Publications by authors named "David S Pasco"

Xanthoparmelia conspersa is rich in specific secondary metabolites but an unexplored lichen species. This work determined the chemical composition and biological activities (anti-microbial, anti-protozoal, and cytotoxic) of its methanolic and hexane extracts. Additionally, we evaluated the potential of these extracts in modulating cancer signaling pathways in HeLa cells.

View Article and Find Full Text PDF

Machaeriols and machaeridiols are unique hexahydrodibenzopyran-type aralkyl phytocannabinoids isolated from Pers. Earlier studies of machaeriol A () and B () did not show any affinity for cannabinoid receptor 1 (CB1 or CNR1), although they are structural analogs of psychoactive hexahydrocannabinol. This study comprehensively reports on the affinities of isolated Pers.

View Article and Find Full Text PDF

Since aerobic glycolysis was first observed in tumors almost a century ago by Otto Warburg, the field of cancer cell metabolism has sparked the interest of scientists around the world as it might offer new avenues of treatment for malignant cells. Our current study claims the discovery of gnetin H (GH) as a novel glycolysis inhibitor that can decrease metabolic activity and lactic acid synthesis and displays a strong cytostatic effect in melanoma and glioblastoma cells. Compared to most of the other glycolysis inhibitors used in combination with the complex-1 mitochondrial inhibitor phenformin (Phen), GH more potently inhibited cell growth.

View Article and Find Full Text PDF

This study aimed to examine if methanolic extracts of Mill. can inhibit HeLa cell proliferation through the modulation of cancer-related signaling pathways. The cytotoxicity and chemical composition of leaves and root extracts were also determined.

View Article and Find Full Text PDF

The purpose of this study was to determine if a methanolic extract of the Pulsatilla patens (L.) Mill. can inhibit the progression of cancer through the modulation of cancer-related metabolic signaling pathways.

View Article and Find Full Text PDF

The anticancer activities of and its constituents have been reported earlier, but their influence on the crosstalk of complex cancer-related signaling metabolic pathways (i.e., transcription factors; TF) has not yet been fully investigated.

View Article and Find Full Text PDF

Research supports the theory that the microbiome of plants and mushrooms produce potent activators of pathogen recognition receptors which are principal contributors to the stimulation of macrophages. We have previously reported that the in vitro macrophage stimulatory activity of water-soluble extracts from 13 different types of edible mushrooms is predominantly due to bacterial components originating from the naturally occurring bacterial communities within these materials. The purpose of the current study was to further investigate the bacterial-dependent activity of the water-soluble extracts and assess whether these 13 types of mushrooms contain water-insoluble beta glucans that activate the dectin-1b signaling pathway.

View Article and Find Full Text PDF

We previously demonstrated that extracts from Echinacea purpurea material varied substantially in their ability to activate macrophages in vitro and that this variation was due to differences in their content of bacterial components. The purpose of the current study was to identify soil conditions (organic matter, nitrogen, and moisture content) that alter the macrophage activation potential of E. purpurea and determine whether these changes in activity correspond to shifts in the plant-associated microbiome.

View Article and Find Full Text PDF

Enteric septicemia of catfish, columnaris disease and streptococcosis, caused by , and , respectively, are the most common bacterial diseases of economic significance to the pond-raised channel catfish industry. Certain management practices are used by catfish farmers to prevent large financial losses from these diseases such as the use of commercial antibiotics. In order to discover environmentally benign alternatives, using a rapid bioassay, we evaluated a crude extract from the roots of muscadine against these fish pathogenic bacteria and determined that the extract was most active against .

View Article and Find Full Text PDF

Enthusiasm for the use of dietary bioactive compounds as chemopreventive agents and adjuvants for current therapies has increased laboratory research conducted on several types of cancers including Head and Neck Squamous Cell Carcinoma (HNSCC). The green chemoprevention movement is a modern approach to highlight healthy lifestyle changes that aim to decrease the incidence of HNSCC. A healthy diet can be an effective way to prevent the development of oral cancers.

View Article and Find Full Text PDF

Recent studies have indicated that a major contributor to the innate immune enhancing properties of some medicinal plants is derived from the cell wall components of bacteria colonizing these plants. The purpose of the current study was to assess if the bacteria present within edible and medicinal mushrooms substantially contribute to the innate immune stimulating potential of these mushrooms. Whole mushrooms from thirteen types of edible fungi and individual parts from Agaricus bisporus were analyzed for in vitro macrophage activation as well as bacterial lipopolysaccharides (LPS) content, cell load, and community composition.

View Article and Find Full Text PDF

Evidence supports the theory that bacterial communities colonizing Echinacea purpurea contribute to the innate immune enhancing activity of this botanical. Previously, we reported that only about half of the variation in in vitro monocyte stimulating activity exhibited by E. purpurea extracts could be accounted for by total bacterial load within the plant material.

View Article and Find Full Text PDF

A growing body of research indicates that oral administration of bacteria (such as probiotics) can exhibit a protective effect against influenza A (H1N1) viral infection in mice. In the present study, we used a mouse model to examine whether oral administration of Immulina(®), a commercial extract from the cyanobacteria Arthrospira (Spirulina) platensis, can reduce the severity of illness resulting from influenza A (H1N1) viral infection. The main active compounds within Immulina(®) are bacterial Braun-type lipoproteins that activate innate immune cells through a toll-like receptor (TLR) 2-dependent pathway.

View Article and Find Full Text PDF

Inflammasome activation has been shown to regulate both innate and adaptive immune responses. It is important to investigate whether immune-enhancing natural products can also activate inflammasome. The current study examined the potential of protein-bound polysaccharide-K (PSK), a hot water extract from Trametes versicolor, to activate inflammasome.

View Article and Find Full Text PDF

Bioassay-guided fractionation of the leaves of Eugenia rigida yielded three stilbenes, (Z)-3,4,3',5'-tetramethoxystilbene (1), (E)-3,4,3',5'-tetramethoxystilbene (2), and (E)-3,5,4'-trimethoxystilbene (3). Their structures were determined using 1D- and 2D-NMR spectroscopy and HRESIMS. The sterically hindered Z-stereoisomer 1, a new natural product, was prepared by time-dependent photoisomerization of the E-isomer (2) under UV irradiation at λ254 nm, while 2,3,5,7-tetramethoxyphenanthrene (5) was identified at λ365 nm by UHPLC/APCI-MS and NMR spectroscopy.

View Article and Find Full Text PDF

Our previous studies indicate that the majority of in vitro monocyte/macrophage activation exhibited by extracts of Echinacea depends on bacterial components. In the present study, total bacterial load was determined within E. purpurea samples and ranged from 6.

View Article and Find Full Text PDF

Immulina®, a commercial extract of Arthrospira (Spirulina) platensis is a potent activator of THP-1 monocytes and CD4+ T cells IN VITRO and enhances several immunological functions in mice. We further characterized Immulina® by determining that Braun-type lipoproteins are responsible for a major portion of the IN VITRO monocyte activation exhibited by this material. In order to understand the effect of Immulina® on NK cell activity, a pilot study was conducted on ten healthy North American individuals who supplemented their diet with Immulina® (400 mg/day) for seven days.

View Article and Find Full Text PDF

We previously reported that the majority of in vitro monocyte/macrophage activation exhibited by extracts of Echinacea and other botanicals depends upon bacterial lipopolysaccharides and Braun-type bacterial lipoproteins. We determined the contribution made by these bacterial components to the overall immune-enhancing activity detected in E. purpurea and E.

View Article and Find Full Text PDF

Purpose: Breast cancer is one of the most prevalent woman cancers. Genomic instability, accumulative mutations, and subsequent changes in intracellular signaling cascades play key roles in the development of human breast cancers. Activation of nuclear factor-kappaB (NF-kappaB) has been implicated in oncogenesis of breast cancers and is known to be associated with resistance to anticancer agents and apoptosis.

View Article and Find Full Text PDF

We have identified potent monocyte/macrophage activating bacterial lipoproteins within commonly used immune enhancing botanicals such as Echinacea, American ginseng and alfalfa sprouts. These bacterial lipoproteins, along with lipopolysaccharides, were substantially more potent than other bacterially derived components when tested in in vitro monocyte/macrophage activation systems. In experiments using RAW 264.

View Article and Find Full Text PDF

Pimpinella essential oils and isolated compounds were screened for their inhibitory activity against NF-kappaB mediated transcription in SW1353 cells. Twelve oils were effective in inhibiting NF-kappaB mediated transcription. Especially the roots of P.

View Article and Find Full Text PDF

Purpose: Nuclear factor-kappaB (NF-kappaB) plays a crucial role in the regulation of inflammatory processes, cell proliferation, and apoptosis. Blocking NF-kappaB signaling may represent a therapeutic strategy in cancer and inflammation therapy. The aim of this study was to investigate the effects of sesquiterpenes isolated from Asteraceae, namely melampolides (enhydrin, tetraludin A) and repandolides (repandins A, B, D and E) on the activation of NF-kappaB, cell growth of cancer cells, cell cycle progression and apoptosis.

View Article and Find Full Text PDF

We reported previously that a high molecular weight polysaccharide fraction (Immulina) from Spirulina was a potent activator of NF-kappa B and induced both IL-1 beta and TNF-alpha mRNAs in THP-1 human monocytes. In the present study, we show that NF-kappa B activation by Immulina is suppressed by antibodies to CD14 and TLR2 but not by antibodies to TLR4. Similarly, NF-kappa B directed luciferase expression was enhanced by Immulina treatment when cells were co-transfected with vectors expressing proteins supporting TLR2- (CD14 and TLR2) but not TLR4-(CD14, TLR4, and MD-2) dependent activation.

View Article and Find Full Text PDF

Background: Aristolochia species are nephrotoxic and carcinogenic. Recent studies showed that aristolochic acid (AA) could induce acute renal failure and tubular lesions in several species and available evidences demonstrate the unequivocal role of AA in so called Chinese herbs nephropathy.

Methods: A series of AA derivatives isolated from Aristolochia spp.

View Article and Find Full Text PDF

The agents responsible for the therapeutic effects of many botanical supplements have not been established in spite of their popularity. Here we show that melanin is a previously unrecognized immunostimulatory compound that is a major component of botanicals traditionally used to enhance immune function. While melanin is present in commonly consumed vegetables, its specific activity is several orders of magnitude less than melanin extracted from these botanicals.

View Article and Find Full Text PDF