Evaluation of Antioxidant, Antidiabetic and Antiobesity Potential of Selected Traditional Medicinal Plants

This study evaluated potential antidiabetic and antiobesity properties in vitro of selected medicinal plants. The hot water (WE) and ethanol extracts (EE) of sweet gale (Myrica gale L.), roseroot (Rhodiola rosea L.), sheep sorrel (Rumex acetosa L.), stinging nettles (Utrica dioica L.) and dandelion (Taraxacum officinale L.) were tested for total antioxidant capacity using ferric reducing antioxidant power (FRAP) and DPPH• scavenging capacity assays, followed by α-amylase, α-glucosidase and formation of advanced glycation end products (AGE) inhibition assays in vitro. Myrica gale EE had the highest total phenolic content (12.4 mmol GAE/L), FRAP value (17.4 mmol TE/L) and DPPH• scavenging activity (IC50 = 3.28 mg/L). Similarly, Myrica gale also exhibited significantly lower IC50 values for the percentage inhibition of α-amylase (IC50 = 62.65 mg/L) and α-glucosidase (IC50 = 27.20 mg/L) compared to acarbose (IC50 = 91.71 mg/L; IC50 = 89.50 mg/L, respectively) (p ≤ 0.05). The 3T3-L1 preadipocyte study also revealed that Myrica gale EE (54.8%) and stinging nettles (62.2% EE; 63.2% WE) significantly inhibited the adipogenesis in adipocytes in vitro (p ≤ 0.05). Polyphenols present in these medicinal plants have the potential to use in managing type 2 diabetes and obesity

Phytochemical-rich medicinal plant extracts suppress bacterial antigens-induced inflammation in human tonsil epithelial cells

Background Pharyngitis is an inflammatory condition of the pharynx and associated structures commonly caused by the Group A streptococci (GAS). There is a growing interest in discovering plant-based anti-inflammatory compounds as potential alternatives to conventional drugs. This study evaluated anti-inflammatory activity of phytochemical-rich extracts prepared from 12 herbal plants using human tonsil epithelial cells (HTonEpiC) in vitro. Methods The HTonEpiC were induced by a mixture of lipoteichoic acid (LTA) and peptidoglycan (PGN) (10 µg/mL; bacterial antigens) for 4 h and then exposed to ethanol extracts (EE) or aqueous extracts (AE) for 20 h. The secretion of four pro-inflammatory cytokines was measured using enzyme-linked immunosorbent assays (ELISA). Total phenolic and total flavonoid contents of the extracts were determined using spectrophotometric methods. Results The herbal plant extracts (≤5 µg/mL) were not cytotoxic to HTonEpiC. The extracts exhibited a broad range of reduction (1.2%–92.6%) of secretion of interleukin-8 (IL-8), human beta defensin-2 (hBD-2), epithelial-derived neutrophil activating protein-78 (ENA-78), and granulocyte chemotactic protein-2 (GCP-2). Both EE and AE of clove, ginger, and echinacea flower and EE from danshen root significantly inhibited the pro-inflammatory cytokine production as induced by LTA and PGN in HTonEpiCs at the concentrations of 1 and 5 µg/mL. Discussion Our observations indicate that danshen root, clove, ginger, and echinacea flower extracts exhibit an anti-inflammatory effect in HTonEpiCs. The most efficacious extracts from danshen root, clove, ginger and echinacea flowers have potential to be used as natural sources for developing phytotherapeutic products in the management of painful inflammation due to streptococcal pharyngitis

Apple flavonols and n-3 polyunsaturated fatty acid-rich fish oil lowers blood C-reactive protein in rats with hypercholesterolemia and acute inflammation

Both quercetin glycosides and omega-3 polyunsaturated fatty acids (n-3 PUFA) are well established for their individual health benefits in ameliorating metabolic disease. However, their combined effects are not well documented. It was hypothesized that the beneficial properties of quercetin glycosides can be enhanced when provided in combination with n-3 PUFA. Therefore, the aim of the present study was to investigate the effects of apple flavonols (AF) and fish oil (FO), alone and in combination, on proinflammatory biomarkers and lipid profiles in rats fed a high-fat diet. Sixty male Wistar rats were randomly divided into 5 groups (n = 12) and fed a high-fat diet for 4 weeks. One of the 5 groups of rats was used as the high-fat control. The other 4 groups of rats were injected with lipopolysaccharide (LPS) (5 mg/kg body weight) intraperitoneally, 5 hours before euthanization. One of these 4 groups was used as the hypercholerolemic and inflammatory control (high-fat with lipopolysaccharide [HFL]), and the other 3 received AF (HFL + 25 mg/kg per day AF), FO (HFL + 1 g/kg per day FO), or the combination (HFL + AF + FO). Compared to the HFL group, the AF, FO, and AF + FO groups showed lower serum concentrations of interleukin-6 and C-reactive protein (CRP) levels. The AF, FO, and AF + FO also had lowered serum triacylglycerol and non-high-density lipoprotein cholesterol (HDL-C) concentrations, but higher HDL-C levels relative to the HFL group. An additive effect was observed on serum CRP in the AF + FO group as compared with the AF or FO groups. The results demonstrated that AF and FO inhibited the production of proinflammatory mediators and showed an improved efficacy to lower serum CRP when administered in combination, and they significantly improved blood lipid profiles in rats with diet-induced hyperlipidemia and LPS-induced acute inflammation. \ua9 2014 Elsevier Inc. All rights reserved.Peer reviewed: YesNRC publication: Ye

Novel quercetin-3-O-glucoside eicosapentaenoic acid ester ameliorates inflammation and hyperlipidemia

Quercetin, a major flavonol, present abundantly in apples and onions, is widely studied for ameliorating metabolic syndrome abnormalities. However, quercetin is mainly present in plant food in the form of quercetin glycosides and has been reported for poor gastrointestinal absorption. The present study was designed with the purpose of imparting a lipophilic property to quercetin-3-O-glucoside (QG) by its acylation with eicosapentaenoic acid (EPA) and to study the influence of eicosapentaenoic acid ester of quercetin-3-O-glucoside (QE) on hyperlipidemia and inflammation in vivo and in vitro. QE was more effective in reducing the production of tumor necrosis factor-alpha (TNF-\u3b1), prostaglandin 2 (PGE2), cyclo-oxygenase (COX)-2 levels and nuclear expression of nuclear factor-kappa B (NF-\u43aB) compared to the parent compounds (QG and EPA) and commercial drugs, after lipopolysaccharides (LPS) induced inflammation in THP-1 derived macrophages. Serum high-density lipoprotein (HDL)-cholesterol was significantly higher and hepatic total cholesterol concentration was lower in the rats fed high-fat diet supplemented with QE, compared to the high-fat diet with inflammation (HFL). The serum concentrations of C-reactive protein (CRP), interleukin (IL)-6, and interferon-gamma (IFN-\u3b3) were significantly lower in QE treatment group than HFL group. EPA conjugated flavonol, QE, had significant anti-inflammatory and hypolipidemic properties and may be effective for the treatment of obesity-related disorders.Peer reviewed: YesNRC publication: Ye

Anti-Inflammatory Activity of Haskap Cultivars is Polyphenols-Dependent

Haskap (Lonicera caerulea L.) berries have long been used for their health promoting properties against chronic conditions. The current study investigated the effect of Canadian haskap berry extracts on pro-inflammatory cytokines using a human monocytic cell line THP-1 derived macrophages stimulated by lipopolysaccharide. Methanol extracts of haskap from different growing locations in Canada were prepared and characterized for their total phenolic profile using colorimetric assays and liquid chromatography—Mass spectrometry (UPLC-MS/MS). Human THP-1 monocytes were seeded in 24-well plates (5 × 105/well) and treated with phorbol 12-myristate 13-acetate (PMA, 0.1 μg/mL) for 48 h to induce macrophage differentiation. After 48 h, the differentiated macrophages were washed with Hank’s buffer and treated with various concentrations of test compounds for 4 h, followed by the lipopolysaccharide (LPS)-stimulation (18 h). Borealis cultivar showed the highest phenolic content, flavonoid content and anthocyanin content (p < 0.05). A negative correlation existed between the polyphenol concentration of the extracts and pro-inflammatory cytokines: Interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α), prostaglandin (PGE2), and cyclooxygenase-2 (COX-2) enzyme. Borealis exhibited comparable anti-inflammatory effects to COX inhibitory drug, diclofenac. The results showed that haskap berry polyphenols has the potential to act as an effective inflammation inhibitor