Golden berry leaf extract containing withanolides suppresses TNF-α and IL-17 induced IL-6 expression in HeLa Cells.

Inflammation, characterized by the overexpression of IL-6 in various tissues, has been reported as a symptom of coronavirus disease 2019. In this study, we established an experimental system for overexpression of IL-6 in HeLa cells stimulated by TNF-α and IL-17, along with identification of anti-inflammatory materials and components from local agricultural, forestry, and fishery resources. We constructed a library of extracts from natural sources, of which 111 samples were evaluated for their anti-inflammatory activities. The MeOH extract of Golden Berry (Physalis peruviana L) leaf was found to exhibit strong anti-inflammatory properties (IC50 = 4.97 µg/mL). Preparative chromatography identified two active constituents, 4ß-hydroxywithanolide E (4ß-HWE) (IC50 = 183 nM) and withanolide E (WE) (IC50 = 65.1 nM). Withanolides are known anti-inflammatory ingredients of Withania somnifera, an Ayurvedic herbal medicine. P. peruviana leaves containing 4ß-HWE and WE should be considered as useful natural resources for anti-inflammatory products.

Dihydroisocoumarins of Hydrangea macrophylla var. thunbergia inhibit binding of the SARS-CoV-2 spike protein to ACE2.

Binding of the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the cognate angiotensin-converting enzyme 2 (ACE2) receptor is the initial step in the viral infection process. In this study, we screened an in-house extract library to identify food materials with inhibitory activity against this binding using enzyme-linked immunosorbent assays and attempted to ascertain their active constituents. Hydrangea macrophylla var. thunbergia leaves were identified as candidate materials. Its active compounds were purified using conventional chromatographic methods and identified as naringenin, dihydroisocoumarins, hydrangenol, and phyllodulcin, which have affinities for the ACE2 receptor and inhibit ACE2 receptor-spike S1 binding. Given that boiled water extracts of H. macrophylla leaves are commonly consumed as sweet tea in Japan, we speculated that this tea could be used as a potential natural resource to reduce the risk of SARS-CoV-2 infection.

Petasin is the main component responsible for the anti-adipogenic effect of Petasites japonicus.

Petasites japonicus is one of the most popular edible wild plants in Japan. Many biological effects of P. japonicus have been reported, including anti-allergy, anti-inflammation, and anticancer effects. Although its anti-obesity effect has been reported in several studies, the most important component responsible for this activity has not been fully elucidated. On screening the components that suppress adipocyte differentiation in 3T3-F442A cells, we found that the extract of the flower buds of P. japonicus has anti-adipogenic effect. Among the known major components of P. japonicus, petasin exhibited a potent anti-adipogenic effect at an IC50 value of 0.95 µM. Quantitative analysis revealed that the active component responsible for most of the anti-adipogenic effects of P. japonicus extract is petasin. Petasin suppressed the expression of markers of mature adipocytes (PPARγ, C/EBPα, and aP2). However, as isopetasin and petasol, analogs of petasin, did not exhibit these effects, it indicates that a double bond at the C11-C12 position and an angeloyl ester moiety were essential for the activity. Petasin affected the late stage of adipocyte differentiation and inhibited the expression of lipid synthesis factors (ACC1, FAS, and SCD1). Additionally, it was revealed that petasin could be efficiently extracted using hexane with minimal amount of pyrrolizidine alkaloids, the toxic components. These findings indicate that P. japonicus extract containing petasin could be a promising food material for the prevention of obesity.

Beneficial effects by intake of Euphausiacea pacifica on high-fat diet-induced obesity.

Obesity is a major health problem showing increased incidence in developed and developing countries. We examined the effect of Euphausia pacifica (E. pacifica) (Pacific Krill) on high-fat diet (HFD)-induced obesity in C57BL/6 mice. No significant differences were observed in average food intake between the HFD and HFD with E. pacifica group, or the low-fat diet (LFD) and LFD with E. pacifica group for 18 weeks. The increased ratio of body weight in the HFD containing E. pacifica group was significantly reduced, being 10% lower than that with HFD group in the 18th week (HFD, 298.6±18.8% vs. HFD with E. pacifica, 267.8±16.2%; p<0.05), while the ratio for the LFD containing E. pacifica group was reduced by 4% compared with LFD group (LFD, 244.2±11.6% vs. LFD with E. pacifica, 234.1±18.0%). There were no effects of E. pacifica on total cholesterol levels in serum and liver, whereas the supplement of E. pacifica tended to decrease triglyceride levels in the HFD groups. The leptin level in serum was significantly decreased in the HFD group (p<0.01) by E. pacifica. The adipocyte area (1926±1275 µm(2)) in the HFD containing E. pacifica group was significantly reduced by 20% (p<0.001) compared with the HFD group. These results suggested that E. pacifica supplementation in the diet is beneficial for the prevention of HFD-induced obesity.

Inhibitory effects of the phenolic fraction from the pomace of Vitis coignetiae on biofilm formation by Streptococcus mutans.

OBJECTIVES: The anti-cariogenic properties of the phenolic fraction from the pomace of Vitis coignetiae (VcPP) were evaluated by in vitro assays and compared with fruit juices from V. coignetiae and common grapes and with other phenolic fractions. The effects of VcPP against the biofilm of Streptococcus mutans were investigated. DESIGN: Sucrose-dependent biofilm formation by S. mutans cultured in the presence of VcPP was measured by crystal violet dye uptake. Inhibition of adhesion to the saliva-coated hydroxyapatite (sHA) beads was quantified using fluorescent-labelled cells. The MIC for S. mutans was determined by colony counting on agar plates containing VcPP. The ability of VcPP to inhibit glucan synthesis by three distinct recombinant glucosyltransferases (Gtfs) was assessed by quantifying the production of water-soluble and -insoluble polysaccharides in bacterial cultures. In addition, the buffering effect of VcPP in cultures of S. mutans was evaluated. RESULTS: VcPP reduced adhesion of S. mutans to sHA and biofilm formation in a dose-dependent manner. The MIC of VcPP was 7.50mg/ml. VcPP inhibited GtfB activity associated with the synthesis of water-insoluble glucans. It also inhibited GtfD activity associated with the synthesis of water-soluble glucans at a concentration which was lower than that used for inhibition of GtfB. VcPP had no effect on acidification associated with glucose utilization by S. mutans. CONCLUSIONS: The current study supports the potential of VcPP as a food additive for reducing caries by inhibiting adhesion to the tooth surface and GtfD-mediated soluble glucan synthesis.