Chemical Composition and Cytotoxic Activity of Eucalyptus torquata Luehm. and Eucalyptus salmonophloia F. Muell. Trunk Bark Essential Oils against Human SW620 and MDA-MB-231 Cancer Cell Lines

In recent years, there has been a growing interest in the screening of natural active ingredients from Eucalyptus essential oils because of their evident importance in practical utility and their undeniable therapeutic properties. Based on this, the aim of the present study was to investigate the chemical profile of the essential oils of the trunk bark of Eucalyptus torquata Luehm. (ETEO), and E. salmonophloia F. Muell. (ESEO), growing in Tunisia. The in vitro cytotoxic properties of the extracted EOs were also evaluated against two human cancer cell lines: breast carcinoma cell lines MDA-MB-231 and colorectal cancer cell lines SW620. The analysis by gas chromatography coupled with mass spectrometry (GC/MS) led to the identification of 32 compounds from the ETEO, with the dominant constituents being the monoterpenes trans-myrtanol (73.4 %) and myrtenol (4.7 %), and the apocarotene (E)-β-ionone (3.9 %). In the case of ESEO, 29 compounds were identified with trans-myrtanol (25.0 %), decanoic acid (22.1 %), nonanoic acid (9.8 %), γ-elemene (6.5 %), γ-maaliene (5.5 %), and α-terpineol (5.3 %) as the main components. The cytotoxicity of EOs against the two chosen cell lines was tested using Crystal Violet Staining (CVS) assay and 5-fluorouracil as a reference drug. The two EOs exhibited a significant dose-dependent inhibition against the viability of the used cell lines. Their inhibitory effects were particularly observed towards SW620 colon carcinoma cells with IC₅₀ values of 26.71±1.22 and 22.21±0.85 μg/mL, respectively, indicating that both oils were more cytotoxic for SW620 cells compared to MDA-MB-231 one.     

Immunogenicity of different stressed IgG monoclonal antibody formulations in immune tolerant transgenic mice

The presence of protein aggregates in biopharmaceutical formulations is of great concern for safety and efficacy reasons. The aim of this study was to correlate the type and amount of IgG monoclonal antibody aggregates with their immunogenic potential. IgG degradation was obtained by freeze-thawing cycles, pH-shift cycles, heating, shaking and metal-catalyzed oxidation. The size, amount, morphology and type of intermolecular bonds of aggregates, as well as structural changes and epitope integrity were characterized. These formulations were injected in mice transgenic (TG) for human genes for Ig heavy and light chains and their non-transgenic (NTG) counterparts. Anti-drug antibody (ADA) titers were determined by bridging ELISA. Both unstressed IgG and freeze-thawed formulation did not induce measurable ADA levels. A mild antibody response was obtained in a fairly small percentage of mice, when injected with shaken, pH-shifted and heated formulations. The metal-catalyzed oxidized IgG formulation was the most immunogenic one, in both ADA titers and number of responders. The overall titers of NTG responders were significantly higher than the ones produced by TG mice, whereas there was no significant difference between the overall number of TG and NTG responders. This study reinforces the important role of protein aggregates on immunogenicity of therapeutic proteins and provides new insight into the immunogenic potential of different types of IgG aggregates. The results indicate that the quality of the IgG aggregates has more impact on the development of an immune response than their quantity or size.     

3D Structure Prediction of Human β1-Adrenergic Receptor via Threading-Based Homology Modeling for Implications in Structure-Based Drug Designing

Dilated cardiomyopathy is a disease of left ventricular dysfunction accompanied by impairment of the β₁-adrenergic receptor (β₁-AR) signal cascade. The disturbed β₁-AR function may be based on an elevated sympathetic tone observed in patients with heart failure. Prolonged adrenergic stimulation may induce metabolic and electrophysiological disturbances in the myocardium, resulting in tachyarrhythmia that leads to the development of heart failure in human and sudden death. Hence, β₁-AR is considered as a promising drug target but attempts to develop effective and specific drug against this tempting pharmaceutical target is slowed down due to the lack of 3D structure of Homo sapiens β₁-AR (hsβADR1). This study encompasses elucidation of 3D structural and physicochemical properties of hsβADR1 via threading-based homology modeling. Furthermore, the docking performance of several docking programs including Surflex-Dock, FRED, and GOLD were validated by re-docking and cross-docking experiments. GOLD and Surflex-Dock performed best in re-docking and cross docking experiments, respectively. Consequently, Surflex-Dock was used to predict the binding modes of four hsβADR1 agonists. This study provides clear understanding of hsβADR1 structure and its binding mechanism, thus help in providing the remedial solutions of cardiovascular, effective treatment of asthma and other diseases caused by malfunctioning of the target protein.     

Salicylic acid is important for basal defense of Solanum tuberosum against Phytophthora infestans

The importance of the signaling compound salicylic acid for basal defense of potato (Solanum tuberosum L. cv. Désirée) against Phytophthora infestans, the causal agent of late blight disease, was assessed using transgenic NahG potato plants which are unable to accumulate salicylic acid. Although the size of lesions caused by P. infestans was not significantly different in wild-type and transgenic NahG plants, real-time polymerase chain reaction analyses revealed a drastic enhancement of pathogen growth in potato plants depleted of salicylic acid. Increased susceptibility of NahG plants correlated with compromised callose formation and reduced early defense gene expression. NahG plants pretreated with the salicylic acid analog 2,6-dichloro-isonicotinic acid allowed pathogen growth to a similar extent as did wild-type plants, indicating that salicylic acid is an important compound required for basal defense of potato against P. infestans.     

The freshwater planarian Dugesia sicula Lepori, 1948 (Platyhelminthes, Tricladida) in Tunisia: ecology, karyology, and morphology

A study was carried out on freshwater planarians of the genus Dugesia from three localities in northern Tunisia: Joumine, Chiba, and Lebna. The three populations are fissiparous under field conditions and do not possess reproductive organs, except for some cases of hyperplastic ovaries in the Joumine population. After five months of breeding under laboratory conditions, with water temparature between 18 and 25?°C and under short photoperiod, 8.33 to 26% of specimens from the Joumine stream became sexualized, together with considerable increase of body length and width. For the other two populations the sexualization rate was very small. Extended period of darkness apparently played a positive role in this sexualization. The phenomenon of sexualization is discussed in the context of reproductive strategies. Histological and karyological studies of the sexualized animals allowed identification of these usually fissiparous planarians as representatives of Dugesia sicula Lepori, 1948. The species is here reported for the first time from Tunisia. The populations are restricted to permanent water basins resulting from the construction of dams in large rivers.     

Simultaneous determination of urinary CEA, ferritin and TPA in Egyptian bladder cancer patients.

Urinary carcinoembryonic antigen (CEA), ferritin (Fer) and tissue polypeptide antigen (TPA) were determined in 328 cases (106 with bladder cancer, 152 with non-malignant urinary tract disease and 70 healthy controls). CEA was determined by the kit supplied by Roche Diagnostica (CEA EIA Doumab 60), ferritin by the Tandem-E Fer kit supplied by Hybritech and TPA by the Prolifigen TPA-IRMA kit supplied by Sangtec Medical. The results of this work revealed that combined determination of urine CEA and Fer, CEA and TPA or Fer and TPA showed higher sensitivity than determination of the individual markers. There was no significant difference between combined and individual marker determination with respect to false positivity in non-malignant urinary tract diseases. At 97% specificity, the sensitivities of urine CEA, Fer and TPA were 82.1%, 71.7% and 90.6%, respectively, while combined urine CEA & Fer, CEA & TPA and Fer & TPA showed sensitivities of 92.5%, 99.1% and 98.1%, respectively. When the specificity was related to the entire non-cancer group (patients with benign urinary tract diseases and normal controls), some reduction in the sensitivities of the combined markers was noted compared to the normal group only. In conclusion, combined determination of urine markers is superior to determination of individual markers in the diagnosis of bladder cancer.