Characterization of physicochemical properties, flavor volatiles and phenolic compounds of feijoa fruit varieties

Thirteen varieties of feijoa (Feijoa sellowiana) fruit were collected and the physical and chemical properties of feijoa peel, flesh, seed, and leaf were analyzed. Large diversities in the physicochemical characteristics and phenolic and volatile composition among various parts and between different varieties of feijoa were observed. Degrees Brix of whole fruits ranged from 10.1 (Anatoki) to 18.0 (No. 2) °Brix. Procyanidin B-type tetramer, procyanidin B-type dimer, and procyanidin C-type trimer had the highest concentrations in all parts and varieties of feijoa. Caffeoyl glucose, dihydroferulic acid 4-O-glucuronide, galloyl glucose, and lariciresinol-sesquilignan were detected in feijoa fruits and leaves. A total of 105 esters, 68 terpenes, 20 alcohols, 31 hydrocarbons, 12 aldehydes, and 11 ketones were related to aromatic attributes of fruits and leaves. Early season and mid-season varieties had larger variations in the chemical properties than late-season varieties. Anatoki, Kakariki, and No.1, have the potential to be developed for attractive flavor and functional properties.

Anti-inflammatory and anti-nociceptive activities of polyphenols from Feijoa fruit and leaves

Many pharmacological activities have been reported from plants polyphenols. The aim of this study was to investigate anti inflammatory and antinociceptive activities of polyphenols from Feijoa sellowiana fruit and leaves. For the anti-inflammatory activity evaluation, inhibition of carrageenan induced edema was used. While for the evaluation of antinociceptive activity of the extract, writhing and hot plate tests in mice were used. Impairment in mouse coordination was evaluated by rota-rode test. Carrageenan induced edema was significantly inhibited by the extract at 50-400 mg kg^-1 doses, when comparison was made with control group. The extract of leaf at the dose of 50 mg kg^-1 i.p. the activity was equipotent with diclofenac (p>0.05). Extract reduced the writhing count in 50-400 mg kg^-1 of doses. Fruit extract showed higher activity than diclofenac (p<0.001) at 400 mg kg^-1 doses. In all tested doses, the extract significantly augmented the pain threshold in hot plate thermal test. No locomotor impairment in mice was induced by the extract at any tested doses. Extract was safe and didnot demonstrate any noxiousness up to 1 g kg^-1 .This study indicates the potential therapeutic use of Feijoa as a potent anti-inflammatory and antinociceptive agent.

Fighting multidrug resistance with a fruit extract: anti-cancer and anti-biofilm activities of Acca sellowiana

In this study, the efficacy of Acca sellowiana fruit acetonic extract on human MDR cancer cells was tested for the first time, and it was demonstrated that the fruit extract is effective on both sensitive and resistant tumor cells. The effects of A. sellowiana extract on bacterial biofilm were also examined for the first time. By crystal violet assays and confocal microscopy analyses, it was demonstrated that the plant extract is able to strongly inhibit biofilm formation of both sensitive and resistant bacterial strains. Furthermore, antimicrobial activity assays and TEM analyses clearly demonstrated the effectiveness of plant extract on planktonic bacterial cells in both sensitive and resistant strains. Altogether, these findings intriguingly expand the panel of activities of A. sellowiana fruit extract with respect to previous reports, and open interesting perspectives to its therapeutic applications.

Feijoa [Acca sellowiana (Berg) Burret] accessions characterization and discrimination by chemometrics

BACKGROUND

Feijoa [Acca sellowiana (Berg) Burret] is a Brazilian native fruit with few commercial-level plantations and high agroindustrial potential. A genotype evaluation experiment was conducted from 1996 onward, aiming to obtain fruits based on the agronomical parameters; however, the selection based on chemical composition had not been evaluated with respect to developing a new cultivar. Accordingly, the present study aimed to discriminate seven accessions of feijoa in terms of nutritional composition, phenolic compounds and antioxidant activity using multivariate analysis (principal component analysis and multivariate contrast), targeting the potential production of a new cultivar with better nutritional value and high antioxidant capacity.

RESULTS

Feijoa husk presented high content of ashes, lipids, proteins, carbohydrates, phenolic compounds and antioxidant activity compared to feijoa pulp. However, only feijoa pulp was selected to multivariate analysis because it is the fruit edible part. Data variability was explained in 78% and the feijoa pulp accessions were discriminated into four groups related to their characteristics. The accession 5 discrimination can be explained by the high content of ashes, carbohydrates, soluble solids, phenolic compounds and antioxidant activity. Accession 6 was also discriminated by the high content of total acidity, pH and proteins, as well as a low content of soluble solids.

CONCLUSION

Feijoa accessions may be indicated for increasing plant selection via hybridization with the other accessions, aiming to produce new cultivars with better nutritional composition and antioxidant capacity. For example, accession 5 is the most suited fruit for human consumption and is a potential plant with respect to becoming a new cultivar. © 2020 Society of Chemical Industry.

Characterization of Polysaccharides from Feijoa Fruits ( Acca sellowiana Berg.) and Their Utilization as Growth Substrates by Gut Commensal Bacteroides Species

Polysaccharides from feijoa fruit were extracted and analyzed; the composition of these polysaccharides conforms to those typically found in the primary cell walls of eudicotyledons. The two major polysaccharide extracts consisted of mainly pectic polysaccharides and hemicellulosic polysaccharides [xyloglucan (77%) and arabinoxylan (16%)]. A collection of commensal Bacteroides species was screened for growth in culture using these polysaccharide preparations and placed into five categories based on their preference for each substrate. Most of the species tested could utilize the pectic polysaccharides, but growth on the hemicellulose was more limited. Constituent sugar and glycosyl linkage analysis showed that species that grew on the hemicellulose fraction showed differences in their preference for the two polysaccharides in this preparation. Our data demonstrate that the members of the genus Bacteroides show differential hydrolysis of pectic polysaccharides, xyloglucan, and arabinoxylan, which might influence the structure and metabolic activities of the microbiota in the human gut.

Screening of Cytotoxicity and Anti-Inflammatory Properties of Feijoa Extracts Using Genetically Modified Cell Models Targeting TLR2, TLR4 and NOD2 Pathways, and the Implication for Inflammatory Bowel Disease

Feijoa has been increasingly studied in the recent decade, while investigations into its bioactivities including anti-inflammatory activity are lacking. In this article, the cytotoxicity and anti-inflammatory properties of feijoa extracts, from flesh, peel and whole fruit, from four cultivars namely APOLLO, UNIQUE, OPAL STAR and WIKI TU are presented. Three inflammatory pathways, Toll-like receptor 2 (TLR2), TLR4 and nucleotide-binding oligomerization domain-containing protein 2 (NOD2), were investigated using genetically modified cell models namely HEK-Blue™ hTLR2, HEK-Blue™ hTLR4, NOD2-WT and NOD2-G908R. Results show that feijoa peel extract induced higher cytotoxicity than flesh and whole fruit extracts, and the APOLLO cultivar was the most anti-inflammatory among the four tested cultivars. The anti-inflammatory activity of feijoa flesh was detected only through the TLR2 pathway, and the activity of feijoa peel and whole fruit was evident mainly through the TLR2 and NOD2 pathways. Most notably, feijoa anti-inflammatory activity was superior to ibuprofen particularly through the TLR2 pathway, with significantly lower secreted embryonic alkaline phosphatase IC50 concentrations (7.88, 12.81, 30.84 and 442.90 μg/mL for APOLLO flesh, peel, whole fruit extract and ibuprofen respectively). These findings indicate that feijoa has great potential to be used in the treatment and prevention of inflammation-related diseases including inflammatory bowel disease.

Bioactivity-Guided Metabolite Profiling of Feijoa ( Acca sellowiana) Cultivars Identifies 4-Cyclopentene-1,3-dione as a Potent Antifungal Inhibitor of Chitin Synthesis

Pathogenic fungi continue to develop resistance against current antifungal drugs. To explore the potential of agricultural waste products as a source of novel antifungal compounds, we obtained an unbiased GC-MS profile of 151 compounds from 16 commercial and experimental cultivars of feijoa peels. Multivariate analysis correlated 93% of the compound profiles with antifungal bioactivities. Of the 18 compounds that significantly correlated with antifungal activity, 5 had not previously been described from feijoa. Two novel cultivars were the most bioactive, and the compound 4-cyclopentene-1,3-dione, detected in these cultivars, was potently antifungal (IC₅₀ = 1-2 μM) against human-pathogenic Candida species. Haploinsufficiency and fluorescence microscopy analyses determined that the synthesis of chitin, a fungal-cell-wall polysaccharide, was the target of 4-cyclopentene-1,3-dione. This fungal-specific mechanism was consistent with a 22-70-fold reduction in antibacterial activity. Overall, we identified the agricultural waste product of specific cultivars of feijoa peels as a source of potential high-value antifungal compounds.

The effects of Feijoa sellowiana fruits on the antioxidant defense system, lipid peroxidation, and tissue morphology in rats

CONTEXT

The fruits of Feijoa sellowiana Berg. (Myrtaceae) have been used to treat goiter in traditional Turkish medicine.

OBJECTIVE

To evaluate the in vivo antioxidant activities of different polarities of the fruit extracts in blood and tissue (liver, kidney, brain, and heart) antioxidant defense systems in standard pellet diet and in high fat diet consumed, male rats were assessed.

MATERIALS AND METHODS

The extracts (methanol, n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous) were administered orally to male rats at 50 mg/kg doses daily for 4 weeks. The blood and tissue malondialdehyde (MDA), reduced glutathione (GSH) levels, plasma nitrate (NO(x)) level, total triiodothyronine (T3), thyroxine, cholesterol, triglyceride, protein, and glucose levels were determined, and erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities; plasma antioxidant activity (AOA) were experimentally studied.

RESULTS

Blood MDA level (7.81 ± 0.4) was significantly decreased; GSH level (29.65 ± 1.21) and AOA (1.52 ± 0.08) were increased in ethyl acetate extract as compared with control and the other extracts. In addition, all the extracts decreased MDA levels and increased GSH levels (except brain tissue homogenate) in the tissue homogenates. Erythrocyte SOD and CAT activity levels were unchanged in F. sellowiana extracts. However, the extracts had no effect on plasma NO(x). In the histopathological examinations, any changes or damage in the vital organs were seen in animals.

CONCLUSION

The experimental data demonstrated that F. sellowiana extracts displayed remarkable antioxidant activity and decreased lipid peroxidation in rats; furthermore, no histopathological changes or damage have been observed in the vital organs of rats.

Bone mineralization enhancing activity of a methoxyellagic acid glucoside from a Feijoa sellowiana leaf extract

The capability of an aqueous methanol extract obtained from the leaves of Feijoa sellowiana Berg. on possible prevention and treatment of osteoporosis has been examined by evaluating its stimulating effect on the two human osteoblastic cell lines HOS58 and SaOS-2. The extract was found to increase significantly the mineralization of cultivated human bone cell, whereby a clear increment (15.3 +/- 2.7%) in von Kossa positive area was determined when administering 25 microg/ml leaf extract. A phytochemical investigation of the extract has demonstrated the high phenolic content and led to the isolation and identification of twenty three of them, among which the new 3-methoxyellagic acid 4-O-beta-glucopyranoside was fully identified. All structures were elucidated on the basis of conventional analytical methods and confirmed by FTMS, 1D- and 2D-NMR data. The new compound was found to cause a significant increase of mineralized area at 20 microg/mL, while at lower concentrations the effect was not significant. However, an increase of the number of mineralized spots (nodules) at all tested concentrations of the compound was observed.

Inhibition of inducible nitric oxide synthase expression by an acetonic extract from Feijoa sellowiana Berg. fruits

Feijoa sellowiana Berg. fruits and especially the acetonic extract have been shown to possess biological activities, although the responsible compounds have never been identified. The present study was designed to evaluate the anti-inflammatory activity of an acetonic extract from F. sellowiana Berg. fruits on the nitric oxide (NO) pathway, which plays an important role in inflammation. To this aim the J774 cell line, which expresses inducible nitric oxide synthase (iNOS) following stimulation with lipopolysaccharide (LPS), has been utilized, and the effects of this extract and its fractions on NO production, iNOS protein expression, and signal pathways involved in its regulation have been evaluated. This study demonstrates that at least some part of the anti-inflammatory activity of the acetonic extract is due to the suppression of NO production by flavone and stearic acid. The mechanism of this inhibition seems to be related to an action on the expression of the enzyme iNOS through the attenuation of nuclear factor kappaB (NF-kappaB) and/or mitogen-activated protein kinase (MAPK) activation.

Feijoa sellowiana derived natural Flavone exerts anti-cancer action displaying HDAC inhibitory activities

Curative properties of some medicinal plants such as the Feijoa sellowiana Bert. (Myrtaceae), have been often claimed, although the corresponding molecular mechanism(s) remain elusive. We report here that the Feijoa acetonic extract exerts anti-cancer activities on solid and hematological cancer cells. Feijoa extract did not show toxic effects on normal myeloid progenitors thus displaying a tumor-selective activity. In the Feijoa acetonic extract, fractionation and subsequent purification and analyses identified Flavone as the active component. Flavone induces apoptosis which is accompanied by caspase activation and p16, p21 and TRAIL over-expression in human myeloid leukemia cells. Use of ex vivo myeloid leukemia patients blasts confirms that both the full acetonic Feijoa extract and its derived Flavone are able to induce apoptosis. In both cell lines and myeloid leukemia patients blasts the apoptotic activity of Feijoa extract and Flavone is accompanied by increase of histone and non-histone acetylation levels and by HDAC inhibition. Our findings show for the first time that the Feijoa apoptotic active principle is the Flavone and that this activity correlates with the induction of HDAC inhibition, supporting the hypothesis of its epigenetic pro-apoptotic regulation in cancer systems.

Secondary metabolites from the leaves of Feijoa sellowiana Berg

The investigation of the lipid extract of leaves of Feijoa sellowiana cultivated along the east coast of Sicily has yielded in addition to the widespread secondary metabolites: alpha-tocopherol, flavone, stigmasterol and beta-carotene, an inseparable mixture of tyrosol esters of lignoceric (1a), cerotic (1b) and montanic (1c) acids, and a novel galactolipid identified as (2S)-1,2,6'-tri-O-[(9Z,12Z,15Z)-octadeca-9,12,15-trienoyl]-3-O-beta-D-galactopyranosyl glycerol (2).