Omayma Eldahshan | Ain Shams University (original) (raw)

Papers by Omayma Eldahshan

BMC complementary medicine and therapies, Jul 10, 2024

BMC complementary medicine and therapies, Jun 14, 2024

BMC complementary medicine and therapies, Apr 12, 2024

Background Polyalthia suberosa (Roxb.) Thwaites (Annonaceae) is a medicinal plant that has been r... more Background Polyalthia suberosa (Roxb.) Thwaites (Annonaceae) is a medicinal plant that has been reported for its various pharmacological potentials, such as its anti-inflammatory, analgesic, antioxidant, and neuropharmacological activities. This study aimed to analyze the leaf essential oils of P. suberosa (PSLO) collected in different seasons, to evaluate the acetylcholinesterase inhibitory activity, and to corroborate the obtained results via in-silico molecular docking studies. Methods The leaf essential oils of P. suberosa collected in different seasons were analyzed separately by GC/MS. The acetylcholinesterase inhibitory activity of the leaves oil was assessed via colorimetric assay. In-silico molecular docking studies were elucidated by virtual docking of the main compounds identified in P. suberosa leaf essential oil to the active sites in human acetylcholinesterase crystal structure. Results A total of 125 compounds were identified where D-limonene (0.07 − 24.7%), α-copaene (2.25 − 15.49%), E-β-caryophyllene (5.17 − 14.42%), 24-noroleana-3,12-diene (12.92%), β-pinene (0.14 − 8.59%), and α-humulene (2.49-6.9%) were the most abundant components. Results showed a noteworthy influence of the collection season on the chemical composition and yield of the volatile oils. The tested oil adequately inhibited acetylcholinesterase enzyme with an IC 50 value of 91.94 µg/mL. Additionally, in-silico molecular docking unveiled that palmitic acid, phytol, p-cymene, and caryophyllene oxide demonstrated the highest fitting scores within the active sites of human acetylcholinesterase enzyme. Conclusions From these findings, it is concluded that P. suberosa leaf oil should be evaluated as a food supplement for enhancing memory.

BMC Complementary Medicine and Therapies, Oct 5, 2023

BMC complementary medicine and therapies, Feb 2, 2024

Biomedicine & Pharmacotherapy, Dec 1, 2022

Life Sciences, May 1, 2023

International journal of pharmacognosy & Chinese medicine, 2017

Many of cytotoxic anticancer natural drugs are used as an adjuvant therapy in cancer treatment an... more Many of cytotoxic anticancer natural drugs are used as an adjuvant therapy in cancer treatment and can potentially increase sensitivity of drug-resistant cancer cells to chemotherapeutical agents [1]. The treatment of cancer with chemotherapeutic agents faces two major problems: chemoresistance and nonspecific toxicity toward normal cells. Many natural polyphenols as genistein, curcumin, resveratrol, silymarin, caffeic acid phenethyl ester, emodin, green tea polyphenols, piperine, oleandrin, ursolic acid, and betulinic acid might be used to sensitize tumor cells to chemotherapeutic agents and radiation therapy by inhibiting pathways that lead to treatment resistance [2]. Saikosaponin B2, isolated from dried root of Bupleurumas, is an effective inhibitor for etoposide-induced NF-kB activation in B16F10NFkB cells. Saikosaponin B2 sensitized etoposide-induced cell death in B16F10 melanoma cells through the induction of apoptosis. In addition, an induction of g-H2AX expression observed, which is a molecular signature for DNA damage, upon the combination treatment of etoposide and saikosaponin B2 [3]. Spongistatin 1 is a macrocyclic lactone that has been isolated from the marine sponges Spirastrella spinispirulifera and Hyrtioserecta. Spongistatin degrades XIAP protein in leukemic cells, which might be the reason for its potentizing effect when combined with other caspase-activating anticancer drugs [4].

PubMed, Nov 1, 2014

Chemical and biological investigations of the extract of Ammania auriculata (Lytheraceae) resulte... more Chemical and biological investigations of the extract of Ammania auriculata (Lytheraceae) resulted in the identification of eight polyphenols (1 - 8) for the first time from this plant, including the gallotannin, 2,3,6-tri-O-galloyl-(α,β)-4C1-glucopyranose (8), for which 1D and 2D-NMR spectra were recorded and assigned for the first time. The structures of all isolates (1 - 8) were elucidated by conventional methods, spectroscopic analysis, including 1D and 2D NMR, and by HR-ESIMS as well. All of the isolated compounds were evaluated for their antioxidant activities, determined by the DPPH and ORAC methods and for their cytotoxicity against the keratinocyte cell line HaCaT using the neutral red assay (NRU) and cell cycle analysis. Compounds 1, 3, 4, 5, and 6 significantly inhibited reactive oxygen species production with ED50 values between 3.22 and 9.79 μg/ml. Compounds 1, 3, 4, and 5 showed cytotoxic activity against HaCaT cells with IC50 values between 30.7 and 84.1 μg/ml. The new galloyl glucose (8) was found not cytotoxic. Ellagitannins, 2,3-hexahydroxy-((α/β)-glucopyranose (1) and 1 -0-galloyl 2,3-hexahydroxy-(α)-glucopyranose (5) possess remarkable antioxidative and comparably weak cytotoxic activity.

European Scientific Journal, ESJ, Feb 28, 2013

Artichoke is a source of biophenols that exhibit lots of pharmacological activities. The aim of t... more Artichoke is a source of biophenols that exhibit lots of pharmacological activities. The aim of the present study is to determine the effect of different extraction methods on the phenolic, and silymarin contents as well as antiradical activities of artichoke leaves and roots. First, the total phenol content was determined by the Folin-Ciocalteu procedure; the gallic acid equivalent values ranged from 16.42-30.28 mg/g. Generally, different leave extracts showed higher contents of phenol than the root extracts. It was found that the methanolic extract of the leaves exhibited the most value of phenolic content (30.28 mg/g) while the root infusion showed the least value (16.42 mg/g). The analysis of silymarin and silybin compounds from each extract was carried out by reversed phase high performance liquid chromatography (RP-HPLC). The infusion extract of leaves showed also the higher content of silymarin than that of root extracts, and the infusion of the leaves exhibited the higher value while the water extract of roots exhibited the least one. Antiradical activities were evaluated using 1, 1-Diphenyl-2-picrylhydrazyl (DPPH 0) free radical and β-carotene bleaching methods. Good correlation (R 2 =0.9752) was found between phenolic content and antioxidant activity. The

Chemistry & Biodiversity, Apr 1, 2017

The composition of the essential oil isolated from leaves and flowers of Pulicaria incisa sub. ca... more The composition of the essential oil isolated from leaves and flowers of Pulicaria incisa sub. candolleana E.Gamal-Eldin was analysed by GC and GC-MS. Forty-nine and sixty-eight compounds were identified from the oils of the leaves and flowers accounting for 86.69% and 84.29%, respectively of the total detected constituents. Both leaves and flowers oils were characterized by the high content of each carvotanacetone with 66.01%, 50.87% and chrysanthenone 13.26%, 24.3% respectively. The cytotoxic activity of both essential oils was evaluated against hepatocellular carcinoma cell line HEPG-2, using MTT assay and vinblastine as a reference drug. Leaf oil showed higher activity with IC50 11.4 μg/mL compared with 37.4 μg/mL for flower oil. The antimicrobial activity of both oils was evaluated using agar well diffusion method towards two representatives for each of Gram positive and Gram negative bacteria as well as four representatives for fungi. The minimum inhibitory concentration of both essential oils against bacterial and fungal strains was obtained in the range of 0.49 - 15.63 μg/mL. This article is protected by copyright. All rights reserved.

Carob leaves (Ceratonia siliqua L.), grown in Egypt have not fully identified in Egypt. Therefore... more Carob leaves (Ceratonia siliqua L.), grown in Egypt have not fully identified in Egypt. Therefore, eight major phenolic compounds were isolated from the aqueous ethanolic extract using different methods of chromatography; gallic acid, quercetin 3-O-4 C 1-B-D-glucoside (Isoquercetin), Kaempferol 3-O-1 C 4-"-Lrhamnoside (Afzelin), Quercetin 3-O-1 C 4-"-L-rhamnoside (Quercitrin), 1,2,6 triO -galloyl-B-D-4 C 1glucopyranose, (-)-Epigallocatechin-3-O-gallate, kaempferol and quercetin. Their structures established by conventional methods of analysis. This is the first phytochemical study of polyphenolic content of carob leaves grown in Egypt.

International journal of pharmacognosy & Chinese medicine, 2017

Nature is considered as an enormous contributor in anticancer drugs. Although more than half cent... more Nature is considered as an enormous contributor in anticancer drugs. Although more than half century had passed on its discovery, taxol is still, till now, a unique anticancer agent. Other compounds as vincristine, vinblastine, camptothecins, etoposide and others are plant derived and effective against cancer.A fact that out of 121 drugs prescribed for cancer treatment till date, 90 are derived from plant sources [1].

Natural Product Research, Sep 19, 2022

Medicinal and Aromatic plants, 2015

Caesalpinieae tribe is one of the largest archaic tribes of subfamily Caesalpinioideae, family Fa... more Caesalpinieae tribe is one of the largest archaic tribes of subfamily Caesalpinioideae, family Fabaceae. Caesalpinieae tribe includes 9 subtribes that have more than 47 genera, including several valuable medicinal plants. Extracts of different plants of Caesalpinieae tribe were reported to possess a wide range of pharmacological activities, including anti-oxidant, anti-bacterial, anti-inflammatory, cytotoxic, anti-diabetic, antifungal, hepatoprotective, gastroprotective, analgesic, anti-arthritic, anti-filarial, antimalarial, anthelmintic, amoebicidal, diuretic, anti-psoriatic, anti-estrogenic, anti-fertility, wound-healing, anxiolytic, cardioprotective, immunomodulatory, anti-HIV activities. Thus, Caesalpinieae tribe includes several plants with a potential for exploitation as a source for plant-based pharmaceutical products. The present review could form a sound basis for further investigation in the potential discovery of new natural bioactive compounds and provide preliminary information for future research.

Acta scientific pharmaceutical sciences, Dec 22, 2020

Abd-Alkhalek and Omayma A Eldahshan. Curcumin, the polyphenolic compound in turmeric exhibited ve... more Abd-Alkhalek and Omayma A Eldahshan. Curcumin, the polyphenolic compound in turmeric exhibited versatile biological effects such as anti-tumor, anti-inflammatory, immunomodulating, antioxidant and antimicrobial [1,2]. It exerted antiviral activities against diverse viruses, such as dengue [3], hepatitis B [4], Zika and chikungunya viruses [5]. Curcumin exerted many effects against COVID-19 infection. It has the ability to modify various targets on molecular base which participate in attaching of COVID-2 as well as its endocytosis in cardiovascular, hepatic, renal cells. It also modulates cellular signaling

Natural Product Research

Rising awareness about the ecological burden of agricultural by-products and their potential indu... more Rising awareness about the ecological burden of agricultural by-products and their potential industrial and medicinal applications spurred the research of waste valorization. Egypt is a chief producer of jasmine oils. However, jasmine dense foliage is an agricultural waste that merits exploitation. Herein, Jasminum grandiflorum leaves were profiled using UPLC-MS, revealing a promising phytochemical composition rich in secoiridoids. Good safety profile was confirmed in vitro on cancerous and normal cell lines and in vivo (LD50>4000 mg/kg). The radioprotective effect of 3500 mg/kg jasmine leaves extract against irradiation-induced lung injury was demonstrated. Biochemical analysis indicated that jasmine extract decreased malondialdehyde level and enhanced the endogenous antioxidants GSH-Px, SOD and CAT levels. Jasmine alleviated the inflammatory response by downregulating the expression of COX-2 and iNOS and reducing the inflammatory mediators, TNF-α, IL-6, NO, and PGE2.Jasmine leaves offer interesting application prospects that add economic and industrial value to agricultural waste.

BMC complementary medicine and therapies, Jul 10, 2024

BMC complementary medicine and therapies, Jun 14, 2024

BMC complementary medicine and therapies, Apr 12, 2024

Background Polyalthia suberosa (Roxb.) Thwaites (Annonaceae) is a medicinal plant that has been r... more Background Polyalthia suberosa (Roxb.) Thwaites (Annonaceae) is a medicinal plant that has been reported for its various pharmacological potentials, such as its anti-inflammatory, analgesic, antioxidant, and neuropharmacological activities. This study aimed to analyze the leaf essential oils of P. suberosa (PSLO) collected in different seasons, to evaluate the acetylcholinesterase inhibitory activity, and to corroborate the obtained results via in-silico molecular docking studies. Methods The leaf essential oils of P. suberosa collected in different seasons were analyzed separately by GC/MS. The acetylcholinesterase inhibitory activity of the leaves oil was assessed via colorimetric assay. In-silico molecular docking studies were elucidated by virtual docking of the main compounds identified in P. suberosa leaf essential oil to the active sites in human acetylcholinesterase crystal structure. Results A total of 125 compounds were identified where D-limonene (0.07 − 24.7%), α-copaene (2.25 − 15.49%), E-β-caryophyllene (5.17 − 14.42%), 24-noroleana-3,12-diene (12.92%), β-pinene (0.14 − 8.59%), and α-humulene (2.49-6.9%) were the most abundant components. Results showed a noteworthy influence of the collection season on the chemical composition and yield of the volatile oils. The tested oil adequately inhibited acetylcholinesterase enzyme with an IC 50 value of 91.94 µg/mL. Additionally, in-silico molecular docking unveiled that palmitic acid, phytol, p-cymene, and caryophyllene oxide demonstrated the highest fitting scores within the active sites of human acetylcholinesterase enzyme. Conclusions From these findings, it is concluded that P. suberosa leaf oil should be evaluated as a food supplement for enhancing memory.

BMC Complementary Medicine and Therapies, Oct 5, 2023

BMC complementary medicine and therapies, Feb 2, 2024

Biomedicine & Pharmacotherapy, Dec 1, 2022

Life Sciences, May 1, 2023

International journal of pharmacognosy & Chinese medicine, 2017

Many of cytotoxic anticancer natural drugs are used as an adjuvant therapy in cancer treatment an... more Many of cytotoxic anticancer natural drugs are used as an adjuvant therapy in cancer treatment and can potentially increase sensitivity of drug-resistant cancer cells to chemotherapeutical agents [1]. The treatment of cancer with chemotherapeutic agents faces two major problems: chemoresistance and nonspecific toxicity toward normal cells. Many natural polyphenols as genistein, curcumin, resveratrol, silymarin, caffeic acid phenethyl ester, emodin, green tea polyphenols, piperine, oleandrin, ursolic acid, and betulinic acid might be used to sensitize tumor cells to chemotherapeutic agents and radiation therapy by inhibiting pathways that lead to treatment resistance [2]. Saikosaponin B2, isolated from dried root of Bupleurumas, is an effective inhibitor for etoposide-induced NF-kB activation in B16F10NFkB cells. Saikosaponin B2 sensitized etoposide-induced cell death in B16F10 melanoma cells through the induction of apoptosis. In addition, an induction of g-H2AX expression observed, which is a molecular signature for DNA damage, upon the combination treatment of etoposide and saikosaponin B2 [3]. Spongistatin 1 is a macrocyclic lactone that has been isolated from the marine sponges Spirastrella spinispirulifera and Hyrtioserecta. Spongistatin degrades XIAP protein in leukemic cells, which might be the reason for its potentizing effect when combined with other caspase-activating anticancer drugs [4].

PubMed, Nov 1, 2014

Chemical and biological investigations of the extract of Ammania auriculata (Lytheraceae) resulte... more Chemical and biological investigations of the extract of Ammania auriculata (Lytheraceae) resulted in the identification of eight polyphenols (1 - 8) for the first time from this plant, including the gallotannin, 2,3,6-tri-O-galloyl-(α,β)-4C1-glucopyranose (8), for which 1D and 2D-NMR spectra were recorded and assigned for the first time. The structures of all isolates (1 - 8) were elucidated by conventional methods, spectroscopic analysis, including 1D and 2D NMR, and by HR-ESIMS as well. All of the isolated compounds were evaluated for their antioxidant activities, determined by the DPPH and ORAC methods and for their cytotoxicity against the keratinocyte cell line HaCaT using the neutral red assay (NRU) and cell cycle analysis. Compounds 1, 3, 4, 5, and 6 significantly inhibited reactive oxygen species production with ED50 values between 3.22 and 9.79 μg/ml. Compounds 1, 3, 4, and 5 showed cytotoxic activity against HaCaT cells with IC50 values between 30.7 and 84.1 μg/ml. The new galloyl glucose (8) was found not cytotoxic. Ellagitannins, 2,3-hexahydroxy-((α/β)-glucopyranose (1) and 1 -0-galloyl 2,3-hexahydroxy-(α)-glucopyranose (5) possess remarkable antioxidative and comparably weak cytotoxic activity.

European Scientific Journal, ESJ, Feb 28, 2013

Artichoke is a source of biophenols that exhibit lots of pharmacological activities. The aim of t... more Artichoke is a source of biophenols that exhibit lots of pharmacological activities. The aim of the present study is to determine the effect of different extraction methods on the phenolic, and silymarin contents as well as antiradical activities of artichoke leaves and roots. First, the total phenol content was determined by the Folin-Ciocalteu procedure; the gallic acid equivalent values ranged from 16.42-30.28 mg/g. Generally, different leave extracts showed higher contents of phenol than the root extracts. It was found that the methanolic extract of the leaves exhibited the most value of phenolic content (30.28 mg/g) while the root infusion showed the least value (16.42 mg/g). The analysis of silymarin and silybin compounds from each extract was carried out by reversed phase high performance liquid chromatography (RP-HPLC). The infusion extract of leaves showed also the higher content of silymarin than that of root extracts, and the infusion of the leaves exhibited the higher value while the water extract of roots exhibited the least one. Antiradical activities were evaluated using 1, 1-Diphenyl-2-picrylhydrazyl (DPPH 0) free radical and β-carotene bleaching methods. Good correlation (R 2 =0.9752) was found between phenolic content and antioxidant activity. The

Chemistry & Biodiversity, Apr 1, 2017

The composition of the essential oil isolated from leaves and flowers of Pulicaria incisa sub. ca... more The composition of the essential oil isolated from leaves and flowers of Pulicaria incisa sub. candolleana E.Gamal-Eldin was analysed by GC and GC-MS. Forty-nine and sixty-eight compounds were identified from the oils of the leaves and flowers accounting for 86.69% and 84.29%, respectively of the total detected constituents. Both leaves and flowers oils were characterized by the high content of each carvotanacetone with 66.01%, 50.87% and chrysanthenone 13.26%, 24.3% respectively. The cytotoxic activity of both essential oils was evaluated against hepatocellular carcinoma cell line HEPG-2, using MTT assay and vinblastine as a reference drug. Leaf oil showed higher activity with IC50 11.4 μg/mL compared with 37.4 μg/mL for flower oil. The antimicrobial activity of both oils was evaluated using agar well diffusion method towards two representatives for each of Gram positive and Gram negative bacteria as well as four representatives for fungi. The minimum inhibitory concentration of both essential oils against bacterial and fungal strains was obtained in the range of 0.49 - 15.63 μg/mL. This article is protected by copyright. All rights reserved.

Carob leaves (Ceratonia siliqua L.), grown in Egypt have not fully identified in Egypt. Therefore... more Carob leaves (Ceratonia siliqua L.), grown in Egypt have not fully identified in Egypt. Therefore, eight major phenolic compounds were isolated from the aqueous ethanolic extract using different methods of chromatography; gallic acid, quercetin 3-O-4 C 1-B-D-glucoside (Isoquercetin), Kaempferol 3-O-1 C 4-"-Lrhamnoside (Afzelin), Quercetin 3-O-1 C 4-"-L-rhamnoside (Quercitrin), 1,2,6 triO -galloyl-B-D-4 C 1glucopyranose, (-)-Epigallocatechin-3-O-gallate, kaempferol and quercetin. Their structures established by conventional methods of analysis. This is the first phytochemical study of polyphenolic content of carob leaves grown in Egypt.

International journal of pharmacognosy & Chinese medicine, 2017

Nature is considered as an enormous contributor in anticancer drugs. Although more than half cent... more Nature is considered as an enormous contributor in anticancer drugs. Although more than half century had passed on its discovery, taxol is still, till now, a unique anticancer agent. Other compounds as vincristine, vinblastine, camptothecins, etoposide and others are plant derived and effective against cancer.A fact that out of 121 drugs prescribed for cancer treatment till date, 90 are derived from plant sources [1].

Natural Product Research, Sep 19, 2022

Medicinal and Aromatic plants, 2015

Caesalpinieae tribe is one of the largest archaic tribes of subfamily Caesalpinioideae, family Fa... more Caesalpinieae tribe is one of the largest archaic tribes of subfamily Caesalpinioideae, family Fabaceae. Caesalpinieae tribe includes 9 subtribes that have more than 47 genera, including several valuable medicinal plants. Extracts of different plants of Caesalpinieae tribe were reported to possess a wide range of pharmacological activities, including anti-oxidant, anti-bacterial, anti-inflammatory, cytotoxic, anti-diabetic, antifungal, hepatoprotective, gastroprotective, analgesic, anti-arthritic, anti-filarial, antimalarial, anthelmintic, amoebicidal, diuretic, anti-psoriatic, anti-estrogenic, anti-fertility, wound-healing, anxiolytic, cardioprotective, immunomodulatory, anti-HIV activities. Thus, Caesalpinieae tribe includes several plants with a potential for exploitation as a source for plant-based pharmaceutical products. The present review could form a sound basis for further investigation in the potential discovery of new natural bioactive compounds and provide preliminary information for future research.

Acta scientific pharmaceutical sciences, Dec 22, 2020

Abd-Alkhalek and Omayma A Eldahshan. Curcumin, the polyphenolic compound in turmeric exhibited ve... more Abd-Alkhalek and Omayma A Eldahshan. Curcumin, the polyphenolic compound in turmeric exhibited versatile biological effects such as anti-tumor, anti-inflammatory, immunomodulating, antioxidant and antimicrobial [1,2]. It exerted antiviral activities against diverse viruses, such as dengue [3], hepatitis B [4], Zika and chikungunya viruses [5]. Curcumin exerted many effects against COVID-19 infection. It has the ability to modify various targets on molecular base which participate in attaching of COVID-2 as well as its endocytosis in cardiovascular, hepatic, renal cells. It also modulates cellular signaling

Natural Product Research

Rising awareness about the ecological burden of agricultural by-products and their potential indu... more Rising awareness about the ecological burden of agricultural by-products and their potential industrial and medicinal applications spurred the research of waste valorization. Egypt is a chief producer of jasmine oils. However, jasmine dense foliage is an agricultural waste that merits exploitation. Herein, Jasminum grandiflorum leaves were profiled using UPLC-MS, revealing a promising phytochemical composition rich in secoiridoids. Good safety profile was confirmed in vitro on cancerous and normal cell lines and in vivo (LD50>4000 mg/kg). The radioprotective effect of 3500 mg/kg jasmine leaves extract against irradiation-induced lung injury was demonstrated. Biochemical analysis indicated that jasmine extract decreased malondialdehyde level and enhanced the endogenous antioxidants GSH-Px, SOD and CAT levels. Jasmine alleviated the inflammatory response by downregulating the expression of COX-2 and iNOS and reducing the inflammatory mediators, TNF-α, IL-6, NO, and PGE2.Jasmine leaves offer interesting application prospects that add economic and industrial value to agricultural waste.