Hepatoprotective Effect of Flavonol Glycosides Rich Fraction from Egyptian Vicia calcarata Desf. Against $CCl_4$-Induced Liver Damage in Rats

Singab, Abdel Nasser B.,Youssef, Diaa T.A.,Noaman, Eman,Kotb, Saeed The Pharmaceutical Society of Korea 2005 Archives of Pharmacal Research Vol.28 No.7

The hepatoprotective activity of flavonol glycosides rich fraction (F-2), prepared from 70% alcohol extract of the aerial parts of V calcarata Desf., was evaluated in a rat model with a liver injury induced by daily oral administration of $CCl_4$ (100 mg/kg, b.w) for four weeks. Treatment of the animals with F-2 using a dose of (25 mg/kg, b.w) during the induction of hepatic damage by $CCl_4$ significantly reduced the indices of liver injuries. The hepatoprotective effects of F-2 significantly reduced the elevated levels of the following serum enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The antioxidant activity of F-2 markedly ameliorated the antioxidant parameters including glutathione (GSH) content, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), plasma catalase (CAT) and packed erythrocytes glucose-6-phosphate dehydrogenase (G6PDH) to be comparable with normal control levels. In addition, it normalized liver malondialdehyde (MDA) levels and creatinine concentration. Chromatographic purification of F-2 resulted in the isolation of two flavonol glycosides that rarely occur in the plant kingdom, identified as quercetin-3,5-di-O-$\beta$-D-diglucoside (5) and kaempferol-3,5-di-O-$\beta$-D-diglucoside (4) in addition to the three known compounds identified as quercetin-3-O-$\alpha$-L-rhamnosyl- (${\rightarrow}6$)-$\beta$-D-glucoside [rutin, 3], quercetin-3-O-$\beta$-D-glucoside [isoquercitrin, 2] and kaempferol-3-O-$\beta$-D-glucoside [astragalin, 1]. These compounds were identified based on interpretation of their physical, chemical, and spectral data. Moreover, the spectrophotometric estimation of the flavonoids content revealed that the aerial parts of the plant contain an appreciable amount of flavonoids (0.89%) calculated as rutin. The data obtained from this study revealed that the flavonol glycosides of F-2 protect the rat liver from hepatic damage induced by $CCl_4$ through inhibition of lipid peroxidation caused by $CCl_4$ reactive free radicals.

Flavonoids from Iris spuria (Zeal) Cultivated in Egypt

Singab, Abdel Nasser B. The Pharmaceutical Society of Korea 2004 Archives of Pharmacal Research Vol.27 No.10

A new 12a-dehydrorotenoid 1, 11-dihydroxy-9, 10-methylenedioxy-12a-dehydrorotenoid (1), together with a new isoflavonoid glycoside tectorigenin-7-O-${\beta}$-glucosyl-4'-O-${\beta}$-glucoside (3), were isolated and identified from the rhizomes of I. spuria (Zeal). In addition, 4 known compounds, tectorigenin (2) tectorigenin-7-O-${\beta}$-glucosyl $(1{\leftrightarrow}6)$ glucoside (4), tectoridin (a tectorigenin- 7-O-${\beta}$-glucoside) (5) and tectorigenin-4'-O-${\beta}$-glucoside (6) were isolated and identified for the first time from this plant. The structures of the isolated compounds were determined by spectroscopic methods (UV, IR, $^1H,\;^{13}C$NMR, DEPT, HMQC, NOESY, and HMBC experiments and MS spectrometry) and by comparison with literature data of known compounds. Compounds 2, 4, 5, and 6 are reported for the first time from this plant through the present study.

Hepatoprotective Effect of Flavonol Glycosides Rich Fraction from Egyptian Vicia calcarata Desf. Against CCl4-Induced Liver Damage in Rats

Abdel Nasser B. Singab,Diaa T. A. Youssef,Eman Noaman,Saeed Kotb 대한약학회 2005 Archives of Pharmacal Research Vol.28 No.7

Role of Nutraceuticals in Obesity Management: A Mechanism and Prospective Supported by Molecular Docking Studies

Abdel Nasser B. Singab,Esraa A. Elhawary,Yasmin A. Elkhawas,Iten M. Fawzy,Ashaimaa Y. Moussa,Nada M. Mostafa 한국식품영양과학회 2024 Journal of medicinal food Vol.27 No.2

Obesity and its comorbidities represent a major health problem worldwide. Treatment by reducing food intakeand physical activity interventions has limited success especially with elderly people with chronic diseases. Nutraceuticals arenaturally originated and successfully used for their physiological and nutritional benefit in health care. They might bealternative means to help lose weight and reduce obesity-associated metabolic disorders with the improvement of health, delaythe aging process, prevention of chronic diseases, increase of life expectancy, or support to the structure or function of thebody. The current study enumerates the inherent role of nutraceuticals in the management of obesity and its related comorbidities. The study is supported with the molecular docking studies discussing the mechanism of action. An attempt tooptimize the role of nutraceuticals is made in this article in addition to widen the scope of its use in this chronic worldwidedisease.

Structural Characterization and In Vitro Cytokines Modulation Effect of New Acetylated Galactomannans from Aloe arborescens

Jilan A. Nazeam,Hala M. El-Hefnawy,Abdel-Naser B. Singab 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.10

Three new galactomannan components designed as AANP-1, AANP-3, and AAAP-7 were isolated from previously purified Aloe arborescence polysaccharide fractions, using ion-exchange, gel filtration, and preparative chromatographic techniques. Based on Fourier transform-infrared, one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy, the main backbone of AANP-1 elucidated as (1 → 4)-linked_α-d-deoxyGalp, (1 → 4) d-Manp, and β-d-2-glup. The sugar residue sequence of AANP-3 was (1 → 4)-linked β-d-NHAC-GAlp with β-d-AcManp side chain that attached to O-4 position. The AAAP-7 repeated units were (1 → 4) d-Manp linked with (1 → 4) d-Galp interspersed with (1 → 3)-α-Manp. The results of high performance size-exclusion chromatography indicated that the approximate molecular weights of AANP-1, AANP-3, and AAAP-7 were 4.2, 2.4, and 2.5 kDa, respectively. The cytokine modulation assay revealed that the isolated components promoted a remarkable release of interleukin (IL)-12 and tumor necrosis factor alpha in comparison with the negative control group, whereas potent significant induction of IL-2 and interferon gamma was detected more than the positive control phytohemagglutinin (P < .05). This is the first report for isolation galactomannans from Aloe arborescence. Moreover, this finding could provide new insights for exploring the biological modifier mechanism in correlation with the knowledge of structural configuration.

Structural Elucidation of Immunomodulators, Acetylated Heteroglycan and Galactosamine, Isolated from Aloe arborescens Leaves

Jilan A. Nazeam,Hala M. El-Hefnawy,Abdel-Naser B. Singab 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.8

Plant polysaccharides gained extended scientific attention for their immunomodulatory effect. However, few scientific studies structurally defined polysaccharides in relation to their biological modifier response. Therefore, the study explored the effect of structurally identified isolated macromolecules from Aloe arborescens against cytokine modulation (interferon [IFN-γ], interleukins [IL-2 and IL-12], and tumor necrosis factor [TNF-α]) in vitro. The structures were elucidated by GC, GPC, FT-IR spectroscopy, 1D NMR, COSY, HMBC, and HSQC. Two acetylated glucomannans (AANP4 and AAAP6), one deoxy-glucogalactan (AANP5), and one deoxy-N-acetyl-[1–4]-galactosamine (AANP2) were isolated. The results showed significant induction for all cytokines and the most potent component was AAAP6; acetylated phenolic glucomannan with a (1 → 3)-linked glucose–mannose and (1 → 4)-linked mannose backbone, which stimulated IL-12 by more than 10-fold compared with phytohemagglutinin (positive control). In conclusion, A. arborescens polysaccharides could be a landmark for development of effective immunotherapeutics against cancer and chronic inflammatory conditions.

Aloe arborescens Polysaccharides: In Vitro Immunomodulation and Potential Cytotoxic Activity

Jilan A. Nazeam,Haidy A. Gad,Ahmed Esmat,Hala M. El-Hefnawy,Abdel-Naser B. Singab 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.5

Different polysaccharides were isolated from the leaves of Aloe arborescens using the gradient power of hydrogen followed by antitumor and immunomodulatory assay. The total polysaccharide content of different fractions, water-soluble polysaccharide (WAP), acid-soluble polysaccharide (ACP), and alkaline-soluble polysaccharide (ALP), was estimated using a phenol-sulfuric acid spectrophotometric method. WAP possessed a higher content of mannose and glucose than either ACP or ALP. In vitro antitumor activity was investigated in three different cancer cell lines, and in vitro immunomodulatory potential was assessed through phagocytosis and lymphocyte transformation assay. The results showed that WAP and ALP exhibited the most significant cytotoxicity against HepG2 human liver cancer cells, with IC50 values of 26.14 and 21.46 μg/mL, respectively. In contrast, ALP was able to enhance lymphocyte transformation, whereas WAP had the most potent phagocytic activity. Molecular weight, total sugar and uronic acid content, Fourier transform-infrared analysis, and linkage type of bioactive polysaccharides were investigated. These findings revealed that the potential antitumor activity of the natural agents WAP and ALP was through an immunomodulation mechanism, which verifies the use of the plant as adjuvant supplement for cancer patients suffering immunosuppression during chemotherapy.