الفهرس 
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Abstract
Algae have received a lot of interest as a source of biologically active substances. This study focuses on the effect of algal extracts as antifungal against some filamentous fungi and yeast and as antioxidant and cytotoxic Synthetic fungal medications is not only expensive and ineffective in the treatment of some diseases, but they are also highly susceptible to modification and have side effects. As a result, new infection-fighting strategy to control fungal infections is required. Natural antifungal compounds extracted from algae are discovered to be the most efficient. This study evaluated crude extracts of Arthrospira platensis (cyanobacteria) which obtained from Phycology Laboratory, Botany Department, Faculty of Science, Tanta University, and four different seaweeds extracts; Ulva fasciata and Ulva compressa (Chlorophyta), Amphiroa rigida Amphiroa rigida (Rhodophyta(Rhodophyta)) were lacerifoliumSargassum and collected from Abu Qir Bay area, Alexandria, Egyptas antifungal against the from the coast of Red Sea,Hurghada, Egypt )Phaeophyta(tested filamentous fungi and yeast (Candida albicans) which isolated from Hospital’s dermatology department’s outpatient clinic, Tanta University , While the other fungi Trichophyton rubrum and Malassezia furfur were obtained from Moubasher Mycological Centre, Assiut University (AUMMC). :The results are summarized as follows 1. Growth curve of cultivated A. platensis was estimated as an optical density (OD) to detect the best period needed for its maximum growth. Maximum optical density that indicates a maximum biomass concentration of 0.720 was observed at 10th day (the end of stationary phase), but further reduction in growth rate was observed at day12th. 2. In vitro, According to well diffusion method, the greatest inhibitory zones against C. albicans and M. furfur were recorded with methanol extract of A. platensis and ethanol extract of S. lacerifolium, respectively. 3. The highest inhibition zones were detected with methanol extract of A. platensis against C. albicans, M. furfur and T. rubrum. The results showed that methanol was the best solvent which affected strongly on the growth of C. albicans and gave a higher inhibition zones 19.2, 17.3 and 11 mm with C. albicans, M. furfur and T. rubrum, respectively. The best fungus affected by the methanol extract of A. platensis was the C. albicans fungus; both were chosen for the in vivo study. 4. Transmission electron micrograph (TEM) was used to differentiate between C. albicans conidia and M. furfur treated with algal extract and non-treated (control group). TEM showed the normal ultrastructure of the two fungi including normal cell wall, plasmalemma and homogeneous cytoplasm. Meanwhile, the TEM micrograph of treated group of C. albicans conidia with A. platensis methanol extract and M. furfur with S. lacerifolium ethanol extract showed mild lysis and vacuolation of the cytoplasmic organelles and rupture of the cell wall. In case of M. furfur, shrinking of internal component to one side of the cell forming a gab between the cell wall and the internal component was observed. 5. Using the genotypic identifications 18S rDNA sequences, comparison of the tested nucleotide sequences with the members of Candida sp in the GenBank revealed 99% similarity with other strains of C. albicans 13531 as accessed from Gene Bank (Accession NO: MH534924) While phylogenetic tree generated from MP analysis based on ITS sequence data of M. furfur AUMMC 11710 (Accession NO: MW136457) associated to other related genes in the ITS gene sequences belonging to Malasseziaceae. 6. In vivo study; the effect of algal extract on the treatment of wounded mice artificially infected with tested fungi. Twenty four male mice aged 8 to10 weeks and weighed 20 to 25 g was used. The experiment contain four groups, each group contain 3 mice. group 1(G1) was left healthy as negative control. group 2(G2) was treated with placebo cream base. group 3 (G3) was treated by applying nystatin cream on the infected area and group 4 (G4) were topically treated by applying slim layer of algal extract cream on the infected wound. Every three days, the diameter of each treated mouse’s wound area was measured. Our results showed that A. platensis methanol extract cream was effective against C. albicans, While S. lacerifolium ethanol extract cream was effective against M. furfur and they are safe in certain concentrations without side effects. At the end of the experiment period (17 days), the algal extract creams accelerates wound healing, complete removal of inflammation and massive hair growth on the infected wound compared to nystatin artificial standard drug. 7. The histological skin section treated with methanol extract of A. platensis cream and S. lacerifolium ethanol extract cream exhibited no hypha swelling and no significant toxic effects when compared to the control. The skin tissue appeared normal with normal epidermis and keratinized fibers of stratum conium which were regularly arranged; they also appeared condensed without any disruption and the dermis appeared normal with minimal inflammatory cellular infiltration while the synthetic antifungal cream nystatin showed partial healing comparing with our natural algal creams. 8. Different methods were used to evaluate the antioxidant activity of the crude algal extracts. The extract of A. platensis recorded the highest antioxidant activity using the DPPH (2, 2- diphenyl-1-picrylhydrazyl) scavenging method with concentration 50 μg.ml-1 of the extract (75.5±0.4 %), followed by ethanol extract of S. lacerifolium, U. compressa, A. rigida and U. fasciata (60.17±0.4, 56.25±0.27, 54.39±0.25 and 52.56±0.26)% respectively. Also A. platensis; showed high levels of antioxidant activity among the tested seaweeds for total antioxidant capacity method (50.2±0.25) followed by S.lacerifolium (40.19±0.27) then U. compressa and U. fasciata, (32.18±0.23 and 26.07±0.09), respectively, while the lowest antioxidant activities was observed in A. rigida (25.34±0.16). While the highest ABTS radical scavenging activity was 80.2±0.21 for A. platensis methanol extract and 61.4±0.14 for S. lacerifolium ethanol extract at 60 μg/ml. followed by U.compressa, U. fasciata and A. rigida (55.9±0.12, 52.3±0.20 and 49.8±0.32), respectively. 9. MTT assay for cytotoxicity, in vitro was carried for both A.platensis methanol extract and S. lacerifolium ethanol extract. A. platensis methanol extract recorded strong cytotoxic activity against HePG2 cell line (IC50 20.56±1.7 μg/ml), moderate cytotoxic activity against MCF7 and Hela cells (IC50 27.99±2.1 and 38.91±2.4 μg/ml, respectively) and with weak cytotoxic activity against the WI38 cell line (IC50 65.82±3.50). While S. lacerifolium ethanol extract showed weak cytotoxic activity against the WI38 and MCF7 cell line (IC50 76.11± 3.9 and 56.54±3.2 μg/mL, respectively) and moderate cytotoxic activity against the HePG2 and Hela cell lines (IC50 33.60 ± 2.3 and 47.71±2.8 μg/ml respectively). Both algal extracts showed no toxicity effect on fibroblast normal cell lines (WI38 ) that prove the safety of extract on normal cell. 10. UltraViolet (UV) spectrum shows absorption peak at 400 nm, and 664 nm indicating the presence of an aromatic compound of both algal extract, While Fourier Transform Infrared (FTIR) detected the prescence of the CH aliphatic group , aromatic CH group, OH, C = O and C = C groups. Gas chromatography/Mass Spectroscopy (GC/MS) results revealed that effective activity of A. platensis methanol extract could be linked to a synergistic impact between their prominent composition mainly Heptadecane (64.664%) ,3,7,11,15-Tetramethyl-2-hexadecen-1-ol (9.276%),Triacetin (1.511%). On the other hand, S. lacerifolium ethanol extract showed the prescence of different compounds mainly3,7,11,15-Tetramethyl-2-hexadecen-1-ol (36.822%) ,Phytol (8.579 %), Heptadecane (3.080%) Naphthalene, 1,2,3,4-tetrahydro-1,4,6-trimethyl (7.71%). These contain active metabolites alkaloids, phytol, fatty acids, hydrocarbons, phenolic, and phthalates being a promising source of antifungal, antioxidant and anti-proliferative compounds for pharmaceutical drug industry. In conclusion: A. platensis methanol extract and S. lacerifolium ethanol extract showed the maximum antifungal activity in vitro, against C. albicans and M. fufur , respectively. In vivo study, the obtained results showed that infected mice skin treated with A. platensis methanol extract and S. lacerifolium ethanol extract caused wound healing and significant decrease in the elevated inflammation and redness with increasing the hair growth compared with un treated group. The histopathological mice skin showed that the algal treatment caused a substantial improvement and restored the histological tissue damage without causing any side effects. A. platensis methanol extract and S. lacerifolium ethanol extract showed the highest antioxidant and cytotoxic activity by using different assays. The cytotoxicity test on normal cells indicated the safety of both extracts at certain concentrations. GC/MS analysis for both algal extracts confirmed the presence of bioactive compounds responsible for the antifungal, antioxidant, cytotoxic activities which recommended these extracts as ingredients for natural drugs.