Morphophysiological changes of Acca sellowiana (Myrtaceae: Myrtoideae) saplings under shade gradient / Alterações morfofisiológicas em mudas de Acca sellowiana (Myrtaceae: Myrtoideae) sob gradiente de sombreamento

Abstract Understanding morphological and physiological changes under different light conditions in native fruit species in juveniles' stage is important, as it indicate the appropriate environment to achieve vigorous saplings. We aimed to verify growth and morphophysiological changes under shade gradient in feijoa (Acca sellowiana (O. Berg) Burret) to achieve good quality saplings adequate to improve cultivation in orchards. The saplings were grown for twenty-one-month under four shading treatments (0%, 30%, 50%, and 80%). Growth, photosynthetic pigments, gas exchanges, chlorophyll fluorescence, and leaf anatomy parameters were evaluated. Saplings under full sun and 30% shade had higher height and diameter growth and dry mass accumulation due to higher photosynthesis rate. As main acclimatization mechanisms in feijoa saplings under 80% shade were developed larger leaf area, reduced leaf blade thickness, and enhanced quantum yield of photosystem II. Even so, the net CO2 assimilation and the electron transport rate was lower and, consequently, there was a restriction on the growth and dry mass in saplings under deep shade. Therefore, to obtain higher quality feijoa saplings, we recommend that it be carried out in full sun or up to 30% shade, to maximize the sapling vigor in nurseries and, later, this light environment can also be used in orchards for favor growth and fruit production.

Resumo A verificação de mudanças morfológicas e fisiológicas sob diferentes condições luminosas em espécies frutíferas nativas em estágio juvenil é importante, uma vez que indicam o ambiente adequado para a formação de mudas com alto vigor. Objetivou-se verificar o crescimento e as alterações morfofisiológicas sob gradiente de sombreamento em mudas de feijoa (Acca sellowiana (O. Berg) Burret) para obter mudas de boa qualidade, adequadas para fomentar os plantios da espécie em pomares. As mudas foram cultivadas por vinte e um meses sob quatro tratamentos de sombreamento (0%, 30%, 50% e 80%). Foram avaliados parâmetros de crescimento, pigmentos fotossintéticos, trocas gasosas, fluorescência da clorofila e anatomia foliar. Mudas a pleno sol e 30% de sombra apresentaram maior crescimento em altura, diâmetro e acúmulo de massa seca, devido à maior taxa de fotossíntese. Como principais mecanismos de aclimatação sob 80% de sombra, as mudas desenvolveram maior área foliar, redução da espessura do limbo foliar e aumento do rendimento quântico do fotossistema II. Mesmo assim, a assimilação líquida de CO2 e a taxa de transporte de elétrons foram menores e, consequentemente, houve restrição ao crescimento e acúmulo de massa seca das mudas no maior nível de sombreamento. Portanto, para a obtenção de mudas de feijoa de maior qualidade, recomendamos que seja realizada a pleno sol ou até 30% de sombra, para maximizar o vigor das mudas em viveiros e, posteriormente, este ambiente de luz também pode ser utilizado em pomares para favorecer o crescimento e a produção de frutos.

Diagrammatical scale to quantify herbivory severity on feijoa leaf caused by Paraulaca dives (Coleoptera: Chrysomelidae).

The aims of this work were to characterize the damage caused by Paraulaca dives in feijoa (Acca sellowiana) and develop a diagrammatic scale to evaluate the severity of herbivory. The evaluations were carried out in a feijoa progenies orchard with eight-year-old. The beetles caused damage mainly on leaves, from October to December (spring season). The distribution of beetles in the orchard occurred randomly, not following a defined pattern of incidence. The diagrammatic scale of herbivory severity was represented by seven levels (1%, 3%, 5%, 7%, 15%, 32%, and 55% of the leaf area consumed). The use of this diagrammatic scale significantly increased the precision and accuracy of severity estimates by inexperienced evaluators. This can help in strategies to control this pest to expand the cultivation of feijoa in Brazil.

Structural characteristics, functional properties, antioxidant and hypoglycemic activities of pectins from feijoa (Acca sellowiana) peel.

The structure characteristics, functional properties, antioxidant and hypoglycemic activities of pectins extracted from feijoa peel with water (FP-W), acid (FP-A) and alkali (FP-B) were investigated. Results showed that the feijoa peel pectins (FPs) were mainly composed of galacturonic acid, arabinose, galactose and rhamnose. FP-W and FP-A had higher proportion of homogalacturonan domain, degree of esterification and molecular weight (for main component) than FP-B; FP-B owned the highest yield, protein and polyphenol contents. FP-W had a compact and smooth surface morphology unlike FP-A and FP-B. FP-W and FP-A had better thermal stability than FP-B. The rheological analysis suggested that the FPs exhibited pseudoplastic fluid behavior, and the elastic characteristics were dominant. Results showed that FP-W and FP-B had superior antioxidant and hypoglycemic activities than FP-A. According to correlation analysis, monosaccharide composition, sugar ratios and degree of acetylation were chief factors affecting the functional properties, antioxidant and hypoglycemic activities of the FPs.

In Vitro and In Vivo Anti-parasitic Activity of Sambucus ebulus and Feijoa sellowiana Extracts Silver Nanoparticles on Toxoplasma gondii Tachyzoites.

BACKGROUND: Current chemical treatments for toxoplasmosis have side effects, researchers are looking for herbal remedies with minimal side effects and the best effectiveness. This study aimed to evaluate the anti-toxoplasmic effects of silver nanoparticles based on Sambucus ebulus (Ag-NPs-S. ebulus) and Feijoa sellowiana (Ag-NPs-F. sellowiana) fruit extracts, in vitro and in vivo. METHODS: Vero cells were treated with different concentrations (0.5, 1, 2, 5, 10, 20, 40 µg/mL) of extracts and pyrimethamine as a positive control. Vero cells were infected with T. gondii and treated with extracts. The infection index and intracellular proliferation of T. gondii were evaluated. The survival rate of infected mice with tachyzoites of T. gondii was examined after intraperitoneal injection of the extracts at a dose of 40 mg/kg/day for 5 days after infection. RESULTS: The Ag-NPs-S. ebulus and Ag-NPs-F. sellowiana, almost similar to pyrimethamine, reduced proliferation index when compared to untreated group. Also, high toxoplasmicidal activity was observed with Ag-NPs-S. ebulus extract. Mice in the treatment groups of Ag-NPs-S. ebulus and pyrimethamine achieved better results in terms of survival than the others. CONCLUSION: The results indicated that Ag-NPs-F. sellowiana and S. ebulus have a significant growth effect on T. gondii in vitro and in vivo. Ag-NPs-S. ebulus extract has a more lethal effect on the parasite than Ag-NPs-F. sellowiana. It is suggested that in future investigate the induction of Toxoplasma-infected cell apoptosis using nanoparticles.

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.

Chemical Composition, Antiaging Activities and Molecular Docking Studies of Essential Oils from Acca sellowiana (Feijoa).

This study aimed to investigate the chemical composition of essential oils isolated from Acca sellowiana (feijoa) leaves and stems and elaborate on their relevance as natural anti-aging, coupled with molecular-docking studies. The isolated oils were analysed using gas chromatography-mass spectrometry analysis and investigated for inhibitory effects against acetylcholinesterase, ß-secretase, collagenase, elastase and tyrosinase. Molecular-modelling study was performed using MOE-Dock program to evaluate binding interactions of major components with the above-mentioned targets. The leaf oil revealed the predominance of caryophyllene oxide (24.3 %), linalool (7.9 %), and spathulenol (6.6 %), while the stem oil was presented by caryophyllene oxide (38.1 %), α-zingiberene (10.1 %) and humulene oxide II (6.0 %). The stem oil expressed superior inhibitory activities against acetylcholinesterase (IC50 =0.15±0.01 µg/mL), ß-secretase (IC50 =3.99±0.23 µg/mL), collagenase (IC50 =408.10±20.80 µg/mL), elastase (IC50 =0.17±0.01 µg/mL) and tyrosinase (IC50 =8.45±0.40 µg/mL). The valuable binding interactions and docking scores were observed for caryophyllene oxide and α-zingiberene with acetylcholinesterase. Besides, α-zingibirene followed by linalool and τ-cadinol revealed tight fitting with collagenase and elastase. Additionally, linalool, spathulenol and τ-cadinol showed the best binding energy to tyrosinase. This study provides valuable scientific data on A. sellowiana as potential candidates for the development of natural antiaging formulations. The current study provided scientific evidence for the potential use of feijoa essential oils in antiaging formulations and as an adjuvant for the prophylaxis against Alzheimer disease.

The effects of Feijoa sellowiana fruit extract on wound healing in rats: a stereological and molecular study.

OBJECTIVE: The aim of this study was to evaluate the anti-inflammatory and wound-healing potential of Feijoa sellowiana fruit extract using stereological and molecular methods in experimental rat models. MATERIALS: Male Wistar rats were divided into four equal groups: non-treated, vehicle, Feijoa sellowiana fruit extract ointment (5% weight/weight) and the reference drug (madecassol). All animals were treated topically once per day. At the end of the study, wound samples were harvested for histological, stereological, immunohistochemical and molecular assessments to determine the in vivo healing potential and anti-inflammatory activity. A high-performance liquid chromatography (HPLC) analysis was performed for the characterisation of the phenolic acids in the extract. RESULTS: The study included 64 rats in total. Our results showed that the wound closure, volume of new epidermis and dermis, density of fibroblasts and blood vessels, and the deposition of collagen were significantly higher in both extract and madecassol groups compared to the non-treated and vehicle groups, with superior healing in the extract group. The transcript for the transforming growth factor (TGF)-ß gene was significantly upregulated in both extract and madecassol groups compared to non-treated and vehicle groups and was highest for the extract group. The density of inflammatory cells and expression levels of the cyclooxygenase (COX)-2 protein and tumour necrosis factor (TNF)-α gene in the extract and madecassol groups, especially in the extract group, were significantly reduced compared to non-treated and vehicle groups. CONCLUSION: Our results confirm that the Feijoa sellowiana fruit extract is a valuable source of antioxidant and anti-inflammatory activities and can allow for damaged tissue in wounds to recover markedly.

Phenolic-rich feijoa extracts from flesh, peel and whole fruit activate apoptosis pathways in the LNCaP cell line.

This study aimed to explore the potential anticancer activity of phenolic-rich feijoa extracts from the flesh, peel, and whole fruit on the human prostate cancer cell line (LNCaP). Results showed that feijoa extracts had cancer-specific anti-proliferative activity on the LNCaP cell line. The anticancer activity of feijoa extracts was shown through activation of the caspase-dependent apoptosis pathway based on the increase of sub-G1 phase in the cell cycle, the decrease of mitochondrial membrane potential, as well as the elevated caspase 3, 8, and 9 activity in the treated LNCaP cells. The anti-cancer activity of feijoa extracts could be attributed to the high total phenolic contents (0.14-0.37 mg GAE/mg dw) and, in particular, the high ellagic acid content (2.662-9.119 µg/mg dw). The successful activation of the caspase-dependent apoptosis pathway indicates that phenolic-rich feijoa extracts have a good potential to be utilized as a functional ingredient in foods and nutraceuticals.

Morphophysiological changes of Acca sellowiana (Myrtaceae: Myrtoideae) saplings under shade gradient.

Understanding morphological and physiological changes under different light conditions in native fruit species in juveniles' stage is important, as it indicate the appropriate environment to achieve vigorous saplings. We aimed to verify growth and morphophysiological changes under shade gradient in feijoa (Acca sellowiana (O. Berg) Burret) to achieve good quality saplings adequate to improve cultivation in orchards. The saplings were grown for twenty-one-month under four shading treatments (0%, 30%, 50%, and 80%). Growth, photosynthetic pigments, gas exchanges, chlorophyll fluorescence, and leaf anatomy parameters were evaluated. Saplings under full sun and 30% shade had higher height and diameter growth and dry mass accumulation due to higher photosynthesis rate. As main acclimatization mechanisms in feijoa saplings under 80% shade were developed larger leaf area, reduced leaf blade thickness, and enhanced quantum yield of photosystem II. Even so, the net CO2 assimilation and the electron transport rate was lower and, consequently, there was a restriction on the growth and dry mass in saplings under deep shade. Therefore, to obtain higher quality feijoa saplings, we recommend that it be carried out in full sun or up to 30% shade, to maximize the sapling vigor in nurseries and, later, this light environment can also be used in orchards for favor growth and fruit production.

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.

Application in situ of biodegradable films produced with starch, citric pectin and functionalized with feijoa (Acca sellowiana (Berg) Burret) extracts: An effective proposal for food conservation.

In this study, biodegradable films produced with starch, citric pectin, and functionalized with antioxidant compounds from feijoa (Acca sellowiana (Berg) Burret) were in situ applied for the conservation of ground beef, bread, and grapes. The results demonstrated that the films produced were an excellent source of stable antioxidant compounds, with antimicrobial activity against Escherichia coli, Salmonella, and Shigella. The bioactive films based on biological macromolecules positively stabilized the polyunsaturated fatty acids and deterioration reactions in ground beef. The release of bioactive compounds from the films was responsible for inhibiting molds and yeasts in bread, increasing their shelf life for 30 days of storage. The application of film coating and packaging in grapes increased postharvest conservation and maintained steady physicochemical characteristics. Therefore, the innovative films produced can release bioactive compounds with antioxidant and antimicrobial activity, and consequently, can be proposed as an effective material for food conservation, increasing the shelf life of perishable food products.

Phytochemical profile, enzyme inhibition activity and molecular docking analysis of Feijoa sellowiana O. Berg.

Feijoa sellowiana leaves and fruits have been investigated as a source of diverse bioactive metabolites. Extract and eight metabolites isolated from F. sellowiana leaves were evaluated for their enzymatic inhibitory activity against α-glucosidase, amylase, tyrosinase, acetylcholinestrerase and butyrylcholinesterase both in vitro and in silico. Feijoa leaves' extract showed strong antioxidant activity and variable levels of inhibitions against target enzymes with a strong anti-tyrosinase activity (115.85 mg Kojic acid equivalent/g). Additionally, α-tocopherol emerged as a potent inhibitor of AChE and BChE (5.40 & 10.38 mmol galantamine equivalent/g, respectively). Which was further investigated through molecular docking and found to develop key enzymatic interactions in AChE and BChE active sites. Also, primetin showed good anti BChE (11.70 mmol galantamine equivalent/g) and anti-tyrosinase inhibition (90.06 mmol Kojic acid equivalent/g) which was also investigated by molecular docking studies. Highlights Isolation of eight bioactive constituents from Feijoa sellowiana leaves. In vitro assays using different enzymatic drug targets were investigated. In silico study was performed to define compound interactions with target proteins. Feijoa leaf is an excellent source of anti-AChE and antityrosinase bioactives.

Antioxidant and antibacterial compounds from feijoa leaf extracts obtained by pressurized liquid extraction and supercritical fluid extraction.

This work investigated the efficiency of pressurized liquid extraction (PLE) and supercritical fluid extraction with cosolvent (SFE) in obtaining feijoa leaf extracts with high antioxidant and antibacterial activities. PLE was performed in customized equipment with environmentally friendly solvents, at 40/80 °C, in dynamic and static mode, and SFE was carried out for 210 min at 30 MPa, 55 °C and 15% ethanol-water as cosolvent. PLE extract (80 °C/ethanol-water/dynamic) provided the highest yield, total phenolic content, and antioxidant activities, but it was not effective as antibacterial agent. In contrast, SFE extract exhibited effectiveness against S. aureus, E. coli, and S. typhimurium, with minimum inhibitory concentration values from 14,211 to 3,553 µg.mL-1. Finally, gallic acid, catechin and isoquercetin were the major phenolics identified by liquid chromatography. Our findings revealed that feijoa leaf extracts by PLE and SFE have remarkable bioactivity, presenting a great potential to be used as natural food additives.

Protective effect of Feijoa sellowianan fruit on testicular toxicity-induced by cadmium chloride.

The purpose of the present study was to investigate the protective potential of Feijoa fruit extract on cadmium chloride (CdCl2 )-induced testicular injury and pituitary-gonadal axis. Adult male Wistar rats were randomly divided into four groups: (a) control (normal saline, orally), (b) cadmium chloride (0.1 mg/kg, single dose, intraperitoneally), (c) Feijoa fruit extract (400 mg/kg, orally for 30 consecutive days) and (d) CdCl2  + Feijoa fruit extract. One day after receiving the last medicine, the LH, FSH, prolactin and testosterone concentration were assayed. Also, sperm parameters and tissue structure of the testis were evaluated. Administration of Feijoa fruit extract after CdCl2 injection in rats ameliorated sperm parameters such as sperm count, morphology, motility and sperm viability, increased levels of LH, FSH, prolactin and testosterone and improved testicular histology. According to the results of this study, it was shown that Feijoa can reduce the destructive side effects of CdCl2 on testicular tissue and sex hormones of the pituitary-gonadal pathway.

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.

Effect of essential oils on the development of Colletotrichum sp. fungus in fragments of Feijoa sellowiana fruits

The aim of this work was to evaluate the effect of the essential oils of Syzygium aromaticum, Cymbopogon citratus, Eucalyptus citriodora and Rosmarinus officinalis on the mycelial development of the fungus Colletotrichum sp. in fragments of Feijoa sellowiana fruits. The essential oils were incorporated in the PDA (Potato-Dextrose-Agar) medium in the concentrations of 250, 500 and 1000 ppm, 0 ppm (PDA only) (negative control), and fungicide fluazinam 1% (positive control). The area under the mycelial growth curve (AUMGC) and percent inhibition of mycelial growth (PIMG) were calculated. In the second evaluation, fruits fragments bordering the disease symptom were immersed in essential oils aqueous solution of S. aromaticum, C. citratus, and E. citriodora, at the concentration of 5000 ppm, 0 ppm (water only - negative control) and fluazinam 1% (positive control). The immersion times in the treatments were: 2, 4, 8, 12 and 24 hours, with subsequent incubation in Agar-Agar medium at 25°C. This evaluation was performed daily for 15 days, observing the moment of fungal germination through the emission of the mycelium. It was verified from the obtained results that all treatments reduced the fungal growth, and the essential oils of C. citratus and S. aromaticum totally inhibited its growth from the dose 500 and 1000 ppm, respectively. Regarding the test on fruit fragments, the essential oil of S. aromaticum at the immersion times of 12 and 24 hours was effective in inhibiting the fungus until the 15th day of evaluation.

New insights into the phenolic compounds and antioxidant capacity of feijoa and cherry fruits cultivated in Brazil.

Acca sellowiana (feijoa) and Eugenia involucrata (cherry) are fruits species of Brazilian biodiversity (Myrtaceae family). In this study, a sampling process was used with three different harvesting sites. The composition of phenolic compounds of these fruits was determined by HPLC-DAD-MS/MS. Moreover, the antioxidant capacity of hydroethanolic extracts against hydrogen peroxide (H2O2), hydroxyl (OH), peroxyl (ROO-) and ABTS radicals was evaluated. Thirty and twenty-seven phenolic compounds were identified in feijoa and cherry, respectively. The major phenolic compounds found were pedunculagin isomer (5040.87, 3443.66 and 1324.95 µg·g-1) in feijoa and procyanidin (1406.54, 1888.00 and 1380.64 µg·g-1) in cherry. Hydroethanolic extract of these fruits was a potent scavenger of free radicals and excellent source of phenolic compounds. In hydroethanolic extracts of feijoa, the phenolic content increased by around 50%, while in the cherry the content was similar to that found in the fruit. For ORAC method, sample 2 of feijoa and cherry showed values of 383 and 126 µM·TE·g-1, respectively, featuring the highest antioxidant capacity. This study is the first to report the identification of castalagin, catechin and epicatechin in feijoa, and rutin in cherry. Besides, the health benefits, these fruits can contribute to biodiversity conservation.

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.

Biogenic Silver and Zero-Valent Iron Nanoparticles by Feijoa: Biosynthesis, Characterization, Cytotoxic, Antibacterial and Antioxidant Activities.

BACKGROUND AND PURPOSE: Green nanotechnology is an interesting method for the synthesis of functional nanoparticles. Because of their wide application, they have set up great attention in recent years. OBJECTIVE: The present research examines the green synthesis of Ag and zero-valent iron nanoparticles (AgNPs, ZVINPs) by Feijoa sellowiana fruit extract. In this synthesis, no stabilizers or surfactants were applied. METHODS: Eco-friendly synthesis of Iron and biogenic synthesis of Ag nanoparticles were accomplished by controlling critical parameters such as concentration, incubation period and temperature. Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM), Energy-Dispersive X-ray Spectroscopy (EDS), Fourier-Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction analysis (XRD), Dynamic Light Scattering (DLS) and UV-Vis were applied to characterize NPs. The cytotoxicity of NPs was investigated in two cell lines, MCF-7 (breast cancer) and AGS (human gastric carcinoma). A high-performance liquid chromatography (HPLC) analysis was also performed for characterization of phenolic acids in the extract. RESULTS: Both NPs displayed powerful anticancer activities against two tumor cell lines with little effect on BEAS-2B normal cells. Synthesized AgNPs and ZVINPs inhibited the growth of all selected bacteria. Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumonia, Staphylococcus aureus, Enterococcus faecalis, Acinetobacter baumannii and Escherichia coli have been studied in two stages. We initially examined the ATCCs followed by clinical strain isolation. Based on the results from resistant strains, we showed that nanoparticles were superior to conventional antibiotics. DPPH (diphenyl-1-picrylhydrazyl) free radical scavenging assay and iron chelating activity were used for the determination of antioxidant properties. Results showed a high antioxidant activity of scavenging free radicals for ZVINPs and powerful iron-chelating activity for AgNPs. Based on the HPLC data, catechin was the major phenolic compound in the extract. CONCLUSION: Our synthesized nanoparticles displayed potent cytotoxic, antibacterial and antioxidant activities.

Volatilome study of the feijoa fruit [Acca sellowiana (O. Berg) Burret.] with headspace solid phase microextraction and gas chromatography coupled with mass spectrometry.

Feijoa is a subtropical bush of the Myrtaceae family. It has unique fruit with organoleptic properties that make it an exotic fruit. Head space solid phase microextraction (HS-SPME) with a 65 µm divinylbenzene/polydimethylsiloxane (DVB/PDMS) fiber and gas chromatography coupled to mass spectrophotometry (GC-MS) was used to study the volatile fraction of feijoa fruit cultured in Caldas, Colombia. The profile analyzed included 134 volatile organic compounds (VOCs). 127 VOCs were classified based on the functional group using the spectral and structural networks correlation analysis. Methyl, ethyl and (Z)-3-hexenyl benzoate with 50% of the volatile composition, were the main compounds. Biosynthesis of the volatilome of feijoa fruit was associated with five main metabolic pathways. This study represents the first analysis of feijoa fruit commercialized in the region. This is an innovator view in elucidation of metabolic pathways that represent the biochemistry of the aroma of this fruit.