Pear pomace water extract suppresses hepatic lipid peroxidation and protects against liver damage in rats fed a high fat/cholesterol diet.

The protective effect of pear pomace water extract (PPWE) against hepatic lipid peroxidation was investigated in rats fed a 41% kcal fat diet containing 0.21% cholesterol (HFCD). For 5 weeks, 200 or 400 mg/kg of PPWE was administrated once daily via oral gavage. Body weights were lower in the PPWE-treated group than in the control group. Serum total antioxidant capacity increased, whereas hepatic thiobarbituric acid reactive substances significantly decreased after the administration of PPWE. PPWE recovered the HFCD-induced reduction of hepatic glutathione S-transferase and glutathione peroxidase activity. The serum alanine aminotransferase and aspartate aminotransferase activities significantly decreased on PPWE treatment. The present investigation suggests that PPWE represents a valuable natural antioxidant source for use in the health food industry.

St. John's Wort (Hypericum perforatum) stimulates human osteoblastic MG-63 cell proliferation and attenuates trabecular bone loss induced by ovariectomy.

BACKGROUND/OBJECFTIVES: The effect of St. John's Wort extract (SJW) on MG-63 cell proliferation and trabecular bone loss induced by ovariectomy was examined. MATERIALS/METHODS: Proliferation, expression of estrogen receptor (ER) α and ER ß, and gene expressions of osteoprotegerin (OPG), osteocalcin (OC) and alkaline phosphatase (ALP) were examined in MG-63 cells treated with or without SJW. Ovariectomized rats were treated with SJW at the dose of 100 or 200 mg/kg/day, ß-estradiol-3-benzoate (E2), or vehicle only (OVX-C), and sham operated rats were treated with vehicle only (Sham-C). Serum ALP and C-telopeptide (CTX), and femoral trabecular bone loss were examined. RESULTS: SJW increased MG-63 cell proliferation and expression of ER α and ER ß, and positive effect was shown on gene expressions of ALP, OC and OPG. SJW also showed estrogen like effect on bone associated with slowing down in trabecular bone loss. Histopathology by H&E showed rats treated with SJW displayed denser structure in metaphyseal region of distal femur compared with rats in OVX-C. SJW was shown to reduce serum CTX in OVX rats. CONCLUSION: The present study provides new insight in preventing estrogen deficiency induced bone loss of SJW and possibility for its application in bone health supplement.

Effect of St. John's Wort (Hypericum perforatum) on obesity, lipid metabolism and uterine epithelial proliferation in ovariectomized rats.

BACKGROUND/OBJECTIVES: This study was conducted to assess the potential of St. John's Wort (Hypericum perforatum) to prevent obesity and abnormalities in lipid metabolism induced by ovariectomy in a rat model without stimulatory activity on uterus. MATERIALS/METHODS: Ovariectomized (OVX) rats were treated for 6 weeks with 70% ethanol extracts of Hypericum perforatum [HPEs: whole plant (WHPE) and flower and leaves (FLHPE)], ß-estradiol-3-benzoate at a dose of 50 µg/kg/day (E2) or vehicle (distilled water). RESULTS: As expected, OVX increased body weight gain and adiposity and showed higher food efficacy ratio. OVX also increased the serum cholesterol as well as insulin resistance, while reducing uterus weight and uterine epithelial proliferation rate. HPEs (WHPE and FLHPE) showed estrogen-like effect on body weight gain, adipose tissue weight and food efficacy ratio in OVX rats. HPEs prevented hypercholesterolemia induced by OVX more effectively than E2. E2 increased uterus weight and epithelial proliferation rate in OVX rats, while HPEs maintained them at the level of the sham-operated animals. CONCLUSIONS: Our finding demonstrates that HPEs can be considered as an effective agent to prevent OVX-induced obesity without stimulatory activity on uterus.