-
1.
Intestinal permeation enhancers: Lessons learned from studies using an organ culture model.
Danielsen, EM
Biochimica et biophysica acta. Biomembranes. 2021;(1):183474
Abstract
Permeation enhancers (PEs) are compounds aimed to increase intestinal uptake of oral drugs with poor bioavailability. This mini-review focuses on results recently obtained with PEs using an intestinal organ culture model. The model predicts which paracellular/transcellular pathways across the epithelium are susceptible to different classes of PEs (mainly surfactants and cell penetrating peptides). PEs: 1) generate a transmembrane transcellular pathway, 2) block apical endocytosis (first step in apical-to-basolateral transcytosis), and 3) perturb normal cell membrane integrity. The results argue that surfactants and cell penetrating peptides are not suitable for use in formulations aimed to exploit transcytosis in oral drug delivery.
-
2.
Culture Medium Development for Microbial-Derived Surfactants Production-An Overview.
Nurfarahin, AH, Mohamed, MS, Phang, LY
Molecules (Basel, Switzerland). 2018;(5)
Abstract
Surfactants are compounds that can reduce the surface tension between two different phases or the interfacial tension of the liquid between water and oil, possessing both hydrophilic and hydrophobic moieties. Biosurfactants have traits that have proven to be advantageous over synthetic surfactants, but these compounds do not compete economically with synthetic surfactants. Different alternatives increase the yield of biosurfactants; development of an economical production process and the usage of cheaper substrates during process have been employed. One of the solutions relies on the suitable formulation of a production medium by including alternative raw materials sourced from agro-wastes, hydrocarbons, or by-products of a process might help in boosting the biosurfactant production. Since the nutritional factors required will be different among microorganisms, the establishment of a suitable formulation for biosurfactant production will be challenging. The present review describes various nutrients and elements considered in the formulation of a production medium with an approach focusing on the macronutrient (carbon, nitrogen source, and C/N ratio), minerals, vitamins, metabolic regulators, and salinity levels which may aid in the study of biosurfactant production in the future.
-
3.
Chemically-Induced Production of Anti-Inflammatory Molecules in Microalgae.
Montero-Lobato, Z, Vázquez, M, Navarro, F, Fuentes, JL, Bermejo, E, Garbayo, I, Vílchez, C, Cuaresma, M
Marine drugs. 2018;(12)
Abstract
Microalgae have been widely recognized as a valuable source of natural, bioactive molecules that can benefit human health. Some molecules of commercial value synthesized by the microalgal metabolism have been proven to display anti-inflammatory activity, including the carotenoids lutein and astaxanthin, the fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), and sulphated polysaccharides. These molecules can accumulate to a certain extent in a diversity of microalgae species. A production process could become commercially feasible if the productivity is high and the overall production process costs are minimized. The productivity of anti-inflammatory molecules depends on each algal species and the cultivation conditions, the latter being mostly related to nutrient starvation and/or extremes of temperature and/or light intensity. Furthermore, novel bioprocess tools have been reported which might improve the biosynthesis yields and productivity of those target molecules and reduce production costs simultaneously. Such novel tools include the use of chemical triggers or enhancers to improve algal growth and/or accumulation of bioactive molecules, the algal growth in foam and the surfactant-mediated extraction of valuable compounds. Taken together, the recent findings suggest that the combined use of novel bioprocess strategies could improve the technical efficiency and commercial feasibility of valuable microalgal bioproducts production, particularly anti-inflammatory compounds, in large scale processes.
-
4.
Comparison of the effectiveness of polyethylene glycol with and without electrolytes in constipation: a systematic review and network meta-analysis.
Katelaris, P, Naganathan, V, Liu, K, Krassas, G, Gullotta, J
BMC gastroenterology. 2016;:42
Abstract
BACKGROUND Polyethylene glycol is commonly used to manage constipation and is available with or without electrolytes. The addition of electrolytes dates back to its initial development as lavage solutions in preparation for gastrointestinal interventions. The clinical utility of the addition of electrolytes to polyethylene glycol for the management of constipation is not established. The objective of this systematic review and network meta-analysis (NMA) was to assess the relative effectiveness of polyethylene glycol with (PEG + E) or without electrolytes (PEG) in the management of functional constipation in adults. METHODS A systematic review was conducted to identify randomised controlled clinical trials that assessed the use of polyethylene glycol in functional constipation. The primary outcome was the mean number of bowel movements per week. RESULTS Nineteen studies were included in the NMA (PEG N = 9, PEG + E N = 8, PEG versus PEG + E N = 2; involving 2247 patients). PEG and PEG + E are both effective, increasing the number of bowel movements per week by 1.8 (95 % Crl 1.0, 2.8) and 1.9 (95 % Crl 0.9, 3.0) respectively versus placebo and by 1.8 (95 % Crl 0.0, 3.5) and 1.9 (95 % Crl 0.2, 3.6) respectively versus lactulose. There was no efficacy difference between PEG + E and PEG (0.1, 95 % Crl -1.1, 1.2) and there were no differences in safety or tolerability. CONCLUSIONS Polyethylene glycol with and without electrolytes are effective and safe treatments for constipation in adults. The addition of electrolytes to polyethylene glycol does not appear to offer any clinical benefits over polyethylene glycol alone in the management of constipation.
-
5.
Contributions of biosurfactants to natural or induced bioremediation.
Lawniczak, L, Marecik, R, Chrzanowski, L
Applied microbiology and biotechnology. 2013;(6):2327-39
-
-
Free full text
-
Abstract
The number of studies dedicated to evaluating the influence of biosurfactants on bioremediation efficiency is constantly growing. Although significant progress regarding the explanation of mechanisms behind biosurfactant-induced effects could be observed, there are still many factors which are not sufficiently elucidated. This corresponds to the fact that although positive influence of biosurfactants is often reported, there are also numerous cases where no or negative effect was observed. This review summarizes the recent finding in the field of biosurfactant-amended bioremediation, focusing mainly on a critical approach towards potential limitations and causes of failure while investigating the effects of biosurfactants on the efficiency of biodegradation and phytoextraction processes. It also provides a summary of successive steps, which should be taken into consideration when designing biosurfactant-related treatment processes.
-
6.
Biosurfactants in agriculture.
Sachdev, DP, Cameotra, SS
Applied microbiology and biotechnology. 2013;(3):1005-16
-
-
Free full text
-
Abstract
Agricultural productivity to meet growing demands of human population is a matter of great concern for all countries. Use of green compounds to achieve the sustainable agriculture is the present necessity. This review highlights the enormous use of harsh surfactants in agricultural soil and agrochemical industries. Biosurfactants which are reported to be produced by bacteria, yeasts, and fungi can serve as green surfactants. Biosurfactants are considered to be less toxic and eco-friendly and thus several types of biosurfactants have the potential to be commercially produced for extensive applications in pharmaceutical, cosmetics, and food industries. The biosurfactants synthesized by environmental isolates also has promising role in the agricultural industry. Many rhizosphere and plant associated microbes produce biosurfactant; these biomolecules play vital role in motility, signaling, and biofilm formation, indicating that biosurfactant governs plant-microbe interaction. In agriculture, biosurfactants can be used for plant pathogen elimination and for increasing the bioavailability of nutrient for beneficial plant associated microbes. Biosurfactants can widely be applied for improving the agricultural soil quality by soil remediation. These biomolecules can replace the harsh surfactant presently being used in million dollar pesticide industries. Thus, exploring biosurfactants from environmental isolates for investigating their potential role in plant growth promotion and other related agricultural applications warrants details research. Conventional methods are followed for screening the microbial population for production of biosurfactant. However, molecular methods are fewer in reaching biosurfactants from diverse microbial population and there is need to explore novel biosurfactant from uncultured microbes in soil biosphere by using advanced methodologies like functional metagenomics.
-
7.
Functional metagenomic strategies for the discovery of novel enzymes and biosurfactants with biotechnological applications from marine ecosystems.
Kennedy, J, O'Leary, ND, Kiran, GS, Morrissey, JP, O'Gara, F, Selvin, J, Dobson, AD
Journal of applied microbiology. 2011;(4):787-99
-
-
Free full text
-
Abstract
Marine ecosystems are home to bacteria which are exposed to a wide variety of environmental conditions, such as extremes in temperature, salinity, nutrient availability and pressure. Survival under these conditions must have necessitated the adaptation and the development of unique cellular biochemistry and metabolism by these microbes. Thus, enzymes isolated from these microbes have the potential to possess quite unique physiological and biochemical properties. This review outlines a number of function-based metagenomic approaches which are available to screen metagenomic libraries constructed from marine ecosystems to facilitate the exploitation of some of these potentially novel biocatalysts. Functional screens to isolate novel cellulases, lipases and esterases, proteases, laccases, oxidoreductases and biosurfactants are described, together with approaches which can be employed to help overcome some of the typical problems encountered with functional metagenomic-based screens.
-
8.
Natural functions of lipopeptides from Bacillus and Pseudomonas: more than surfactants and antibiotics.
Raaijmakers, JM, De Bruijn, I, Nybroe, O, Ongena, M
FEMS microbiology reviews. 2010;(6):1037-62
-
-
Free full text
-
Abstract
Lipopeptides constitute a structurally diverse group of metabolites produced by various bacterial and fungal genera. In the past decades, research on lipopeptides has been fueled by their antimicrobial, antitumour, immunosuppressant and surfactant activities. However, the natural functions of lipopeptides in the lifestyles of the producing microorganisms have received considerably less attention. The substantial structural diversity of lipopeptides suggests that these metabolites have different natural roles, some of which may be unique to the biology of the producing organism. This review gives a detailed overview of the versatile functions of lipopeptides in the biology of Pseudomonas and Bacillus species, and highlights their role in competitive interactions with coexisting organisms, including bacteria, fungi, oomycetes, protozoa, nematodes and plants. Their functions in cell motility, leading to colonization of novel habitats, and in the formation and development of highly structured biofilms are discussed in detail. Finally, this review provides an update on lipopeptide detection and discovery as well as on novel regulatory mechanisms and genes involved in lipopeptide biosynthesis in these two bacterial genera.
-
9.
Systematic review: adverse event reports for oral sodium phosphate and polyethylene glycol.
Belsey, J, Epstein, O, Heresbach, D
Alimentary pharmacology & therapeutics. 2009;(1):15-28
-
-
Free full text
-
Abstract
BACKGROUND Screening colonoscopy exposes healthy patients to the risk of serious adverse events associated with bowel preparation. Randomized controlled trials are not an effective method for evaluating this risk. AIM: To search published literature in order to characterize the risk of adverse events associated with oral polyethylene glycol (PEG) or sodium phosphate (NaP). METHODS A systematic review identified case reports of any serious events associated with PEG or NaP. Reports to the Food and Drug Administration (FDA) were also examined. RESULTS Fifty-eight publications of significant events in 109 patients using NaP and 22 patients using PEG were identified. As the total number of prescriptions issued is unknown, rates for the two agents cannot be directly compared. Most commonly reported were electrolyte disturbances, renal failure and colonic ulceration for NaP and Mallory-Weiss tear, electrolyte disturbances and allergic reactions for PEG between January 2006 and December 2007; there were 171 cases of renal failure reported to the FDA following use of NaP and 10 following PEG. CONCLUSIONS Adverse events following bowel preparation are uncommon, but potentially serious. Given that many of these patients are healthy individuals undergoing screening, the benefit/risk ratio must be carefully considered when deciding which preparation to prescribe in individual patients.
-
10.
Commonly used preparations for colonoscopy: efficacy, tolerability, and safety--a Canadian Association of Gastroenterology position paper.
Barkun, A, Chiba, N, Enns, R, Marcon, M, Natsheh, S, Pham, C, Sadowski, D, Vanner, S
Canadian journal of gastroenterology = Journal canadien de gastroenterologie. 2006;(11):699-710
Abstract
INTRODUCTION The increased demand for colonoscopy, coupled with the introduction of new bowel cleansing preparations and recent caution advisories in Canada, has prompted a review of bowel preparations by the Canadian Association of Gastroenterology. METHODS The present review was conducted by the Clinical Affairs group of committees including the endoscopy, hepatobiliary/transplant, liaison, pediatrics, practice affairs and regional representation committees, along with the assistance of Canadian experts in the field. An effort was made to systematically assess randomized prospective trials evaluating commonly used bowel cleansing preparations in Canada. RESULTS Polyethylene glycol (PEG)-; sodium phosphate (NaP)-; magnesium citrate (Mg-citrate)-; and sodium picosulphate, citric acid and magnesium oxide (PSMC)-containing preparations were reviewed. Regimens of PEG 2 L with bisacodyl (10 mg to 20 mg) or Mg-citrate (296 mL) are as effective as standard PEG 4 L regimens, but are better tolerated. NaP preparations appear more effective and better tolerated than standard PEG solutions. PSMC has good efficacy and tolerability but head-to-head trials with NaP solutions remain few, and conclusions equivocal. Adequate hydration during preparation and up to the time of colonoscopy is critical in minimizing side effects and improving bowel cleansing in patients receiving NaP and PSMC preparations. All preparations may cause adverse events, including rare, serious outcomes. NaP should not be used in patients with cardiac or renal dysfunction (PEG solution is preferable in these patients), bowel obstruction or ascites, and caution should be exercised when used in patients with pre-existing electrolyte disturbances, those taking medications that may affect electrolyte levels and elderly or debilitated patients. Health Canada's recommended NaP dosing for most patients is two 45 mL doses 24 h apart. However, both safety and efficacy data on this dosing schedule are lacking. Many members of the Canadian Association of Gastroenterology expert panel administer both doses within 24 h, as studied in clinical trials, after careful one-on-one discussion of risks and benefits in carefully selected patients. Safety data on PSMC and combination preparations in North America are limited and clinicians are encouraged to keep abreast of developments in this area. CONCLUSIONS All four preparations reviewed provided effective bowel cleansing for colonoscopy in the majority of patients, with varying tolerability. Adequate hydration is essential in patients receiving the preparations.