Black rice (Oryza sativa L.) extracts induce osteoblast differentiation and protect against bone loss in ovariectomized rats

Resistant starch from black rice, Oryza sativa L. var. ameliorates renal inflammation, fibrosis and injury in insulin resistant rats

It has recently been reported that black rice (BR) extract has anti-obesity, anti-diabetic, and anti-osteoporosis effects. It has been shown to reduce obese-related kidney dysfunction in animal models. This study aimed to investigate the effect of resistant starch from BR (RS) on renal inflammation, oxidative stress, and apoptosis in obese insulin resistant rats. Male Wistar rats were divided into six groups: normal diet (ND), ND treated with 150 mg of RS (NDRS150), high-fat (HF) diet, HF treated with 100 and 150 mg of RS (HFRS100), (HFRS150), and HF treated with metformin as a positive control. Insulin resistance was shown in the HF rats by glucose intolerance, increased insulin, total area under the curve of glucose and homeostasis model assessment of insulin resistance and dyslipidemia. The resulting metabolic disturbance in the HF rats caused renal inflammation, fibrosis and apoptosis progressing to kidney injury and dysfunction. Prebiotic RS including anthocyanin from BR at doses of 100 and 150 mg ameliorated insulin resistance, dyslipidemia and liver injury. Treatment with RS reduced TGF-β fibrotic and apoptotic pathways by inhibition of NF-κB and inflammatory cytokines which potentially restore kidney damage and dysfunction. In conclusion, prebiotic RS from BR ameliorated obesity induced renal injury and dysfunction by attenuating inflammatory, fibrotic, and apoptotic pathways in insulin resistant rats induced by HF.

Functional role of cyanidin-3-O-glucoside in osteogenesis: A pilot study based on RNA-seq analysis

Cyanidin-3-O-glucoside (C3G) is the most widely distributed anthocyanin and it can reportedly reduce the risk of osteoporosis, but the molecular mechanism by which C3G promotes bone formation is poorly understood. In the current study, RNA sequencing (RNA-seq) was used to investigate the mechanism of action of C3G in osteogenesis. MC3T3-E1 mouse osteoblasts were divided into a C3G (100 μmol/L)-treated group and a vehicle-treated control group, and differentially expressed genes (DEGs) in groups were evaluated via RNA-seq analysis. The functions of the DEGs were evaluated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, and the genes were validated by quantitative real-time PCR. The RNA-seq analysis identified 34 genes that were upregulated in C3G-treated cells compared to vehicle-treated cells, and 17 that were downregulated GO and KEGG pathway analyses indicated that these genes were highly enriched in functions related to lysosomes and glycolipid biosynthesis, among others. The differential expression of ATPase H+-transporting V0 subunit C (Atp6v0c), chemokine (C-X3-C motif) ligand 1 (Cx3cl1), and lymphocyte antigen 6 complex, locus A (Ly6a) genes was validated by quantitative real-time-PCR. Because these genes have been previously implicated in osteoporosis, they are potential target genes of C3G action in MC3T3-E1 cells. These results provide molecular level evidence for the therapeutic potential of C3G in the treatment of osteoporosis and other disorders of bone metabolism.

Efficacy of black rice extract on obesity in obese postmenopausal women: a 12-week randomized, double-blind, placebo-controlled preliminary clinical trial

OBJECTIVES

Postmenopausal obesity is a paramount health concern among older women. Black rice is a well-known pigmented rice variety with a higher anthocyanin content. Both in vitro and in vivo studies have demonstrated the effects of black rice on obesity. The present study aimed to investigate the effects of black rice extract (BRE) on obesity among obese postmenopausal women from Korea.

METHODS

This was a 12-week, randomized, double-blind, placebo-controlled preliminary clinical trial. The participants were postmenopausal women who had stopped menstruating for more than a year. Specifically, 105 participants were randomly assigned to the BRE (1 g/d) or placebo (maltodextrin, 1 g/d) group.

RESULTS

Eighty-eight participants completed the study, 47 in the intervention group and 41 in the placebo group. At the study endpoint, dual-energy x-ray absorptiometry assessment showed that the BRE group had a significantly lower trunk fat (P = 0.04), total fat (P = 0.04), and total body fat percentage (P = 0.04) than did the placebo group. The body fat percentage (P = 0.04) was lower in the BRE group with marginal significance, and there were no significant differences in anthropometric measures such as weight, body mass index, waist circumference, or waist-to-hip ratio estimated by bioelectrical impedance analysis.

CONCLUSION

BRE supplementation for 12 weeks seems to be effective in reducing fat accumulation in postmenopausal women.

The role of Ca2+ /Calcineurin/NFAT signalling pathway in osteoblastogenesis

The bone remodelling process is closely related to bone health. Osteoblasts and osteoclasts participate in the bone remodelling process under the regulation of various factors inside and outside. Excessive activation of osteoclasts or lack of function of osteoblasts will cause occurrence and development of multiple bone‐related diseases. Ca²⁺/Calcineurin/NFAT signalling pathway regulates the growth and development of many types of cells, such as cardiomyocyte differentiation, angiogenesis, chondrogenesis, myogenesis, bone development and regeneration, etc. Some evidences indicate that this signalling pathway plays an extremely important role in bone formation and bone pathophysiologic changes. This review discusses the role of Ca²⁺/Calcineurin/NFAT signalling pathway in the process of osteogenic differentiation, as well as the influence of regulating each component in this signalling pathway on the differentiation and function of osteoblasts, whereby the relationship between Ca²⁺/Calcineurin/NFAT signalling pathway and osteoblastogenesis could be deeper understood.

Gastroprotective Activities of Ethanol Extract of Black Rice Bran (Oryza sativa L.) in Rats

Black rice is a type of rice in the Oryza sativa L. species. There are numerous reports regarding the pharmacological actions of black rice bran, but scientific evidence on its gastroprotection is limited. This study aimed to evaluate the gastroprotective activities of black rice bran ethanol extract (BRB) from the Thai black rice variety Hom Nil (O. sativa L. indica) as well as its mechanisms of action, acute oral toxicity in rats, and phytochemical screening. Rat models of gastric ulcers induced by acidified ethanol, indomethacin, and restraint water immersion stress were used. After pretreatment with 200, 400, and 800 mg/kg of BRB in test groups, BRB at 800 mg/kg significantly inhibited the formation of gastric ulcers in all gastric ulcer models, and this inhibition seemed to be dose dependent in an indomethacin-induced gastric ulcer model. BRB could not normalize the amount of gastric wall mucus, reduce gastric volume and total acidity, or increase gastric pH. Although BRB could not increase NO levels in gastric tissue, the tissue MDA levels could be normalized with DPPH radical scavenging activity. These results confirm the gastroprotective activities of BRB with a possible mechanism of action via antioxidant activity. The major phytochemical components of BRB comprise carotenoid derivatives with the presence of phenolic compounds. These components may be responsible for the gastroprotective activities of BRB. The 2000 mg/kg dose of oral BRB showed no acute toxicity in rats and confirmed, in part, the safe uses of BRB.

Cyanidin-3-glucoside Regulates Osteoblast Differentiation via the ERK1/2 Signaling Pathway

Osteoporosis, characterized by a gradual decrease in the number of osteoblasts and a gradual increase in bone resorption of osteoclasts in bone tissue, is a global chronic disease, which severely impairs the quality of life of the elderly. Therefore, it is extremely urgent to study the prevention and treatment of osteoporosis. It has been reported that anthocyanins can regulate bone metabolism and prevent osteoporosis. Cyanidin-3-O-glucoside (C3G), the most common type of anthocyanin in nature, widely exists in a variety of vegetables and fruits. Although it has been shown that C3G has multiple effects on osteoclasts, its impact(s) and underlying mechanism(s) on osteoblasts are still not clear. Here, we evaluated the effect of C3G on cell proliferation and differentiation of osteoblasts (extracted from the hip joint of patients with osteoporosis) and MC3T3-E1 (a kind of osteoblast cell line from mice). We also test the ability of osteoblasts to mineralize after C3G treatment. To find the underlying mechanism of the above effects, we further evaluated the role of the ERK signaling pathway in C3G regulation of osteoblasts. The results showed that C3G treatment enhanced osteoblast proliferation rate, osteoblast mineralization points, the mRNA levels and protein expression levels of OC (osteocalcin), and the level of ERK phosphorylation, which could be blocked by pretreatment with ERK signaling pathway inhibitor. The above results not only indicate that the ERK pathway was involved in C3G regulation of osteoblast differentiation but also provide strong suggestive evidence that osteoblasts may be promising targets in preventive and therapeutic strategies for osteoporosis.

Anthocyanin-Enriched Riceberry Rice Extract Inhibits Cell Proliferation and Adipogenesis in 3T3-L1 Preadipocytes by Downregulating Adipogenic Transcription Factors and Their Targeting Genes

Riceberry rice (Oryza sativa L.) is a new pigmented variety of rice from Thailand. Despite its high anthocyanin content, its effect on adipogenesis and adipocyte function remains unexplored. We investigated whether Riceberry rice extract (RBE) impacted cell proliferation by examining viability and cell cycle, using preadipocyte 3T3-L1 cells. To test RBE's effect on adipocyte formation, cells were cultured in adipogenic medium supplemented with extract and adipocyte number and triglyceride levels were quantified. Furthermore, Akt1 phosphorylation along with RT-qPCR and intracellular calcium imaging were performed to obtain an insight into its mechanism of action. The effect of RBE on adipocyte function was investigated using glucose uptake and lipolysis assays. Treatment of cells with RBE decreased preadipocyte number without cytotoxicity despite inducing cell cycle arrest (p < 0.05). During adipogenic differentiation, RBE supplementation reduced adipocyte number and triglyceride accumulation by downregulating transcription factors (e.g., PPARγ, C/EBPα, and C/EBPβ) and their target genes (p < 0.05). The Akt1 phosphorylation was decreased by RBE but insignificance, however, the extract failed to increase intracellular calcium signals. Finally, the treatment of adipocytes with RBE reduced glucose uptake by downregulating Glut4 mRNA expression and enhanced isoproterenol-induced lipolysis (p < 0.05). These findings suggest that RBE could potentially be used in the treatment of obesity by inhibiting adipocyte formation and proliferation.

Small molecules for mesenchymal stem cell fate determination

Mesenchymal stem cells (MSCs) are adult stem cells harboring self-renewal and multilineage differentiation potential that are capable of differentiating into osteoblasts, adipocytes, or chondrocytes in vitro, and regulating the bone marrow microenvironment and adipose tissue remodeling in vivo. The process of fate determination is initiated by signaling molecules that drive MSCs into a specific lineage. Impairment of MSC fate determination leads to different bone and adipose tissue-related diseases, including aging, osteoporosis, and insulin resistance. Much progress has been made in recent years in discovering small molecules and their underlying mechanisms control the cell fate of MSCs both in vitro and in vivo. In this review, we summarize recent findings in applying small molecules to the trilineage commitment of MSCs, for instance, genistein, medicarpin, and icariin for the osteogenic cell fate commitment; isorhamnetin, risedronate, and arctigenin for pro-adipogenesis; and atractylenolides and dihydroartemisinin for chondrogenic fate determination. We highlight the underlying mechanisms, including direct regulation, epigenetic modification, and post-translational modification of signaling molecules in the AMPK, MAPK, Notch, PI3K/AKT, Hedgehog signaling pathways etc. and discuss the small molecules that are currently being studied in clinical trials. The target-based manipulation of lineage-specific commitment by small molecules offers substantial insights into bone marrow microenvironment regulation, adipose tissue homeostasis, and therapeutic strategies for MSC-related diseases.

Anthocyanin-rich extract from black rice (Oryza sativa L. Japonica) ameliorates diabetic osteoporosis in rats

Diabetic osteoporosis (DOP) is a systemic endocrine-metabolic osteopathy which has the characteristics of bone mineral density (BMD) reduction and bone microstructural destruction. Although anthocyanin-rich extract from black rice (AEBR) was reported to have a beneficial effect on diabetic rats, no studies have been performed on whether black rice anthocyanins are beneficial for diabetic osteoporosis. Therefore, in this study, a streptozotocin-induced diabetic rat model was established to investigate the protective effect of AEBR on diabetes-induced osteoporosis and its possible mechanism. AEBR at three doses (0.5, 1.0, and 2.0 g kg^-1 d^-1) were administered by oral gavage to diabetic rats for 8 weeks. The blood glucose, BMD, bone histomorphometry parameters, serum bone turnover biomarkers, bone marrow adipocyte numbers, as well as osteoprotegerin (OPG), runt-related transcription factor 2 (RUNX 2), and receptor activator of nuclear factor-κ B ligand (RANKL) protein expression in bone and serum were detected. The results indicated that AEBR dose-dependently decreased the blood glucose, increased the BMD, and decreased the serum bone turnover markers. The bone microstructure and osteoclast numbers in bone tissues returned to normal in the high AEBR dosage group; at the same time, the AEBR dose-dependently suppressed bone marrow adipogenesis. The RUNX 2 as well as the OPG/RANKL ratio in diabetic rats' bone tissues increased significantly in the AEBR treatment group. Our results indicate that AEBR administration can ameliorate bone loss caused by diabetes; this is mainly attributed to its inhibition of bone turnover, suppression of bone marrow adipogenesis, and up-regulation of RUNX 2 and the OPG/RANKL expression ratio.

Black Rice (Oryza sativa L.) Fermented with Lactobacillus casei Attenuates Osteoclastogenesis and Ovariectomy-Induced Osteoporosis

The aim of the present study was to investigate the antiosteoclastogenic effects of black rice (Oryza sativa L.) fermented with Lactobacillus casei (LAB) in RANKL-induced RAW macrophage cells and its antiosteoporosis activity against ovariectomy-induced osteoporosis in rats. LAB extract (LABE) treatment attenuated receptor activator of nuclear factor-kappa B (NF-κB) ligand-induced osteoclastic differentiation in RAW cells by inhibiting intercellular reactive oxygen species generation and downregulating the activation of mitogen-activated protein kinases and NF-κB, leading to the downregulation of c-Fos and expression of nuclear factor of activated T cells c1. This consequently suppressed the expression of osteoclast-specific genes including those for cathepsin K, tartrate-resistant acid phosphatase, calcitonin receptor, and integrin β3. Oral administration of LABE protected against ovariectomy-induced bone loss by significantly inhibiting bone architecture alterations and improving serum bone turnover markers in ovariectomized rats. The findings suggest that the antiosteoporotic activity of LABE may be derived from its antiosteoclastic and anti-bone-resorptive activities. LABE has potential as a promising functional material or substrate to prepare protective agents for osteoporosis and osteoclast-mediated bone diseases.

Ferulic acid may target MyD88-mediated pro-inflammatory signaling - Implications for the health protection afforded by whole grains, anthocyanins, and coffee

Higher dietary intakes of anthocyanins have been linked epidemiologically to decreased risk for metabolic syndrome, type 2 diabetes and cardiovascular events; clinical trials and rodent studies evaluating ingestion of anthocyanin-rich extracts confirm favorable effects of these agents on endothelial function and metabolic syndrome. However, these benefits of anthocyanins are lost in rats whose gut microbiome has been eliminated with antibiotic treatment - pointing to bacterial metabolites of anthocyanins as the likely protective agents. A human pharmacokinetic assessment of orally administered cyanidin-3-O-glucoside, a prominent anthocyanin, has revealed that, whereas this compound is minimally absorbed, ferulic acid (FA) is one of its primary metabolites that appears in plasma. FA is a strong antioxidant and phase 2 inducer that has exerted marked anti-inflammatory effects in a number of rodent and cell culture studies; in particular, FA is highly protective in rodent models of diet-induced weight gain and metabolic syndrome. FA, a precursor for lignan synthesis, is widely distributed in plant-based whole foods, mostly in conjugated form; whole grains are a notable source. Coffee ingestion boosts plasma FA owing to gastrointestinal metabolism of chlorogenic acid. Hence, it is reasonable to suspect that FA mediates some of the broad health benefits that have been associated epidemiologically with frequent consumption of whole grains, anthocyanins, coffee, and unrefined plant-based foods. The molecular basis of the anti-inflammatory effects of FA may have been clarified by a recent study demonstrating that FA can target the adaptor protein MyD88; this plays an essential role in pro-inflammatory signaling by most toll-like receptors and interleukin-1β. If feasible oral intakes of FA can indeed down-regulate MyD88-dependent signaling, favorable effects of FA on neurodegeneration, hypothalamic inflammation, weight gain, adipocyte and beta cell function, adiponectin secretion, vascular health, and cartilage and bone integrity can be predicted. Since FA is well tolerated, safe, and natural, it may have great potential as a protective nutraceutical, and clinical trials evaluating its effects are needed.

Enhanced Antioxidant Activity of Bioactives in Colored Grains by Nano-Carriers in Human Lens Epithelial Cells

The use of phytochemicals for preventing chronic diseases associated with oxidative stress such as cataracts is hindered by their low bioavailability. The effects of nano-carriers on the antioxidant activities of extracts of black rice with giant embryo (BRGEx) and soybeans (SBx) have been determined in human lens epithelial B3 cells. Scanning (SEM) and transmission electron microscopy (TEM) demonstrated that rGO (reduced graphene oxide) has a flat surface unlike GO (graphene oxide), which has a distinctive wrinkled structure with defects. UPLC analysis revealed 41.9 μg/100 g of γ-oryzanols in water extract of BRGE, and 111.8 μg /100 g of lutein, 757.7 μg/100 g of γ-tocotrienol, 4071.4 μg/100 g of γ-tocopherol in 40% ethanol extract of soybeans, respectively. Even though a low concentration of BRGEx alone did not show any antioxidant activity in B3 cells, co-treatment of BRGEx with rGO together substantially reduced hydrogen peroxide and methylglyoxal-induced DNA damage, as determined by phosphorylated γH2AX. In addition, SBx with rGO also attenuated DNA damage. Furthermore, intracellular reactive oxygen species were significantly decreased by combining extracts of these colored grains with rGO. These results suggest a potential application of nanocarriers for enhancing the bioavailability of phytochemicals.

Differential effects of dietary flavonoids on adipogenesis

Propose

Obesity is a fast growing epidemic worldwide. During obesity, the increase in adipose tissue mass arise from two different mechanisms, namely, hyperplasia and hypertrophy. Hyperplasia which is the increase in adipocyte number is characteristic of severe obese patients. Recently, there has been much interest in targeting adipogenesis as therapeutic strategy against obesity. Flavonoids have been shown to regulate several pathways and affect a number of molecular targets during specific stages of adipocyte development.

Methods

Presently, we provide a review of key studies evaluating the effects of dietary flavonoids in different stages of adipocyte development with a particular emphasis on the investigations that explore the underlying mechanisms of action of these compounds in human or animal cell lines as well as animal models.

Results

Flavonoids have been shown to regulate several pathways and affect a number of molecular targets during specific stages of adipocyte development. Although most of the studies reveal anti-adipogenic effect of flavonoids, some flavonoids demonstrated proadipogenic effect in mesenchymal stem cells or preadipocytes.

Conclusion

The anti-adipogenic effect of flavonoids is mainly via their effect on regulation of several pathways such as induction of apoptosis, suppression of key adipogenic transcription factors, activation of AMPK and Wnt pathways, inhibition of clonal expansion, and cell-cycle arrest.

Pueraria lobate Inhibits RANKL-Mediated Osteoclastogenesis Via Downregulation of CREB/PGC1β/c-Fos/NFATc1 Signaling

Puerariae radix, the dried root of Pueraria lobate Ohwi, is known to prevent bone loss in ovariectomized mice; however, the precise molecular mechanisms are not understood. In this study, we investigated the effects and underlying mechanisms of action of Puerariae radix extract (PRE) on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. PRE dose-dependently inhibited osteoclast differentiation and formation, decreased the bone-resorbing activity of osteoclasts, and downregulated the expression of osteoclast differentiation marker genes. The expression of osteoclastogenic factors produced by PRE-treated osteoblasts such as RANKL, macrophage colony-stimulating factor (M-CSF), and osteoprotegerin (OPG) was comparable to that of untreated (control) cells. However, the formation of osteoclasts via bone marrow cell and calvaria-derived osteoblast co-cultures was suppressed by PRE treatment. Therefore, the inhibitory effects of PRE on osteoclastogenesis clearly targeted osteoclasts, but not osteoblasts. PRE treatment considerably reduced RANKL-induced mitogen-activated protein kinases (MAPKs) activity, especially c-Jun N-terminal kinase, in osteoclast precursor cells. In addition, PRE markedly suppressed cAMP response element-binding protein (CREB) activation and the induction of peroxisome proliferator-activated receptor gamma coactivator 1β (PGC1β), which stimulate osteoclastogenesis - an effect that was not observed for puerarin and 17-β estradiol. Finally, PRE treatment significantly repressed the expression of c-Fos and the nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), which is a master transcription factor for osteoclastogenesis in vitro and in vivo. Overall, these results strongly suggest that PRE is an effective inhibitor of RANKL-induced osteoclastogenesis and may be a potent therapeutic agent for bone-related diseases such as osteoporosis, rheumatoid arthritis, and periodontitis.

Recent advances on bioactivities of black rice

PURPOSE OF REVIEW

Black rice has been consumed for centuries in Asian countries such as China, Korea or Japan. Nowadays, extracts and derivatives are considered as beneficial functional foods because of their high content in several bioactive molecules such as anthocyanins, other phenolics and terpenoids. The purpose of this review is to summarize and discuss recent developments on black rice bioactivities.

RECENT FINDINGS

Some sterols and triterpenoids with potential anticancer properties already tested in vitro and in vivo have been isolated and identified from bran extracts of black rice. Protection against osteoporosis has been suggested for the first time for black rice extracts. Because of its antioxidant and anti-inflammatory properties, black rice also protects liver and kidney from injuries. One clinical study reported the interest of black rice in case of alcohol withdrawal.

SUMMARY

Several advances have been recently achieved on the understanding of the potential biological effects of black rice and its derivatives. They further confirm that black rice should be considered as a promising source of health-promoting functional foods targeting a large set of noninfectious diseases. However, more clinical studies are needed to support the findings highlighted in this review.

Purple corn silk: A potential anti-obesity agent with inhibition on adipogenesis and induction on lipolysis and apoptosis in adipocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Corn silk or the stigma of Zea mays L. has traditionally been used in weight loss stimulation and treatment of cystitis, urinary infections and obesity. Purple corn silk, rich of polyphenolic substances, was reported on anti-diabetic and anti-obesity effect in animal studies. However, scientific evidence on mechanisms and targets of action of purple corn silk related to adipocyte life cycle has been limited.

AIM OF STUDY

To determine phytochemical compositions and investigate anti-obesity potential of the purple corn silk focusing on interruption of adipocyte life cycle; effect on pre-adipocyte proliferation, adipogenesis, adipocyte lipolysis, and apoptosis.

MATERIALS AND METHODS

The ethanolic purple corn silk extract (PCS) was prepared and investigated for phytochemical compositions by LC/MS/MS technique and anti-obesity potential using murine 3T3-L1 cell line. Using methyl thiazole tetrazolium (MTT) assay, the effects on pre-adipocytes and adipocyte viability and on pre-adipocytes proliferation at 24-, 48-, and 72-h incubation period were evaluated. In addition, anti-adipogenesis via inhibition on adipocyte differentiation and reduction of total lipid accumulation was evaluated using Oil Red O staining and spectrophotometric methods, respectively. The lipolysis effect was determined by measurement of glycerol released content using glycerol test kit after 48-h treatment of PCS to adipocytes. Apoptosis inductive effect was done by using 2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride (DAPI) staining method.

RESULTS

The polyphenols including anthocyanins, quercetin and phenolic acids and derivatives were found as the major chemical compositions of the PCS. With multiple-stages interruption on the adipocyte life cycle, anti-obesity effect of PCS was interestingly demonstrated. When compared to the control, the PCS at concentration range between 250-1000 μg/mL showed anti-adipogenesis effect as expressing of significant inhibition on pre-adipocyte proliferation at all incubation period (43.52±5.28 - 75.51±9.09%) and significant decreasing of total lipid accumulation at concentration of 500μg/mL (80.22±6.58%) and 1000μg/mL (69.62±5.42%). Moreover, the PCS exhibited lipolysis and apoptosis inductive effect with dose dependent manner and significance at concentration of 1000μg/mL by increase of released glycerol content (173.88±6.13% of the control) and of nuclei condensing and apoptotic bodies (with relative apoptosis induction as 131.74±1.64% of the control).

CONCLUSION

Our data has evidenced the anti-obesity potential of PCS related interruption at multiple stages of adipocyte life cycle. Its potency was attributed to inhibition on adipocyte proliferation and adipogenesis as well as induction on lipolysis and apoptosis at high concentration. However, further in vivo investigation should be considered to insist the possibility in applications of PCS in prevention and treatment of obesity.

Improvement of blood glucose levels and obesity in mice given aronia juice by inhibition of dipeptidyl peptidase IV and α-glucosidase

Aronia berries have many potential effects on health. Previous human studies have shown that aronia juice may be useful for treatment of obesity disorders. Recently, we have reported that aronia juice has an inhibitory effect on dipeptidyl peptidase (DPP IV) activity and that the DPP IV inhibitor in aronia juice was identified as cyanidin 3,5-diglucoside. In this study, we found that body weights and blood glucose levels were reduced in diabetes model KK-Ay mice given aronia juice. We also found that weights of white adipose tissues were reduced in KK-Ay mice given aronia juice. Furthermore, levels of DPP IV activity in the serum and liver from KK-Ay mice were lower than those in the serum and liver from C57BL/6JmsSlc mice. Interestingly, although levels of DPP IV activity were not changed in the serum and liver from aronia-juice-administered KK-Ay mice, levels of DPP IV activity were increased in those from aronia-juice-administered C57BL/6JmsSlc mice. Furthermore, α-glucosidase activity was inhibited in the upper region of the small intestine from aronia-juice-administered KK-Ay mice but not in the lower region. Inhibition of α-glucosidase activity in the upper portion of the small intestine induced a reduction of glucose-dependent insulinotropic polypeptide (GIP) level. The results suggest that DPP IV activity in diabetic mice is inhibited by aronia juice, that the GIP level in the upper region of the small intestine is reduced by inhibition of α-glucosidase activity and that weights of adipose tissues are reduced by aronia juice.

Dual Role of Cyanidin-3-glucoside on the Differentiation of Bone Cells

Cyanidin-3-glucoside (C3G) is one of the major components of anthocyanin, a water-soluble phytochemical. Recent studies demonstrated the chemopreventive and chemotherapeutic activities of C3G in various conditions, including cancer, although the precise effects of C3G on osteoclast and osteoblast differentiation remain unclear. Here, we investigated the role of C3G in the differentiation of bone-associated cells and its underlying mechanism. C3G inhibited receptor activator of nuclear factor kappa-B ligand (RANKL)–mediated osteoclast differentiation and formation in a dose-dependent manner and downregulated the expression of osteoclast differentiation marker genes. Pretreatment with C3G considerably reduced the induction of extracellular signal–regulated kinase, c-Jun N-terminal kinase, and p38 mitogen-activated kinases activation by RANKL in osteoclast precursor cells. Furthermore, C3G dramatically inhibited the expression of c-Fos and nuclear factor of activated T-cells, cytoplasmic 1, which are important transcription factors for osteoclast differentiation and activation. The formation of osteoclasts in coculture of bone marrow cells and calvaria-derived osteoblasts was also inhibited by C3G treatment, although the expression of macrophage colony-stimulating factor and RANKL (master factors for osteoclast differentiation and formation) and osteoprotegerin (a decoy receptor for RANKL) on osteoblasts was unaffected. The inhibitory effect of C3G on osteoclastogenesis is therefore targeted specifically to osteoclasts but not osteoblasts. Moreover, analysis of the expression levels of osteoblast differentiation marker genes and alizarin red staining showed that osteoblast differentiation and matrix formation increased after C3G treatment. Taken together, these results strongly suggest that C3G has a dual role in bone metabolism, as an effective inhibitor of osteoclast differentiation but also as an activator of osteoblast differentiation. Therefore, C3G may be used as a potent preventive or therapeutic agent for bone-related diseases, such as osteoporosis, rheumatoid arthritis, and periodontitis.