aboveground carbon density (ACD) values of mature primary forest stands (171 Mg/ha) were comparable to those of mature continental tropical forests. M. polymorpha-dominated second-growth stands attained nearly 50% of ACD values of mature primary forests after less than 30 years of post-disturbance succession and exhibited aboveground carbon accumulation rates of ~3 Mg C·ha^-1 ·year^-1 . Such rates were comparable to those of second-growth forests in continental tropics. Rates of ACD accumulation by second-growth forests dominated by nonnative F. moluccana stands were similar, or slightly greater than, those of M. polymorpha-dominated stands. However, M. polymorpha individuals were virtually absent from stands dominated by either P. cattleianum or F. moluccana. Taken together, results demonstrated that re-establishment and rapid accumulation of C mass by M. polymorpha stands during secondary succession is certainly possible, but only where populations of nonnative species have not already colonized areas during early stages of secondary succession.

Cattleianal and Cattleianone: Two New Meroterpenoids from Psidium cattleianum Leaves and Their Selective Antiproliferative Action against Human Carcinoma Cells

The Myrteacae family is known as a rich source of phloroglucinols, a group of secondary metabolites with notable biological activities. Leaves of Psidium cattleianum were extracted with chloroform: methanol 8:2 to target the isolation of phloroglucinol derivatives. Isolated compounds were characterized using different spectroscopic methods: nuclear magnetic resonance (NMR), ultra-violet (UV) and mass spectrometry (MS). Two new phloroglucinols were evaluated for cytotoxicity against a panel of six human cancer cell lines, namely colorectal adenocarcinoma cells (HT-29 and HCT-116); hepatocellular carcinoma cells (HepG-2); laryngeal carcinoma (Hep-2); breast adenocarcinoma cells (MCF7 and MDA-MB231), in addition to normal human melanocytes HFB-4. Additionally, cell cycle analysis and annexin-V/FITC-staining were used to gain insights into the mechanism of action of the isolated compounds. The new phloroglucinol meroterpenoids, designated cattleianal and cattleianone, showed selective antiproliferative action against HT-29 cells with IC₅₀’s of 35.2 and 32.1 μM, respectively. Results obtained using cell cycle analysis and annexin-V/FITC-staining implicated both necrosis and apoptosis pathways in the selective cytotoxicity of cattleianal and cattleianone. Our findings suggest that both compounds are selective antiproliferative agents and support further mechanistic studies for phloroglucinol meroterpenoids as scaffolds for developing new selective chemotherapeutic agents.

Red araçá pulp microencapsulation by hydrolyzed pinhão starch, and tara and arabic gums

BACKGROUND

Red araçá is a Brazilian native species whose fruits are rich in phenolic acids, flavonoids, anthocyanins, and carotenoids. To preserve the properties of compounds during processing, red araçá pulp (RAP) was encapsulated by hydrolyzed pinhão starch (PS), tara gum (TG), and arabic gum (AG) in different blends in equal proportions, serving as a coating material.

RESULTS

Fresh RAP had a gallic acid equivalent of 3098 mg per 100 g of dry weight, 156.29 μg β-carotene per gram of dry weight, total anthocyanins of 18 mg per 100 g of dry weight and exhibited high antioxidant activity. The highest encapsulation efficiency achieved with the PS, TG, and AG blend was 80.4% for the total carotenoids, and that for the total anthocyanins was 76% with the TG and AG blend. Only one step of antioxidant activity degradation was identified, and the carrier system PSTG was efficient at maintaining the antioxidant activity, with half-life of 23.60-37.27 days.

CONCLUSION

The use of PS alone as a coating material or associated with TG and AG gums resulted in improved retention of bioactive compounds, these being an excellent alternative coating material since they improved the stability of the antioxidant activity of RAP. © 2020 Society of Chemical Industry.

Berries grown in Brazil: anthocyanin profiles and biological properties

BACKGROUND

Phytochemical profiles of two Brazilian native fruits - pitanga (red and purple) and araçá (yellow and red) - as well as strawberry cultivars Albion, Aromas and Camarosa, blackberry cultivar Tupy and blueberry cultivar Bluegen cultivated in Brazil were characterized for total phenolic content and total anthocyanin content by liquid chromatography coupled to a photodiode array and a quadrupole time-of-flight mass spectrometer. Radical scavenging, antiherpes and cytotoxic activities of these berry extracts were also evaluated.

RESULTS

Blueberry presented the highest total anthocyanin content (1202 mg cyanidin-O-glucoside equivalents kg^-1 fresh fruit), while strawberry cultivar Aromas presented the highest total phenolic content (13 550 mg gallic acid equivalents kg^-1 fresh fruit). Liquid chromatographic-mass spectrometric analysis resulted in the identification of 21 anthocyanins. To the best of our knowledge this is the first report of cyanidin-O-glucoside in yellow and red Araçá fruit and the first time eight anthocyanins have been reported in pitanga fruits. DPPH and ABTS assays showed that blueberry cultivar Bluegen, blackberry cultivar Tupy and pitanga (red and purple) showed the most promising antiradical activities, respectively. No relevant cytotoxicity against three cancer cell lines or antiherpes activity was detected under the experimental conditions tested.

CONCLUSION

Total anthocyanin content of all fruits had a strong positive correlation with their free radical scavenging activity, suggesting anthocyanins contribute to the antioxidant potential of these fruits. © 2018 Society of Chemical Industry.

Antioxidant, antihyperglycemic, and antidyslipidemic effects of Brazilian-native fruit extracts in an animal model of insulin resistance

Objective: Insulin resistance (IR) plays an important role in the development of many diseases, such as diabetes mellitus. Therefore, the aim of the present study was to evaluate the effects of the extracts from fruits native to Brazil on metabolic parameters and hepatic oxidative markers in an animal model of insulin resistance induced by dexamethasone (DEX).

Methods: Wistar rats received water or extracts of Eugenia uniflora or Psidium cattleianum, once a day for 21 days. For the last 5 days, the rats received an intraperitoneal injection of saline or DEX.

Results: DEX caused a reduction in body weight gain and relative pancreatic weight, as well as glucose intolerance, and an increase in serum glucose and triacylglycerol levels. The extracts were found to prevent hyperglycemia and hypertriglyceridemia. DEX caused an increase in the levels of thiobarbituric acid-reactive substances and reactive oxygen species production in the liver of rats, and both extracts prevented these changes. In addition, hepatic glutathione peroxidase activity was reduced by DEX. However, total thiol content and activities of catalase, superoxide dismutase, and delta-aminolevulinate dehydratase were not altered in any of the tested groups.

Conclusion: Fruit extracts of E. uniflora and P. cattleianum exhibited considerable antihyperglycemic, antidyslipidemic, and antioxidant effects, and may be useful in the therapeutic management of alterations due to IR.

Gradients of metabolite accumulation and redifferentiation of nutritive cells associated with vascular tissues in galls induced by sucking insects

Plant cells respond to abiotic and biotic stimuli, which generate adaptive phenotypes in plant organs. In the case of plant galls, cell phenotypes are adaptive for the gall inducer and assume characteristics mainly linked to its protection and nutrition. Herein, the cytological development and histochemical profile of Nothotrioza cattleiani galls, a sucking insect, on the leaves of Psidium cattleianum are compared with those of other galls, especially N. myrtoidis galls, searching for conserved and divergent alterations in cell fates and cycles. Leaf cell fates are completely changed within galls, except for epidermal cells, but the comparison between Nothotrioza spp. galls shows conserved fates. Nevertheless, cytological development of N. cattleiani galls is different from the standby-redifferentiation of N. myrtoidis galls. Starch and lignins, and reducing sugars form centrifugal and centripetal gradients of accumulation, respectively. Proteins, total phenolics, terpenoids, proanthocyanidins and reactive oxygen species are detected in bidirectional gradients, i.e. weak or undetectable reaction in the median cortical cells that is gradually more intense in the cell layers towards the inner and outer surfaces of the gall. True nutritive cells associated with vascular tissues, together with the bidirectional gradients of metabolite accumulation, are herein reported for the first time in insect galls. The globoid galls of N. cattleiani, though macro-morphologically similar to the galls of N. myrtoidis, are distinct and unique among insect galls, as far as the cellular, subcellular and histochemical traits are concerned. Thus, the traits of the galls on P. cattleianum studied herein represent the extended phenotypes of their inducers.

Comparative analysis of aroma compounds and sensorial features of strawberry and lemon guavas (Psidium cattleianum Sabine)

The aroma of strawberry and lemon guava fruits (Psidium cattleianum Sabine) was studied by sensory analysis, gas chromatography-olfactometry (GC-O) and quantitative analysis. Volatiles released from the pulps were collected in a trapping system consisting of LiChrolut EN resins and eluted with dichloromethane/methanol. In total, 23 odour zones were detected by GC-O, of which 16 were found in the extract from the strawberry guava pulp and 17 in the extract from the lemon guava pulp. Among the compounds identified, only 10 were common to both strawberry and lemon guavas. The descriptive sensorial analysis differentiated between the aroma profiles of the strawberry guava pulp with the descriptor "tomato" and the lemon guava pulp with the descriptor "tropical fruit". The typical aroma of the guava fruits was dominated by the presence of numerous aldehydes and ketones among which (Z)-3-hexenal was the most intense odorant, while 1,8-cineole and linalool were also revealed as important aroma constituents.