Protective mechanisms of loquat leaf extract and ursolic acid against diabetic pro-inflammation.

The pharmacological effectiveness of loquat leaf extract (LE) and its important component, ursolic acid (UA), in the treatment of diabetes mellitus, has been well established in traditional medicine; however, the mechanism underlying their action is still unclear. We evaluated the protective effects of LE and UA against hyperglycemia-induced advanced glycation end product (AGE) formations and hepatic pro-inflammation. Oral administration of UA and LE at a dose of 50 mg/kg/day for 15 days yielded no significant hypoglycemic effect in diabetic db/db mice. UA and LE suppressed hepatic oxidative stress and AGE formation in diabetic mice, and this was followed by the downregulated mitogen-activated protein kinase signaling and nuclear factor κ B (NF-κB) activity. To identify the molecular target of LE and UA, a docking simulation was performed, and this predicted UA to bind to liver kinase B1 (LKB1), an upstream of AMP-activated protein kinase (AMPK)/transcription factor forkhead box O3 (FOXO3) axis. UA reversed the high-glucose-induced downregulation of LKB1-AMPK1-FOXO3 activation and antioxidant gene transcription. These findings demonstrated the antioxidant and anti-inflammatory effects of UA and LE against hyperglycemia-induced hepatic inflammation. Furthermore, we speculate that the LKB1/AMPK/FOXO3 pathway is a potential target responsible for these beneficial effects of LE and UA.

Effects of intercropping with Solanum photeinocarpum and its post-grafting generations on cadmium accumulation in loquat (Eriobotrya japonica).

Cadmium (Cd) contamination of orchard soils is a global problem that has been increasing. To decrease the Cd accumulation in fruits, intercropping the orchard crops with hyperaccumulator plants has been used for soil remediation. A pot and a field experiment were conducted to study the effects of intercropping the potential Cd-hyperaccumulator Solanum photeinocarpum and its post-grafting generations with loquat (Eriobotrya japonica) on the growth and Cd uptake of these two plant species. In the pot experiment, intercropping improved the biomass, Cd content, Cd extraction, and root-to-shoot Cd translocation in both species. Intercropping increased the DNA methylation levels, antioxidant enzyme activity, and soluble protein content of loquat seedlings. These results indicate that intercropping could improve the phytoremediation of S. photeinocarpum and its post-grafting generations and increase the Cd uptake in loquat seedlings. In the field experiment, intercropping increased the Cd contents in the old branches, while it decreased that in the young branches and fruits of loquat. These findings indicate that intercropping could increase the Cd uptake in old tissues but reduce the Cd uptake in young tissues and fruits of loquat. So, intercropping loquat with S. photeinocarpum and its post-grafting generations could be used in Cd-contaminated orchards.

Intercropping the potential Cd-hyperaccumulator Solanum photeinocarpum and its post-grafting generations with loquat mutually promoted the growth of two plant species, and also promoted the cadmium uptakes in S. photeinocarpum and old branches of loquat, while inhibited the Cd uptake in the loquat young tissues (young branches and fruits). These results are the new findings of the intercropping.

Compounds isolated from Eriobotrya deflexa leaves protect against ultraviolet radiation B-induced photoaging in human fibroblasts.

Ultraviolet (UV) irradiation leads to skin photoaging because of the upregulation of matrix metalloproteinase (MMP)-1 and downregulation of type I collagen and tissue inhibitor of metalloproteinase (TIMP)-1. Eriobotrya deflexa (Hemsl.) Nakai (Rosaceae) is a flowering plant endemic to Taiwan, and its leaves have been used as an expectorant and in antitussive folk remedy. Our previous studies have demonstrated that an E. deflexa leaf extract functions as a free radical scavenger. The current evaluated the antiphotoaging effect of partitioned fractions and specific compounds from the leaves of E. deflexa by using bioguided isolation, compound identification, and biological activity testing with UVB-irradiated human fibroblasts (WS-1 cells). E. deflexa leaves were extracted with 95% ethanol and then partitioned using a sequential treatment of n-hexane, ethyl acetate, and n-butanol (n-BuOH). The bioactive n-BuOH fraction was used for isolation and purification through chromatography. The compounds were identified by analyzing their physical and spectroscopic properties. We identified eight compounds from this fraction; of these compounds, 3-O-α-l-rhamnopyranosyl-(1‴→6″)-ß-d-galactopyranoside (1), hyperin (2), afzelin (5), and cryptochlorogenic acid methyl ester (7) were isolated from E. deflexa for the first time, and they exhibited MMP-1 inhibition activity. The IC50 values were 96.5, 89.5, 93.4, and 92.8µM for 1, 2, 5, and 7, respectively. These compounds also enhanced the expression of procollagen type I, and TIMP-1 and hyperin (2) were found to be most effective with IC50 values of 56.7 and 70.3µM, respectively. Hyperin (2) could reduce intracellular reactive oxygen species production in UVB-irradiated WS-1 cells, with the corresponding IC50 value being 80.7µM. Liquid chromatography triple-quadrupole mass spectrometry was used for the quantitative and chemical fingerprint analysis of active compounds. Quercetin 3-O-α-l-rhamnopyranosyl-(1‴→6″)-ß-d-galactopyranoside (1), hyperin (2), afzelin (5), and cryptochlorogenic acid methyl ester (7) constituted 24.2±3.9, 5.5±1.0, 3.4±0.3, and 67.1±8.1mg/g of dry weight in the active n-BuOH fraction, respectively. Our results demonstrate that the extract and the isolated active compounds from E. deflexa leaves possess the potential for protection against skin photoaging.

Volatile metabolite profiling reveals the changes in the volatile compounds of new spontaneously generated loquat cultivars.

In recent years, the advantageous traits of three new loquat cultivars have drawn the attention of breeders and growers. All three have spontaneously arisen from the 'Algerie' cultivar: the new 'Xirlero' cultivar is a bud mutant of 'Algerie', while 'Amadeo' and 'Raúl' arose as chance seedlings. Following a non-targeted approach based on HS-SPME-GC-MS, the volatile compounds profile of the fruits from the new cultivars were obtained and compared to the original 'Algerie' cultivar. Carboxylic acids clearly dominated the volatile profile of all the loquat cultivars, but esters, aldehydes, ketones and alcohols were also predominant compounds. Interestingly when the bud mutant event did not lead to marked changes in the volatile compounds complement, pronounced changes in the volatile composition of chance seedling-generated cultivars 'Amadeo' and 'Raúl' were observed. 'Amadeo' fruits showed lower levels of 2-methyl butanoic acid and much higher levels of methylhexanoate, methylbutanoate and 2-hydroxy-5-methylacetophenone. The 'Raúl' cultivar also had a distinctive volatile profile characterised by high levels of C6-aldehydes, (E)-2-hexanal, 2-hexenal, (Z)-3-hexenal and hexanal, and several carotenoid-derived volatiles; e.g. 2-pentene-1,4-dione 1-(1,2,2-trimethylcyclopentyl), (S)-dihydroactinidiolide, isodurene, cis-geranyl acetone, ß-damascenone, ß-ionone, α-ionone and 3,4-dehydro-ß-ionone. These changes in volatiles were associated with a more intense flavour in cultivars 'Amadeo' and 'Raúl', according to the sensory evaluation of the flavour intensity carried out by a semi-trained panel. A metabolomic correlation network analysis provided insights as to how volatiles were regulated, and revealed that the compounds modified in 'Amadeo' were uncoupled from the rest of the volatilome, while the volatiles modified in 'Raul' changed according to specific groups. To conclude, this work provides a holistic view of how the loquat volatilome was affected, and this information was integrated with the physical-chemical-sensory attributes to understand the changes that occur in the new cultivars.

[Research on ursolic acid production of Eriobotrya japonica cell suspension culture in WAVE bioreactor].

Through scale-up cultivation of Eriobotrya japonica suspension cells using WAVE bioreactor, the cell growth and ursolic acid (UA) accumulation were studied. The comparison test was carried out in the flask and the reactor with cell dry weight (DW) and UA content as evaluation indexes. The culture medium, DW and UA content were compared in 1 L and 5 L working volumes of bioreactor. The orthogonal test with main actors of inoculation amount, speed and angle of rotation was developed to find the optimal combination, in 1 L working volume of bioreactor. DW of the cell growth and the UA content in bioreactor were higher than those of the shaker by 105.5% and 27.65% respectively. In bioreactor, the dynamic changes of elements in the fluid culture, the dry weight of the cell growth and the UA content in 1 L and 5 L working volumes were similar. Inoculation of 80 g, rotational speed of 26 r · min(-1), and angle of 6 ° was the optimal combination, and the cell biomass of 19.01 g · L(-1) and the UA content of 27.750 mg · g(-1) were achieved after 100 h cultivation in 1 L working volume of bioreactor. WAVE Bioreactor is more suitable than flasks for the E. japonica cell suspension culture, and culture parameters can be achieved from 1 L to 5 L amplification.

Systems pharmacology dissection of the anti-inflammatory mechanism for the medicinal herb Folium eriobotryae.

Inflammation is a hallmark of many diseases like diabetes, cancers, atherosclerosis and arthritis. Thus, lots of concerns have been raised toward developing novel anti-inflammatory agents. Many alternative herbal medicines possess excellent anti-inflammatory properties, yet their precise mechanisms of action are yet to be elucidated. Here, a novel systems pharmacology approach based on a large number of chemical, biological and pharmacological data was developed and exemplified by a probe herb Folium Eriobotryae, a widely used clinical anti-inflammatory botanic drug. The results show that 11 ingredients of this herb with favorable pharmacokinetic properties are predicted as active compounds for anti-inflammatory treatment. In addition, via systematic network analyses, their targets are identified to be 43 inflammation-associated proteins including especially COX2, ALOX5, PPARG, TNF and RELA that are mainly involved in the mitogen-activated protein kinase (MAPK) signaling pathway, the rheumatoid arthritis pathway and NF-κB signaling pathway. All these demonstrate that the integrated systems pharmacology method provides not only an effective tool to illustrate the anti-inflammatory mechanisms of herbs, but also a new systems-based approach for drug discovery from, but not limited to, herbs, especially when combined with further experimental validations.

Nonfluorescent chlorophyll catabolites in loquat fruits (Eriobotrya japonica Lindl.).

Nonfluorescent chlorophyll catabolites (NCCs) and nonfluorescent dioxobilane chlorophyll catabolites (NDCCs) are the terminal compounds of the chlorophyll degradation pathway that may display beneficial properties to human health related to their antioxidant properties, which were recently shown. A profile of NCCs/NDCC of the loquat fruit Eriobotrya japonica Lindl. is described. From the 13 known different NCC structures described to date, three have been identified in loquats. Two new structures not defined so far were characterized in loquat fruits: Ej-NCC2, which corresponds to the methyl ester at C13(2) of Bn-NCC1 and in very low amount Ej-NDCC1, the only NDCC found in loquats. Keto-enol tautomerism at the C13(1) position in NCCs is described for the first time as a regular process in chlorophyll catabolism, probably through a nonspecific mechanism since almost all the chlorophyll catabolites structures detected in fruits of loquat present keto and enol tautomers. The results obtained have been possible through a high-performance liquid chromatography coupled with electrospray ionization ion trap and quadropole time-of-flight mass spectrometry fitted with a powerful postprocessing software.

Phytochemical content, antioxidants and cell wall metabolism of two loquat (Eriobotrya japonica) cultivars under different storage regimes.

Changes in quality, phytochemical content and cell wall metabolism of two loquat cultivars (Eriobotrya japonica cvs. 'Morphitiki', 'Karantoki') under different storage regimes were studied. The fruit were harvested at commercial maturity stage and analyzed after 1, 3, 5, 7, and 11 days maintenance at room temperature (RT, ∼ 20°C) or after cold storage (14 days at 4°C) and additional ripening at RT for 1, 3 and 5 days, respectively. Compositional analysis revealed substantial cultivar differences; the 'Morphitiki' fruit was more acidic and showed higher contents of total phenolics, flavonoids and hydroxycinnamic acid-derivatives as well as greater antioxidant potency. Although firmness did not change markedly during storage, the cell wall exhibited extensive remodeling. Greater changes were observed in the pectin backbones than in polyuronide side chains and cross-linking glycans. Polygalacturonase (PG) showed better association with cell wall solubilization at RT than the enzymes involved in arabinan or galactan disassembly. During postharvest ripening after harvest, 'Karantoki' showed more extensive pectin solubilization than 'Morphitiki'. Interestingly, cold storage inhibited the cell wall disassembly in 'Karantoki' but not in 'Morphitiki', suggesting that the cultivars may differ in their susceptibility to chilling-related wall disorders. Low temperature-induced alterations in wall disassembly may impact juice and phytochemical release upon consumption.

Flavonoids, phenolics, and antioxidant capacity in the flower of Eriobotrya japonica Lindl.

Flavonoids and phenolics are abundant in loquat flowers. Methanol had the highest extraction efficiency among five solvents, followed by ethanol. Considering the safety and residue, ethanol is better as extraction solvent. The average content of flavonoids and phenolics of loquat flower of five cultivars were 1.59 ± 0.24 and 7.86 ± 0.87 mg/g DW, respectively, when using ethanol as extraction solvent. The contents of both bioactive components in flowers at different developmental stages and in the various flower tissues clearly differed, with the highest flavonoids and phenolics content in flowers of stage 3 (flower fully open) and petal, respectively. The antioxidant capacity was measured using FRAP, DPPH, and ABTS methods. The values of ABTS method was highest, followed by DPPH, the lowest was FRAP, when using vitamin C equivalent antioxidant capacity (VCEAC) as unit. Correlation analysis showed that the ABTS method showed the highest correlation coefficients with flavonoids and phenolics, i.e., 0.886 and 0.973, respectively.

Regulation and improvement of triterpene formation in plant cultured cells of Eriobotrya japonica Lindl.

Loquat (Eriobotrya japonica Lindl) is a traditional Chinese medicinal plant that contains triterpenes, which have been shown to exhibit pharmaceutical activities. In this study, we investigated various different culture conditions for cultured cells of loquat to produce triterpenes, including illumination, carbon source, nutrient composition and culture system. When cultured on 2.5mg/l of 6-benzyladenine, 1mg/l of naphthalene acetic acid and 30 g/l of sucrose at 25 ± 2 °C in the dark for 30 days, the nutrient composition significantly regulated the cell growth and triterpene production. Supplied with the Murashige and Skoog medium reached higher level of dry weight (1.27 ± 0.09 g per flask) and total triterpene production (151.54 ± 12.58 mg/g of cultured cells), and the N6 medium produced tormentic acid but inhibited other triterpene products, while the B5 medium produced relatively high corosolic acid. Also found, suspension cultures of loquat cell could achieve high productivity as callus culture.