Comparison of bioactive compound contents and in vitro and ex vivo antioxidative activities between peel and flesh of pear (Pyrus pyrifolia Nakai)

Modulatory Effect of Pyrus pyrifolia Fruit and its Phenolics on Key Enzymes against Metabolic Syndrome: Bioassay-Guided Approach, HPLC Analysis, and In Silico Study

This study aims to isolate the active constituents of Pyrus pyrifolia Nakai fruits using a bioassay-guided fractionation approach, test their activity in vitro against key enzymes for metabolic disorders, and support it with molecular docking simulations. The antioxidant potential of the methanolic extract (ME), its polar (PF), and non-polar fractions (NPF), along with the inhibitory activity against α-glucosidase, α-amylase, lipase, angiotensin I converting enzyme (ACE), renin, inducible nitric oxide synthase (iNOS), and xanthine oxidase (XO) were assessed. The PF exhibited the highest antioxidant and enzyme inhibitory activity. Purification of PF yielded rutin, isoquercitrin, isorhamnetin-3-O-β-D-glucoside, chlorogenic acid, quercetin, and cinnamic acid. HPLC-UV analysis of the PF allowed for the quantification of 15 phenolic compounds, including the isolated compounds. Cinnamic acid was the most powerful antioxidant in all assays and potent enzyme inhibitor against the tested enzymes (α-glucosidase, α-amylase, lipase, ACE, renin, iNOS, and XO). Additionally, it showed high affinity to target α-glucosidase and ACE active sites with high docking scores (calculated total binding free energy (ΔGbind) -23.11 kcal/mol and - 20.03 kcal/mol, respectively]. A 20-ns molecular dynamics simulation using MM-GBSA analysis revealed a stable conformation and binding patterns in a stimulating environment of cinnamic acid. Interestingly, the isolated compounds' dynamic investigations including RMSD, RMSF, and Rg demonstrated a stable ligand - protein complex to the active site of iNOS with ΔGbind ranging from - 68.85 kcal/mol to -13.47 kcal/mol. These findings support the notion that P. pyrifolia fruit is a functional food with multifactorial therapeutic agents against metabolic syndrome-associated diseases.

Comparative Analysis of the Quality in Ripe Fruits of Cuiguan Pear from Different Regions

The Cuiguan pear is called "June snow" and the skin is thin; the meat is crisp and juicy; the taste is thick and fresh; and the juice is rich and sweet. In this study, the volatile organic compounds and the sensory and physicochemical parameters of the Cuiguan pear from four different regions of China (Sichuan (SC), Shangdong (SD), Chongming (CM), Zhuanghang (ZH)) were assessed. The highest differences in the physicochemical parameters were observed between four regions. The volatile fingerprints of GC-IMS showed great differences in the volatile of the Cuiguan pear, which suggested that the aroma of pears could be largely impacted by origin areas. (E)-ethyl-2-hexenoate can be used to distinguish between the 'CM' and pears from other regions. High contents of 2-heptanone, 1-pentanol, 1-butanol, 3-methylbutanol, butyl 2-methylbutanoate, heptyl acetate and butyl acetate were observed in the 'SD'. Dimethyl trisulfide, 6-methyl-5-hepten-2-one, 3-hydroxy-2-butanone, 1-penten-3-one, beta-pinene, γ-terpinene, propanal, (e)-2-pentenal, (e)-2-heptenal, 1-pentanol and 3-methyl-1-pentanol were primarily contained in the 'ZH'. Principal component analysis showed that there was very good discrimination based on the information obtained from GC-IMS for four samples. These findings were in agreement with the sensory analysis. In the opinion of the respondents to the consumer test, 'ZH' resulted in the most appreciated sample based on the average scores of the acceptability. This study provides some reference for the development and utilization of the Cuiguan pear.

Improvement of Sourdough and Bread Qualities by Fermented Water of Asian Pears and Assam Tea Leaves with Co-Cultures of Lactiplantibacillus plantarum and Saccharomyces cerevisiae

Qualities of sourdough and sourdough bread using fermented water from Asian pears and Assam tea leaves with Lactiplantibacillus plantarum 299v and Saccharomyces cerevisiae TISTR 5059 as starter cultures were evaluated. Changes in the growth of lactic acid bacteria and yeast, pH, sourdough height, total phenolic contents (TPCs) and antioxidant activities detected by ORAC, FRAP and DPPH radical scavenging assays were monitored during sourdough production. Mature sourdough was achieved within 4 h after 18 h retard fermentation and used for bread production. The bread was then analyzed to determine chemical and physical properties, nutritional compositions, TPCs, antioxidant activities and sensory properties as well as shelf-life stability. Results showed that fermented water significantly promoted the growth of yeast and increased TPCs and antioxidant activities of sourdough. Compared to common sourdough bread, fermented water sourdough bread resulted in 10% lower sugar and 12% higher dietary fiber with improved consumer acceptability; TPCs and antioxidant activities also increased by 2–3 times. The fermented water sourdough bread maintained microbial quality within the standard range, with adequate TPCs after storage at room temperature for 7 days. Fermented water from Asian pears and Assam tea leaves with L. plantarum 299v and S. cerevisiae TISTR 5059 as starter cultures improved dough fermentation and bread quality.

A review of pears (Pyrus spp.), ancient functional food for modern times

BACKGROUND

Pears have been world-widely used as a sweet and nutritious food and a folk medicine for more than two millennia.

METHODS

We conducted a review from ancient literatures to current reports to extract evidence-based functions of pears.

RESULTS

We found that pears have many active compounds, e.g., flavonoids, triterpenoids, and phenolic acids including arbutin, chlorogenic acid, malaxinic acid, etc. Most of researchers agree that the beneficial compounds are concentrated in the peels. From various in vitro, in vivo, and human studies, the medicinal functions of pears can be summarized as anti-diabetic,-obese, -hyperlipidemic, -inflammatory, -mutagenic, and -carcinogenic effects, detoxification of xenobiotics, respiratory and cardio-protective effects, and skin whitening effects. Therefore, pears seem to be even effective for prevention from Covid-19 or PM2.5 among high susceptible people with multiple underlying diseases.

CONCLUSION

For the current or post Covid-19 era, pears have potential for functional food or medicine for both of communicable and non-communicable disease.

Use of ultra-performance liquid chromatography-tandem mass spectrometry on sweet cherries to determine phenolic compounds in peel and flesh

BACKGOUND

Sweet cherries (Prunus avium L.) are rich in polyphenols and have high antioxidant potential. This study deals with the use of ultra-performance liquid chromatography-tandem mass spectrometry on five cherry cultivars, namely Caihong, Sunburst, Summit, 23-51 and Valeri, to determine the free, conjugated and bound phenolics in peel and flesh.

RESULTS

Phenolics varied widely based on cherry cultivars and edible parts. Valeri showed the highest phenolics in peel, while the flesh of 23-51 contained a higher amount of phenolic substances compared with the other cherries, mainly due to high levels of cyanidin-3-O-rutinoside, which was the most abundant phenolic in sweet cherry. Most of the phenolics, except for ferulic acid and vanillic acid, were present at a higher level in peel than in flesh. Principal component analysis indicated that compared with different edible parts, the phenolic compounds were more influenced by cultivar.

CONCLUSIONS

Cultivar had a much greater impact on the accumulation of phenolics than edible parts. The peel of Valeri contained the highest phenolics; for the flesh, 23-51 had the highest levels. The high variability in phenolic compounds in peel and flesh among cultivars may be useful for breeding and underlines the importance of germplasm conservation activities. © 2019 Society of Chemical Industry.

Preparation and Characterization of Callus Extract from Pyrus pyrifolia and Investigation of Its Effects on Skin Regeneration

In the present study, an aqueous extract was prepared using calli from the in vitro-derived leaves of Pyrus pyrifolia cultured in Murashige and Skoog medium containing picloram for a plant growth regulator. The major biological components in the callus extract were identified as uridine (1), adenosine (2), and guanosine (3). In terms of the antioxidant activity, at 300 µg/mL, the extract exhibited free radical scavenging activity of 76.9% ± 2.88% in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, comparable to that of 44 µg/mL ascorbic acid (82.5% ± 3.63%). In addition, the IC50 values for inhibition of advanced glycation end product formation from collagen and elastin were 602 ± 2.72 and 3037 ± 102.5 µg/mL, respectively. The extract significantly promoted keratinocyte and fibroblast cell proliferation in a dose-dependent manner. Moreover, fibroblasts treated with 1.36 µg/mL extract exhibited a 1.60-fold increase in procollagen type I C-peptide level compared to controls. The in vitro wound recovery rates of keratinocytes and fibroblasts were also 75% and 38% greater, respectively, than those of serum-free controls at 9 and 36 h after extract treatment (1.36 µg/mL). Additionally, the extract flux across the human epidermis increased by 1598% after its incorporation into elastic nanoliposomes (NLs). Therefore, elastic NLs loaded with Pyrus pyrifolia callus extract have potential use as skin rejuvenators and antiaging ingredients in cosmetic formulations.

Chemical composition and antioxidant capacity of different anatomical parts of pear (Pyrus communis L.)

Sugar, organic acid, triterpenoid and phenolic composition as well as antioxidant capacity of different anatomical parts of pear were studied. Fruits and leaves of 'Radana' pear (Pyrus communis L.) were used. The results showed great quantitative differences in the composition of the pear pulp, peel, leaves and seeds. Fructose was the major sugar in pulp, seeds and peel (227.46, 45.36 and 67.49 g/kg dry mass [DM], respectively), while sorbitol was predominant in leaves (40.66 g/kg DM). Malic acid was the major organic acid, followed by citric and shikimic acids. The highest concentration of triterpenoids (3460.5 μg/g DM) was determined in pear peel, and ursolic acid was predominant. Leaves were characterized by the highest amount of phenolics (5326.7 mg/100 g DM) and the highest DPPH and FRAP values (2027.9 and 3539.6 μmol TE/100 g DM, respectively). Pear leaves and seeds may be selected as potential sources of phytochemicals.