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 Eriobotrya japonica seed extract on 5-fluorouracil-induced mucositis in hamsters.

In this study, we investigated the effects of an Eriobotrya japonica seed extract (ESE) on mucositis using a 5-fluorouracil (5-FU)-induced mucositis hamster model. This model was prepared by intraperitoneally administering 90 mg/kg of 5-FU to hamsters on Day 1, scratching 1 cm(2) of the left cheek pouch of hamsters with a wire brush on Days 2, 3, and 4, and intraperitoneally administering 60 mg/kg of 5-FU on Day 5. Mucositis was evaluated based on the mucositis score at the mucositis site, left cheek pouch thickness, histological findings on HE staining, and plasma lipid peroxide levels. On Day 10, the mucositis score and left cheek pouch thickness in the ESE group were significantly lower than those in the tap water group. Histologically, the two groups showed a defect of the cheek pouch epithelium on Day 6. On Day 10, epithelial injury and bacterial infection were noted in the tap water group. However, in the ESE group, similar findings were not observed. On Day 6, the plasma lipid peroxide level in the tap water group was significantly higher than that in the normal group. In the ESE group, the plasma lipid peroxide level was significantly lower than that in the tap water group. These results suggest that ESE is useful for treating chemotherapy-induced mucositis.

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.