Hanaa Essa - Academia.edu (original) (raw)

Papers by Hanaa Essa

Research paper thumbnail of Ultrasonically-extracted marine polysaccharides as potential green antioxidant alternatives

Proceedings of 1st International Electronic Conference on Applied Sciences, 2020

Marine-extracted sulfated polysaccharides (SPs) have been the subject of myriad research since th... more Marine-extracted sulfated polysaccharides (SPs) have been the subject of myriad research since they are considered an eco-friendly source of biologically active compounds. Meanwhile, food and pharmaceutical industries are urgently producing natural sugar substitutes and antioxidants as alternatives to synthetic ones which are associated with cytotoxicity and safety issues. This study assesses the potential of using marine SPs obtained via the ultrasonic-assisted extraction of different marine species, to utilize them as antioxidant sugar substitutes. The carbohydrate, total phenolic contents and antioxidant activities were measured for SP extracts of the algal species of Ulva lactuca, Jania rubens and the marine plant mangrove Avicennia marina. These SPs were structurally elucidated by Fourier Transform Infrared (FTIR) spectroscopic and high-performance liquid chromatography (HPLC) analyses. The results revealed that SPs' highest yield percent was obtained from Ulva lactuca, 5.50 ± 0.25%. The SPs of Avicennia marina had the highest carbohydrate content, 44 ± 1% and antioxidant activity, 78.85 ± 0.06 at the 100 μg/mL concentration and 89.50 ± 0.21 at the 250 μg/mL concentration. Meanwhile, the highest phenolic content was exhibited by algal SPs obtained from Jania rubens, 132.60 ± 2.50 mgGa/g. Results also showed that all extracts have potent antioxidant activity, while the highest antioxidant activity belonged to the SPs of Avicennia marina owing possibly to their balanced glucose and galactose contents as measured by HPLC. This work emphasizes the need to consider sulfated polysaccharides from marine sources for their antioxidant activity and to correlate it with their monosaccharide content to determine the effect of reducing sugar concentration on the antioxidant activity.

Research paper thumbnail of Formulation and clinical evaluation of silymarin pluronic-lecithin organogels for treatment of atopic dermatitis

Drug Design, Development and Therapy, 2016

Silymarin is a naturally occurring flavonoid drug; evidence from recent research has highlighted ... more Silymarin is a naturally occurring flavonoid drug; evidence from recent research has highlighted its use as a potential treatment for atopic dermatitis (AD). Both poor water solubility and drug permeability have hindered the percutaneous absorption of silymarin. Formulation of silymarin into pluronic-lecithin organogel (PLO) basis for topical skin delivery is the main aim of this work. Six different PLO formulations were prepared containing various pluronic to lecithin ratios using two cosolvent systems of ethyl alcohol and dimethyl sulfoxide. Formulation 2 (20% pluronic and 3% lecithin) was found to be the optimal base for topical delivery of silymarin as it showed optimum pH, viscosity, drug content, and satisfactory in vitro silymarin permeation. The silymarin PLO formulation significantly relieved inflammatory symptoms of AD such as redness, swelling, and inflammation. These findings warrant the ability for application of these novel silymarin PLO formulations as a novel treatment for AD.

Research paper thumbnail of Assessment of the State-of the-Art Developments in the Extraction of Antioxidants From Marine Algal Species

There is a current increasing demand for antioxidants in food, pharmaceutical, and medical applic... more There is a current increasing demand for antioxidants in food, pharmaceutical, and medical applications. Bioactive compounds, particularly sulfated polysaccharides (SPs) extracted from marine algal species were found to exhibit remarkable antioxidant activities. Various extraction methods have been reported in this regard, including conventional, as well as modern techniques, such as ultrasonic-, microwave-, and enzyme-assisted extraction. These were conducted using different solvents and under varying operating conditions of temperature, time, and solvent to substrate ratio. In this review, we critically assess the state-of-the-art methods for extracting antioxidants with emphasis on SPs, from green, red, and brown algae. The evaluation will be primarily based on the yields and antioxidant activities of the extracted SPs, in addition to other technical, economic, and environmental criteria.

Research paper thumbnail of Biogenic copper nanoparticles from Avicennia marina leaves: Impact on seed germination, detoxification enzymes, chlorophyll content and uptake by wheat seedlings

PLOS ONE

Biogenic copper nanoparticles (Cu NPs) were synthesized using the aqueous crude extract of mangro... more Biogenic copper nanoparticles (Cu NPs) were synthesized using the aqueous crude extract of mangrove leaves, Avicennia marina (CE). GC-MS metabolite profiling of CE showed that their carbohydrates are mainly composed of D-mannose (29.21%), D-fructose, (18.51%), L-sorbose (12.91%), D-galactose (5.47%) and D-Talose (5.21%). Ultra-fine nanoparticles of 11.60 ±4.65 nm comprising Cu2O and Cu(OH)2 species were obtained with a carbohydrate and phenolic content of 35.6±3.2% and 3.13±0.05 mgGA/g, respectively. The impact of the biogenic Cu NPs on wheat seedling growth was dose-dependent. Upon treatment with 0.06 mg/mL of Cu NPs, the growth was promoted by 172.78 ± 23.11 and 215.94 ± 37.76% for wheat root and shoot, respectively. However, the lowest relative growth % of 81.94 ± 11.70 and 72.46 ± 18.78% were recorded for wheat root and shoot, respectively when applying 0.43 mg/mL of Cu NPs. At this concentration, peroxidase activity (POX) of the germinated wheat seeds also decreased, while asco...

Research paper thumbnail of Nano-Formulations of Copper Species Coated with Sulfated Polysaccharide Extracts and Assessment of Their Phytotoxicity on Wheat (Triticum aestivum L.) Seedlings in Seed Germination, Foliar and Soil Applications

Applied Sciences

Copper nanoparticles were synthesized via a bioreduction using sulfated polysaccharides (SPs) ext... more Copper nanoparticles were synthesized via a bioreduction using sulfated polysaccharides (SPs) extracted from Avicennia marina mangrove leaves and their phytotoxicity effect on wheat (Triticum aestivum L.) seedlings was assessed. As analyzed by high-performance liquid chromatography (HPLC), SPs extract constituted mainly 49.3% glucose, 24.6% galactose and 20.5% glucouronic acid by mol. A nanoformulation of ultrafine Cu2O/Cu(OH)2 nanoparticles coated with SPs (Cu NPs) was prepared with an average particle size of 2.11 ± 0.64 nm and a slightly negatively-charged zeta potential of 11 ± 0.46 mV. Applying high concentrations of Cu NPs on wheat seeds inhibited the respective shoot and root relative growth percentages, yielding 13.22 ± 9.91 and 36.72 ± 18.51% at 0.06 mg/mL of the nanoformulation. Comparable values were obtained when the seeds were subjected to 0.06 mg/L of SPs extract applied in the free form. In a foliar application, 0.06 mg/mL of Cu NPs reduced the respective total chloro...

Research paper thumbnail of Towards optimizing the conventional and ultrasonic-assisted extraction of sulfated polysaccharides from marine algae

IOP Conference Series: Materials Science and Engineering

Recently, there has been a growing interest in sulfated polysaccharides extracted from various na... more Recently, there has been a growing interest in sulfated polysaccharides extracted from various natural sources due to their versatile biological activities that find great use in biomedical and industrial applications. In the present study, sulfated polysaccharides were extracted from green algae, Ulva lactuca and red algae, Jania rubens collected from Alexandria city coast, Egypt. Conventional and ultrasonic-assisted extraction methods were investigated under different operating parameters and the optimum conditions for extraction were obtained based on the yield. Algal extracts with optimum SPs yields were then tested for their phenolic and sugar contents, as well as their 1, 1-Diphenyl-2-picrylhydrazyl (DPPH) antioxidant activities. Optimum yields of both green and red algae were obtained via extraction under ultrasonic conditions for 4h. Higher yields were produced from the green algae as compared to the red ones. However, red algal extracts showed relatively higher antioxidant activities, possibly due to their higher mannose content.

Research paper thumbnail of ChemInform Abstract: Novel Nucleoside Analogues: First Synthesis of Pyridine-4-thioglycosides and Their Cytotoxic Evaluation

Research paper thumbnail of Novel Nucleoside Analogues: First Synthesis of Pyridine-4-Thioglycosides and Their Cytotoxic Evaluation

Nucleosides, Nucleotides and Nucleic Acids, 2015

The reaction of sodium 2,2-dicyanoethene-1,1-bis(thiolate) with 2-cyano-N-arylacetamides afforded... more The reaction of sodium 2,2-dicyanoethene-1,1-bis(thiolate) with 2-cyano-N-arylacetamides afforded sodium pyridine-4-thiolates, coupling of the latters with 2,3,4,6-tetra-O-acetyl-D-gluco- and D-galactopyranosyl bromides, respectively, afforded new pyridine-4-thioglycosides. Ammonolysis of the latter compounds afforded the free thioglycosides. The antitumor activities of the synthesized compounds were tested against human tumor cell lines; lung (A549), colon (HCT116), liver (HEPG2), and prostate (PC3).

Research paper thumbnail of Ultrasonically-extracted marine polysaccharides as potential green antioxidant alternatives

Proceedings of 1st International Electronic Conference on Applied Sciences, 2020

Marine-extracted sulfated polysaccharides (SPs) have been the subject of myriad research since th... more Marine-extracted sulfated polysaccharides (SPs) have been the subject of myriad research since they are considered an eco-friendly source of biologically active compounds. Meanwhile, food and pharmaceutical industries are urgently producing natural sugar substitutes and antioxidants as alternatives to synthetic ones which are associated with cytotoxicity and safety issues. This study assesses the potential of using marine SPs obtained via the ultrasonic-assisted extraction of different marine species, to utilize them as antioxidant sugar substitutes. The carbohydrate, total phenolic contents and antioxidant activities were measured for SP extracts of the algal species of Ulva lactuca, Jania rubens and the marine plant mangrove Avicennia marina. These SPs were structurally elucidated by Fourier Transform Infrared (FTIR) spectroscopic and high-performance liquid chromatography (HPLC) analyses. The results revealed that SPs' highest yield percent was obtained from Ulva lactuca, 5.50 ± 0.25%. The SPs of Avicennia marina had the highest carbohydrate content, 44 ± 1% and antioxidant activity, 78.85 ± 0.06 at the 100 μg/mL concentration and 89.50 ± 0.21 at the 250 μg/mL concentration. Meanwhile, the highest phenolic content was exhibited by algal SPs obtained from Jania rubens, 132.60 ± 2.50 mgGa/g. Results also showed that all extracts have potent antioxidant activity, while the highest antioxidant activity belonged to the SPs of Avicennia marina owing possibly to their balanced glucose and galactose contents as measured by HPLC. This work emphasizes the need to consider sulfated polysaccharides from marine sources for their antioxidant activity and to correlate it with their monosaccharide content to determine the effect of reducing sugar concentration on the antioxidant activity.

Research paper thumbnail of Formulation and clinical evaluation of silymarin pluronic-lecithin organogels for treatment of atopic dermatitis

Drug Design, Development and Therapy, 2016

Silymarin is a naturally occurring flavonoid drug; evidence from recent research has highlighted ... more Silymarin is a naturally occurring flavonoid drug; evidence from recent research has highlighted its use as a potential treatment for atopic dermatitis (AD). Both poor water solubility and drug permeability have hindered the percutaneous absorption of silymarin. Formulation of silymarin into pluronic-lecithin organogel (PLO) basis for topical skin delivery is the main aim of this work. Six different PLO formulations were prepared containing various pluronic to lecithin ratios using two cosolvent systems of ethyl alcohol and dimethyl sulfoxide. Formulation 2 (20% pluronic and 3% lecithin) was found to be the optimal base for topical delivery of silymarin as it showed optimum pH, viscosity, drug content, and satisfactory in vitro silymarin permeation. The silymarin PLO formulation significantly relieved inflammatory symptoms of AD such as redness, swelling, and inflammation. These findings warrant the ability for application of these novel silymarin PLO formulations as a novel treatment for AD.

Research paper thumbnail of Assessment of the State-of the-Art Developments in the Extraction of Antioxidants From Marine Algal Species

There is a current increasing demand for antioxidants in food, pharmaceutical, and medical applic... more There is a current increasing demand for antioxidants in food, pharmaceutical, and medical applications. Bioactive compounds, particularly sulfated polysaccharides (SPs) extracted from marine algal species were found to exhibit remarkable antioxidant activities. Various extraction methods have been reported in this regard, including conventional, as well as modern techniques, such as ultrasonic-, microwave-, and enzyme-assisted extraction. These were conducted using different solvents and under varying operating conditions of temperature, time, and solvent to substrate ratio. In this review, we critically assess the state-of-the-art methods for extracting antioxidants with emphasis on SPs, from green, red, and brown algae. The evaluation will be primarily based on the yields and antioxidant activities of the extracted SPs, in addition to other technical, economic, and environmental criteria.

Research paper thumbnail of Biogenic copper nanoparticles from Avicennia marina leaves: Impact on seed germination, detoxification enzymes, chlorophyll content and uptake by wheat seedlings

PLOS ONE

Biogenic copper nanoparticles (Cu NPs) were synthesized using the aqueous crude extract of mangro... more Biogenic copper nanoparticles (Cu NPs) were synthesized using the aqueous crude extract of mangrove leaves, Avicennia marina (CE). GC-MS metabolite profiling of CE showed that their carbohydrates are mainly composed of D-mannose (29.21%), D-fructose, (18.51%), L-sorbose (12.91%), D-galactose (5.47%) and D-Talose (5.21%). Ultra-fine nanoparticles of 11.60 ±4.65 nm comprising Cu2O and Cu(OH)2 species were obtained with a carbohydrate and phenolic content of 35.6±3.2% and 3.13±0.05 mgGA/g, respectively. The impact of the biogenic Cu NPs on wheat seedling growth was dose-dependent. Upon treatment with 0.06 mg/mL of Cu NPs, the growth was promoted by 172.78 ± 23.11 and 215.94 ± 37.76% for wheat root and shoot, respectively. However, the lowest relative growth % of 81.94 ± 11.70 and 72.46 ± 18.78% were recorded for wheat root and shoot, respectively when applying 0.43 mg/mL of Cu NPs. At this concentration, peroxidase activity (POX) of the germinated wheat seeds also decreased, while asco...

Research paper thumbnail of Nano-Formulations of Copper Species Coated with Sulfated Polysaccharide Extracts and Assessment of Their Phytotoxicity on Wheat (Triticum aestivum L.) Seedlings in Seed Germination, Foliar and Soil Applications

Applied Sciences

Copper nanoparticles were synthesized via a bioreduction using sulfated polysaccharides (SPs) ext... more Copper nanoparticles were synthesized via a bioreduction using sulfated polysaccharides (SPs) extracted from Avicennia marina mangrove leaves and their phytotoxicity effect on wheat (Triticum aestivum L.) seedlings was assessed. As analyzed by high-performance liquid chromatography (HPLC), SPs extract constituted mainly 49.3% glucose, 24.6% galactose and 20.5% glucouronic acid by mol. A nanoformulation of ultrafine Cu2O/Cu(OH)2 nanoparticles coated with SPs (Cu NPs) was prepared with an average particle size of 2.11 ± 0.64 nm and a slightly negatively-charged zeta potential of 11 ± 0.46 mV. Applying high concentrations of Cu NPs on wheat seeds inhibited the respective shoot and root relative growth percentages, yielding 13.22 ± 9.91 and 36.72 ± 18.51% at 0.06 mg/mL of the nanoformulation. Comparable values were obtained when the seeds were subjected to 0.06 mg/L of SPs extract applied in the free form. In a foliar application, 0.06 mg/mL of Cu NPs reduced the respective total chloro...

Research paper thumbnail of Towards optimizing the conventional and ultrasonic-assisted extraction of sulfated polysaccharides from marine algae

IOP Conference Series: Materials Science and Engineering

Recently, there has been a growing interest in sulfated polysaccharides extracted from various na... more Recently, there has been a growing interest in sulfated polysaccharides extracted from various natural sources due to their versatile biological activities that find great use in biomedical and industrial applications. In the present study, sulfated polysaccharides were extracted from green algae, Ulva lactuca and red algae, Jania rubens collected from Alexandria city coast, Egypt. Conventional and ultrasonic-assisted extraction methods were investigated under different operating parameters and the optimum conditions for extraction were obtained based on the yield. Algal extracts with optimum SPs yields were then tested for their phenolic and sugar contents, as well as their 1, 1-Diphenyl-2-picrylhydrazyl (DPPH) antioxidant activities. Optimum yields of both green and red algae were obtained via extraction under ultrasonic conditions for 4h. Higher yields were produced from the green algae as compared to the red ones. However, red algal extracts showed relatively higher antioxidant activities, possibly due to their higher mannose content.

Research paper thumbnail of ChemInform Abstract: Novel Nucleoside Analogues: First Synthesis of Pyridine-4-thioglycosides and Their Cytotoxic Evaluation

Research paper thumbnail of Novel Nucleoside Analogues: First Synthesis of Pyridine-4-Thioglycosides and Their Cytotoxic Evaluation

Nucleosides, Nucleotides and Nucleic Acids, 2015

The reaction of sodium 2,2-dicyanoethene-1,1-bis(thiolate) with 2-cyano-N-arylacetamides afforded... more The reaction of sodium 2,2-dicyanoethene-1,1-bis(thiolate) with 2-cyano-N-arylacetamides afforded sodium pyridine-4-thiolates, coupling of the latters with 2,3,4,6-tetra-O-acetyl-D-gluco- and D-galactopyranosyl bromides, respectively, afforded new pyridine-4-thioglycosides. Ammonolysis of the latter compounds afforded the free thioglycosides. The antitumor activities of the synthesized compounds were tested against human tumor cell lines; lung (A549), colon (HCT116), liver (HEPG2), and prostate (PC3).