Triptolide Administration Alters Immune Responses to Mitigate Insulin Resistance in Obese States.

Individuals who are overweight or obese are at increased risk of developing prediabetes and type 2 diabetes, yet the direct molecular mechanisms that connect diabetes to obesity are not clear. Chronic, sustained inflammation is considered a strong risk factor in these interactions, directed in part by the short-lived gene expression programs encoding for cytokines and pro-inflammatory mediators. In this study, we show that triptolide administration in the C57BL/6 diet-induced obese mice at up to 10 µg/kg/day for 10 weeks attenuated the development of insulin resistance and diabetes, but not obesity, in these animals. Significant reductions in adipose tissue inflammation and improved insulin sensitivity were observed in the absence of changes in food intake, body weight, body composition, or energy expenditure. Analysis of the core cluster of biomarkers that drives pro-inflammatory responses in the metabolic tissues suggested TNF-α as a critical point that affected the co-development of inflammation and insulin resistance, but also pointed to the putatively protective roles of increased COX-2 and IL-17A signaling in the mediation of these pathophysiological states. Our results show that reduction of diet-induced inflammation confers partial protection against insulin resistance, but not obesity, and suggest the possibility of achieving overweight phenotypes that are accompanied by minimal insulin resistance if inflammation is controlled.

Plant-Based Support of Respiratory Health during Viral Outbreaks.

Respiratory viruses are linked to major epidemic events that have plagued humans through recorded history and possibly much earlier, ranging from common colds, influenza, and coronavirus infections to measles. However, difficulty in developing effective pharmaceutical solutions to treat infected individuals has hindered efforts to manage and minimize respiratory viral outbreaks and the associated mortality. Here we highlight a series of botanical interventions with different and often overlapping putative mechanisms of action to support the respiratory system, for which the bioactive pharmacophore was suggested and the initial structure-activity relationships have been explored (Bupleurum spp., Glycyrrhiza spp., Andrographis spp.), have been proposed with uncertainty (Echinacea spp., Zingiber spp., Verbascum spp., Marrubium spp.), or remained to be elucidated (Sambucus spp., Urtica spp.). Investigating these metabolites and their botanical sources holds potential to uncover new mediators of the respiratory health outcomes as well as molecular targets for future break-through therapeutic interventions targeting respiratory viral outbreaks.

All Polyphenols Are Not Created Equal: Exploring the Diversity of Phenolic Metabolites.

Dietary intake of plant polyphenols is significant, and many of them enter a human body as a highly diverse pool of ring-fission phenolic metabolites arising from digestion and microbial catabolism of the parental structures. Difficulty in designing the uniform intervention studies and limited tools calibrated to detect and quantify the inherent complexity of phenolic metabolites hindered efforts to establish and validate protective health effects of these molecules. Here, we highlight the recent findings that describe novel complex downstream metabolite profiles with a particular focus on dihydrophenolic (phenylpropanoic) acids of microbial origin, ingested and phase II-transformed methylated phenolic metabolites (methylated sinks), and small phenolic metabolites derived from the breakdown of different classes of flavonoids, stilbenoids, and tannins. There is a critical need for precise identification of the individual phenolic metabolite signatures originating from different polyphenol groups to enable future translation of these findings into break-through nutritional interventions and dietary guidelines.

Gel formulated with Bryophyllum pinnatum leaf extract promotes skin wound healing in vivo by increasing VEGF expression: A novel potential active ingredient for pharmaceuticals.

Bryophyllum pinnatum (Crassulaceae) is used in traditional medicine for treating skin wounds. In our previous study, a topical gel containing B. pinnatum aqueous leaf extract showed a preclinical anti-inflammatory effect in in vivo acute edema models. In continuation, the present study aims to evaluate the phytochemical content and the stability of a formulation in gel containing B. pinnatum aqueous leaf extract and its healing properties and mechanism of action through an experimental model of induction of skin wounds in rats and in vitro assays. The animals were treated topically for 7 or 14 days with a formulation in gel containing extract at 5% or a placebo or Fibrinase® in cream. In addition, to establish some quality control parameters, the total phenolic content (TPC), total flavonoid content (TFC), and a study focusing on the phytochemical and biological stability of a gel for 30 days at two different conditions (room temperature and 40°C/75% RH) were performed. Gel formulation containing extract showed a TPC and TFC of 2.77 ± 0.06 mg of gallic acid/g and 1.58 ± 0.03 mg of quercetin/g, respectively. Regarding the stability study, the formulation in gel showed no significant change in the following parameters: pH, water activity, chromatographic profile, and the content of the major compound identified in the extract. The gel formulation containing extract stimulated skin wound healing while reducing the wound area, as well as decreasing the inflammatory infiltrate, reducing the levels of IL-1ß and TNF-α, and stimulating angiogenesis with increased expression of VEGF, an effect similar to Fibrinase. In conclusion, the gel formulation containing extract exhibited relevant skin wound healing properties and, therefore, has the potential to be applied as a novel active ingredient for developing wound healing pharmaceuticals.

Endocannabinoid System and Its Regulation by Polyunsaturated Fatty Acids and Full Spectrum Hemp Oils.

The endocannabinoid system (ECS) consists of endogenous cannabinoids, their receptors, and metabolic enzymes that play a critical homeostatic role in modulating polyunsaturated omega fatty acid (PUFA) signaling to maintain a balanced inflammatory and redox state. Whole food-based diets and dietary interventions linked to PUFAs of animal (fish, calamari, krill) or plant (hemp, flax, walnut, algae) origin, as well as full-spectrum hemp oils, are increasingly used to support the ECS tone, promote healthy metabolism, improve risk factors associated with cardiovascular disorders, encourage brain health and emotional well-being, and ameliorate inflammation. While hemp cannabinoids of THC and CBD groups show distinct but complementary actions through a variety of cannabinoid (CB1 and CB2), adenosine (A2A), and vanilloid (TRPV1) receptors, they also modulate PUFA metabolism within a wide variety of specialized lipid mediators that promote or resolve inflammation and oxidative stress. Clinical evidence reviewed in this study links PUFAs and cannabinoids to changes in ECS tone, immune function, metabolic and oxidative stress adaptation, and overall maintenance of a well-balanced systemic function of the body. Understanding how the body coordinates signals from the exogenous and endogenous ECS modulators is critical for discerning the underlying molecular mechanisms of the ECS tone in healthy and disease states. Nutritional and lifestyle interventions represent promising approaches to address chronic metabolic and inflammatory disorders that may overlap in the population at risk. Further investigation and validation of dietary interventions that modulate the ECS are required in order to devise clinically successful second-generation management strategies.

Rheum rhaponticum Root Extract Improves Vasomotor Menopausal Symptoms and Estrogen-Regulated Targets in Ovariectomized Rat Model.

Ovarian insufficiency and ovariectomy are characterized by deregulated heat loss mechanisms. Unlike hormone therapy, ERr 731 (a standardized botanical extract of Siberian rhubarb Rheum rhaponticum L. high in rhaponticin) acts like a selective estrogen receptor modulator for ERß receptors and may offer a higher degree of safety while maintaining the desired efficacy profile. In this study, we examined the relationship between oral administration of ERr 731 and the underlying components of skin vasomotion responses in an ovariectomized (OVX) rat model. ERr 731 dose-dependently reduced tail skin temperature (Tskin) values by an average of 1 °C. The rapid onset of this effect was observed in 1 and 3 mg/kg/day ERr 731 groups as early as day 2 of administration, and remained in place for the duration of the treatment (2 weeks). Substituting ERr 731 after E2 withdrawal helped maintain body temperature similarly to E2 alone, suggesting the usefulness of ERr 731 for replacing existing hormonal therapy in humans. ERr 731 also acted as a highly selective agonist for ERß in the hypothalamus of OVX rats, as well as in ERα/ß cell-based reporter assays. These data validate the OVX/Tskin rat model as a suitable screening platform to evaluate botanical and pharmaceutical treatments of menopause, while providing further evidence for the efficacy of ERr 731 towards alleviating vasomotor menopausal symptoms and improving wellbeing during the menopausal transition.

Enhanced stability of berry pomace polyphenols delivered in protein-polyphenol aggregate particles to an in vitro gastrointestinal digestion model.

Stability of protein-polyphenol aggregate particles, created by complexing polyphenols from blueberry and muscadine grape pomaces with a rice-pea protein isolate blend, was evaluated in an in vitro gastrointestinal model. Recovery index (RI; % total phenolics present post-digestion) was 69% and 62% from blueberry and muscadine grape protein-polyphenol particles, compared to 23% and 31% for the respective pomace extracts. Anthocyanins RI was 52% and 42% from particles (6% and 13% from pomace extracts), and proanthocyanidins RI was 77% and 73% from particles (25% and 14% from pomace extracts), from blueberry and grape, respectively. Protein-polyphenol particle digests retained 1.5 to 2-fold higher antioxidant capacity and suppressed the expression of pro-inflammatory cytokines, iNOS, IL6, and IL1ß, compared to unmodified extract digests, which only suppressed IL6. Protein-polyphenol particles as a delivery vehicle in foods may confer better stability during gastrointestinal transit, allow protected polyphenols to reach the gut microbiota, and preserve polyphenol bioactivity.

Distinct Fractions of an Artemisia scoparia Extract Contain Compounds With Novel Adipogenic Bioactivity.

Adipocytes are important players in metabolic health and disease, and disruption of adipocyte development or function contributes to metabolic dysregulation. Hence, adipocytes are significant targets for therapeutic intervention in obesity and metabolic syndrome. Plants have long been sources for bioactive compounds and drugs. In previous studies, we screened botanical extracts for effects on adipogenesis in vitro and discovered that an ethanolic extract of Artemisia scoparia (SCO) could promote adipocyte differentiation. To follow up on these studies, we have used various separation methods to identify the compound(s) responsible for SCO's adipogenic properties. Fractions and subfractions of SCO were tested for effects on lipid accumulation and adipogenic gene expression in differentiating 3T3-L1 adipocytes. Fractions were also analyzed by Ultra Performance Liquid Chromatography- Mass Spectrometry (UPLC-MS), and resulting peaks were putatively identified through high resolution, high mass accuracy mass spectrometry, literature data, and available natural products databases. The inactive fractions contained mostly quercetin derivatives and chlorogenates, including chlorogenic acid and 3,5-dicaffeoylquinic acid, which had no effects on adipogenesis when tested individually, thus ruling them out as pro-adipogenic bioactives in SCO. Based on these studies we have putatively identified the principal constituents in SCO fractions and subfractions that promoted adipocyte development and fat cell gene expression as prenylated coumaric acids, coumarin monoterpene ethers, 6-demethoxycapillarisin and two polymethoxyflavones.

Structural constraints and importance of caffeic acid moiety for anti-hyperglycemic effects of caffeoylquinic acids from chicory.

SCOPE: Chicory (Cichorium intybus L.) is a perennial herb often consumed as a vegetable, whereas the ground and roasted roots are blended as a coffee substitute. Caffeoylquinic or chlorogenic acids (CQA), the abundant intermediates of lignin biosynthesis in chicory, have been reported to improve glucose metabolism in humans, but the functional group in their structure responsible for this effect has not been yet characterized. METHODS AND RESULTS: Here, we showed that three di-O-caffeoylquinic acids suppressed hepatic glucose production in H4IIE rat hepatoma cells by reducing expression of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK), two key enzymes that regulate hepatic gluconeogenesis. Direct comparisons between CQAs and their metabolites (3-caffeoylquinic, caffeic, and quinic acids) revealed the caffeic acid moiety alone was responsible for the observed effects. Further analysis suggested the activation of PI3K and MAPK pathways as a method of controlling gene expression was shared between caffeoylquinic and caffeic acids. These compounds promoted increased mitochondrial respiration and cellular metabolism, in part by inducing oxidative phosphorylation and proton leak. CONCLUSION: We concluded that the caffeic acid moiety was important for suppression of hepatic gluconeogenesis and hyperglycemia, ultimately strengthening the link between dietary interventions based on caffeic acid-containing plant foods and healthy glucose metabolism.

Acceleration of cutaneous wound healing by brassinosteroids.

Brassinosteroids are plant growth hormones involved in cell growth, division, and differentiation. Their effects in animals are largely unknown, although recent studies showed that the anabolic properties of brassinosteroids are possibly mediated through the phosphoinositide 3-kinase/protein kinase B signaling pathway. Here, we examined biological activity of homobrassinolide (HB) and its synthetic analogues in in vitro proliferation and migration assays in murine fibroblast and primary keratinocyte cell culture. HB stimulated fibroblast proliferation and migration and weakly induced keratinocyte proliferation in vitro. The effects of topical HB administration on progression of wound closure were further tested in the mouse model of cutaneous wound healing. C57BL/6J mice were given a full-thickness dermal wound, and the rate of wound closure was assessed daily for 10 days, with adenosine receptor agonist CGS-21680 as a positive control. Topical application of brassinosteroid significantly reduced wound size and accelerated wound healing in treated animals. mRNA levels of transforming growth factor beta and intercellular adhesion molecule 1 were significantly lower, while tumor necrosis factor alpha was nearly suppressed in the wounds from treated mice. Our data suggest that topical application of brassinosteroids accelerates wound healing by positively modulating inflammatory and reepithelialization phases of the wound repair process, in part by enhancing Akt signaling in the skin at the edges of the wound and enhancing migration of fibroblasts in the wounded area. Targeting this signaling pathway with brassinosteroids may represent a promising approach to the therapy of delayed wound healing.

Effects of pregnane glycosides on food intake depend on stimulation of the melanocortin pathway and BDNF in an animal model.

Pregnane glycosides appear to modulate food intake by possibly affecting the hypothalamic feeding circuits; however, the mechanisms of the appetite-regulating effect of pregnane glycosides remain obscure. Here, we show that pregnane glycoside-enriched extracts from swamp milkweed Asclepias incarnata at 25-100 mg/kg daily attenuated food intake (up to 47.1 ± 8.5% less than controls) and body weight gain in rats (10% for males and 9% for females, respectively) by activating melanocortin signaling and inhibiting gastric emptying. The major milkweed pregnane glycoside, ikemagenin, exerted its appetite-regulating effect by decreasing levels of agouti-related protein (0.6-fold) but not NPY satiety peptides. Ikemagenin treatment also increased secretion of brain-derived neurotropic factor (BDNF) downstream of melanocortin receptors in the hypothalamus (1.4-fold) and in the C6 rat glioma cell culture in vitro (up to 6-fold). These results support the multimodal effects of pregnane glycosides on feeding regulation, which depends on the activity of the melanocortin signaling pathway and BDNF.

Antiplasmodial activity of cucurbitacin glycosides from Datisca glomerata (C. Presl) Baill.

The traditionally used antimalarial plant, Datisca glomerata (C. Presl) Baill, was subjected to antiplasmodial assay guided fractionation. This led to the isolation of seven cucurbitacin glycosides, datiscosides I-O, along with two known compounds, datiscoside and datiscoside B, from the aerial parts of D. glomerata. Their structures and relative stereochemistry were determined on the basis of mass spectrometry, 1D and 2D NMR spectroscopic data. Antiplasmodial IC(50) values were determined for all isolated compounds against a chloroquine sensitive strain of Plasmodium falciparum (D10), which were also evaluated in vitro for their antileishmanial activity against Leishmania tarentolae. Cytotoxicity was evaluated against rat skeletal muscle cells (L6) and Chinese ovarian hamster cells (CHO). The antiplasmodial activity of the compounds was moderate and ranged from 7.7 to 33.3 µM. None of the compounds showed appreciable antileishmanial activity. The compounds displayed cytotoxicity against L6 but not CHO mammalian cells.

Antiparasitic compounds from Cornus florida L. with activities against Plasmodium falciparum and Leishmania tarentolae.

AIM OF THE STUDY: The objective of this study was to identify the antiplasmodial constituents from the bark of Cornus florida L., a plant traditionally used in North America for the treatment of malaria. METHODS AND MATERIALS: Dried and powdered bark was extracted with 95% ethanol. The resultant extract was subjected to in vitro antiplasmodial-guided fractionation against Plasmodium falciparum (D10 strain). Antiplasmodial IC(50) values were calculated for pure compounds. Compounds were also assayed against Leishmania tarentolae, and rat skeletal myoblast L6 cells to assess antileishmanial activity and cytotoxicity, respectively. RESULTS: Antiplasmodial-guided fractionation afforded 8 compounds: betulinic acid (1), ursolic acid (2), ß-sitosterol (3), ergosta-4,6,8,22-tetraene-3-one (4), 3ß-O-acetyl betulinic acid (5), 3-epideoxyflindissol (6), 3ß-O-cis-coumaroyl betulinic acid (7), 3ß-O-trans-coumaroyl betulinic acid (8), of which, (6) is for the first time here isolated from a natural product and (4), (7) and (8) are reported for the first time from this genus. In vitro IC(50) values against P. falciparum for (4) (61.0 µM) (6) (128.0 µM), (7) (10.4 µM), (8) (15.3 µM) are reported for the first time. Antileishmanial IC(50) values are reported here for the first time for (4) (11.5 µM), (6) (1.8 µM), (7) (8.3 µM) and (8) (2.2 µM). Cytotoxicity against L6 cells is reported for all compounds. CONCLUSIONS: The compounds isolated in this study, while displaying moderate in vitro antiplasmodial activity, do not fully support the historical importance of C. florida as an antimalarial remedy in North America. The traditional remedy may exert its well documented effects by mechanisms unrelated to direct antiplasmodial action. While not traditionally used to treat Leishmania, this work shows that several constituents of C. florida possess promising in vitro antileishmanial activity.

Akt-dependent anabolic activity of natural and synthetic brassinosteroids in rat skeletal muscle cells.

Brassinosteroids are plant-derived polyhydroxylated derivatives of 5α-cholestane, structurally similar to cholesterol-derived animal steroid hormones and insect ecdysteroids. In this study, we synthesized a set of brassinosteroid analogues of a natural brassinosteroid (22S,23S)-homobrassinolide (HB, 1), including (22S,23S)-homocastasterone (2), (22S,23S)-3α-fluoro-homobrasinolide (3), (22S,23S)-3α-fluoro-homocastasterone (4), (22S,23S)-7-aza-homobrassinolide (5), and (22S,23S)-6-aza-homobrassinolide (6) and studied their anabolic efficacy in the L6 rat skeletal muscle cells in comparison to other synthetic and naturally occurring brassinosteroids (22R,23R)-homobrassinolide (7), (22S,23S)-epibrassinolide (8), and (22R,23R)-epibrassinolide (9). Presence of the 6-keto group in the B ring and stereochemistry of 22α,23α-vicinal hydroxyl groups in the side chain were critical for the anabolic activity, possibly due to higher cytotoxicity of the 22ß,23ß-hydroxylated brassinosteroids. All anabolic brassinosteroids tested in this study selectively activated PI3K/Akt signaling pathway as evident by increased Akt phosphorylation in vitro. Plant brassinosteroids and their synthetic derivatives may offer a novel therapeutic strategy for promoting growth, repair, and maintenance of skeletal muscles.

Antiplasmodial activity of aporphine alkaloids and sesquiterpene lactones from Liriodendron tulipifera L.

AIM OF THE STUDY: The objective of this study was to isolate and characterize the active constituents of the traditionally used antimalarial plant Liriodendron tulipifera by antiplasmodial-assay guided fractionation. MATERIALS AND METHODS: Bark and leaves were extracted with solvents of increasing polarity. Fractions were generated using flash chromatography, counter current chromatography and preparative HPLC and subjected to in vitro antiplasmodial and cytotoxicity assays. Active fractions were subjected to further fractionation until pure compounds were isolated, for which the IC(50) values were calculated. RESULTS AND DISCUSSION: Six known aporphine alkaloids, asimilobine (1), norushinsunine (2), norglaucine (3), liriodenine (4), anonaine (5) and oxoglaucine (6) were found to be responsible for the antiplasmodial activity of the bark. Leaves yielded two known sesquiterpene lactones, peroxyferolide (7) and lipiferolide (8) with antiplasmodial activity. The antiplasmodial activity of (2) (IC(50)=29.6 µg/mL), (3) (IC(50)=22.0 µg/mL), (6) (IC(50)=9.1 µg/mL), (7) (IC(50)=6.2 µg/mL) and (8) (IC(50)=1.8 µg/mL) are reported for the first time. CONCLUSION: This work supports the historical use of Liriodendron tulipifera as an antimalarial remedy of the United States and characterizes its antiplasmodial constituents.