Maha M. Salama

In Vitro activities of plant extracts from Saudi Arabia against malaria, leishmaniasis, sleeping sickness and Chagas disease

The in vitro activity of the methanol extracts of 51 plants randomly collected from the Kingdom of Saudi Arabia and some of their fractions (petroleum ether, chloroform, ethyl acetate and aqueous) were evaluated against Plasmodium falciparum, Trypanosoma brucei brucei, T. cruzi and Leishmania infantum, as well as toxicity against MRC‐5 fibroblast cells. Ten crude methanolic extracts that demonstrated potent and adequately selective antiprotozoal activity were subjected to solvent fractionation using petroleum ether, ethyl acetate and chloroform. Only three samples showed promising antiprotozoal activity. Argemone ochroleuca (CHCl3 fraction) showed pronounced activity against P. falciparumGHA (IC50 0.32 μg/mL) and T. cruzi (IC50 0.30 μg/mL) with low cytotoxicity against MRC‐5 cells (CC50 11.6 μg/mL). Capparis spinosa (EtOAc fraction) showed pronounced activity against P. falciparumGHA with an IC50 0.50 μg/mL in the absence of toxicity against MRC‐5 cell line (CC50 > 30 μg/mL). Heliotropium curassavicum (CHCl3 fraction) showed similar activity against P. falciparum (IC50 0.65 μg/mL; MRC‐5 CC50 > 30 μg /mL). These three extracts will be subjected for further extensive studies to isolate and identify their active constituents. Copyright

Cytotoxic compounds from the leaves of Gaillardia aristata Pursh. growing in Egypt

Ten compounds, neopulchellin (1), 6α- hydroxyneopulchellin (2), β-sitosterol-3-O-β-D-glucoside (3), apigenin (4), quercitin (5), eupafolin (6), kaempferol-3-methoxy-7-O-α-L-rhamnoside (7), apigenin-7-O-β-D-glucopyranoside (8), α-amyrin (9) and β-sitosterol (10), were isolated from the leaves of Gaillardia aristata by applying bioassay guided fractionation. The cytotoxicity was traced against two human cancer cell lines (breast (MCF7) and colon (HCT116)). The highest cytotoxicity was revealed by compounds 1 and 2 (isolated from chloroform extract); with IC50 values of 0.43, 0.32 µg mL−1 against MCF7 and 0.46, 0.34 µg mL−1 against HCT116, respectively. Compounds 9 and 10 (isolated from the n-hexane extract) exhibited lower IC50 values of 3.05, 2.35 µg mL−1 against MCF7 and 3.05, 2.35 µg mL−1 against HCT116, respectively, while compounds 4–7 obtained from the ethyl acetate extract revealed the lowest cytotoxicity. Identification of the aforementioned compounds was carried out on the basis of their physico-chemical properties and spectral analysis (UV, EI/MS, 1D and 2D).

Molluscicidal and Mosquitocidal Activities of the Essential oils of Thymus capitatus Hoff. et Link. and Marrubium vulgare L.

Steam distillation of essential oils of aerial parts of Thymus capitatus and Marrubium vulgare L. collected at North cost of Egypt yielded 0.5% and 0.2%, respectively. Results of Gas chromatography-mass spectrometry analyses of the two samples identified 96.27% and 90.19% of the total oil composition for T. capitatus and M. vulgare, respectively. The two oil samples appeared dominated by the oxygenated constituents (88.22% for T. capitatus and 57.50% for M. vulgare), composed of phenols, mainly carvacrol (32.98%) and thymol (32.82%) in essential oil of T. capitatus, and thymol (34.55%) in essential oil of M. vulgare. It was evaluated the molluscicidal activity of T. capitatus and M. vulgare essential oils on adult and eggs of Biomphalaria alexandrina as well as their mosquitocidal activity on Culex pipiens. The LC50 and LC90 of T. capitatus essential oil against adult snails was 200 and 400 ppm/3hrs, respectively, while for M. vulgare it was 50 and 100 ppm/3hrs, respectively. Moreover, M. vulgare showed LC100 ovicidal activity at 200 ppm/24 hrs while T. capitatus oil showed no ovicidal activity. It was verified mosquitocidal activity, with LC50 and LC90 of 100 and 200 ppm/12hrs respectively for larvae, and 200 and 400 ppm/12hrs respectively for pupae of C. pipiens.

In Vitro and In Vivo Anticancer Activity of the Fruit Peels of Solanum melongena L. against Hepatocellular Carcinoma

Background: The fruit peels’ of Solanum melongena L. which is a common vegetable in Egypt, were investigated for biologically active metabolites in an approach to find any medicinal benefits from such waste products.Methods: The Methanol Extract of the Peels (MEP) was subjected to fractionation and purification for the isolation of its major constituents. Identification of the compounds was carried out on the basis of physico-chemical properties and spectral analysis (1H NMR, 13C NMR, COSY and HMBC). The MEP together with the isolated compounds were tested against five human cancer cell lines representing the most common types of cancer in Egypt: colon cancer cell line (HCT116), larynx cancer cell line (HEP2), breast cancer cell line (MCF7), cervix cancer cell line (HELA) and liver cancer cell line (HEPG2). MEP was tested in vivo against the CCl4- induced hepatocelular carcinoma (HCC) in rats at two dose levels (100 and 200 mg/kg.b.wt).Results: Five steroidal compounds; three steroidal alkaloids: solasodine (S1), solamargine (S4) and solasonine (S5) together with two steroidal glycosides: β-sitosterol-3-O- β-D-glucoside (S2) and poriferasterol-3-O- β-D-glucoside (S3) were isolated. The MEP and the five isolated compounds exhibited moderate to potent activities against the tested human cancer cell lines however their pronounced activity was revealed against HEPG2, accordingly, MEP was tested in vivo against the CCl4- induced Hepatocelular Carcinoma (HCC) in rats. The MEP showed a dose dependent anticancer activity through stabilization of the hepato-cells revealed by reduction in α-fitorotein (AFP) (which could considered as tumor marker), it also restored the levels of AST, ALT and albumin in a dose dependent manner. Histopathology of liver tissues treated with MEP strongly supported our results.Conclusion: Our findings supported the reuse of such waste products as a new remedy for treating cancer.

In vitro anti-influenza virus activity of a cardiotonic glycoside from Adenium obesum (Forssk.)

Methanolic extracts of six Saudi plants were screened for their in vitro antiviral activity using influenza virus A/PR/8/34 (H1N1) and MDCK cells in an MTT assay. The results indicated that the extracts of Adeniumobesum and Tephorosianubica possessed antiviral activity (99.3 and 93.3% inhibition at the concentration of 10 μg/ml, respectively). Based on these results A. obesum was selected for further study by applying bioactivity-guided fractionation to isolate its antiviral principle. The antiviral principle was isolated from the chloroform fraction through solvent fractionation, combined open liquid chromatography and HPLC. The isolated active compound A was identified as oleandrigenin-β-D-glucosyl (1→4)-β-D-digitalose, on the basis of its spectral analysis (MS, 1D and 2D NMR). The isolated glycoside showed reduction of virus titre by 69.3% inhibition at concentration of 1 μg/ml (IC(50)=0.86 μg/ml).

Phenylalkylamine alkaloids from Stapelia hirsuta L.

Four alkaloids of the phenethylamine derivatives have been isolated from the n-butanol fraction of the aerial parts of Stapelia hirsuta L. The structures of the isolated alkaloids were determined as N-acetyl hordenine (a new natural compound), hordenine, candicine and hordenine-1-O-β-D-glucoside, in addition to luteolin-7-O-β-D-glucopyranoside.

A new α-glucosidase inhibitor from Achillea fragrantissima (Forssk.) Sch. Bip. growing in Egypt

α-Glucosidase inhibitors (AGIs) represent a class of oral antidiabetic drugs that delay the absorption of ingested carbohydrates, reducing the postprandial glucose and insulin peaks to reach normoglycaemia. In this study, a bioassay-guided fractionation of the ethanolic extract of the aerial parts of Achillea fragrantissima (Forssk.) Sch. Bip. growing in Egypt led to the isolation of a new potent AGI; acacetin-6-C-(6″-acetyl-β-d-glucopyranoside)-8-C-α-l-arabinopyranoside (5) alongside with four known compounds: chondrillasterol (1), quercetin-3,6,7-trimethyl ether (chrysosplenol-D) (2), isovitexin-4′-methyl ether (3) and isovitexin (4). The structure of the new compound (5) was elucidated on the basis of its spectral data, including HR-FAB-MS, UV, 1H NMR, 13C NMR, 1H–1H COSY, HSQC and HMBC. The new compound (5) exhibited the most significant α-glucosidase inhibitory activity (IC50 1.5 ± 0.09 μg/mL). Under the assay conditions, all the tested compounds were more potent than the positive control acarbose (IC50 224 ± 2.31 μg/mL).

Bioguided isolation of pentacyclic triterpenes from the leaves of Alstonia scholaris (Linn.) R. Br. growing in Egypt

Ethanolic and aqueous extracts of the leaves and flowers of Alstonia scholaris were evaluated for their antioxidant activity by investigating their effect on blood glutathione levels in alloxan-induced diabetic rats. The ethanolic extract of the leaves was the most active; therefore, its cytotoxicity against HepG2 cells was also tested. Promising GI50 values of 1.96, 4.34 and 4.65 µg mL–1 were observed for the extract, its chloroform and ethyl acetate fractions, respectively. The chloroform active subfraction I (GI50 = 2.97 µg mL–1) yielded betulin (1), betulinic acid (2) and ursolic acid (3) upon purification. Compounds 1–3 were identified using spectroscopic techniques and by comparison with reported data. GLC of unsaponifiable and saponifiable fractions of the hexane extract revealed β-sitosterol (7.37%) and n-tetracosane (54.4%) to be the major sterol and hydrocarbon components, respectively. Linoleic acid (48.89%) was the predominant fatty acid.

Anti-acetylcholinesterase potential and metabolome classification of 4 Ocimum species as determined via UPLC/qTOF/MS and chemometric tools.

Ocimum (sweet basil) is a plant of considerable commercial importance in traditional medicine worldwide as well as for the flavor and food industry. The goal of this study was to examine Ocimum extracts anti-acetylcholinesterase activity and to correlate the activity with their secondary metabolites profiles via a metabolome based ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) approach coupled to chemometrics. The metabolomic differences in phenolics from leaves derived from 4 Ocimum species: Ocimum basilicum, Ocimum africanum, Ocimum americanum and Ocimum minimum were assessed. Under optimized conditions, 81 metabolites were identified including 21 hydroxy cinnamic acids, 4 benzoic acid conjugates, 14C/O flavonoid conjugates, 2 alcohols, 5 acyl sugars, 4 triterpenes and 12 fatty acids. Several salviolanic acid derivatives including salviolanic acid A, B, C & I found in Salvia, were found in Ocimum herein for the first time. Unsupervised principal component analysis (PCA) and supervised orthogonal projection to latent structures-discriminant analysis (OPLS-DA) were further used for comparing and classification of samples. A clear separation among the four investigated Ocimum species was revealed, with O. africanum samples found most enriched in hydroxy cinnamates conjugates (HC) and flavonoids. To the best of our knowledge, this is the first report for compositional differences among Ocimum leaves via a metabolomic approach revealing that among examined species O. africanum leaves present a better source of Ocimum bioactive metabolites. The anticholinesrase activity of examined species was further assessed with a potent IC50 values for O. americanum, O. africanum, O. basilicum ranging from 2.5 to 6.6mg/ml, whereas O. minimum was least active with IC50 of 31.4mg/ml. Furthermore, major HC i.e., caftaric, chlorogenic and rosmarinic acids identified in extracts via UPLC-MS analysis exhibited IC50 values of 24, 0.5 and 7.9mg/ml respectively, suggesting that HCs are likely to mediate for the anticholinesterase effect in Ocimum extracts.

Cytotoxic activity of acyl phloroglucinols isolated from the leaves of Eucalyptus cinerea F. Muell. ex Benth. cultivated in Egypt.

Two acyl phloroglucinol compounds namely; Sideroxylonal B (1) and Macrocarpal A (2) were isolated from the Sideroxylonal-Rich Extract (SRE) of the juvenile leaves of Eucalyptus cinerea; F. Muell. ex Benth cultivated in Egypt. Identification of the isolated compounds was established on the basis of physico-chemical properties and spectral analysis (1D & 2D NMR). The two compounds were isolated for the first time from this species. The SRE alongside with the isolated compounds were tested against three human cancer cell lines; MCF7 (breast carcinoma cell line), HEP2 (laryngeal carcinoma), CaCo (colonic adenocarcinoma) and one type of normal human cell line;10 FS (fibroblast cells). The SRE, (1), and (2) showed cytotoxic activity with IC50 13.6 ± 0.62, 7.2 ± 0.5, 14.8 ± 0.55 μg mL−1 against HEP2 respectively, 11.6 ± 0.47, 4 ± 0.36, 11.4 ± 0.45 μg mL−1 against CaCo, respectively, and 8.6 ± 0.29, 4.4 ± 0.25, and 7.8 ± 0.3 μg mL−1 against MCF7, respectively. Meanwhile, the (SRE) together with (1) and (2) exhibited low cytotoxicity against normal cell line 10 FS, with IC50 55.4 ± 1.4, 43 ± 0.8 and 50.1 ± 1.12 μg mL−1, respectively. The antiprofilerative activity of the tested compounds was evaluated. The cell cycle profile of cells treated with Sideroxylonal-B and Macrocarpal-A indicates possible S-phase specific effects.