Aziza M. Amer

Isolation of biologically active constituents from Moringa peregrina (Forssk.) Fiori. (family: Moringaceae) growing in Egypt

Background: Moringa peregrina is a wild plant that grown in the eastern desert mountains in Egypt. Although, this plant is native to Egypt, no details studies were traced on its chemical composition and biological activity. Materials and Methods: The different fractions of the ethanolic extract of the dried aerial parts of the plants were subjected to fractionation and purification on various silica and sephadex columns for the isolation of the major compounds which were tested for there anticancer activity. The aqueous and ethanolic extract as well as its different fractions were tested for antihyperglycemic effect on Streptozitocin-induced diabetes in rats. Results: Investigation of the different fractions of the ethanolic extract of the aerial parts of M. peregrina yielded lupeol acetate (1), β-amyrin (2), α-amyrin (3), β-sitosterol (4), β-sitosterol-3-O-glucoside (5), apigenin (6), rhamnetin (7), neochlorogenic acid (10), rhamnetin-3-O-rutinoside (12), and 6-methoxy-acacetin-8-C-β-glucoside (13) which were isolated for the first time from the plant. Compound (13) was isolated for the first time from genus Moringa. In addition, quercetin (8), chryseriol-7-O-rhamnoside (9) and quercetin-3-O-rutinoside (11) were also isolated. Identification has been established by spectral data (UV, MS, IR, 1H, 1H -1H COSY, and 13C-NMR). The major isolated compounds were found to have valuable cytotoxic activities against breast (MCF 7) and colon (HCT 116) cancer cell lines and their activities were comparable to the reference drug doxorubicin. On the other hand, the aqueous and ethanolic extracts as well as the n-hexane fraction were found to have potent antihyperglycemic effect on Streptozitocin-induced diabetes in rats. Conclusion: The Egyptian plant M. peregrina is rich in biologically active ingredients which showed potent cytotoxic activity and also its ethanolic extraxt exert a significant antihyperglycemic effect.

Pharmacokinetic and tissue distribution of doxycycline in broiler chickens pretreated with either: Diclazuril or halofuginone

Following IV injection of doxycycline in a dose of 20 mg kg(-1) b.wt., its serum concentration was best fitted in two-compartment open model in chickens fed either on control or on anticoccidials-containing rations. Diclazuril and halofuginone resulted in a significant short distribution half-life (t(½α)) (7.17±0.39 and 11.88±1.05 min, respectively) and increased total body clearance (Cl(tot)) 0.37±0.024 and 0.295±0.034 L/kg/h, respectively. Following oral dosing the tested drug absorbed with t(½ab) of 41.38±1.6, 17.48±0.86 and 41.83±1.8 min, respectively and their C(max) values (3.18±0.18, 5.425±0.48 and 0.986±0.037 μg/ml) were attained at 2.07±0.097, 1.403±0.074 and 2.55±0.106 h. For doxycycline alone and in presence of diclazuril and halofuginone, respectively. Systemic bioavailability was 22.64±3.46, 86.74±9.23 and 22.38±3.09%, respectively. Following IM injection t(½ab) were 9.096±1.34 for doxycycline alone, 16.24±2.21 and 15.6±1.7 min in the presence of diclazuril and halofuginone, respectively. C(max) was 3.10±0.28, 4.63±0.57 and 0.55±0.07 μg/ml reached at 0.8±0.083, 1.13±0.126 and 1.21±0.105 h. For the antibiotic alone, and in presence of either diclazuril and halofuginone, respectively. Systemic bioavailability was 22.41±3.86, 88.97±12.9 and 12.31±0.99% in chickens fed on anticoccidial-free, diclazuril- and halofuginone-containing rations, respectively. Both the tested anticoccidials induced higher doxycycline tissue residues in all tested tissue samples.

Effect of aflatoxicosis on the kinetic behaviour of ceftiofur in chickens

The kinetic behaviour of ceftiofur sodium was studied in aflatoxin treated chickens for 30 days and in non-treated chickens, following oral, intramuscular and intravenous administrations of 10 mg kg(-1) bodyweight of ceftiofur. Aflatoxicosis resulted in a more significant decrease in ceftiofur serum concentration in the treated than in non-treated chickens following oral and intravenous administrations. The kinetic behaviour showed that following intravenous injection the elimination half life time t0.5 (el) was significantly shorter in the treated chickens (1.75+/-0.03 hours) than in non-treated chickens (4.23+/-0.05 hours). Following oral administration, the kinetic behaviour revealed a longer absorption half-life [t0.5 (ab), 62.74+/-1.59 minutes] in the treated chickens than in non-treated (50.46+/-5.07 minutes), with lower Cmax 23.25+/-0.42 microg ml(-1) at long tmax (3.05+/-0.07 hour) in treated chickens than in non-treated (Cmax 27.83+/-1.28 at tmax 2.39+/-0.07 hours).

Effect of three anthelmentics on disposition kinetics of florfenicol in goats.

The pharmacokinetic aspects of florfenicol (FLO) were investigated via intravenous (I.V.) and intramuscular (I.M.) injections in five goats at a dose of 20 mg kg(-1) b.wt. Animals were pre-treated with albendazole orally in a dose of 2.5 mg kg(-1) b.wt, ivermectin or rafoxanide subcutaneously in a dose 0.2 and 7.5 mg kg(-1) b.wt, respectively. Florfenicol was injected intramuscularly two hours following anthelmentic administration and blood samples were taken by jugular venapuncture at standardized intervals. The concentrations of florfenicol (FLO) in serum were determined by high performance liquid chromatography (HPLC) method. The obtained results revealed that ivermectin administration did not induce a significant difference in serum florfenicol concentration between anthelmentic-treated and non-treated goats. On the other hand, goats pre-treated with rafoxanide or albendazole showed a significant decrease in serum florfenicol level as compared to non-anthementic treated goats. The absorption half-life (t(½ab)), C(max), AUMC, AUC and systemic bioavailability (F%) are significantly decreased, whereas elimination half-life (t(½el)) and MRT are increased in goats pre-treated by the three tested anthementics.

Prevalence and antimicrobial resistance profile of Staphylococcus species in chicken and beef raw meat in Egypt.

Coagulase-positive (CPS) and coagulase-negative (CNS) staphylococci cause staphylococcal food poisoning. Recently, CPS and CNS have received increasing attention due to their potential role in the dissemination of antibiotic resistance markers. The present study aimed to evaluate CPS and CNS species distribution and their antibiotic resistance profile isolated from chicken and beef meat. Fifty fresh, uncooked chicken parts and 50 beef meat cuts (local n=27; imported n=23) were used. One hundred staphylococcal isolates belonging to 11 species were isolated and identified from chicken (n=50) and beef (n=50) raw meat samples. Staphylococcus hyicus (26/100), lugdunensis (18/100), aureus (15/100) and epidermidis (14/100) were dominant. S. aureus was 100% resistant to penicillin and sulfamethoxazole/trimethoprim. Vancomycin-resistant S. aureus showed intermediate resistance (51%), which might indicate the dissemination of vancomycin resistance in the community and imply food safety hazards. The percentage of resistance to β-lactams was variable, with the highest resistance being to penicillin (94%) and lowest to ampicillin-sulbactam (22%). Antimicrobial resistance was mainly against penicillin (94%), clindamycin (90%) and sulfamethoxazole/trimethoprim (82%). The results indicate that chicken and beef raw meat are an important source of antibiotic-resistant CPS and CNS.

Antimicrobial Resistance, Biofilm Formation and mecA Characterization of Methicillin-Susceptible S. aureus and Non-S. aureus of Beef Meat Origin in Egypt

Methicillin-resistant Staphylococcus aureus (MRSA) have been found in various farm animal species throughout the world. Yet, methicillin-susceptible S. aureus (MSSA), methicillin-susceptible non-S. aureus (MS-NSA), and methicillin-resistant non-S. aureus (MR-NSA) were not investigated. Therefore, we persued to determine the diversity in their phenotypic virulence assay, phenotypic antimicrobial resistance profile and molecular characterization in one of the food chains in Egypt. Samples were collected during 2013 from beef meat at retail. Twenty seven isolates comprising five species (S. hyicus, S. aureus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus) were characterized for their antibiotic resistance phenotypic profile and antibiotic resistance genes (mecA, cfr, gyrA, gyrB, and grlA). Out of the 27 Staphylococcus isolates only one isolate was resistant to the 12 antibiotics representing nine classes. Raw beef meat sold across the Great Cairo zone, contains 66.7% of MRS, with highest prevalence was reported in S. aureus (66.7%), while the MRS non-S. aureus strains constituted 66.7% from which S. hyicus (60%), S. intermedius (33.3%), S. schleiferi subsp. coagulans (100%), and S. lentus (100%) were MRS. Seven S. aureus, six S. hyicus, four S. schleiferi subsp. coagulans, three S. intermedius, and one S. lentus isolates although being resistant to oxacillin yet, 11/27 (40.7%) carried the mecA gene. At the same time, the cfr gene was present in 2 of the nine S. aureus isolates, and totally undetectable in S. hyicus, S. schleiferi subsp. coagulans, S. intermedius, and S. lentus. Although, global researches largely focused into MRSA and MR-NSA in animals on pigs, the analysis of our results stipulates, that buffaloes and cattle could be MRSA dispersers and that this theme is not specific to pigs. Detection of MSSA virulence determinants is a must, as although oxacillin resistance may be absent yet, the MSSA may carry the virulence determinants which could be a source of perilous S. aureus for the human community.

Pharmacokinetics of chloramphenicol in normal and Escherichia coli infected chickens

1. Disposition kinetics were compared in healthy chickens and in chickens naturally infected with E. coli following the intravenous, intramuscular and oral administration of chloramphenicol in a single dose of 20 mg/kg body weight. 2. Lower serum chloramphenicol concentration in diseased chickens were reported after intravenous injection, but they were higher than normal 30 min after intramuscular and oral administration. Following intravenous injection the volume of distribution was increased in diseased chickens. 3. The biological half-life in normal chickens was 8.32 +/- 0.5 h and was prolonged in diseased birds (26.21 +/- 0.2 h). The body clearance of chloramphenicol was reduced in diseased chickens. 4. The rate of absorption of chloramphenicol was delayed after administration via the oral route but the extent of absorption was increased. The maximum concentration was higher and it was reached after a longer time in diseased than in normal chickens after administration by both intramuscular and oral routes.

Effect of chronic lead intoxication on the distribution and elimination of amoxicillin in goats.

A study of amoxicillin pharmacokinetics was conducted in healthy goats and goats with chronic lead intoxication. The intoxicated goats had increased serum concentrations of liver enzymes (alanine aminotransferase and γ-glutamyl transferase), blood urea nitrogen, and reactivated δ-aminolevulinic acid dehydratase compared to the controls. Following intravenous amoxicillin (10 mg/kg bw) in control and lead-intoxicated goats, elimination half-lives were 4.14 and 1.26 h, respectively. The volumes of distribution based on the terminal phase were 1.19 and 0.38 L/kg, respectively, and those at steady-state were 0.54 and 0.18 L/kg, respectively. After intramuscular (IM) amoxicillin (10 mg/kg bw) in lead-intoxicated goats and control animals, the absorption, distribution, and elimination of the drug were more rapid in lead-intoxicated goats than the controls. Peak serum concentrations of 21.89 and 12.19 µg/mL were achieved at 1 h and 2 h, respectively, in lead-intoxicated and control goats. Amoxicillin bioavailability in the lead-intoxicated goats decreased 20% compared to the controls. After amoxicillin, more of the drug was excreted in the urine from lead-intoxicated goats than the controls. Our results suggested that lead intoxication in goats increases the rate of amoxicillin absorption after IM administration and distribution and elimination. Thus, lead intoxication may impair the therapeutic effectiveness of amoxicillin.