الفهرس 
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Abstract
The aim of the present study was to investigate the phytoconstituents present in Flacourtia rukam Zoll & A. Mortizi leaves and bark, Archontophoenix alexandrae (Wendl. & Drude) and Dictyosperma album (Bory) H.Wendl & drude ex.Scheff leaves and to estimate their in vitro anticancer, antimicrobial, antileishmanial, antitrypanosomal, antimalarial, antioxidant and anti-inflammatory activities.
Part I: Phytochemical study
Chapter 1: Preliminary phytochemical screening of the three plants under study
Carbohydrates and/or glycosides, tannins, free and flavonoids as well as sterols and /or triterpenes were detected in all tested extracts.
Chapter 2: Quantitative determination of total phenolics and total flavonoids content.
The total phenolics content and total flavonoids content using Folin–Ciocalteu reagent and AlCl3, respectively for Flacourtia rukam leaves and bark, Archontophoenix alexandrae and Dictyosperma album leaves were evaluated spectrophotometrically. The results of phenolics content are in the order of the Dictyospermaalbum leaves > Flacourtia rukam leaves > Flacourtia rukam bark > Archintophoenix alexandae leaves with the values of 56.63, 54.96, 26.32 and 8.60 mg GAE/g, respectively. The total flavonoids content is in the order of Flacourtia rukam leaves > Dictyospermaalbum leaves > Archintophoenix alexandae leaves with the values of 39.97, 13.72 and 3.97 mg RE/g, respectively. While flavonoids content cannot be detected in Flacourtia rukam bark.
Chapter 3: Phytochemical study of Flacourtia rukam leaves and bark
Phytochemical investigation of Flacourtia rukam Zoll & Mortizi leaves and bark led to the isolation and characterization of six new compounds; 2-[(benzoyloxy)methyl]-phenyl-O-β-D-xylosyl-(1→2)-β-glucopyranoside (F7), 2-[(benzoyloxy)methyl]-4-hydroxyphenyl-O-β-D-xylosyl-(1→2)-β-glucopyranoside (F8), 2-hydroxy-5-(2-hydroxyphenoxy)phenoxy-β-glucopyranoside (F9), 2,3,6-dibenzofurantriol (F10), biphenyl-1,1′,2,2′-tetraol (F11) and (2S,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-3,5-dihydroxy-2H,8H-pyrano[2,3-f]chromen-8-one (F18). In addition to 12 known compounds which were isolated for the first time from F. rukam; 6′-(caffeoyl) (1-1′) β-D-glucopyranosyl-catechol (F12), rutin (F13), isoquercitrin (F14), dipyrocatechol-O-β-D-glucopyranoside ester of bis (6,7-dihydroxyphenyl)- 2, 2′′′′-cyclobutane dicarboxylic acid (dodegranoside B, F15), dipyrocatechol-O-β-D-glucopyranoside ester of 8,2′-epoxy-7,4′,5′-trihydroxynapthalene-2,3-dicarboxylic acid (dodegranoside C, F16), apigenin (F3), catechol (F4), resorcinol (F5), β-sitosterol-β-D-glucoside (F6), phytol (F1), β- sitosterol (F2) , friedelen (F17).
Chapter 4: Phytochemical study of Archontophoenix alexandrae (Wendl. & Drude) leaves.
Phytochemical investigation of Archontophoenix alexandrae led to the isolation and characterization of eight compounds; stigmasterol and β‐sitosterol mixture, β-sitosterol-β-D-glucoside, tricin, quercetin, luteolin, rutin and entepicatechin-(2α→7, 4α→8)-ent-catechin.
Chapter 5: Phytochemical studies of Dictyosperma album (Bory) H.Wendl. & drude ex.Scheff leaves
Phytochemical investigation of Dictyosperma album led to the isolation and characterization of six compounds; stigmasterol and β‐sitosterol mixture, β-sitosterol-β-D-glucoside, tricin, rutin and orientin.
Part II: Biological study
Chapter 1: Antimicrobial activity
Total ethanolic extracts, all fractions and isolated compounds except F5, F7, F15-18 (due to lack of quantity) were investigated for their in vitro antimicrobial effect against Candida albicans ATCC 90028, C. glabrata ATCC 90030, C. krusei ATCC 6258, Cryptococcus neoformans ATCC 90113, and Aspergillus fumigatus ATCC 204305, Staphylococcus aureus ATCC 29213, methicillin-resistant S. aureus ATCC 33591 (MRS), Escherichia coli ATCC 35218, Pseudomonas aerµginosa ATCC 27853, and Mycobacterium intracellulare ATCC 23068. All tested samples showed no activity except compound F11 (Biphenyl-1, 1′,2, 2′-tetrol) exhibited a marginal activity against E.coli with IC50=20 µg/mL.
Chapter 2: Antiprotozoal activity
Antimalarial activity
The total ethanol extract and its different fractions for Flacourtia rukam leaves and bark, Archontophoenix alexandrae and Dictyosperma album leaves as well as all isolated compounds except F5 and F7 (due to lack of quantity) were investigated for their in vitro antimalarial effect against D6 (chloroquine sensitive) and W2 (chloroquine-resistant) strains of Plasmodium falciparum. The results showed
Flacourtia rukam total extract showed higher activity against both Plasmodium falciparum D6 and Plasmodium falciparum W2 (IC50= 21.360, 14.417 µg/mL, respectively) with selectivity index 2.2, 3.3 than that of A. alexandrae (33.173, 20.484 µg/mL, respectively) with selectivity index ranging from 1.4, 2.3. while that of D. album lack the activity against Plasmodium falciparum D6 and showed a poor activity against Plasmodium falciparum W2 ((IC50 = 41.695 µg/mL, with selectivity index 1.1).while their polar fractions (ethyl acetate and butanol) showed no activity.
Non-polar fractions of Flacourtia rukamleaves and bark (hexane and dichloromethane) showed a good activity againstP. falciparum W2 with selectivity index (SI) ranging from 5.6- 2.2 and gainst P. falciparum D6 with selectivity index ranging from 4.5- 2.5.
Archontophoenix alexandrae total extract showed a higher activity against P. falciparum W2 (IC50= 20.484µg/mL, SI > 2.3)than P. falciparum D6 (33.173 µg/mL, SI >1.4), Archontophoenix alexandrae non-polar fractions showed a good activity especially against P. falciparum D6 with SI ranging from 5.1-5.6.
Dictyosperma album total extract showed poor activity against P. falciparum W2 and showed no activity against P. falciparum D6. But its fractions (hexane, dichloromethane, ehyl acetate and butanol) showed agood activity against P. falciparumD6 (IC50 =15.243, 17.527, 12.359 and 26.002µg/mL, SI=1.8-3.9) and against P. falciparum W2 (IC50 = 11.522, 11.057, 10.531, 19.535 µg/mL, SI=2.4-4.5).
All tested compounds showed inactivity against Plasmodium falciparum D6 and Plasmodium falciparum W2.
Antileishmanial and antitrypanosomal
All isolated compounds from Flacourtia rukam except F5, F7, F15-18 (due to lack of quantity) were investigated for their in vitro antileishmanial and antitrypanosomal activities. The results revealed that compound F11 (Biphenyl-1, 1′,2, 2′-tetrol), only exhibited a good antitrypanosomal activity with IC50=6.66 µg/mL and IC90=9.68 µg/mL compared to the positive control difluoromethyl ornithine (DFMO) (3.62, 8.41 µg/mL) respectively. Compound F3 (Apigenin) and F4 (Catechol) exhibited antitrypanosomal activity with IC50= 8.98, 8.2 µg/mL; respectively.
Chapter 3: Cytotoxic activity
In vitro cytotoxic activity for the total ethanolic extract of Flacourtia rukam leaves and bark, Archontophoenix alexandrae and Dictyosperma album leaves was determined against five human cancer cell lines: melanoma (SK-MEL), breast cancer (BT-549), oral cancer (KB ), ovary cancer (SKOV-3), and cervical cancer (HeLa) and two noncancerous kidney cell lines (LLC-PK1 and VERO). All tested samples showed no activity against the used human cancer cell lines (SK-MEL, KB, BT-549, SKOV-3 and HeLa) and the two noncancerous kidney cell lines (LLC-PK1 and VERO) up to a concentration of 200 µg/mL.
Chapter 4: Antioxidant activity
In vitro antioxidant activity for the total ethanolic extracts of Flacourtia rukam leaves and bark, Archontophoenix alexandrae and Dictyosperma album leaves using DPPH assay. The antioxidant activity is in the order of Flacourtia rukam bark >Dictyosperma album leaves > Flacourtia rukam leaves > Archintophoenix alexandae leaves with the values of 212.51, 243.51 235.07 and 129.40 µg AECE/g, respectively.
Chapter 5: Anti-inflammatory activity
The total ethanolic extracts of Flacourtia rukam (leaves and bark) as well as all isolated compounds (except F1, F5, F7, F10 and F18; due to lack of quantity) were tested for in vitro anti-inflammmatory assay which was determined by proteinase inhibitory activity (Trypsin inhibition). The higher activity of the leaves ethanolic extract (IC50= 116.5 µg/mL) must be due to compounds F3, F4, F8, F11, F15 and F16 which showed a significant activity with IC50= 41.1, 54.7, 44.1,47.5, 62.6 and 79.8 µg/mL.