Osama Salama

Prof. Osama Salama


Research Focus & Metrics

Academic Career Length

47Years (1980-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
12 January 2020 in Molecules
Verified
Journal Article
Open access
PDF file
NKNoha Hassan Khalil
Noha Hassan Khalil
MBMokhtar Bishr
Mokhtar Bishr
SDSamar Desouky
Samar Desouky
OSOsama Salama
Osama Salama
Ammi visnaga L. (Visnaga daucoides Gaertn., Family Apiaceae), also known as Khella Baldi or toothpick weed, is an annual or biennial herb indigenous to the Mediterranean region of North Africa, Asia, and Europe. The plant is known to have been used in traditional medicine a long time ago. Nowadays, it is used in modern medicine to treat many aliments such as renal colic and coronary insufficiency, and is used as an antioxidant, antifungal, and antibacterial, with a larvicidal effect on mosquito larvae. Peer-reviewed studies show that these pharmacological activities are due its valuable chemical constituents that include mainly essential oil, polyphenolic compounds including flavonoids, as well as γ-pyrones, represented mainly by khellin and visnagin. Its essential oil is reported to have antiviral, antibacterial, and larvicidal effects, while its flavonoid content is responsible for its antioxidant activity. Its γ-pyrone content has a powerful effect on facilitating the passage of kidney stones and relieving renal colic, in addition to having a relaxant effect on smooth muscle including that of the coronary arteries. The current review represents the progress in research on A. visnaga in terms of either its chemistry or biological activities. This review represents scientific support material for the use of the plant by the pharmaceutical industry.


6 January 2020 in Marine Drugs
Verified
Journal Article
Open access
PDF file
YEYasmin Elkhawas
Yasmin Elkhawas
AEahmed elissawy
ahmed elissawy
MEMohamed Said Elnaggar
Mohamed Said Elnaggar
Nada MostafaNada Mostafa
Nada Mostafa
Eman Al-SayedEman Al-Sayed
Eman Al-Sayed
OSOsama Salama
Osama Salama
One of the most widely distributed soft coral species, found especially in shallow waters of the Indo-Pacific region, Red Sea, Mediterranean Sea, and also the Arctic, is genus Sacrophyton. The total number of species belonging to it was estimated to be 40. Sarcophyton species are considered to be a reservoir of bioactive natural metabolites. Secondary metabolites isolated from members belonging to this genus show great chemical diversity. They are rich in terpenoids, in particular, cembranoids diterpenes, tetratepenoids, triterpenoids, and ceramide, in addition to steroids, sesquiterpenes, and fatty acids. They showed a broad range of potent biological activities, such as antitumor, neuroprotective, antimicrobial, antiviral, antidiabetic, antifouling, and anti-inflammatory activity. This review presents all isolated secondary metabolites from species of genera Sacrophyton, as well as their reported biological activities covering a period of about two decades (1998–2019). It deals with 481 metabolites, including 323 diterpenes, 39 biscembranoids, 11 sesquiterpenes, 53 polyoxygenated sterols, and 55 miscellaneous and their pharmacological activities.

14 November 2019 in Molecules
Verified
Journal Article
Open access
PDF file
NFNoha Fathallah
Noha Fathallah
MRMarwa Raafat
Marwa Raafat
MIMarwa Issa
Marwa Issa
MAMarwa Abdel-Aziz
Marwa Abdel-Aziz
MBMokhtar Bishr
Mokhtar Bishr
OSOsama Salama
Osama Salama
Ammi majus L.; Family Apiaceae; is a plant indigenous to Egypt. Its fruits contain bioactive compounds such as furanocoumarins and flavonoids of important biological activities. An endophytic fungus was isolated from the fruits and identified as Aspergillus amstelodami (MK215708) by morphology, microscopical characterization, and molecular identification. To our knowledge this is the first time an endophytic fungus has been isolated from the fruits. The antimicrobial activity of the Ammi majus ethanol fruits extract (AME) and fungal ethyl acetate extract (FEA) were investigated, where the FEA showed higher antimicrobial activity, against all the tested standard strains. Phytochemical investigation of the FEA extract yielded five prenylated benzaldehyde derivative compounds isolated for the first time from this species: Dihydroauroglaucin (1), tetrahydroauroglaucin (2), 2-(3,6-dihydroxyhepta-1,4-dien-1-yl)-3,6-dihydroxy-5-(dimethylallyl)benzaldehyde (3), isotetrahydroauroglaucin )4), and flavoglaucin (5). Structure elucidation was carried out using (1H- and 13C-NMR). Fractions and the major isolated compound 1 were evaluated for their antimicrobial and antibiofilm activity. Compound 1 showed high antimicrobial activity against Escherichia coli with minimum inhibitory concentration (MIC) = 1.95 µg/mL, Streptococcus mutans (MIC = 1.95 µg/mL), and Staphylococcus aureus (MIC = 3.9 µg/mL). It exhibited high antibiofilm activity with minimum biofilm inhibitory concentration (MBIC) = 7.81 µg/mL against Staphylococcus aureus and Escherichia coli biofilms and MBIC = 15.63 µg/mL against Streptococcus mutans and Candida albicans and moderate activity (MBIC = 31.25 µg/mL) against Pseudomonas aeruginosa biofilm. This reveals that dihydroauroglaucin, a prenylated benzaldehyde derivative, has a broad spectrum antimicrobial activity. In conclusion, it was observed that the MICs of the FEA are much lower than that of the AME against all susceptible strains, confirming that the antimicrobial activity of Ammi majus may be due to the ability of its endophytic fungi to produce effective secondary metabolites.

28 January 2020 in AMB Express
Verified
Journal Article
Open access
PDF file
NKNoha Hassan Khalil
Noha Hassan Khalil
SFSahar Fikry
Sahar Fikry
OSOsama Salama
Osama Salama
Myrrh is the resinous exudate obtained by the incision in Commiphora molmol trees (Family Burseraceae). The bactericidal activity of its hexane extract was compared to its essential oil (MEO) using viable count technique against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (Ps. aeruginosa). MEO exhibited a better activity with > 99.999% killing of both tested strains after 2 h contact time. MEO was tested using the same technique against four multidrug resistant isolates: S. aureus (MRSA, sputum), Escherichia coli (E. coli, urine), Ps. aeruginosa (wound) and Klebsiella pneumonia (K. pneumonia, sputum). Highest bactericidal activity was observed against Ps. aeruginosa while lowest was against K. pneumonia (99.59 and 54.04% killing, respectively after 2 h contact time). A cream and mouthwash were formulated using 5% v/v MEO. The cream showed a better activity against Ps. aeruginosa than S. aureus (95.11 and 86.76% killing, respectively after 2 h contact time). The in vitro treatment of ca 107 CFU/ml S. aureus cells suspended in 10% saliva with the mouthwash produced ca 46% killing within the first 15 min reaching ca 99.999% after 30 min. Cytotoxic studies of both the essential oil and hexane extract on human liver cancer (Hep G2), human breast cancer (MCF-7) and colon cancer cell lines (HCT-116) revealed a promising in vitro activity. Highest activity was recorded for the essential oil on MCF-7 with IC50 10.93 ± 0.32 μg/ml. GC/MS analysis allowed the identification of 17 and 9 compounds representing 92.01 and 99.99% of the hexane extract and essential oil, respectively. Furano-eudesma-1,3-diene (15.99%) and 2-acetoxy-furano-diene (26.82%) were the major identified compounds in the hexane extract and essential oil, respectively. These results indicate that Myrrh essential oil is a promising antibacterial and cytotoxic agent that can be formulated in suitable dosage forms.

26 March 2019 in AMB Express
Verified
Journal Article
Open access
PDF file
SFSahar Fikry
Sahar Fikry
NKNoha Hassan Khalil
Noha Hassan Khalil
OSOsama Salama
Osama Salama
Origanum vulgare L. (Lamiaceae) is a widespread flavoring culinary and medicinal herb. The present study aimed at investigating the antimicrobial activity of Origanum vulgare (OV) essential oil (EO) through illustrating its biostatic, biocidal and the dynamics of the biocidal activity against 11 different microorganisms. GC/MS of OV EO allowed the identification of 32 compounds representing 99.94% of the oil. The two major identified compounds were terpinen-4-ol (38.35%) and trans-sabinene hydrate (10.06%). Different methods were employed to illustrate the biostatic activity of OV EO. Results of the biostatic studies on OV EO using agar and broth dilution methods showed that Staphylococcus aureus (S. aureus) was the most sensitive organism; with a Minimum inhibitor concentration (MIC) 1.18 mg/ml. Agar diffusion method showed that the highest activity was observed against Bordetella bronchiseptica (Br. bronchiseptica), Saccharomyces cerevisiae (S. cerevisiae), Bacillus subtilis (B. subtilus) and Staphylococcus epidermidis (S. epidermidis) with inhibition zones 38 ± 1.5, 29.5 ± 0.8, 26.9 ± 0.9 and 26.9 ± 1.1 mm, respectively. Studying the dynamics of 1% v/v OV essential oil emulsion over a period of 6 h revealed that Escherichia coli (E. coli), B. subtilis, S. epidermidis and S. cerevisiae had the fastest response. Also increasing concentrations of OV oil emulsion increased the rate of cell killing and the duration of growth lag phase increased correspondingly. These data indicated that OV EO produces a concentration and time-dependent antimicrobial activity.