Joo-Wan Kim

Effects of Polycan on calcium bioavailability in two different rat models of osteoporosis

This study evaluated the effects of Polycan, a β-glucan produced by Aureobasidium pullulans SM-2001, on calcium (Ca) bioavailability in an ovariectomy (OVX) model and a thyroparathyroidectomy (TPTX) model of osteoporosis in the SD rat. Polycan (62.5, 125, and 250 mg/kg body weight) was administered daily with an oral gavage for 4 weeks in both the OVX group (beginning 10 weeks following OVX surgery) and the TPTX group (beginning 4 days following TPTX surgery) while a commercial food product containing 1% milk-borne Ca was available ad libitum. After 4 weeks of Polycan administration, all animals were sacrificed and changes in bone mineral density (BMD) in the femur, tibia, and lumbar vertebrae (L6) were analyzed using dual-energy X-ray absorptiometry. Ca intake was calculated based on the amount of food intake during the 24 h period prior to sacrifice and the Ca balance, absorption, and retention ratios were calculated based on Ca intake, urinary and faecal Ca content, and Ca balance. Polycan treatment resulted in a marked increase in the BMD of the femur, tibia, and L6 relative to the OVX and TPTX controls with concomitant increases in Ca bioavailability and decreases in secreted Ca. These findings indicate that Polycan may enhance the absorption and bioavailability of Ca and improve Ca balance.

In vitro Activities of Polycalcium, a Mixture of Polycan and Calcium Lactate-Gluconate, on Osteoclasts and Osteoblasts

The present study evaluated the beneficial effects of polycalcium (a mixture of Polycan and calcium lactate-gluconate 1:9 [g/g]) on osteoporosis using in vitro assays. Cell proliferation and alkaline phosphatase activities of osteoblasts (human primary osteoblasts) and osteoclast differentiation of RAW264.7 cells (murine osteoclast progenitor cells) treated with different concentrations of polycalcium for various periods were assessed. Osteoblast proliferation was stimulated and prevented RANKL-induced osteoclast differentiation of RAW264.7 cells. These results support the development of ideal anti-osteoporotic agents, such as polycalcium, that exhibit properties that accelerate bone formation and inhibit bone resorption.

The Effects of Topical Application of Polycal (a 2:98 (g/g) Mixture of Polycan and Calcium Gluconate) on Experimental Periodontitis and Alveolar Bone Loss in Rats.

The aim of this study was to observe whether Polycal has inhibitory activity on ligation-induced experimental periodontitis and related alveolar bone loss in rats following topical application to the gingival regions. One day after the ligation placements, Polycal (50, 25, and 12.5 mg/mL solutions at 200 μL/rat) was topically applied to the ligated gingival regions daily for 10 days. Changes in bodyweight, alveolar bone loss index, and total number of buccal gingival aerobic bacterial cells were monitored, and the anti-inflammatory effects were investigated via myeloperoxidase activity and levels of the pro-inflammatory cytokines IL-1β and TNF-α. The activities of inducible nitric oxide synthase (iNOS) and lipid peroxidation (MDA) were also evaluated. Bacterial proliferation, periodontitis, and alveolar bone loss induced by ligature placements were significantly inhibited after 10 days of continuous topical application of Polycal. These results indicate that topical application of Polycal has a significant inhibitory effect on periodontitis and related alveolar bone loss in rats mediated by antibacterial, anti-inflammatory, and anti-oxidative activities.

Laxative effects of fermented rice extract (FRe) in normal rats

The present study was performed to evaluate the laxative effects of fermented rice extract (FRe) in normal rats. FRe was orally administered at doses of 100, 200, and 300 mg/kg once per day for 15 days, and the changes in fecal parameters (fecal pellet numbers, weights, and water contents), gastrointestinal transit ratio, fecal mucus contents, colonic mucus-producing cell numbers, and mean colonic mucosa thicknesses were examined in normal rats. The laxative effects of FRe were compared with those of sodium picosulfate. At the three doses administered, FRe treatment resulted in marked increases in fecal pellet numbers and water contents discharged over 24 h, surface mucus thickness in the colonic lumen, intestinal charcoal-transit ratio, and in thickness and mucus-producing goblet cell number of the colonic mucosa with decreases in fecal pellet numbers and mean diameters remaining in the colonic lumen in comparison to the vehicle control. With the exception of intestinal charcoal-transit ratio, the effects of FRe were less marked than those of sodium picosulfate. The results of this study suggest that FRe has a laxative effect without causing diarrhea, as compared with sodium picosulfate, and FRe may be highly effective as a complementary medicine in humans suffering from lifestyle-induced constipation.

Anti-obesity effects of yellow catfish protein hydrolysate on mice fed a 45% kcal high-fat diet

Obesity contributes to the etiologies of a variety of comorbid conditions, such as type 2 diabetes, hypertension and cardiovascular disease. In the present study, the anti-obesity effects of yellow catfish protein hydrolysate (YPh) were observed in mice fed a 45% kcal high-fat diet (HFD) compared with those of mice treated with simvastatin. The HFD-fed control mice exhibited noticeable increase in body weight, and whole-body and abdominal fat densities, periovarian and abdominal wall-deposited fat pad weight, as well as in the levels of triglycerides (TG), blood total cholesterol (TC), low-density lipoprotein, alanine aminotransferase, aspartate aminotransferase, creatinine, blood urea nitrogen, and in the fecal TG and TC contents. However, they exhibited a decrease in serum high-density lipoprotein levels. In addition, an increase was detected in periovarian and dorsal abdominally deposited fat pad thickness, adipocyte hypertrophy, the number of steatohepatitis regions, hepatocyte hypertrophy and lipid droplet deposition-related renal tubular vacuolation degenerative lesions, along with increased hepatic lipid peroxidation and a deteriorated endogenous antioxidant defense system (glutathione, catalase and superoxide dismutase). However, all the above-mentioned obesity-related complications were dose-dependently and significantly inhibited after 84 days of thye consecutive oral administration of 125, 250 and 500 mg/kg YPh. In addition, YPh dose-dependently depleted the liver endogenous antioxidant defense system and inhibited hepatic lipid peroxidation. Overall, the effects of 250 mg/kg YPh on HFD-induced obesity and related complications were similar or more potent than those of 10 mg/kg simvastatin. These results indicate that YPh is a promising new potent medicinal ingredient for possible use in the treatment of obesity and related complications.

Acute dermal and ocular irritation testing of rice bran supercritical CO2 extract (RB-SCE) and 0.5% RB-SCE essence product

This study was conducted to investigate the acute dermal and ocular irritation potential of rice bran supercritical CO2 extract (RB-SCE) and a 0.5% RB-SCE essence product in rabbits and guinea pigs. No abnormal clinical signs attributable to RB-SCE were detected. In the dermal irritation test, erythema, eschar, and edema formation was observed at 24 h of RB-SCE treatment, and the skin returned to normal after 72 h. The dermal primary irritation index (PII) of RB-SCE was 2.71; thus it was classified as a moderate irritant. In the ocular irritation test, there were no clinical signs related to the application of the RB-SCE; thus it was classified as a non-irritant according to the Draize scoring system. In a skin sensitivity test in rabbits, no abnormal clinical signs attributable to RB-SCE essence were observed and the PII was 0 because there was no evidence of erythema, eschar, or edema. In the guinea pig skin sensitivity test, no abnormal body weight changes or increased mortality was detected. Sensitization to the RB-SCE essence was 0%; thus it was classified as a very weak irritant.

Dermal toxicity study of rice bran supercritical CO2 extract in Sprague-Dawley rats

The present study was carried out to evaluate the dermal toxicity of topically administered rice bran supercritical CO2 extract (RB-SCE; 500, 1,000, and 2,000 mg/kg) in male and female rats when given as a single dose and a 4-week repeated dose. In all rats that underwent the single-dose toxicity test, there were no abnormal changes in clinical signs or body weight and no deaths or abnormal gross necropsy findings related to RB-SCE. Based on the above results, the LD50 is >2,000 mg/kg in both sexes. In all rats that underwent the 4-week repeated dermal toxicity test, there were no abnormal RB-SCEassociated changes with respect to external signs, urine and blood, or organs. The no-observed-adverse-effect level (NOAEL) of RB-SCE was thus considered to be 2,000 mg/kg/day for both sexes and the target organ. RB-SCE can be regarded as a very safe agent for topical dermal administration at a moderate dose.

Blood glycemia-modulating effects of melanian snail protein hydrolysates in mice with type II diabetes

Freshwater animal proteins have long been used as nutrient supplements. In this study, melanian snail (Semisulcospira libertina) protein hydrolysates (MPh) were found to exert anti-diabetic and protective effects against liver and kidney damage in mice with type II diabetes adapted to a 45% kcal high-fat diet (HFD). The hypoglycemic, hepatoprotective and nephroprotective effects of MPh were analyzed after 12 weeks of the continuous oral administration of MPh at 125, 250 and 500 mg/kg. Diabetic control mice exhibited an increase in body weight, and blood glucose and insulin levels, with a decrease in serum high-density lipoprotein (HDL) levels. In addition, an increase in the regions of steatohepatitis, hepatocyte hypertrophy, and lipid droplet deposit-related renal tubular vacuolation degenerative lesions were detected, with noticeable expansion and hyperplasia of the pancreatic islets, and an increase in glucagon- and insulin-producing cells, insulin/glucagon cell ratios in the endocrine pancreas and hepatic lipid peroxidation, as well as decreased zymogen contents. Furthermore, a deterioration of the endogenous antioxidant defense system was observed, with reduced glucose utilization related hepatic glucokinase (GK) activity and an increase in hepatic gluconeogenesis-related phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6pase) activity. However, all of these diabetic complications were significantly inhibited by oral treatment with MPh in a dose-dependent manner. In addition, the marked dose-dependent inhibition of hepatic lipid peroxidation, the depletion of the liver endogenous antioxidant defense system, and changes in hepatic glucose-regulating enzyme activities were also observed. The results of this study suggest that MPh exerts potent anti-diabetic effects, along with the amelioration of related complications in mice with type II diabetes. The overall effects of MPh at a dose of 125 mg/kg on HFD-induced diabetes and related complications were similar or more potent than those of metformin (250 mg/kg).