Effects of 3'-hydroxyfarrerol (IdB 1031), a novel flavonoid agent, on phagocyte products

Finger Citron Extract Ameliorates Glycolipid Metabolism and Inflammation by Regulating GLP-1 Secretion via TGR5 Receptors in Obese Rats

Finger citron (FC) is one of many traditional Chinese herbs that have been used to treat obesity. The aim of this study was to elucidate the pharmacological effects and mechanisms of FC on obese rats. Rats were fed with a high-fat diet as a model of obesity and treated with FC at three different dosages for 6 weeks. Pathology in liver tissue was observed. Glucose levels, lipids levels, and inflammatory indicators in serum were evaluated by enzyme‐linked immunosorbent assay. Furthermore, the expression of G protein-coupled receptor 5 (TGR5) pathway genes in rat colon tissue was detected by reverse transcription-polymerase chain reaction analysis (RT-PCR). Our result revealed that FC alleviates obesity by reducing body weight (BW) and waist circumference, managing inflammation and improving glycolipid metabolism, liver function, and liver lipid peroxidation in vivo. In addition, the mechanism of FC on obesity is possibly the stimulation of glucagon-like peptide-1 (GLP-1) secretion by activating the TGR5 pathway in intestinal endocrine cells. Our studies highlight the obesity reduction effects of FC and one of the mechanisms may be the activation of the TGR5 pathway in intestinal endocrine cells.

Anti-glaucoma potential of hesperidin in experimental glaucoma induced rats

Glaucoma is well-known clinical eye conditions that damage the optic nerve due to abnormal pressure conditions in eye. Hesperidin is well-known glycoside widely present in the citrus fruits, and its aglycone form is known as hesperetin. Hesperidin is major flavone found in orange fruits. Hypotensive effect of hesperidin in acute and chronic glaucoma rats, glutamate level in vitreous humour and glutathione (GSH) level in aqueous humour were determined following 25, 50 and 100 mg/kg of hesperidin treatment. Acetazolamide (5 mg/kg) was used as positive control. Hesperidin treatment significantly reduced the increased intraocular pressure (IOP) level in dextrose induced ocular hypertension than saline treated rats. The effect of hesperidin was comparable to the positive control acetazolamide. Similarly, hesperidin treatment significantly reduced the IOP level in prednisolone acetate induced ocular hypertension than saline treated rats. In the aqueous humour, hesperidin treatment increased the glutathione level 125%, 184.4% and 231.2% at 25, 50 and 100 mg/kg of hesperidin respectively. In the vitreous humour, hesperidin treatment reduced the glutamate level 9.9%, 13.2% and 25.3% at 25, 50 and 100 mg/kg of hesperidin respectively. Histopathological analysis of normal saline treated rats showed morphological alteration in ciliary bodies. However, rats treated with hesperidin showed the reduced level of morphological alteration in ciliary bodies. Taking all these data together, it is suggested that the hesperidin supplementation was effective against glaucoma in experimental rats.

Anti-inflammatory and Antimicrobial Effects of Anthocyanin Extracted from Black Soybean on Chronic Bacterial Prostatitis Rat Model

OBJECTIVE

To investigated the anti-inflammatory and antimicrobial effects of anthocyanins extracted from black soybean on the chronic bacterial prostatitis (CBP) rat model.

METHODS

The Sprague-Dawley rats were divided into 4 groups, including control, ciprofloxacin, anthocyanins and anthocyanins with ciprofloxacin groups (n=8 in each group). Then, drip infusion of bacterial suspension (Escherichia coli Z17 O2:K1:H-) into Sprague-Dawley rats was conducted to induce CBP. In 4 weeks, results of prostate tissue, urine culture, and histological analysis on the prostate were analyzed for each group.

RESULTS

The use of ciprofloxacin, anthocyanins, and anthocyanins with ciprofloxacin showed statistically significant decreases in bacterial growth and improvements in the reduction of prostatic inflammation compared with the control group (P<0.05). The anthocyanins with ciprofloxacin group showed a statistically significant decrease in bacterial growth and improvement in prostatic inflammation compared with the ciprofloxacin group (P<0.05).

CONCLUSIONS

These results suggest that anthocyanins may have anti-inflammatory and antimicrobial effects, as well as a synergistic effect with ciprofloxacin. Therefore, we suggest that the combination of anthocyanins and ciprofloxacin may be effective in treating CBP to obtain a higher rate of treatment success.

The neuroprotective effect of hesperidin in NMDA-induced retinal injury acts by suppressing oxidative stress and excessive calpain activation

We found that hesperidin, a plant-derived bioflavonoid, may be a candidate agent for neuroprotective treatment in the retina, after screening 41 materials for anti-oxidative properties in a primary retinal cell culture under oxidative stress. We found that the intravitreal injection of hesperidin in mice prevented reductions in markers of the retinal ganglion cells (RGCs) and RGC death after N-methyl-D-aspartate (NMDA)-induced excitotoxicity. Hesperidin treatment also reduced calpain activation, reactive oxygen species generation and TNF-α gene expression. Finally, hesperidin treatment improved electrophysiological function, measured with visual evoked potential, and visual function, measured with optomotry. Thus, we found that hesperidin suppressed a number of cytotoxic factors associated with NMDA-induced cell death signaling, such as oxidative stress, over-activation of calpain, and inflammation, thereby protecting the RGCs in mice. Therefore, hesperidin may have potential as a therapeutic supplement for protecting the retina against the damage associated with excitotoxic injury, such as occurs in glaucoma and diabetic retinopathy.

Bilberries and their anthocyanins ameliorate experimental colitis

Bilberries have positive effects in acute and chronic diarrhea. Patients with inflammatory bowel disease (IBD) report on improved symptoms upon ingestion. Bilberries contain approximately 10% of anthocyanins (ACs), which have anti-oxidative, anti-carcinogenic, and anti-inflammatory properties. We investigated whether experimental colitis can be ameliorated by dried bilberries or ACs. Acute and chronic dextrane sodium sulphate (DSS) colitis were induced in Balb/c mice by 2.5% DSS in the drinking water. Mice were fed with dried bilberries or ACs, respectively. Cytokines were determined in supernatants from mesenteric lymph nodes (MLNs) by ELISA and apoptosis was investigated by terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assays. Oral administration of bilberries during acute DSS-induced colitis ameliorated disease severity and reduced secretion of IFN-γ and tumor necrosis factor from mesenteric lymph node cells. Dried bilberries also improved chronic DSS-colitis. Ingestion of ACs reduced intestinal inflammation in acute and chronic DSS-colitis with decreased histological scores and cytokine secretion. Both bilberries and ACs prevented inflammation-induced apoptosis in colonic epithelial cells. Taken together, ingestion of dried bilberries had positive effects on various parameters especially in acute DSS-colitis. Oral administration of ACs resulted in an amelioration of acute colitis as well as chronic colitis. These promising results justify a clinical study on their therapeutic effect in inflammatory bowel disease patients.

Effects of naturally occurring dihydroflavonols from Inula viscosa on inflammation and enzymes involved in the arachidonic acid metabolism

The anti-inflammatory properties of three flavanones isolated from Inula viscosa, sakuranetin, 7-O-methylaromadendrin, and 3-acetyl-7-O-methylaromadendrin, have been tested both in vitro and in vivo. Acute inflammation in vivo was induced by means of topical application of 12-O-tetradecanoylphorbol 13-acetate (TPA) to mouse ears or by subcutaneous injection of phospholipase A(2) (PLA(2)) into mouse paws. The test compounds were evaluated in vitro for their effect on both the metabolism of arachidonic acid and on the release and/or activity of enzymes involved in the inflammatory response such as elastase, myeloperoxidase (MPO), and protein kinase C (PKC). The most active compounds in vivo against PLA(2)-induced paw oedema were 7-O-methylaromadendrin (ED(50)=8 mg/kg) and sakuranetin (ED(50)=18 mg/kg). In contrast, the most potent compound against TPA-induced ear oedema was 3-acetyl-7-O-methylaromadendrin (ED(50)=185 microg/ear), followed by sakuranetin (ED(50)=205 microg/ear). In vitro, the latter compound was the most potent inhibitor of leukotriene (LT) B(4) production by peritoneal rat neutrophils (IC(50)=9 microM) and it was also the only compound that directly inhibited the activity of 5-lipoxygenase (5-LOX). 3-Acetyl-7-O-methylaromadendrin also inhibited LTB(4) production (IC(50)=15 microM), but had no effect on 5-LOX activity. The only flavanone that inhibited the secretory PLA(2) activity in vitro was 7-O-methylaromadendrin. This finding may partly explain the anti-inflammatory effect observed in vivo, although other mechanisms such as the inhibition of histamine release by mast cells may also be implicated. Sakuranetin at 100 microM was found to inhibit elastase release, although this result is partly due to direct inhibition of the enzyme itself. At the same concentration, 7-O-methylaromadendrin only affected the enzyme release. Finally, none of the flavanones exhibited any effect on MPO or PKC activities. Taken together, these findings indicate that sakuranetin may be a selective inhibitor of 5-LOX.

Inhibition of inducible isoforms of cyclooxygenase and nitric oxide synthase by flavonoid hesperidin in mouse macrophage cell line

Previous data have shown that a citrus flavanone, hesperidin possesses chemopreventive efficacies. We designed to investigate the inhibitory effect of hesperidin on lipopolysaccharide (LPS)-induced over-expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) proteins, over-production of prostaglandin E2 (PGE2) and nitric oxide (NO) using mouse macrophage cells. Treatment with hesperidin suppressed production of PGE2, nitrogen dioxide (NO2), and expression of iNOS protein. In the case of COX-2, hesperidin did not affect the protein level. Our data indicate hesperidin as a COX-2 and iNOS inhibitor, which might be related to the anti-inflammatory and anti-tumorigenic efficacies.

Protective effect of wogonin on endotoxin-induced lethal shock in D-galactosamine-sensitized mice

The effects of wogonin, a major flavonoid from Scutellaria baicalensis Georgi, on lipopolysaccharide (LPS)-induced lethal shock in mice was investigated. Wogonin pretreatment prevented the lethal shock in mice injected with D-galactosamine (D-GalN) and LPS, but not in mice injected with a high dose of LPS. Wogonin definitely inhibited the hepatic injury in mice injected with D-GalN, and LPS and reduced the level of circulating tumor necrosis factor (TNF)-alpha. The reduction was more marked in mice injected with D-GalN and LPS compared with that in mice injected with a high dose of LPS. Wogonin pretreatment did not inhibit the lipid peroxidation in mice receiving either D-GalN and LPS or a high dose of LPS. Wogonin inhibited the in vitro production of TNF-alpha and nitric oxide in LPS-stimulated RAW 264.7 cells. The mechanism of the protective effect of wogonin on the lethal shock in mice injected with D-GalN and LPS is discussed.

Flavonoids protect mice from two types of lethal shock induced by endotoxin

The protective effect of flavonoids on two types of lethal endotoxic shock was studied. A lethal endotoxic shock was induced by administration of lipopolysaccharide (LPS) into D-galactosamine (D-GalN)-sensitized mice and another one was done by administration of a high dose of LPS into normal mice. Pretreatment with a series of flavonoids protected mice from two types of endotoxin lethality. Flavonoid pretreatment reduced the serum tumor necrosis factor-alpha (TNF-alpha) level in mice injected with D-GalN and LPS, but not in mice injected with a high dose of LPS. TNF-alpha-induced lethal shock in D-GalN-sensitized mice was also protected by pretreatment with flavonoids, suggesting that flavonoids augmented the resistance to TNF-alpha lethality. On the other hand, flavonoids reduced the plasma level of lipid peroxides in mice injected with a high dose of LPS, but not in D-GalN-sensitized mice. Taken together, these results indicated that flavonoids might protect mice from two types of endotoxin lethality. The protective mechanism of flavonoids in each endotoxin lethality is discussed.

Effect of biflavones of Ginkgo biloba against UVB-induced cytotoxicity in vitro

The effect of Ginkgo biloba extract on Ultraviolet B (UVB) irradiated fibroblasts was examined by using a neutral red dye uptake assay and a lactic dehydrogenase (LDH) release assay. Crude extract along with individual components, including flavone-glycosides and biflavones, were applied to cultured normal human skin fibroblasts for 12 hours, and 0, 20, 40 and 80 mJ/cm2 of UVB were irradiated. Two synthetic flavonoids, quercetin and rutin, which have polyphenol structures close to the flavonoids in Ginkgo biloba extract, were used to compare any structure-related activity under the same conditions. At the concentrations (from 0.25 to 2 mg/ml) treated with biflavone components (isoginkgetin/ginkgetin, sciadopitysin) and quercetin, high neutral red dye uptake was detected with gradual increases in UVB irradiation. The time-course release of LDH was determined as the cytotoxicity index (%) during 24 hours following a high dose UVB irradiation (200 mJ/cm2), and the pattern of this cytotoxicity index was similar to that of the neutral red dye uptake results. Sciadopitysin, isoginkgetin/ginkgetin and quercetin treatments lowered cytotoxicity indices to 50.81, 67.81 and 62.19%, respectively, compared to 95.38% for the untreated control. The antioxidant potential of biflavones of Ginkgo biloba could be explained on the basis of structure-related activity; hydroxy- and methyl-substitutions on the basic structure of these flavonoids played a role, as other reports have suggested.