VALIDATION OF THE SULFO-PHOSPHO-VANILLIN (SPV) METHOD FOR THE DETERMINATION OF LIPID CONTENT IN OLEAGINOUS MICROORGANISMS

A novel approach to pH-Responsive targeted cancer Therapy: Inhibition of FaDu cancer cell proliferation with a pH low insertion Peptide-Conjugated DGAT1 inhibitor

Targeting enzymes involved in lipid metabolism is increasingly recognized as a promising anticancer strategy. Efficient inhibition of diacylglycerol O-transferase 1 (DGAT1) can block fatty acid (FA) storage. This, in turn, triggers an increase in free polyunsaturated FA concentration, leading to peroxidation and ferroptosis. In this study, we report the development of a pH-sensitive peptide (pHLIP)-drug conjugate designed to selectively deliver DGAT1 inhibitors to cancer cells nested within the acidic microenvironment of tumors. We utilized two previously established pHLIP sequences for coupling with drugs. The study of DGAT1 conjugates in large unilamellar vesicles (LUVs) of different compositions did not reveal enhanced pH-dependent insertion compared to POPC LUVs. However, using in vitro 3D tumor spheroids, significant antiproliferative effects were observed upon exposure to pHLIP-T863 (DGAT1 inhibitor) conjugates, surpassing the inhibitory activity of T863 alone. In conclusion, our study provides the first evidence that pHLIP-based conjugates with DGAT1 inhibitors have the potential to specifically target the acidic compartment of tumors. Moreover, it sheds light on the limitations of LUV models in capturing the pH-dependency of such conjugates.

Microscopic characterization, TLC fingerprinting and optimization of total lipid content from Euphorbia neriifolia (L.) using response surface methodology

Euphorbia neriifolia (EN) is a medicinal plant used to treat a variety of ailments in traditional systems. Despite numerous studies on pharmacological activities, no information was available on the microscopic study of this plant. This is the first study that has been attempted to fill this need by performing the light and field emission scanning electron microscopy (FESEM) of leaf, stem, and latex. The powder microscopy of several organs (leaves, stem, and bark) and exudate (latex) of EN was carried out using safranine, fast green, phloroglucinol, and other standard solutions at different magnifications. The chemical fingerprinting of petroleum ether extract was accomplished by using thin layer chromatography. The optimization of total lipid content from the EN leaf under ultrasound-assisted extraction (UAE) and soxhlet extraction (SE) procedure was determined using response surface methodology (RSM). The studied factors that affect the lipid content were: solvent ratio, extraction temperature, and extraction time. Several notable characteristics observed in the leaf of EN are amphistomatic leaves with anticlinical cell walls, anomocytic stomata, spongy mesophyll cells, elongated palisade cells, angular collenchyma, and U-shaped vascular bundle. The plano-convex midrib is covered by polygonal to oval-shaped cuticles and contains anomocytic stomata. The circular petiole has no trichomes and contains laticifers, crystals, and idioblasts. The circular stem was observed with trichomes, hypodermis, collenchyma, parenchymatous cells, central pith, pentagonal stellar region, cambium, and 2-4 times more xylem that of phloem. All of the powdered plant parts and exudate under study contained trichomes, xylem vessels, wood fibers, cork cells, starch grains, calcium oxalate crystals, idioblasts, lignified cork, tannin content, stone cells, and oil globules. The blackish-green colored petroleum ether extract with semi-solid consistency showed the greatest percent (%) yield of 4% in the latex of EN. The thin layer chromatography (TLC) examination of petroleum ether extract of EN leaf produced a maximum 6 spots with Rf values of 0.16, 0.58, 0.62, 0.73, and 0.96 in the mobile phase of petroleum ether-acetone (8:2). In terms of optimization, the dark green colored UAE extract with semi-sticky consistency showed highest % yield of 4.5% whereas the yellowish green colored SE extract of sticky consistency showed the highest % yield of 4.9%. The findings showed that there were not many differences in the total lipid content between UAE (0.16%) and SE (0.11%). However, the best optimum condition for lipid content extraction analysis was obtained as follows: solvent ratio (PE:HE) 50:50, extraction temperature 50°C, extraction time 45 min for UAE, and solvent ratio (PE:HE) 60:40, extraction temperature 45°C, and extraction time of 24 h for SE. Hence, this study signifies the various noteworthy microscopic features along with the presence of different phytocompounds through TLC and best optimized condition for the extraction of lipids from different parts of EN. As no previous study has been reported, the outcomes obtained from the current study prove to be beneficial in the identification of species, quality control, and detection of any adulteration from the laboratory and commercial samples of EN. RESEARCH HIGHLIGHTS: The percent yield was found to be maximum in latex extract (4%). The leaf pet ether extract was separated into 6 bands with different Rf values. The extracted compounds from Euphorbia neriifolia leaves were categorized into non-polar heat tolerant. The highest total lipid yield (0.1119) was obtained at solvent ratios 60:40 of PE:HE (petroleum ether: petroleum hexane).

Tumor targeted delivery of mycobacterial adjuvant encapsulated chitosan nanoparticles showed potential anti-cancer activity and immune cell activation in tumor microenvironment

Targeting immunotherapeutics inside the tumor microenvironment (TME) with intact biological activity remains a pressing issue. Mycobacterium indicus pranii (MIP), an approved adjuvant therapy for leprosy has exhibited promising results in clinical trials of lung (NSCLC) and bladder cancer. Whole MIP as well as its cell wall fraction have shown tumor growth suppression and enhanced survival in mice model of melanoma, when administered peritumorally. Clinically, peritumoral delivery remains a procedural limitation. In this study, a tumor targeted delivery system was designed, where chitosan nanoparticles loaded with MIP adjuvants, when administered intravenously showed preferential accumulation within the TME, exploiting the principle of enhanced permeability and retention effect. Bio-distribution studies revealed their highest concentration inside the tumor after 6 h of administration. Interestingly, MIP adjuvant nano-formulations significantly reduced the tumor volume in the treated groups and increased the frequency of activated immune cells inside the TME. For chemoimmunotherapeutics studies, MIP nano-formulation was combined with standard dosage regimen of Paclitaxel. Combined therapy exhibited a further reduction in tumor volume relative to either of the MIP nano formulations. From this study a three-pronged strategy emerged as the underlying mechanism; chitosan and Paclitaxel have shown direct role in tumor cell death and the MIP nano-formulation activates the tumor residing immune cells which ultimately leads to the reduced tumor growth.

Optimization of the Sulfo-Phospho-Vanillin Assay for Total Lipid Normalization in Untargeted Quantitative Lipidomic LC-MS/MS Applications

Liquid chromatography (LC)-mass spectrometry (MS)/MS lipidomic normalization is generally performed by equalizing pre-extraction sample materials or via DNA or protein pre-quantitation methods, which have known measurement inaccuracies. We propose the use of the sulfo-phospho-vanillin assay (SPVA), a total lipid colorimetric analysis, as a pre-quantitation method to normalize lipids in lipidomic LC-MS/MS applications. The assay has been applied to a 300 μL well volume in a 96-well plate and tested using Avanti total lipid standards of porcine brain and E. coli. Assay parameters for lipid sample volume, sulfuric acid, vanillin/phosphoric acid, post-reaction incubation time, and wavelength are optimized for robust application to biologically sourced lipid samples. Standard test samples were prepared using three concentrations covering approximately 100 μg/mL range. The optimized assay yielded test sample errors less than 10%, indicating a precise and accurate assay performance. The test samples were then analyzed by LC-MS/MS and normalized using SPVA pre-quantitation and pseudo-mass normalization. The detected lipids showed smaller standard deviations and greater relative concentration differences compared to the pseudo-mass normalized lipids, showing promise as a normalization method.

Targeting cancer cells in acidosis with conjugates between the carnitine palmitoyltransferase 1 inhibitor etomoxir and pH (low) Insertion Peptides

Targeting enzymes involved in tumor metabolism is a promising way to tackle cancer progression. The inhibition of carnitine palmitoyltransferase 1 (CPT1) by etomoxir (Eto) efficiently slows down the growth of various cancers. Unfortunately, the clinical use of this drug was abandoned because of hepatotoxic effects. We report the development of pH-sensitive peptide (pHLIP)-drug conjugate to deliver Eto selectively to cancer cells exposed to acidic microenvironmental conditions. A newly designed sequence for the pHLIP peptide, named pHLIPd, was compared with a previously published reference pHLIP peptide, named pHLIPr. We showed that the conjugate between pHLIPd and Eto has a better pH-dependent insertion and structuration than the pHLIPr-based conjugate inside POPC vesicles. We observed antiproliferative effects when applied on acid-adapted cancer cells, reaching a larger inhibitory activity than Eto alone. In conclusion, this study brings the first evidence that pHLIP-based conjugates with a CPT1 inhibitor has the potential to specifically target the tumor acidic compartment and exert anticancer effects while sparing healthy tissues.

Assessing pollen nutrient content: a unifying approach for the study of bee nutritional ecology

Poor nutrition and landscape changes are regularly cited as key factors causing the decline of wild and managed bee populations. However, what constitutes 'poor nutrition' for bees currently is inadequately defined. Bees collect and eat pollen: it is their only solid food source and it provides a broad suite of required macro- and micronutrients. Bees are also generalist foragers and thus the different pollen types they collect and eat can be highly nutritionally variable. Therefore, characterizing the multidimensional nutrient content of different pollen types is needed to fully understand pollen as a nutritional resource. Unfortunately, the use of different analytical approaches to assess pollen nutrient content has complicated between-studies comparisons and blurred our understanding of pollen nutrient content. In the current study, we start by reviewing the common methods used to estimate protein and lipids found in pollen. Next, using monofloral Brassica and Rosa pollen, we experimentally reveal biases in results using these methods. Finally, we use our collective data to propose a unifying approach for analysing pollen nutrient content. This will help researchers better study and understand the nutritional ecology-including foraging behaviour, nutrient regulation and health-of bees and other pollen feeders. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.

Evaluation of the ecological health and food chain on the shores of four River Nile Islands, Egypt

This study was conducted to evaluate the impact of human activities on the ecological health and food chain at the shores of four Nile Islands in Great Cairo including El-Qeratten, El-Waraq, El-Zamalek, and El-Manial. Water quality, bacteria, phytoplankton, benthic algae, zooplankton, macrobenthic invertebrates, and bony fishes were examined at each island shore over two seasons including the lowest and the highest flow (February and July 2020, respectively). The obtained results showed that the average values of most of the chemicals in Nile Island's water were within the Egyptian water quality limits. Discriminant analysis of physicochemical factors revealed a similarity between El-Waraq and El-Qerateen and between El-Manial and El-Zamalek. El-Qeratten was the most polluted island. It has the highest total and fecal coliform bacteria count (3.155 and 3.050 Log MPN/100 mL, respectively). El-Zamalek shores have the highest phytoplankton (33,582 cells × 10⁴ L^-1) and zooplankton count (310,891 organisms × m^-3) and phyto-biochemical values. Biochemical analysis of phytoplankton demonstrated the richness of the bulk by protein (> 85% of biomass), indicating that phytoplankton has a high nutritional value. Elevated zooplankton count was recorded at El-Zamalek, which coincided with the peak of phytoplankton abundance. Mollusca were the dominant macrobenthic invertebrates on most of the island's shores. Bony fishes were represented by 27 species and two crustaceans. The levels of the metals in fish samples were compared with the food safety guideline endorsed by the World Health Organization and Food and Agriculture Organization (WHO/FAO) to evaluate the toxicity level.

UHPLC-ESI-QqTOF Analysis and In Vitro Rumen Fermentation for Exploiting Fagus sylvatica Leaf in Ruminant Diet

In recent years, animal husbandry has aimed at improving the conditions of livestock animals useful for humans to solve environmental and health problems. The formulation of animal feeds or supplements based on antioxidant plant compounds is considered a valuable approach and an alternative for livestock productivity. Forest biomass materials are an underestimated source of polyphenolic compounds whose sustainable recovery could provide direct benefits to animals and, indirectly, human nutrition. In this context, an alcohol extract from leaves of Fagus sylvatica L. was first investigated through an untargeted ultra-high-performance liquid chromatography-high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) approach. Then, it was fractionated into a fatty acid-rich and a polyphenolic fraction, as evidenced by total lipid, phenol, and flavonoid content assays, with antiradical and reducing activity positively correlated to the latter. When tested in vitro with rumen liquor to evaluate changes in the fermentative parameters, a significant detrimental effect was exerted by the lipid-rich fraction, whereas the flavonoid-rich one positively modulated the production of volatile fatty acids (i.e., acetate, butyrate, propionate, etc.).

Correlation between the Macronutrient Content of Dental Calculus and the FFQ-Based Nutritional Intake of Obese and Normal-Weight Individuals

The growing epidemic of chronic diseases afflicting both developed and developing countries is related to diet and lifestyle. The current dietary assessment still has many constraints, particularly related to the objectivity of data gathering. Dental calculus, which is usually considered as medical waste in dental treatment, turns out to be a provider of abundant oral information. The objective of this study is to obtain the correlation between the macronutrient content of dental calculus and nutritional intake based on FFQ. This research is an analytic observational study with a case-control study design. Samples consisting of 35 obese individuals and 21 normal-weight individuals were taken using purposive sampling. The nutritional intake data were obtained using FFQ. The macronutrient content of dental calculus was checked using a colorimetric assay. The comparison between obese individuals and normal-weight individuals was tested using the Mann–Whitney test and T-test. The correlation between the macronutrient content of dental calculus and nutritional intake based on FFQ was measured using Spearman's rank-order correlation. The results showed there was a correlation between the macronutrient content of dental calculus and macronutrient intake based on FFQ. However, strong correlation was found only between fat intake with the total lipid content of dental calculus with rs = 0.521 and between carbohydrate intake with the total carbohydrate content of dental calculus with rs = 0.519. It was concluded that carbohydrate, protein, and lipid intake can be assessed using dental calculus. Dental calculus can be an alternative source of noninvasive, inexpensive, and specific dietary biomarkers.

Bioprocessing of cultivated Chlorella pyrenoidosa on poultry excreta leachate to enhance algal biomolecule profile for resource recovery

The aim of this work was to study the cultivation of Chlorella pyrenoidosa on poultry excreta leachate to enhance the biochemical composition of algal biomass. The growth of microalgae was analyzed with different concentrations of poultry excreta leachate in BG-11 and distilled water. The biomolecules observed have high value in the form of carbohydrates (0.64 gL^-1), protein (1.02 gL^-1), chlorophyll (20 µg mL^-1) and lipid amount (0.49 gL^-1) with PEL _BG -25%. Biomass produced in PEL _BG -25% was also found to be 60% (2.5 gL^-1) higher than the BG-11 medium as a control (1.5gL^-1). Recovery of nutrients was observed with leachate wastewater concentration in terms of nitrate (84.2%), ammonium nitrogen (53.1%), and inorganic phosphate (96.2%). Hence, sustainability of microalgae cultivation in wastewater provides a new insight for resource utilization.

Characterization of Chlamydomonas Very High Light-tolerant Mutants for Enhanced Lipid Production

Biodiesel production from microalgae is still not commercially realized due to the high cost of production. High light-tolerance has been suggested as a desirable phenotype for efficient cultivation in large scale production systems under fluctuating outdoor conditions. Nevertheless, it has not been shown if algae with such a phenotype would have better efficiency for lipid production. To determine lipid productivity in high light-tolerant mutants, and to understand the pathways involved in high light-tolerant phenotype, two very high light-tolerant mutants of the green alga Chlamydomonas reinhardtii - CAL028_01_28 and CAL034_01_48 - were selected from eighteen high light-tolerant mutants from the CAL collection. Under high light intensity conditions, and the presence of reactive oxygen species, which are conditions constantly experienced by algae growing in open-pond environments, these strains exhibited higher photosynthetic efficiency and improved survival. The physiological characterization of these mutants revealed that the detoxification of ROS by carotenoids and antioxidant enzymes is crucial for their growth under high light conditions. Neither mutant was affected in terms of its ability to accumulate lipid under nitrogen-depleted condition. More importantly, lipid productivity under high light conditions increased twofold in these mutants compared to that of the wild-type. Taken together, very high light-tolerant mutants confer a high potential for biofuel production under outdoor conditions, and their improved ability to survive under oxidative stress is an important key for efficient growth under outdoor conditions.

Influence of cellular lipid content on influenza A virus replication

Influenza A virus (IAV) depends on the metabolism of its cellular host to provide energy and essential factors, including lipids, for viral replication. Previous studies have shown that fatty acids (FAs) play an important role in IAV replication and that inhibition of FA biosynthesis can diminish viral replication. However, cellular lipids can either be synthesized intracellularly or be imported from the extracellular environment. Interfering with FA import mechanisms may reduce the cellular lipid content and inhibit IAV replication. To test this hypothesis, MDCK and Detroit 562 cells were infected with IAV followed by exposure to palmitic acid and inhibitors of FA import. Replication of IAV significantly increased when infected cells were supplied with palmitic acid. This enhancement could be reduced by adding an FA import inhibitor. The addition of palmitic acid significantly increased the cellular lipid content, and this increased level was reduced by treatment with an FA import inhibitor. These results show that reducing the cellular lipid level might be an approach for IAV therapy.

Artificial dry surface biofilm models for testing the efficacy of cleaning and disinfection

Dry surface biofilms (DSB) harbouring pathogens are widespread in healthcare settings, are difficult to detect and are resistant to cleaning and disinfection interventions. Here, we describe a practical test protocol to palliate the lack of standard efficacy test methods for DSB. Staphylococcus aureus DSB were produced over a 12-day period, grown with or without the presence of organic matter, and their composition and viability were evaluated. Disinfectant treatment was conducted with a modified ASTM2967-15 test and reduction in viability, transferability and biofilm regrowth post-treatment were measured. Dry surface biofilms produced over a 12-day period had a similar carbohydrates, proteins and DNA content, regardless of the presence or absence of organic matter. The combination of sodium hypochlorite (1000 ppm) and a microfiber cloth was only effective against DSB in the absence of organic load. With the increasing concerns of the uncontrolled presence of DSB in healthcare settings, the development of effective intervention model in the presence of organic load is appropriate for the testing of biocidal products, while the use of three parameters, log₁₀ reduction, transferability and regrowth, provides an accurate and practical measurement of product efficacy. SIGNIFICANCE AND IMPACT OF THE STUDY: The widespread presence of biofilms on dry surfaces in healthcare settings has been recently documented. These dry surface biofilms (DSB) present an unprecedented challenge to cleaning and disinfection processes. Here, we describe a practical efficacy protocol based on an in vitro Staphylococcus aureus DSB model. The protocol measures reduction in viability, transferability and biofilm regrowth post-treatment to provide altogether a practical assessment of product efficacy against dry surface biofilms.

Preservative and Irritant Capacity of Biosurfactants From Different Sources: A Comparative Study

One of the most important challenges for pharmaceutical and cosmetic industries is solubilization and preservation of their active ingredients. Therefore, most of these formulations contain irritant chemical additives to improve their shelf-life and the solubility of hydrophobic ingredients. An interesting alternative to chemical surfactants and preservatives is the use of biosurfactants; thus, their surfactant properties and composition make them more biocompatible than their chemical counterparts. Moreover, some biosurfactants have shown antimicrobial activity in addition to their detergent capacity. In this work, the antimicrobial and irritant effect of 2 biosurfactant extracts was studied: one produced in a controlled fermentation process with Lactobacillus pentosus and the other produced from corn stream by spontaneous fermentation. The results showed a strong antimicrobial activity of the biosurfactant extract obtained from corn stream on pathogenic bacteria, in comparison with the L. pentosus biosurfactant extract. Moreover, both biosurfactants did not produce any irritant effect on the chorioallantoic membrane of hen's egg assay contrary to sodium dodecyl sulfate. This is the first study dealing with the application of biosurfactant extracts on sensitive biological membranes, and this is the first time that the preservative capacity of a biosurfactant extract obtained in spontaneous fermentation is being evaluated, achieving promising results.