Suppression of pro-inflammatory signalling pathways by sulforaphane

Low-grade inflammation has been associated with the risk of chronic pathologies including cancer, atherosclerosis and type 2 diabetes. Epidemiological studies demonstrate an inverse correlation between diets rich in cruciferous vegetables and risk of cancer, cardiovascular disease mortality and circulating levels of pro-inflammatory cytokines. Sulforaphane (SF), an isothiocyanate obtained from broccoli, has many biological functions. The aim of this thesis was to test whether SF was able to suppress pro-inflammatory signalling using in vitro models of chronic inflammation. In human monocytes (PBMCs and THP-1 cells), physiologically relevant concentrations of SF significantly suppressed the production of LPS-induced cytokines IL-6, IL-1β and TNFα. The suppression was also observed with all genes induced by 1ng/ml LPS as measured by whole genome arrays. In addition, it was demonstrated that SF could directly interact with thiol groups of cysteine residues 609 and 246 within the LPS receptor, TLR4 under non-reducing conditions, to reduce the levels of inflammatory mediators that are produced in response to LPS. The anti-inflammatory effect of SF was not restricted to the TLR4 pathway, and significant reductions were observed in NF-κB activity induced in response to TLR2 and NOD2 ligands. These findings were translated into a more complex in vitro model, investigating the effect of SF on lipid accumulation within adipocytes and adipose tissue inflammation in response to macrophage-conditioned medium (MaCM) using human SGBS adipocytes. SF at 10μM significantly reduced levels of lipid accumulation within adipocytes and increased the expression of carnitine palmitoyltransferase-1A (CPT1A), suggesting a role in energy metabolism, a process often disrupted in obesity. In addition, a significant suppression in SGBS adipocyte IL-1β and IL-6 expression was observed when adipocytes were exposed to MaCM from SF-treated macrophages, when SF was used at a concentration as low as 2μM. This work demonstrates that concentrations of SF that could be achieved via reasonable broccoli consumption can suppress pro-inflammatory cytokine production, induced in response to a number of signalling pathways in addition to suppression of lipid accumulation and adipose tissue inflammation. The relevance of this data supports the concept that consumption of broccoli could lead to a reduction in the chronic inflammatory status in vivo as well as a suppression of lipid accumulation within adipocytes, to reduce the risk of developing chronic disease

Variations in flow resistance in small agricultural streams due to idealized aquatic vegetation distributions

The work reported here considers flow resistance due to vegetation in the smallest of surface water drainage channels – streams and agricultural drainage ditches of the order of 1m wide and 10cm deep. The second investigation explored the way in which the spatial distribution of obstacles to the flow affected flow resistance in these small channels. In practice, such obstacles in these channels are usually patches of aquatic vegetation. However, vegetation has complex hydraulic properties. Therefore, to elucidate the specific effects of the spatial pattern of obstacles, we used arrays of hydraulically-simpler obstacles, namely sandbags. We found that the maximum efficiency of energy conversion from potential energy to kinetic energy in the flow occurred when the sandbags covered 50% of the total area they occupied. If they were more spread out than this, it allowed the creation of individual wakes, which between them increased energy dissipation; if they were more piled up, this caused plunging of the flow over them, which also increased energy dissipation, though to a much lesser extent that individual wake formation

Plant patch hydrodynamics in streams : Mean flow, turbulence, and drag forces

Peer reviewedPreprin

Creating patches of comprehension and filling gaps in knowledge:physical modelling contributions to joined-up understanding of heterogeneous eco-scapes

Most “eco-scapes” (by which I mean spatial distributions of ecosystems), including those in aquatic environments, are heterogeneous, a condition which can be indicative of a healthy, resilient diversity of habitats, or of fragmentation, stress and decay. This heterogeneity is often conceptualised in terms of “patches” and “gaps”, amongst other spatial elements. Interactions between the ambient hydrodynamics and patches and gaps in organism distributions are therefore central to determining ecosystems’ structure, functioning, possible future trajectories and responses to anthropogenic interventions. This paper will review work carried out over the past few years aimed at understanding these interactions and their implications, which has used physical modelling as its primary modus operandi. The key findings of this work are that the nature and density of gap-patch boundaries, and the relative locations of patches and patch-wakes, are of overriding importance in determining how the organisms and hydrodynamics influence each other and the morphological, sedimentary and biogeochemical aspects of their wider environments. This paper discusses these issues using examples from studies of two keystone coastal organisms, seagrasses and mussels, and suggests ways in which research in this area might best try to proceed

Agricultural Research for Development in the Tropics: Caught between Energy Demands and Food Needs

We have shown in this analysis, that there is no easy answer to the question: is biofuel out competing food production for natural resources. We feel that when addressing this issue future discussions need to include a broader view on the global consequences of regional and national actions. It is necessary to base decisions not on short-term political or economic arguments but on the long term balance for resources and environmental health, both providing the basis for the livelihood of future generations. Therefore, efforts must be made to calculate the real carbon balance and water foot prints for every item and process involved in the production chains and base decisions on the least detrimental approach to crop and energy production and not on the most economical, which basically means cheapest by today’s definition