Eriobotrya japonica Water Extract Characterization: An Inducer of Interferon-Gamma Production Mainly by the JAK-STAT Pathway

Abstract

Eriobotrya japonica (Thunb.) Lindl. (Loquat) (EJ) has been used as a medicinal plant to treat chronic bronchitis, coughs, phlegm, high fever and gastro-enteric disorders. Since the traditional use of EJ is related to modulating inflammation processes, our earlier studies on EJ leaves were performed on the water extract to investigate specific cytokines' modulation. These earlier studies, however, have shown that EJ leaf water extract (WE) and the water phase (WP) induce cytokines' production in in vitro and in vivo models. Therefore, the aim of this study was to specify the group(s) of compounds in EJ leaves that have this immunomodulatory activity and their mechanism of action. WE was obtained from boiling the leaves followed by butanol extraction, yielding a butanol-water phase (WP). WP was then subjected to methanol:acetone fractionation, yielding upper (MAU) and lower (MAL) phases. For further fractionation, MAU was subjected to column chromatography followed by elution with ethanol:water (EW), methanol:ethanol (ME) and, lastly, acetone:water (AW), respectively, to reveal three sub-fractions; MAU-EW, MAU-ME and MAU-AW. MAU-AW significantly increased IFN-γ production from unstimulated and stimulated mouse spleen cells, as well as CD3+ T cells and natural killer cells. Furthermore, the fold increase of IFN-γ production by MAU-AW was concentration dependent, higher than the parent extract or any of the other sub-fractions, and such an IFN-γ increase was reversed by two JAK-STAT inhibitors. In addition, MALDI-TOF-MS analysis of the extracts and sub-fractions showed compounds with molecular weights of >500 Daltons. The MAU-AW sub-fraction contained more polar compounds, such as flavonol and caffeic glycosides. In conclusion, these polar compounds in the EJ extract are responsible for inducing IFN-γ production. Further chemical elucidation is warranted to lead to a specific IFN-γ inducer and an immunomodulator in polarizing immune cells and balancing immune responses in certain diseases.

Hepatoprotective Effect of Loquat Leaf Flavonoids in PM2.5-Induced Non-Alcoholic Fatty Liver Disease via Regulation of IRs-1/Akt and CYP2E1/JNK Pathways

“…As a traditional Chinese medicine, Loquat Leaf ( Eriobotrya japonica (Thunb.) Lindl (Rosaceae)) has been widely used in the treatment of respiratory diseases for centuries, such as pharyngolaryngitis, bronchitis, chronic bronchitis cough, and chronic obstructive pulmonary disease (COPD) [ 20 ]. Extracts of Loquat Leaf also have shown other bioactivities, especially the effect on metabolic disorders, including anti-diabetic, hypolipidemic, and anti-obesity activities [ 21 , 22 , 23 ].…”

A Functional Food Mixture “Protector” Reinforces the Protective Immune Parameters against Viral Flu Infection in Mice

“…After 24 h of intraperitoneal administration, “Protector” significantly increased the production of IFN-γ in peripheral blood and spleen ( Figure 1 ) in a dose-dependent manner. In comparison to a known inducer of both cytokines (EJ) [ 38 , 39 , 40 ], 10 µg of “Protector” produced a similar to higher levels of IFN-γ in blood and spleen. A similar pattern of enhancement was observed with IL-12 (data not shown).…”

“…Animals received a single intraperitoneal (i.p.) injection of 1 mL sterile PBS containing 0.2 µm-filtered amounts (0, 1, 10, 100 µg) of “Protector” or Eriobotrya japonica water extract (EJ), as a positive control and a stimulator of IL-12 and IFN-γ [ 38 , 39 , 40 ]. Twenty-four hours later, mice were sacrificed by cervical dislocation, and each mouse blood sample was directly collected from the cardiac chamber, placed into a pre-chilled tube, weighed and incubated with 2 mL of ice-cold endotoxin-free PBS containing 0.1% Igepal CA-630 under ice for 10 min [ 41 ].…”

“…Each extract of this mixture has been shown to modulate the immune system in favor of either stimulating an event or cascade of events in the immune system [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ] or reducing inflammatory processes [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ] that could result during flu infection. The latter anti-inflammatory effect, however, depends on the type of extract (or part of the extract), isolated fraction, and the model used [ 38 , 39 , 40 ]. Therefore, in order to evaluate the potential of “Protector” in stimulating/modulating the immune system and supporting the protective immune parameters against viral flu infection, we performed several experiments in mice showing its potential to enhance/modulate the production of (a) IFN-γ and IL-12 without and with immunization of the flu vaccine; (b) protective hemagglutinin inhibition (HAI) antibodies following flu vaccination; and (c) the pro-constructive IL-22, and inflammatory-induced IL-6, following flu vaccination.…”

Enhanced Corrosion Resistance of Carbon Steel in Hydrochloric Acid Solution by Eriobotrya Japonica Thunb. Leaf Extract: Electrochemical Study

“…belongs to the genus Rosa, which is prevalent in most provinces of southern China. The fruit of this plant, one of the important subtropical fruits, and its leaves have been used medicinally to treat coughs, colds, chronic bronchitis, phlegm, high fever, and gastro-enteric disorders [ 28 ].…”