Browsing by Author "Barre, Mohamed Soleiman"

Boswellia and Commiphara species are highly important aromatic plants belonging to the Burseraceae family. In the present study, three different species of these plants, Boswellia frereana (BF), Boswellia carterii (BC), and Commiphora myrrha (CM), were screened for their anti microbial activities. This research investigate the antibacterial activities of the crude extracts and essential oils obtained from the oleo gum resin against the cariogenic bacteria Streptococcus mutans (S. mutans), and Lactobacillus sp (L. sp.). Two different methods were used to extract bioactive compounds of the plant exudates: Organic solvent extraction was performed with Acetone, Methanol, and Hexane to produce crude extract while hydro distillation was used for essential oil extraction. The BF methanol extract exhibited the highest antimicrobial activity among the crude extracts with (10mm) inhibition zone for the two bacteria, followed by methanolic extract of CM (8mm) inhibition for S.mutans and (6mm) for L. sp respectively. However, BF essential oil displayed the best inhibition zone (16mm), where the other two essential oils (CM and BC) inhibition varied between 6mm and 2mm respectively. The BF and CM essential oils exhibited equal MIC (12.5μl/ml) and MBC (25μl/ml) on both bacteria species, while B. carterii essential oil gave two fold of these numbers (MIC 25μl/ml and MBC 50μl/ml) on S. mutans, but in the case of Lactobacillus sp it agreed with the other two essential oils. In organic solvents, the highest yield of crude extracts were 90% for BF and 80% for BC, yield of 10% was recorded on CM when hexane is used. Methanol extract of BF and BC were 65% and 68% while CM highest yield obtained on methanol was 30%. Acetone extracted 78% of BF, 60% of BC, and 22% of CM. Through hydro-distillation process, 8% of BF, 6% of CM, and 5% of BC essential oil was recovered. The hydro-distillation process was optimized in order to get the highest yield of BF essential oil. Following process optimization by FCCCD, with 13 runs of experiment, the highest BF essential oil production was achieved at 8.5%, using 10% solid/solvent ratio, and 3.5hours of distillation time, which slightly higher than the standard yield. Finally characterization of essential oil by Gas chromatography Mass spectrometry (GC-MS) revealed about 62 compounds present in the BF essential oil. The major chemical compounds in this oil are listed in Apendix F, where the β-Thujene, o-Cymene, and β-Phellandrene were found to be major components of the Boswellia frereana essential oil with estimation of 58.3%, 7.3% and 4.7% respectively. In the case of BC essential oil nearly 90 compounds were identified. However, some compounds exhibited significant quantities in the essential oil, where α-Pinene (44.82%), Sabinene (8.94%), D-Limonene (7.1%), o-Cymene (1.37%), Cyclohexene, 4-methyl-1-(1-methylethyl)- (4.26%), Neoisolongifolene (6.9%), and Acetic acid, octyl ester (4.43%) represent the major constituents of the oil (77.82%). Whereas, C. myrrha analysis revealed more than 100 different compounds mostly trace elements but, the most abundant compounds were; (1) d-α-Pinene at 3.74% (2) isofuranogermacrene at 33.5% (3) β-Elemene at 5.66% (4) Germacrene D 2.11% (5) α-Selinene 2.03%. These five compounds comprise nearly 50% of the essential oil chemical constituents. At the end of the study the B. frereana essential oil was selected as the best of all extracts for its high antibacterial activity and optimum yield of essential oil, compared to the other two oleo gum resins.

Boswellia carterii essential oil (BCEO) is considered a biologically important aromatic volatile oil for its antimicrobial and antioxidant activities. It is extracted from the harvested oleo gum resin, mostly by the hydro-distillation process. However, the delicacy and vulnerability of the BCEO to the environmental conditions (temperature, humidity, and extreme pH) reduced its biological activity tremendously. Hence, to overcome these challenges this research implemented the microencapsulation method of BCEO by the spray drying process. Chitosan, Polyethylene glycol (PEG), and Gum Arabic (GA) were compared for their encapsulating abilities of BCEO. Hence, the first two polymers showed less solubility in water and incompatibility to the spray drying process, respectively. Whereas the GA shows excellent water solubility and high compatibility with the spray drying process, hence, optimization of the process parameters was performed to obtain the best microencapsulation efficiency (EE). Effects of three factors i.e. inlet air temperature (IAT) feed flow rate (FFR) and aspirator (AS) on the quality of the micro-particles obtained were investigated. Hence, the BCEO Microparticles (mp) obtained by IAT, FFR, and AS at 160oC, 5-7ml/min, and 80-90%, respectively, show the highest EE (75%), the lowest moisture content (4%), and the best antimicrobial and antioxidant activities. Microparticles characterization analysis showed that it has good stability with (ζ-potential of -28mV), non-homogenous particle size, hence higher Polydispersity index (PDI >0.5), lower moisture content (4 to 12%), which is good for the prolonged shelf life of the particles. Furthermore, scanning electron microscopy (SEM), Thermogravimetric, and differential scanning calorimetry analysis (TGA & DSC) of the samples uncovered a spherical shape of the particles and their maximum degradation point of 300oC respectively. No functional group interaction was noticed between encapsulated BCEO and its coating GA polymer when Fourier transform infrared spectroscopy (FTIR) was implemented. Finally, the selected sample of BCEOmp has been tested for its biological (antimicrobial and antioxidant) activity, the DPPH method was implemented for antioxidant activity elucidation, hence, the gradient increase trend of the antioxidant activity is showing a dose-dependent phenomenon. The IC50 value of the Ascorbic acid (AA) was approximated at 7.5μg/mL, whereas the IC50 value of the microencapsulated BCEO was estimated at 9.79μg/ml. Moreover, the encapsulated BCEO exhibited a highly significant zone of inhibition (30±3mm), which are comparable to and even sometimes better than that of the Tetracycline drug (used as a positive control). Adding to that its minimum inhibitory and minimum bactericidal concentrations (MIC & MBC) (16 - 32 μg/mL and 32 - 60 μg/mL respectively) are highly significant, considering this is a crude EO and not a purified compound contrary to that of the standard drug. In conclusion, the BCEO's vulnerability to the environmental conditions could be overcome by implementing the microencapsulation method which protected the EO from surrounding environmental conditions. Moreover, the GA polymer exhibited excellent encapsulating properties.