Papers by sebastien farnaud
Greenwich Academic Literature Archive (University of Greenwich), Apr 10, 2016
Introduction: Iron deficiency anaemia (IDA) is a significant public health problem in Northern Gh... more Introduction: Iron deficiency anaemia (IDA) is a significant public health problem in Northern Ghana especially amongst women and children. Leafy green vegetables are major contributors to iron intake in this part of the world; poor iron bioavailability from these food sources may be part of the reason for the high prevalence of IDA. Evidence suggests that sweet potato and Moringa leaves might be better sources of bioavailable iron, compared with other leafy green vegetables, as both have high levels of iron, and also beta−carotene − a dietary factor that has been suggested to improve iron bioavailability. Aims/Hypothesis: Our research aims were to evaluate iron bioavailability of sweet potato and Moringa leaves in comparison with other leafy green vegetables commonly consumed in Ghana. We hypothesized that iron uptake from sweet potato and Moringa leaves would be higher compared with the other tested vegetables. Methods: We used the Caco−2 cell/in vitro digestion system; Caco−2 cell ferritin formation was used as a surrogate marker of iron bioavailability. In addition, we also measured levels of other nutrients and dietary factors known to affect iron bioavailability: beta−carotene, iron, calcium, zinc, ascorbate, phytates and polyphenols. Results: Iron bioavailability from all tested vegetables was poor despite relatively high absolute levels of iron in the leaf samples (14.5 − 24.6 mg/100 grams dry weight); there was no statistically significant difference in iron uptake between any of the tested varieties or the control sample with no added iron. Levels of phytates and polyphenols, known inhibitors of iron uptake, were high and probably accounted for the low iron bioavailability of tested leaves. As expected, beta−carotene levels were highest in the sweet potato and Moringa leaves (ranging from 47−98 micrograms retinol activity equivalent)/gram freeze dried leaf) − approximately 100% more compared with the other leafy green vegetables, with the exception of the purple leafed sweet potato variety tested that had approximately the same amount of beta−carotene as the commonly consumed vegetables. Conclusion: In our in vitro model neither sweet potato nor Moringa leaves demonstrated good iron bioavailability suggesting that increased consumption of these vegetables would not lead to improved iron status. However, both leaves were good sources of beta−carotene, and further testing in vivo to evaluate whether they could impact on vitamin A status may be warranted.
Frontiers in Nutrition, Nov 1, 2022
Influence of vitamin D supplementation on immune function of healthy aging people: A pilot random... more Influence of vitamin D supplementation on immune function of healthy aging people: A pilot randomized controlled trial.
World Journal of Gastroenterology, Feb 7, 2019
Liver fibrosis is characterised by excessive deposition of extracellular matrix that interrupts n... more Liver fibrosis is characterised by excessive deposition of extracellular matrix that interrupts normal liver functionality. It is a pathological stage in several untreated chronic liver diseases such as the iron overload syndrome hereditary haemochromatosis, viral hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis and diabetes. Interestingly, regardless of the aetiology, iron-loading is frequently observed in chronic liver diseases. Excess iron can feed the Fenton reaction to generate unquenchable amounts of free radicals that cause grave cellular and tissue damage and thereby contribute to fibrosis. Moreover, excess iron can induce fibrosis-promoting signals in the parenchymal and non-parenchymal cells, which accelerate disease progression and exacerbate liver pathology. Fibrosis regression is achievable following treatment, but if untreated or unsuccessful, it can progress to the irreversible cirrhotic stage leading to organ failure and hepatocellular carcinoma, where resection or transplantation remain the only curative options. Therefore, understanding the role of iron in liver fibrosis is extremely essential as it can help in formulating iron-related diagnostic, prognostic and treatment strategies. These can be implemented in isolation or in combination with the current approaches to prepone detection, and halt or decelerate fibrosis progression before it reaches the irreparable stage. Thus, this review narrates the role of iron in liver fibrosis. It examines the underlying mechanisms by which excess iron can facilitate fibrotic responses. It describes the role of iron in various clinical pathologies and lastly, highlights the significance and potential of iron-related proteins in the diagnosis and therapeutics of liver fibrosis.
Proceedings of the 16th International Conference on Environmental Science and Technology, Nov 19, 2022
Printed circuit boards (PCBs) are a necessity for electronic equipment to function especially in ... more Printed circuit boards (PCBs) are a necessity for electronic equipment to function especially in the telecommunication industries. From a PCB for broadcasting networks to PCBs for office communications they are what makes electronic communications equipment operate. The sophistication possible with modern electronic and microelectronic devices depends ultimately on the materials they are made from. Metals have assumed a vital role in electronics at every stage in their evolution. PCBs are rich in base and precious metals, and should be considered as secondary resources. Bioleaching is a proven green and sustainable method for metal recovery as demonstrated in the mining industry, but application to recover metals from electronic equipment is still limited. In this study, bioleaching is applied for the first time to the telecommunications products that have reached the end of their useful life. Because several biological and physicochemical parameters can influence bioleaching, the first step in this study was to analyse the metal content of PCBs. In the second part, the effect of different parameters on bioleaching is investigated, with the aim of improving metal recovery. Altogether, the study aims to demonstrate the effectiveness of bioleaching for metal recovery from WEEE.
Obesity Reviews, Jul 13, 2023
SummaryThe complex and multifactorial etiology of obesity creates challenges for its effective lo... more SummaryThe complex and multifactorial etiology of obesity creates challenges for its effective long‐term management. Increasingly, the gut microbiome is reported to play a key role in the maintenance of host health and wellbeing, with its dysregulation associated with chronic diseases such as obesity. The gut microbiome is hypothesized to contribute to obesity development and pathogenesis via several pathways involving food digestion, energy harvest and storage, production of metabolites influencing satiety, maintenance of gut barrier integrity, and bile acid metabolism. Moreover, the gut microbiome likely contributes to the metabolic, inflammatory, and satiety benefits and sustained weight‐loss effects following bariatric procedures such as sleeve gastrectomy. While the field of gut microbiome research in relation to obesity and sleeve gastrectomy outcomes is largely in its infancy, the gut microbiome nonetheless holds great potential for understanding some of the mechanisms behind sleeve gastrectomy outcomes as well as for optimizing post‐surgery benefits. This review will explore the current literature within the field as well as discuss the current limitations, including the small sample size, variability in methodological approaches, and lack of associative data, which need to be addressed in future studies.
Greenwich Academic Literature Archive (University of Greenwich), 2015
Introduction: Iron deficiency anaemia (IDA) is a significant public health problem in Northern Gh... more Introduction: Iron deficiency anaemia (IDA) is a significant public health problem in Northern Ghana especially amongst women and children. Leafy green vegetables are major contributors to iron intake in this part of the world; poor iron bioavailability from these food sources may be part of the reason for the high prevalence of IDA. Evidence suggests that sweet potato and Moringa leaves might be better sources of bioavailable iron, compared with other leafy green vegetables, as both have high levels of iron, and also beta−carotene − a dietary factor that has been suggested to improve iron bioavailability. Aims/Hypothesis: Our research aims were to evaluate iron bioavailability of sweet potato and Moringa leaves in comparison with other leafy green vegetables commonly consumed in Ghana. We hypothesized that iron uptake from sweet potato and Moringa leaves would be higher compared with the other tested vegetables. Methods: We used the Caco−2 cell/in vitro digestion system; Caco−2 cell ferritin formation was used as a surrogate marker of iron bioavailability. In addition, we also measured levels of other nutrients and dietary factors known to affect iron bioavailability: beta−carotene, iron, calcium, zinc, ascorbate, phytates and polyphenols. Results: Iron bioavailability from all tested vegetables was poor despite relatively high absolute levels of iron in the leaf samples (14.5 − 24.6 mg/100 grams dry weight); there was no statistically significant difference in iron uptake between any of the tested varieties or the control sample with no added iron. Levels of phytates and polyphenols, known inhibitors of iron uptake, were high and probably accounted for the low iron bioavailability of tested leaves. As expected, beta−carotene levels were highest in the sweet potato and Moringa leaves (ranging from 47−98 micrograms retinol activity equivalent)/gram freeze dried leaf) − approximately 100% more compared with the other leafy green vegetables, with the exception of the purple leafed sweet potato variety tested that had approximately the same amount of beta−carotene as the commonly consumed vegetables. Conclusion: In our in vitro model neither sweet potato nor Moringa leaves demonstrated good iron bioavailability suggesting that increased consumption of these vegetables would not lead to improved iron status. However, both leaves were good sources of beta−carotene, and further testing in vivo to evaluate whether they could impact on vitamin A status may be warranted.
WPI nanocarriers encapsulating FeSO4 (WPI-NC) were prepared using cold homogenisation method. The... more WPI nanocarriers encapsulating FeSO4 (WPI-NC) were prepared using cold homogenisation method. The mucoadhesive polysaccharide chitosan (CHI) was added to the aqueous phase to prepare chitosan coated nanocarriers (WPI-CHI-NC). Nanocarrier physiochemical characteristics were assessed by particle size, zeta potential and morphological analysis. Iron uptake from formulations was compared by caco-2 cell uptake experiments using simulated GI fluid, with intracellular ferritin protein as a measure of iron absorption and pure FeSO4 as reference. Potential toxic effects of nanocarrier formulations on caco-2 cells were assessed by carrying out the colourimetric MTT assay incubating caco-2 cell monolayers with formulations diluted at a final iron concentrations of 20, 50 and 100 µM (and equivalent volumes of corresponding blank iron-free nanocarriers). FeSO4 was used as a reference standard for quantitaive iron absorption experiments. Equivalent amounts of iron (20 µM) from each formulation was added to caco-2 cells cultured in six-well plates (n = 6 per sample) for 2 hours, the estimated physiological transit time through the duodenum, and cells harvested after 24 hours. Intracellular ferritin concentration was determined by ELISA. Ferritin concentrations were then standardised against total protein concentration and ng ferritin/mg protein considered an indice of iron absorption in Caco-2 cells. Data is presented as mean ± SEM and difference between samples was analysed by ANOVA followed by Tukey's post-hoc test using the PRISM software package. Methods WPI nanocarriers encapsulating FeSO4 (WPI-NC) were prepared using cold homogenisation method. The mucoadhesive polysaccharide chitosan (CHI) was added to the aqueous phase to prepare chitosan coated nanocarriers (WPI-CHI-NC). Nanocarrier physiochemical characteristics were assessed by particle size, zeta potential and morphological analysis. Iron uptake from formulations was compared by caco-2 cell uptake experiments using simulated GI fluid, with intracellular ferritin protein as a measure of iron absorption and pure FeSO4 as reference. Potential toxic effects of nanocarrier formulations on caco-2 cells were assessed by carrying out the colourimetric MTT assay incubating caco-2 cell monolayers with formulations diluted at a final iron concentrations of 20, 50 and 100 µM (and equivalent volumes of corresponding blank iron-free nanocarriers). FeSO4 was used as a reference standard for quantitaive iron absorption experiments. Equivalent amounts of iron (20 µM) from each formulation was added to caco-2 cells cultured in six-well plates (n = 6 per sample) for 2 hours, the estimated physiological transit time through the duodenum, and cells harvested after 24 hours. Intracellular ferritin concentration was determined by ELISA. Ferritin concentrations were then standardised against total protein concentration and ng ferritin/mg protein considered an indice of iron absorption in Caco-2 cells. Data is presented as mean ± SEM and difference between samples was analysed by ANOVA followed by Tukey's post-hoc test using the PRISM software package.
Greenwich Academic Literature Archive (University of Greenwich), 2015
Introduction: Iron deficiency anaemia (IDA) is a significant public health problem in Northern Gh... more Introduction: Iron deficiency anaemia (IDA) is a significant public health problem in Northern Ghana especially amongst women and children. Leafy green vegetables are major contributors to iron intake in this part of the world; poor iron bioavailability from these food sources may be part of the reason for the high prevalence of IDA. Evidence suggests that sweet potato and Moringa leaves might be better sources of bioavailable iron, compared with other leafy green vegetables, as both have high levels of iron, and also beta−carotene − a dietary factor that has been suggested to improve iron bioavailability. Aims/Hypothesis: Our research aims were to evaluate iron bioavailability of sweet potato and Moringa leaves in comparison with other leafy green vegetables commonly consumed in Ghana. We hypothesized that iron uptake from sweet potato and Moringa leaves would be higher compared with the other tested vegetables. Methods: We used the Caco−2 cell/in vitro digestion system; Caco−2 cell ferritin formation was used as a surrogate marker of iron bioavailability. In addition, we also measured levels of other nutrients and dietary factors known to affect iron bioavailability: beta−carotene, iron, calcium, zinc, ascorbate, phytates and polyphenols. Results: Iron bioavailability from all tested vegetables was poor despite relatively high absolute levels of iron in the leaf samples (14.5 − 24.6 mg/100 grams dry weight); there was no statistically significant difference in iron uptake between any of the tested varieties or the control sample with no added iron. Levels of phytates and polyphenols, known inhibitors of iron uptake, were high and probably accounted for the low iron bioavailability of tested leaves. As expected, beta−carotene levels were highest in the sweet potato and Moringa leaves (ranging from 47−98 micrograms retinol activity equivalent)/gram freeze dried leaf) − approximately 100% more compared with the other leafy green vegetables, with the exception of the purple leafed sweet potato variety tested that had approximately the same amount of beta−carotene as the commonly consumed vegetables. Conclusion: In our in vitro model neither sweet potato nor Moringa leaves demonstrated good iron bioavailability suggesting that increased consumption of these vegetables would not lead to improved iron status. However, both leaves were good sources of beta−carotene, and further testing in vivo to evaluate whether they could impact on vitamin A status may be warranted.
Title: Novel potato protein-polysaccharide nano-formulations for oral nutrient delivery Study Obj... more Title: Novel potato protein-polysaccharide nano-formulations for oral nutrient delivery Study Objective(s): Bioactive molecules (minerals, vitamins and phytochemicals) have diverse health promoting effects and are used to supplement diet as nutraceuticals. The potential health benefits of several nutraceuticals are limited by lack of stability, reduced activity and low bioavailability. Nano-formulation presents an appealing means of preserving beneficial characteristics while potentially enhancing absorption and potency. Food derived biopolymers such as proteins and polysaccharides are relatively inexpensive, biocompatible, and already used widely in food/ nutraceutical industries. They thus present an attractive resource to formulate nano-vehicles for stabilisation and delivery of nutraceutical bioactives. The aim of our study was to use novel natural source food derived ingredients to formulate nanocarriers for nutrient delivery applications. Iron was selected as a model nutrient for our initial study since i.) iron has a poor sensory profile ii.) is highly reactive rendering it particularly challenging to formulate iii.) iron deficiency is the most common nutritional deficiency worldwide. Method: Nanocarriers incorporating ferrous sulphate (FeSO4 elemental iron equivalent; Fe) and corresponding iron free (BLANK) were prepared by modified nanoprecipitation method with varying protein : polysaccharide ratios. Batches (4) of nanocarriers were formulated with potato protein isolate (PP, ≥95% protein content) and two varieties of the crustacean derived natural polysaccharide chitosan (chitosan HCL – CH; chitosan oligosaccharide – CO): i.) PP+CH-Fe ii.) PP+CH-BLANK ii.) PP+CO-Fe iv.) PP+CO-BLANK. Nanocarrier iron incorporation efficiency was determined by colourimetric iron detection. Nanocarrier physiochemical characteristics were assessed by particle size, zeta potential and transmission electron microscopy analysis. Cellular uptake was evaluated using the human intestinal cell line caco-2 in simulated gastrointestinal fluid and cytotoxicity was determined in presence of increasing concentrations of BLANK and iron loaded nanocarriers (upto 48 hour time-point). Gut pathogenic microbe access to nanoentrapped iron was determined by comparative of growth measurement at 600 nm. Results: Novel potato protein-chitosan blend nanocarriers were successfully fabricated using our optimised protocol. Nanocarriers demonstrated high iron entrapment efficiency (>80%), rounded morphology and a submicron size range (<500 nm) known to favour intestinal permeability as well as stability. Chitosan HCL as well as chitosan oligosaccharide conferred a net positive surface charge that may promote enhanced interaction and uptake in intestinal enterocytes. Nanocarriers demonstrated intestinal iron absorption (as determined by intracellular ferritin) significantly higher than free FeSO4 control (n = 6, P ≤ 0.05), and were non-toxic under experimental conditions (48 h incubation). A decreased iron bioavailability for pathogenic microbes was observed with nanocarrier entrapped iron as compared to free FeSO4. Conclusions: • We demonstrate for the first time the development of novel potato protein-chitosan blend nanocarriers for formulation and delivery of nutrients and the use of potato protein isolate as a novel biomaterial for food formulation. • High absorption with reduced bioavailability to pathogenic microbes presents interesting avenues for oral nutrient delivery. • Our results using the model nutrient (iron) suggests the potential of these delivery systems for high efficacy nutraceutical product formulations for food, beverages and cosmetic applications. • The delivery system is highly versatile, suitable for a range of nutraceuticals, and supports an ‘all natural’ label claim. Funding: Dr MG Zariwala personal research reserve fund.
RSC Advances
A serious environmental problem is associated with the accumulation of solid waste on the Earth.
Global NEST International Conference on Environmental Science & Technology
PCBs, as one of the most valuable streams of e-waste, are a considerable source of precious metal... more PCBs, as one of the most valuable streams of e-waste, are a considerable source of precious metals, but also contain considerable amounts of plastic and ceramic. These non-metallic fractions interfere with and can inhibit the efficiency of metal recovery, particularly for precious and rare earth metals, which are present in e-waste in very low concentrations. In this work, electro-mechanical pre-treatment was applied in order to remove ceramic and plastic fractions from e-waste prior to the application of the bioleaching process. Metal content with and without mechanical separation, as well as metal dissolution and behaviour in the bioleaching process were compared. The results obtained illustrate the beneficial effects of separating the metallic from the non-metallic fraction prior the bioleaching process for the recovery of precious, rare earth and base metals from e-waste.
Frontiers in Nutrition
ObjectivesThis study aims to investigate the influence of vitamin D supplementation on immune fun... more ObjectivesThis study aims to investigate the influence of vitamin D supplementation on immune function of healthy older adults.Materials and methodsDesigned as a randomized controlled trial, 21 participants (55–85 years) completed the study during May–November 2018 in Coventry, England. The participants were randomized into vitamin D or the control group, stratified by age, gender and body mass index. The vitamin D group (n = 12) took vitamin D3 tablets of 1,000 IU/day for 12 weeks plus vitamin D education leaflet, while the control group (n = 9) were only provided with the leaflet. At baseline, 6 and 12 weeks, plasma 25(OH)D levels and immunological and metabolic parameters including phagocytic activity of granulocytes and monocytes, tumor necrosis factor, interleukin 6, lymphocyte subsets and fasting blood glucose and lipid were measured. Dietary vitamin D intake was analyzed at baseline and week 12. Data were presented as mean ± SD. Two-way repeated measures ANOVA and independent...
Enzyme and Microbial Technology
Journal of the Taiwan Institute of Chemical Engineers
Current Developments in Nutrition
Objectives The study aims to investigate the influence of vitamin D (VD) supplement on immune fun... more Objectives The study aims to investigate the influence of vitamin D (VD) supplement on immune function of the healthy older people. Methods Designed as a randomized control trial, 21 participants (55–85) years old took part and completed the study (20 White, 1 Indian) during May-November 2018 in Coventry, England. The participants were randomized into two groups, VD and control, stratified by age, gender and body mass index (BMI). The VD group (n = 11) took VD3 of 25 μg/day for 12 weeks, while the control group (n = 9) were only provided with educational information of VD. At baseline, 6 weeks and 12 weeks, plasma 25(OH)D levels and immune parameters including phagocytic activity of granulocytes and monocytes, tumour necrosis factor (TNF), interleukin 6 (IL-6), lymphocyte subsets (Th, Tc and natural killer cells), and fast blood glucose and lipid were measured. Dietary VD intake was analysed at baseline and week 12. The data were presented as mean ± standard error (SE) and analysed ...
Journal of Sustainable Metallurgy, 2022
Electronic waste is a dominant global issue with over 50 million tons generated annually. Still, ... more Electronic waste is a dominant global issue with over 50 million tons generated annually. Still, as an amalgamation of precious and rare raw materials, electronic waste is a considerable economic resource with the most valuable components located on the printed circuit boards. Gold is widely used in electronics in numerous applications, although principally for contact points and external connectors. The recovery of gold, due to its high value, is one of the main motivations for recycling e-waste. Although pyrometallurgy and hydrometallurgy processing are still the preferred modes of recovery for gold, the use of high-energy consuming pyro-methods, and the use of gold cyanidation that uses harmful lixiviants are increasingly discouraged. Thiourea has received attention as an alternative lixiviant for gold leaching due to its fast reaction kinetics and less harmful nature. This review aims to provide an up-to-date evaluation of thiourea-gold leaching studies from electronic waste, wi...
World Journal of Gastroenterology, 2019
Liver fibrosis is characterised by excessive deposition of extracellular matrix that interrupts n... more Liver fibrosis is characterised by excessive deposition of extracellular matrix that interrupts normal liver functionality. It is a pathological stage in several untreated chronic liver diseases such as the iron overload syndrome hereditary haemochromatosis, viral hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis and diabetes. Interestingly, regardless of the aetiology, iron-loading is frequently observed in chronic liver diseases. Excess iron can feed the Fenton reaction to generate unquenchable amounts of free radicals that cause grave cellular and tissue damage and thereby contribute to fibrosis. Moreover, excess iron can induce fibrosis-promoting signals in the parenchymal and non-parenchymal cells, which accelerate disease progression and exacerbate liver pathology. Fibrosis regression is achievable following treatment, but if untreated or unsuccessful, it can progress to the irreversible cirrhotic stage leading to organ failure and hepatocellular carcinoma, where resection or transplantation remain the only curative options. Therefore, understanding the role of iron in liver fibrosis is extremely essential as it can help in formulating iron-related diagnostic, prognostic and treatment strategies. These can be implemented in isolation or in combination with the current approaches to prepone detection, and halt or decelerate fibrosis progression before it reaches the irreparable stage. Thus, this review narrates the role of iron in liver fibrosis. It examines the underlying mechanisms by which excess iron can facilitate fibrotic responses. It describes the role of iron in various clinical pathologies and lastly, highlights the significance and potential of iron-related proteins in the diagnosis and therapeutics of liver fibrosis.
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Papers by sebastien farnaud