Calorie Restriction Effect of Heat-Processed Onion Extract (ONI) Using In Vitro and In Vivo Animal Models.

Onion (Allium cepa L.) is widely consumed as food or medicinal plant due to its well-defined health benefits. The antioxidant and antihyperlipidemic effects of onion and its extracts have been reported well. However, very limited information on anti-hyperglycemic effect is available in processed onion extracts. In our previous study, we reported that Amadori rearrangement compounds (ARCs) produced by heat-processing in Korean ginseng can reduce carbohydrate absorption by inhibiting intestinal carbohydrate hydrolyzing enzymes in both in vitro and in vivo animal models. To prove the enhancement of anti-hyperglycemic effect and ARCs content by heat-processing in onion extract, a correlation between the anti-hyperglycemic activity and the total content of ARCs of heat-processed onion extract (ONI) was investigated. ONI has a high content of ARCs and had high rat small intestinal sucrase inhibitory activity (0.34 ± 0.03 mg/mL, IC50) relevant for the potential management of postprandial hyperglycemia. The effect of ONI on the postprandial blood glucose increase was investigated in Sprague Dawley (SD) rats fed on sucrose or starch meals. The maximum blood glucose levels (Cmax) of heat-processed onion extract were significantly decreased by about 8.7% (from 188.60 ± 5.37 to 172.27 ± 3.96, p < 0.001) and 14.2% (from 204.04 ± 8.73 to 175.13 ± 14.09, p < 0.01) in sucrose and starch loading tests, respectively. These results indicate that ARCs in onion extract produced by heat-processing have anti-diabetic effect by suppressing carbohydrate absorption via inhibition of intestinal sucrase, thereby reducing the postprandial increase of blood glucose. Therefore, enhancement of ARCs in onion by heat-processing might be a good strategy for the development of the new product on the management of hyperglycemia.

Antioxidant and Anti-Osteoporosis Activities of Chemical Constituents of the Stems of Zanthoxylum piperitum.

Two new lignans, zanthoxyloside C (1) and zanthoxyloside D (2), together with nine known compounds comprising lignans (3-5), flavonoids (6-8), and phenolics (9-11), were isolated from the methanol extract of the stems of Zanthoxylum piperitum. All isolates were evaluated for their antioxidant and anti-osteoporotic activities using oxygen radical absorbance capacity (ORAC), cupric reducing antioxidant capacity (CUPRAC), and tartrate-resistant acid phosphatase (TRAP) assays. Compounds 7-10 showed peroxyl radical-scavenging capacities and 4, 6-7, and 9 showed reducing capacities. Moreover, compounds 3, 6-9, and 11 significantly suppressed TRAP activities. These results indicated that the stems of Z. piperitum could be an excellent source for natural antioxidant and anti-osteoporosis.

Antioxidant and anti-osteoporotic effects of anthraquinones and related constituents from the aqueous dissolved Aloe exudates.

In this study, 25 known anthraquinones and related compounds were isolated from aqueous dissolved Aloe exudates. The antioxidant and anti-osteoporotic activities of the isolated compounds were then investigated. Compounds 8, 11, 20, and 23 showed good antioxidant activity based on peroxyl radical-scavenging and reducing capacity assays at a concentration of 10.0 µM. Additionally, compounds 7, 9, 15-16, 18, 21-22 and 24-25 showed potent peroxyl radical-scavenging activities with values ranging from 5.28 to 14.60 at 10.0 µM. Moreover, compounds 8, 11, 15, 20 and 22 exhibited significantly suppressed tartrate-resistant acid phosphatase (TRAP) activity in nuclear factor-κB ligand-activated osteoclastic RAW 264.7 cells, with values of 125.67, 118.54, 127.64, 125.82 and 124.98%, respectively. These results indicate that Aloe is an excellent source of antioxidant and anti-osteoporotic phytochemicals.

Anti-Osteoclastic Activity of Artemisia capillaris Thunb. Extract Depends upon Attenuation of Osteoclast Differentiation and Bone Resorption-Associated Acidification Due to Chlorogenic Acid, Hyperoside, and Scoparone.

The present study attempts to elucidate the anti-osteoporotic activity of Artemisia capillaris Thunb. in the form of anti-osteoclastic effect and responsible bioactive compounds. The contents of chlorogenic acid, caffeic acid, hyperoside, isoquercitrin, isochlorogenic acid A, and scoparone in Artemisia capillaris hydroethanolic extract (ACHE) were 38.53, 0.52, 4.07, 3.03, 13.90, and 6.59 mg/g, respectively. ACHE diminished osteoclast differentiation and bone resorption due to chlorogenic acid, hyperoside, and scoparone. In addition, ACHE attenuated acidification as well as reducing tumor necrosis factor receptor-associated factor 6 (TRAF6) expression and its association with vacuolar H⁺-adenosine triphosphatase (V-ATPase). Furthermore, chlorogenic acid, hyperoside, and scoparone from A. capillaris abrogated the association of V-ATPase with TRAF6, suggesting that the blockage of bone resorption by A. capillaris was partially mediated by reducing acidification through down-regulating interaction of V-ATPase with TRAF6 due to scoparone as well as chlorogenic acid and hyperoside. These results imply that the anti-osteoclastic effect of A. capillaris through down-regulating osteoclast differentiation and bone resorption may contribute to its anti-osteoporotic effect.

Two new naphthalene glucosides and other bioactive compounds from the carnivorous plant Nepenthes mirabilis.

Two new naphthalene diglucosides named nepenthosides A (1) and B (2), together with eleven known compounds (3-13), were isolated from the carnivorous plant Nepenthes mirabilis. The structures of these compounds were elucidated based on extensive spectroscopic analysis, including 1D- and 2D-NMR, and MS. The antioxidant activities of compounds 1-13 were evaluated in terms of their peroxyl radical-scavenging (trolox equivalent, TE) and reducing capacities. All isolates showed peroxyl radical-scavenging and reducing activities at concentrations of 1.0 and 10.0 µM. Anti-osteoporotic activities were investigated using murine osteoclastic RAW 264.7 cells. Compounds 1-7 and 9-12 significantly suppressed tartrate-resistant acid phosphatase activity down to 91.13 ± 1.18 to 42.39 ± 1.11%, relative to the control (100%) in nuclear factor-κB ligand (RANκL)-induced osteoclastic RAW 264.7 macrophage cells.

The anti-osteoporosis and antioxidant activities of chemical constituents from Chrysanthemum indicum flowers.

Two new compounds, chrysinoneside A (1) and (-)-trans-chrysanthenol-6-O-ß-D-glucopyranoside (2), along with 17 known compounds (3-19) were isolated from Chrysanthemum indicum flowers. The total phenolic and flavonoid contents of various fractions were determined. The EtOAC fraction had the highest total phenolic content (525.84 ± 23.51 mg GAE/g DR) and the total flavonoid content (63.49 ± 3.32 mg QE/g DR). The EtOAc and water fractions showed the greatest peroxyl radical-scavenging capacity and the ability to reduce Cu(I) ions, with ORAC and CUPRAC values ranging from 24.00 ± 0.44 to 28.06 ± 1.35 and 16.90 ± 0.51 to 49.77 ± 0.97 µM, respectively. Compounds 5-11, 18, and 19 displayed strong effects in both peroxyl radical-scavenging and reducing capacity assays at a concentration of 10 µM. The anti-osteoporosis activity of these compounds was also evaluated. Compounds 10, 13, and 19 exhibited the most potent tartrate-resistant acid phosphatase activity in receptor activator of nuclear factor-κB ligand-induced osteoclastic RAW 264.7 cells with values of 105.95 ± 1.18, 110.32 ± 3.95, and 112.58 ± 6.42%, respectively.

In vitro evaluation of the antioxidant and cytotoxic activities of constituents of the mangrove Lumnitzera racemosa Willd.

This study performed phytochemical and bioactive assessments of the mangrove Lumnitzera racemosa Willd. leaves. Bioassay-guided fractionation of the methanolic extracts led to the identification of thirty-six compounds (1-36), their structures were elucidated using detailed NMR spectroscopic and MS analysis. The extracts, fractions, and the isolated compounds were screened for potential antioxidant and cytotoxic activities. Antioxidant assays were performed using peroxyl radical-scavenging and reducing assays, whereas cytotoxicity was measured using MTT assays in HL-60 and Hel-299 cell lines. The methanolic extract, CH2Cl2 and n-BuOH fractions (10.0 µg/mL) exhibited potent antioxidant activity, with Trolox equivalent (TE) values of 24.94 ± 0.59, 28.34 ± 0.20, and 27.09 ± 0.37 (µM), respectively. In addition, the isolated compounds exerted cytotoxic effects in a dose-dependent manner; compounds 1 and 14 exhibited the most potent cytotoxicity in HL-60 cells, with IC50 values of 0.15 ± 0.29 and 0.60 ± 0.16 µM, respectively. To clarify the mechanism(s) behind these cytotoxic effects, we measured the time-dependent changes in apoptotic markers including the condensation and fragmentation of nuclear chromatin, and the downregulation of p-ERK1/2, p-AKT, and c-Myc levels.

Evaluation of the antioxidant and anti-osteoporosis activities of chemical constituents of the fruits of Prunus mume.

The present study investigated the antioxidant and anti-osteoporosis activities of phytochemicals in the fruits of Prunus mume. From the methanol extract, three new acylated sucroses, mumeoses P-R (1-3), were isolated together with 20 known compounds (4-23). Compounds 1-3 showed potent peroxyl radical-scavenging activities and 12-19 showed both potent peroxyl radical-scavenging and reducing activities. The anti-osteoporosis activity was evaluated using murine pre-osteoblastic MC3T3-E1 cells and pre-osteoclastic RAW 264.7 cells. Compounds 2 and 3 (cis-trans isomers), 5, 7, 8, and 10 significantly stimulated the differentiation of pre-osteoblastic MC3T3-E1 cells to increase collagen synthesis or mineralization functions of osteoblasts, while compounds 5, 6, 9, 10, 12, 14-16, 18, 20, and 22 significantly suppressed tartrate-resistant acid phosphatase activity in receptor activator of nuclear factor-κB ligand-induced osteoclastic RAW 264.7 cells. These results indicated that the fruits of P. mume are an excellent source of antioxidant and anti-osteoporosis phytochemicals.

Scopoletin and scopolin isolated from Artemisia iwayomogi suppress differentiation of osteoclastic macrophage RAW 264.7 cells by scavenging reactive oxygen species.

Artemisia iwayomogi has been used as a folk medicine for treating various diseases including inflammatory and immune-related diseases. Scopoletin (1) and scopolin (2) were isolated from this species. Scopoletin (1) showed more potent peroxyl radical-scavenging capacity, reducing capacity, and cellular antioxidant capacity compared to scopolin (2). The inhibitory effect of 1 on the receptor activator of nuclear factor κB ligand-induced osteoclastic differentiation of RAW 264.7 macrophage cells was also more potent than that of 2. The production of general reactive oxygen species (ROS) and superoxide anions during differentiation of preosteoclastic RAW 264.7 cells into osteoclasts was attenuated by compounds 1 and 2. These findings indicate that the suppressive effects of 1 and 2 on the differentiation of preosteoclastic RAW 264.7 cells is partially due to their intracellular antioxidant capacity, as they can scavenge ROS and play an important signaling role in the differentiation process.

In vitro and intracellular antioxidant capacity of thymyl methyl ether as a major component in Blumea lanceolaria (Roxb.) Druce leaf oil.

Thymyl methyl ether is a major component of Blumea lanceolaria (Roxb.) Druce leaves. In this study, the antioxidant capacity of thymyl methyl ether and its better known hydroxylated form thymol was examined using oxygen radical absorption capacity and intracellular antioxidant capacity assays. Thymol displayed stronger peroxyl radical and hydroxyl radical-scavenging capacity, as well as reducing capacity than those of thymyl methyl ether, which can be explained by its hydrogen or electron donating capacity. However, thymyl methyl ether exhibited potent protection against peroxyl radical and Cu(2+)-induced oxidative stress when compared to thymol in the intracellular antioxidant capacity and lipid peroxidation assays using HepG2 cells. These results illustrate the higher cell membrane permeability of thymyl methyl ether to thymol and its transformation to thymol, which results in potent intracellular antioxidant capacity contributing to protection against lipid peroxidation.

Mulberry leaf extract reduces postprandial hyperglycemia with few side effects by inhibiting α-glucosidase in normal rats.

Mulberry (Morus alba L.) leaf extract (MLE) was investigated as a potent plant-derived α-glucosidase inhibitor with low α-amylase inhibitory activity. MLE was prepared by heating in an autoclave at 121 °C for 15 minutes, and its in vitro and in vivo antihyperglycemic activities were investigated. The adverse side effects of MLE were analyzed by measuring the weight and volume of the cecum, stool color, starch content in the cecum, and the integrity of intestinal transporting capacity. The in vitro inhibitory activity of MLE on intestinal α-glucosidase was potent and that on intestinal α-amylase was very weak compared with acarbose. Sugar loading tests with starch, maltose, and sucrose showed that MLE may reduce postprandial increases in blood glucose by acting as an intestinal α-glucosidase inhibitor. Feeding tests suggested that MLE may exhibit fewer adverse side effects than other α-glucosidase inhibitors, such as abdominal flatulence and meteorism, which are attributed to the impaired digestion of starch by strong inhibition of intestinal α-amylase. These results suggest that MLE could be used in the development of pharmaceutical foods to control the blood glucose levels of diabetic patients by inhibiting intestinal α-glucosidase with reduced side effects.

In vitro and in vivo anti-hyperglycemic effects of Omija (Schizandra chinensis) fruit.

The entrocytes of the small intestine can only absorb monosaccharides such as glucose and fructose from our diet. The intestinal absorption of dietary carbohydrates such as maltose and sucrose is carried out by a group of α-glucosidases. Inhibition of these enzymes can significantly decrease the postprandial increase of blood glucose level after a mixed carbohydrate diet. Therefore, the inhibitory activity of Omija (Schizandra chinensis) extract against rat intestinal α-glucosidase and porcine pancreatic α-amylase were investigated in vitro and in vivo. The in vitro inhibitory activities of water extract of Omija pulp/skin (OPE) on α-glucosidase and α-amylase were potent when compared to Omija seeds extract (OSE). The postprandial blood glucose lowering effect of Omija extracts was compared to a known type 2 diabetes drug (Acarbose), a strong α-glucosidase inhibitor in the Sprague-Dawley (SD) rat model. In rats fed on sucrose, OPE significantly reduced the blood glucose increase after sucrose loading. Furthermore, the oxygen radical absorbance capacity (ORAC) of OSE and OPE was evaluated. OPE had higher peroxyl radical absorbing activity than OSE. These results suggest that Omija, which has high ORAC value with α-glucosidase inhibitory activity and blood glucose lowering effect, could be physiologically useful for treatment of diabetes, although clinical trials are needed.

Chemical constituents and antioxidant activity of Ficus callosa.

One new megastigmane glycoside, ficalloside (1), and eleven known compounds, were isolated from methanol extract of Ficus callosa leaves by repeated column chromatography. Their structures were established on the basis of spectral and chemical evidence. The antioxidant activities of these compounds were measured using the oxygen radical absorbance capacity (ORAC) assay. Compound 8 exhibited potent antioxidant activity of 10.6 microM trolox equivalents at the concentration of 2 microM. At this concentration, compounds 4-7 and 9-12 showed significant antioxidant activity with ranging of 2.1-6.1 microM trolox equivalents.

Antioxidant activity of a new C-glycosylflavone from the leaves of Ficus microcarpa.

By bioactive-guided fractionation of methanol extract of the Ficus microcarpa leaves, one new C-glucosylflavone, ficuflavoside (1), one new megastigmane glycoside, ficumegasoside (8), and twelve known compounds including flavonoids (2-6), phenylpropanoids (7), megastigmanes (9-11) and sterol derivatives (12-14) were isolated. Their chemical structures were elucidated by mass, 1D, and 2D NMR spectroscopies. The antioxidant activities of these compounds were measured using the oxygen radical absorbance capacity methods. Compounds 1-6 exhibited potent antioxidant activities of 6.6-9.5µM Trolox equivalents at the concentration of 2.0µM. The results indicated 2, 3, and 5 having meaningful reducing capacity of copper (I) ions concentration of 6.1-8.4µM.

Flavonol content in the water extract of the mulberry (Morus alba L.) leaf and their antioxidant capacities.

UNLABELLED: The biological activities of the mulberry (Morus alba L.) leaf have been attributed to its flavonoid content. The water extract of the mulberry leaf (WEML) was prepared by autoclaving at 121 °C for 15 min, and the flavonol content of the WEML was determined by HPLC The WEML contained 4 flavonols in the following order: quercetin-3-ß-D-glucose (QT-G) > quercetin-3-O-glucose-6″-acetate (QT-GA) > rutin (RT) > quercetin (QT). In the oxygen radical absorbance capacity (ORAC) assay, QT had the highest peroxyl radical-scavenging capacity and a similar hydroxyl radical-scavenging capacity as its glycosides (QT-G, QT-GA, and RT). QT exhibited a stronger cellular antioxidant capacity (CAC) against 2,2'-Azobis(2-amidinopropane) dihydrochloride (AAPH)- and Cu²âº-induced oxidative stress in HepG2 cells compared to its glycosides, indicating that the intracellular antioxidant capacity of QT and its glycosides may depend upon both the permeability across the cell membrane and the peroxyl or hydroxyl radical-scavenging capacity. PRACTICAL APPLICATION: The information presented might be used for developing mulberry leaf-based functional foods.

In vitro and in vivo antihyperglycemic effect of 2 amadori rearrangement compounds, arginyl-fructose and arginyl-fructosyl-glucose.

During the heat processing of raw ginseng to produce red ginseng, amino acid derivatives such as arginyl-fructose (AF) and arginyl-fructosyl-glucose (AFG) are formed at high levels, through amadori rearrangement, the early step of Maillard reaction, from arginine and glucose or maltose, respectively. However, very limited information is available about the effect of the structural difference between AF and AFG on various biological activities. This is the first report of the mode of action and effect of AF and AFG on the type 2 diabetes management related inhibition of postprandial hyperglycemia in vitro and in animal model. In our previous study, standards AF and AFG were chemically synthesized and in this study their inhibitory activities against rat intestinal α-glucosidases and porcine pancreatic α-amylase were investigated in vitro. The IC(50) value of the in vitro inhibitory activity of AF and AFG on rat intestinal sucrase was high and in similar levels (6.40 and 6.20 mM, respectively). Additionally, a mild pancreatic α-amylase inhibitory activity was observed, with IC(50) values 36.30 and 37.60 mM for AF and AFG, respectively. The effect of AF and AFG on the postprandial blood glucose increase after meal was investigated in Sprague Dawley rats fed on starch or sucrose meals. Both amadori compounds significantly reduced the postprandial blood glucose levels after starch or sucrose loading. These results indicate that AF and AFG, Maillard reaction products, may have antidiabetic effect by suppressing carbohydrate absorption in the gastrointestinal level, and thereby reducing the postprandial increase of blood glucose.

Heat processing decreases Amadori products and increases total phenolic content and antioxidant activity of Korean red ginseng.

The functional properties of Korean red ginseng (KRG) are known to be dependent upon the extent of heat processing. We demonstrated that repeated heat processing in the preparation of KRG decreased its arginyl-fructosyl-glucose (AFG) content and metal chelating capacity. On the other hand, the total phenolic compound content, in vitro peroxyl radical scavenging ability, and cellular peroxyl and hydroxyl radical scavenging ability increased with repeated heat processing. The peroxyl radical scavenging ability of KRG may be due to the total phenolic compound content. The hydroxyl radical scavenging ability of KRG seems to result mainly from the chelating ability of Amadori compounds such as arginyl-fructose and AFG. The protective ability of KRG against Cu²(+)-induced oxidative stress in hepatoma HepG2 cells may be due to permeability into the cell membrane rather than antioxidant activity. These results can be used to predict the physiological functions of KRG in in vivo models.

Antimicrobial activities of 1,4-benzoquinones and wheat germ extract.

We evaluated the antibacterial activities of selected edible Korean plant seeds against the food-borne pathogens Staphylococcus aureus KCTC1927, Escherichia coli KCTC2593, Salmonella typhimurium KCTC2054, and Bacillus cereus KCTC1014. While screening for antibacterial agents, we discovered that wheat germ extract contains 2,6-dimethoxy-1,4-benzoquinone (DMBQ) and is highly inhibitory to S. aureus and B. cereus. This is the first report of the antibacterial activity of wheat germ extract. We also investigated the antibacterial activities of the 1,4- benzoquinone standards 1,4-benzoquinone (BQ), hydroquinone (HQ), methoxybenzoquinone (MBQ), and 2,6-dimethoxy- 1,4-benzoquinone (DMBQ). DMBQ and BQ were the most highly inhibitory to S. aureus and S. typhimurium, followed by MBQ and HQ. MICs for DMBQ and BQ ranged between 8 and 64 microgram/ml against the four foodborne pathogens tested. DMBQ and BQ showed significant antibacterial activity; the most sensitive organism was S. aureus with an MIC of 8 microgram/ml. BQ exhibited good activity against S. typhimurium (32 microgram/ml) and B. cereus (32 microgram/ml). The results suggest that wheat germ extract has potential for the development of natural antimicrobials and food preservatives for controlling foodborne pathogens.

Two new C-glucosyl benzoic acids and flavonoids from Mallotus nanus and their antioxidant activity.

Two new 2-C-beta-D-glucopyranosyl benzoic acid derivatives named mallonanosides A (1) and B (2) were isolated from the methanolic extract of the leaves of Mallotus nanus along with five known flavonoids, kaempferin (3), juglanin (4), quercitrin (5), myricitrin (6), and rhoifolin (7). Their structures were established on the basis of spectral and chemical evidence. Their antioxidant activities were shown to depend on the number of hydroxyl groups, and the location and species of sugar moiety.

The effect of Eucommia ulmoides leaf supplementation on the growth performance, blood and meat quality parameters in growing and finishing pigs.

The aim of the present study was to investigate the effect of Eucommia ulmoides leaf (EUL) supplementation on the growth performance, blood and meat quality parameters in growing and finishing pigs. Ninety gilts (L x LW x D, 20 kg initialBW) were housed 10 per pen in a front-open building with three replicate pens per treatment. Experimental treatment was started from the beginning of the growing stage (20 +/- 3 kg) by supplementing EUL at 0(C), 3(T1) and 5% (T2) to the growing and finishing diet. Pigs were slaughtered by electrical stunning at 105 +/- 3 kg live weight. Average daily feed intake (ADFI, kg/day) decreased (P < 0.05) by addition of EUL in growth performance, average daily gain (ADG, kg/day) was lower (P < 0.05) in T1 and T2 than in C. In hematology, leukocytes (WBC, 10(3)/mm(3)) decreased (P < 0.05) in T1 and T2 than in C. Erythrocytes (RBC, 10(6)/mm(3)), hemoglobin (HGB, g/dL) and hematocrit (HCT, %) increased (P < 0.05) in T1 and T2 than in C. Platelet (PLT, 10(3)/mm(3)) was lower (P < 0.05) in T2 than in C and T1. In biochemical composition of serum, total protein (g/dL), r-GTP (micro/L), total cholesterol (mg/dL) and triglycerides (mg/dL) were lower (P < 0.05) in T1 and T2 than in C. On longissimus dorsi muscle, crude protein was higher (P < 0.05) in T1 than in C. Crude ash was higher (P < 0.05) in T1 and T2 than in C. Yellow to blue color scale (CIE b*) in meat color was higher (P < 0.05) in T2 than in C. CIE b* in back fat color was higher (P < 0.05) in T2 than in the other treatments. In sensory evaluation scores for fresh meat, the values of meat color, fat color, drip loss and marbling were not significantly affected by addition of EUL. In cooked meat, the values of chewiness and overall acceptability were higher (P < 0.05) in T1 and T2 than in C. The results indicate that the addition of EUL affected growth performance, blood parameters and meat quality parameters in growing and finishing pigs.