Ameliorative effects of Eriobotrya japonica seed extract on cellular aging in cultured rat fibroblasts.

To investigate the effects of Eriobotrya japonica seed extract (ESE) on cellular aging, intracellular calcium homeostasis in young and senescent cells was analyzed using a rat fibroblast culture as an in vitro model system and a calcium imaging technique. The application of bradykinin (BK) transiently elicited intracellular calcium ion (Ca(2+)) increased in most of the young fibroblasts, whereas these responses were scarcely observed or were significantly attenuated in senescent cells. However, the long-term treatment of senescent cells with ESE (for 7 days) dose-dependently increased the amplitude of BK-induced responses and the percentage of BK-responding cells. In particular, most senescent cells could respond to BK with long-term treatment with ESE (1.0% or 2.0%), an effect that reinstated the percentage of BK-responding cells to the same level as that in young cells. The effects of ESE on amplitude or percentage of responding cells were not observed in young cells. Moreover, the time to half decay, which was significantly longer in senescent cells than that in young cells, was shortened in senescent cells with long-term treatment with ESE. These results suggest that treatment with an adequate concentration of ESE renders BK-induced Ca(2+) dynamics in senescent cells similar to those in young cells. Therefore, ESE can retard and/or protect against cellular aging and may be useful for elucidating the antiaging processes.

Eriobotrya japonica seed extract and deep sea water protect against indomethacin-induced gastric mucosal injury in rats.

We have previously reported that Eriobotrya japonica seed extract (ESE) is effective for the treatment of various gastric mucosal injuries. For the pharmaceutical preparation of ESE, we are evaluating deep sea water (DSW), which contains trace elements and has a homeostasis-enhancing effect, as the solvent. In this study, we prepared DSW containing ESE (ESE + DSW) and evaluated its usefulness for the prevention of gastric mucosal injuries using non-steroidal anti-inflammatory drug-induced acute gastric mucosal injury models in male Wistar/ST rats. Gastric mucosal injury models were prepared by administering indomethacin at 30 mg/kg orally to the rats after a 24-h fast. ESE was prepared by a routine procedure and administered at the same concentration as in the administration to humans. The rats were divided into the following 6 groups: ESE, DSW, ESE + DSW, tap water (control), rebamipide (positive control), or untreated. Gastric mucosal injuries were evaluated by measuring the injury area, lipid peroxide (LPO) level, antioxidative enzyme level, and volume of mucus. The injury area and LPO levels in plasma and gastric tissue were significantly reduced in the ESE and ESE + DSW groups compared with the control and DSW group. The plasma and gastric tissue antioxidative enzyme levels were significantly higher in the ESE and ESE + DSW groups than in the control group. These results suggest that DSW, when combined with ESE, inhibits antioxidative enzymes, and enhances the gastric mucosal protecting effect of ESE.

Immunomodulatory effect of Eriobotrya japonica seed extract on allergic dermatitis rats.

We examined the immunomodulatory effect of Eriobotrya japonica seed extract (ESE) on rat allergic dermatitis elicited by repeated dinitrofluorobenzene (DNFB) application on the ear. Oral administration of ESE significantly inhibited development of allergic dermatitis based on lower ear thickness and serum immunoglobulin E (IgE) levels. Th1 cytokine interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), Th2 cytokine interleukin-4 (IL-4) and interleukin-10 (IL-10) in the lesional skin were determined. Oral administration of ESE significantly decreased IL-4 while significantly increasing IL-10 in lesional skin, and the lower levels of IFN-gamma and IL-2 were reversed by oral administration of ESE. The infiltration of eosinophils in the lesional skin was decreased by oral administration of ESE. These results suggested that ESE exerts anti-allergic actions by improving the balance of Th1/Th2 in allergic dermatitis.

Effects of Eriobotrya japonica seed extract on oxidative stress in rats with non-alcoholic steatohepatitis.

OBJECTIVES: Non-alcoholic steatohepatitis is associated with the deposition of lipid droplets in the liver, and is characterised histologically by the infiltration of inflammatory cells, hepatocellular degeneration and liver fibrosis. Oxidative stress may play an important role in the onset and deterioration of non-alcoholic steatohepatitis. We previously reported that an Eriobotrya japonica seed extract, extracted in 70% ethanol, exhibited antioxidant actions in vitro and in vivo. In this study, we examined the effect of this extract in a rat model of non-alcoholic steatohepatitis. METHODS: The seed extract was given in the drinking water to fats being fed a methionine-choline-deficient diet for 15 weeks. KEY FINDINGS: Increases in alanine aminotransferase and aspartate aminotransferase levels were significantly inhibited in rats fed the seed extract compared with the group on the diet alone. Formation of fatty droplets in the liver was also inhibited. Antioxidant enzyme activity in liver tissue was higher than in the diet-only group and lipid peroxidation was reduced compared with rats that also received the extract. Expression of 8-hydroxy-2'-deoxyguanosine and 4-hydroxy-2-nonenal was lower in the rats given the seed extract than in the diet-only group. In the former, liver tissue levels of transforming growth factor-beta and collagen were also decreased. CONCLUSIONS: Thus, the E. japonica seed extract inhibited fatty liver, inflammation and fibrosis, suggesting its usefulness in the treatment of non-alcoholic steatohepatitis.

Animal studies supporting the inhibition of mast cell activation by Eriobotrya japonica seed extract.

OBJECTIVES: The potent antioxidant activity of Eriobotrya japonica seed extract (ESE) and its usefulness in the prevention and treatment of various disorders has been reported previously. Its antioxidant activity associated with beta-sitosterol and polyphenols contained in the extract was also validated. In this study, anti-allergic activity of Eriobotrya japonica seed extract was investigated. METHODS: The inhibition of histamine release-mediated type 1 allergy by Eriobotrya japonica seed extract was used as an index. KEY FINDINGS: The administration of this extract inhibited histamine release from rat mast cells, suggesting its usefulness in allergic disease treatment. In an experiment using a guinea-pig allergic rhinitis model, this extract reduced the frequency of sneezing and nose-scratching. CONCLUSIONS: These results suggest that Eriobotrya japonica seed extract may contribute to the relief of allergic disease-related symptoms.

Gastroprotective activity of Eriobotrya japonica seed extract on experimentally induced gastric lesions in rats.

The effect of Eriobotrya japonica seed extract (ESE) prepared with 70% ethanol on gastric mucosal injury was investigated. Six experimental models with different action mechanisms were used for the evaluation. Three concentrations of ESE were prepared for each model. ESE administration was initiated 14 days before induction of gastric mucosal injury, and its effect was investigated. ESE inhibited formation of gastric mucosal injury.

Effect of orally administered Eriobotrya japonica seed extract on allergic contact dermatitis in rats.

The anti-allergic activity of Eriobotrya japonica seeds extract (ESE) was investigated. Oral administration of ESE dramatically inhibited ear swelling due to allergic contact dermatitis caused by repeated application of two antigens, 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one (oxazolone) and dinitrofluorobenzene (DNFB), respectively. The increase of histamine content in inflamed ear tissue induced by oxazolone and DNFB was significantly antagonized by orally administered ESE. Eosinophil peroxidase and myeloperoxidase activity in both models was suppressed by orally administered ESE. Tumour necrosis factor-alpha in the inflamed region caused by repeated application of DNFB was also significantly suppressed. The findings suggest that ESE may be effective for treating allergic contact dermatitis.

Scavenging of reactive oxygen species by Eriobotrya japonica seed extract.

We have clarified that Eriobotrya japonica seed extract has strong antioxidative activity, and is effective for the prevention and treatment of various diseases, such as hepatopathy and nephropathy. In this study, to investigate the influences of components of Eriobotrya japonica seed extract on its antioxidative activity, extracts were prepared using various solvents (n-hexane (Hex), ethyl acetate (EtOAc), n-butanol (n-BuOH), methanol (MeOH) and H2O) and the antioxidative activity of the solvent fractions and components was evaluated based on the scavenging of various radicals (DPPH and O2(-)) measured by the ESR method and the inhibition of Fe3+-ADP induced NADPH dependent lipid peroxidation in rat liver microsomes. The radical scavenging activities and inhibitory activities on lipid peroxidation differed among the solvent fractions and components. In the n-BuOH, MeOH and H2O fractions, radical scavenging activity and inhibitory activity on lipid peroxidation were high. In addition, these fractions contained abundant polyphenols, and the radical scavenging activity increased with the polyphenol content. In the low-polar Hex and EtOAc fractions, the radical scavenging activity was low, but the lipid peroxidation inhibition activity was high. These fractions contained beta-sitosterol, and the inhibitory activity on lipid peroxidation was high. Based on these findings, the antioxidative activity of Eriobotrya japonica seed extract may be derived from many components involved in a complex mechanism, resulting in high activity.

The effect of Eriobotrya japonica seed extract on oxidative stress in adriamycin-induced nephropathy in rats.

Eriobotrya japonica has been used as a medicinal plant for a long time, and its leaves are known to have many physiological actions such as anti-inflammatory, antitussive, and expectoran. In contrast, Eriobotrya japonica seeds are only known to contain amygdalin, and almost no investigations of its pharmacological action have been performed. Moreover, some anticancer agents such as adriamycin cause renal disorders as an adverse effect, and the mechanism of the adverse effect is considered to involve oxidative stress. We have reported that Eriobotrya japonica seed extract has an inhibitory effect on liver disorders. In this study, we prepared a 70% ethanol extract of Eriobotrya japonica seeds and administered the extract to rats with renal disorder induced by a single administration of 7 mg/kg body weight adriamycin, and investigated the usefulness of the extract. Increases in indices of renal function, plasma urea nitrogen, were significantly inhibited in rats treated with the Eriobotrya japonica extract compared to rats treated with tap water. In addition, the renal tissue level of reduced glutathione was significantly high in rats that ingested the extract, while the lipid peroxide levels in plasma and renal tissue were significantly low. However, no effect on renal tissue antioxidative enzymes was observed, suggesting that Eriobotrya japonica seed extract has direct antioxidative action. Based on these findings, Eriobotrya japonica seed extract may be effective in reducing the oxidative stress of adriamycin-induced renal disorder. Therefore, ingestion of Eriobotrya japonica seed extract may contribute to a reduction of the adverse effects of adriamycin.

Effect of Sho-saiko-to extract on hepatic inflammation and fibrosis in dimethylnitrosamine induced liver injury rats.

Sho-saiko-to extract, a Chinese herbal medicine, is widely used for treatment of chronic hepatitis in Japan. However, it is not clear what conditions Sho-saiko-to extract improves hepatic inflammation and fibrosis. We therefore induced various stages of liver injury in model rats and administered Sho-saiko-to extract. We then evaluated the liver inflammation and liver fibrosis-improving effects of Sho-saiko-to extract. The liver injury model rats were produced by administration of various doses of dimethylnitrosamine (DMN) and Sho-saiko-to extract was administered to these rats. Then the liver inflammation and fibrosis-improving effects of Sho-saiko-to extract were evaluated according to L-asparate aminotransferase (AST), L-alanine aminotransferase (ALT), liver retinoid levels, levels of hydroxyproline, Transforming Growth Factor-beta (TGF-beta), and the liver fibrosis area. These indicators depended on the total doses of DMN. The ability of Sho-saiko-to extract to improve liver inflammation and fibrosis was limited to the following levels of the respective parameters: AST levels (234-264 U/l), ALT levels (208-232 U/l), TGF-beta levels (1102-1265 pg/g liver tissue), hydroxyproline levels (633-719 nmol/g liver tissue), and liver fibrosis area (9.7-10.6 times for normal rat). These findings suggested that Sho-saiko-to extract is effective in the treatment of liver inflammation and fibrosis up to a certain degree of severity, but it produces no improvement in more severe cases.

Effects of extract derived from Eriobotrya japonica on liver function improvement in rats.

Eriobotrya japonica is considered a medicinal plant, and its leaves (Eriobotrya folia) have been used to treat skin diseases, as well as to relieve inflammation, pain, coughing, and sputa. In our evaluation of the pharmacological efficacy of the seed extracts, constituents of the seeds were found to contain the unsaturated fatty acids linolenic and linoleic acids and the sterol beta-sitosterol in the 70% EtOH and the MeOH extracts. The seed extracts were orally administered to rats with dimethylnitrosamine-induced hepatopathy, and blood L-asparate aminotransferase (AST) and L-alanine aminotransferase (ALT) levels, liver retinoid level, and hydroxyproline level were measured. Liver fibrosis rates calculated after Azan-Mallory staining and evaluation of the liver function-improving effects of extracts were showed that AST, ALT, and hydroxyproline levels and liver fibrosis rates were significantly lower, and retinoid levels were significantly higher in hepatopathic rats treated with 70% EtOH and MeOH extracts of the seed than in water-treated control rats. This suggests that the positive effect on liver function of the extracts varies depending on the extracting solvent used. 70% EtOH and MeOH extract of the seeds inhibited the development of liver fibrosis in hepatopathic rats, thus exhibiting potent improvement. The unsaturated linolenic and linoleic acids and the sterol beta-sitosterol contained in these extracts may also contribute to the improvement of liver function.