Anti-Neoplastic Effects of Annonacin against Renal Cell Carcinoma

Background and Objectives: Renal cell carcinoma is the most common and lethal form of all renal cancers, and accounts for 4.1% of all cancer cases in Qatar. Mutations to Von-Hippel Lindeau (VHL) gene in renal cells activates hypoxia inducible factor-1 alpha (HIF-1?) response pathway, and contributes to increased proliferation and progression to renal cell carcinoma. Hence, chemotherapeutic modalities available to treat renal cell carcinoma are targeted toward modulation of the VHL-HIF response pathway. Annonacin, a potent cytotoxic mono-tetrahydrofuran acetogenin found in Annonaceae plants, has been demonstrated to exert anticancer activity against breast cancer; however, its therapeutic potential against renal cell carcinoma is yet to be determined. Hence the objective of this study is to investigate anti-neoplastic potential of annonacin in renal carcinoma cells. Methods: We investigated the effect of annonacin - at concentrations ranging from 0.5 to 2 ?M - on cell viability (using MTT assay and Alamar blue assay), and the protein expression of markers of HIF signaling pathway (HIF-1?), mTOR pathway (Thr-389 phosphorylation of p70S6 kinase), cell cycle progression (p21 levels), and apoptosis (caspase-3 expression) in CaKi-2 cells, a human renal carcinoma cell line. The cells were treated with annonacin for 24 or 48 hours and assessed for the aforementioned parameters. Results: hour annonacin treatment caused a significant and dose-dependent decrease in the viability of CaKi-2 cells, i.e., 42% in 0.5 ?M, 36% in 1 ?M and 29% in 2 ?M annonacin treatment groups as compared to control set at 100%. This was further confirmed by Alamar blue assay, which revealed a significant decrease in the viability of CaKi-2 cells upon treatment with annonacin for 48 h. The expression of HIF-1? was reduced by 68% at 24 h in CaKi-2 cells treated with 2 ?M annonacin. In addition, the expression of p21 (a key molecule that inhibits transition of cells from G1 to S phase in cell cycle) was induced by 1.34-fold in 0.5 ?M annonacin-treated cells indicating an arrest in G1 phase of cell cycle. This was further confirmed through cell cycle analysis using Tali cytometer, in which annonacin treated groups (0.5 ?M and 1 ?M) showed cell cycle arrest at G1 phase, i.e., 57% of cells in G1 phase with 0.5 ?M annonacin treated vs. 7% of cells in G1 phase in control group. In addition, a dose-dependent decrease in the phosphorylation of p70S6 kinase (a downstream target of mTOR) was observed with annonacin treatment at both 24 and 48 h end-points. This suggests that treatment of annonacin has possibly led to the inhibition of mTOR, in addition to suppression of HIF-1? activation, and underscores the cross-talk between HIF pathway and mTOR signaling pathway in renal cell carcinoma. Conclusions: Our findings demonstrate that annonacin treatment (at concentrations ranging from 0.5 to 2 ?M) inhibits HIF-1? and mTOR activation and causes cell cycle arrest at G1 phase and induces apoptosis in renal cell carcinoma. These findings indicate that annonacin exerts anti-cancer effects via modulation of HIF and mTOR signaling pathways, resulting in alterations in the cell cycle and activation of apoptosis in renal cell carcinoma. In conclusion, our study for the first time unveils the therapeutic potential of annonacin to inhibit the progression of renal cell carcinoma. Further studies in vivo are required to establish its efficacy to treat patients with renal cell carcinoma.qscienc

Effect of Aqueous Extract of Passiflora edulis on Biochemical and Hematological Parameters of Wistar Albino Rats

Passiflora edulis is traditionally used in folk lore medicine for the treatment of various ailments. To validate its use in traditional medicine, it is important to evaluate its toxicity in the animal system. Therefore, this study aimed to evaluate the toxicological effects of oral administration of aqueous leaf extract of P. edulis in Wistar albino rats. Acute toxicity tests were conducted by the oral administration of 200, 500, 1000 and 2000 mg/kg body weight of the animal. In subacute study, they were administered with various doses of aqueous extract of P. edulis (100, 200, 300, and 400 mg/kg body weight) to evaluate its toxicity for a period of 7 days. The effect of aqueous extract of P. edulis on organ weight, hematological, renal, and hepatic markers were analyzed. In acute toxicity study, no mortality was seen with in 24 h of the administration of P. edulis extract. No signs of neurological and behavioral changes were noticed with in 72 h. In the subacute study, the extract intake has not changed the hematological parameters such as RBC, WBC, and platelets and it was also found that the plasma level of amino transferases, ALP, urea, uric acid and, creatinine were also not altered by the administration of P. edulis extract throughout the study. The weight of organ was found to be unaltered in all the doses selected. The acute toxicity study reveals that the oral administration of the extract was found to be safe up to the dose level of 2000 mg/kg. The subacute study indicates that the extract is safe on the bone marrow function and it is neither hepatotoxic nor nephrotoxic. This supports the safety use of the aqueous extract of P. edulis in pharmacological studies

Nuclear Receptor DHR96 Acts as a Sentinel for Low Cholesterol Concentrations in Drosophila melanogaster▿

All eukaryotic cells have to maintain cholesterol concentrations within defined margins in order to function normally. Perturbing cholesterol homeostasis can result in a wide range of cellular and systemic defects, including cardiovascular diseases, as well as Niemann-Pick and Tangier diseases. Here, we show that DHR96 is indispensable for mediating the transcriptional response to dietary cholesterol and that it acts as a key regulator of the Niemann-Pick type C gene family, as well as of other genes involved in cholesterol uptake, metabolism, and transport. DHR96 mutants are viable and phenotypically normal on a standard medium but fail to survive on diets that are low in cholesterol. DHR96 mutants have aberrant cholesterol levels, demonstrating a defect in maintaining cholesterol homeostasis. Remarkably, we found that a high-cholesterol diet phenocopied the genomic profile of the DHR96 mutation, indicating that DHR96 resides at the top of a genetic hierarchy controlling cholesterol homeostasis in insects. We propose a model whereby DHR96 is activated when cellular cholesterol concentrations drop below a critical threshold in order to protect cells from severe cholesterol deprivation

Retinopathy of Type 1 Diabetes in Arab Countries: Systematic Review and Meta-Analysis.

To conduct a systematic review and meta-analysis of retinopathy prevalence in patients with type 1 diabetes (T1D) in 22 Arab countries. We systematically searched 4 different literature databases (PubMed, Science Direct, Web of Science and Embase), from the date of inception until December 2017, to collect all the information about patients with T1D who developed retinopathy complications; for statistical analysis, we used MetaXL to evaluate the pooled prevalence estimate and the subgroup prevalence estimates employing double arcsine transformation and inverse variance heterogeneity models. Our search strategy returned 475 studies, of which 39 met our inclusion criteria; of those, 16 were eligible for meta-analysis that were captured only in 15 Arab countries, through 45 years (1969-2014). The number of retinopathy patients was 396 out of 1,931 patients with T1D. The prevalence of retinopathy was 19% (95% CI 10-28%). Substantial heterogeneity was observed (Q 240.78, p < 0.0001, I2 93.77%, 95% CI 91.35-95.52%); however, no single study considerably affected the overall pooled prevalence estimate. Almost one fifth of T1D patients in 15 Arab countries have diabetic retinopathy, therefore it is important to improve the care of patients with T1D and in Arab countries to avoid the development of such a devastating complication