Tamer M. Abdelghany

Critical adverse effects and frequent administration, three times per day, limit the use of flutamide (FLT) as a chemotherapeutic agent in the treatment of prostate cancer. Therefore, our research aimed to develop new cholesterol-based nanovesicles for delivering FLT to malignant cells in an endeavor to maximize its therapeutic efficacy and minimize undesired adverse effects. Draper–Lin small composite design was used to optimize the critical quality attributes of FLT-loaded niosomes and ensure the desired product quality. The influence of the selected four independent variables on mean particle size (Y₁), zeta potential (Y₂), drug entrapment efficiency (Y₃), and the cumulative drug release after 24 h (Y₄) was examined. The optimized nanovesicles were assessed for their in vitro cytotoxicity, ex-vivo absorption via freshly excised rabbit intestine as well as in vivo pharmacokinetics on male rats. TEM confirmed nanovescicles’ spherical shape with bilayer structure. Values of dependent variables were 748.6 nm, −48.60 mV, 72.8% and 72.2% for Y₁, Y₂, Y₃ and Y₄, respectively. The optimized FLT-loaded niosomes exerted high cytotoxic efficacy against human prostate cancer cell line (PC-3) with an IC₅₀ value of 0.64 ± 0.04 µg/mL whilst, it was 1.88 ± 0.16 µg/mL for free FLT. Moreover, the IC₅₀ values on breast cancer cell line (MCF-7) were 0.27 ± 0.07 µg/mL and 4.07 ± 0.74 µg/mL for FLT-loaded niosomes and free FLT, respectively. The permeation of the optimized FLT-loaded niosomes through the rabbit intestine showed an enhancement ratio of about 1.5 times that of the free FLT suspension. In vivo pharmacokinetic study displayed an improvement in oral bioavailability of the optimized niosomal formulation with AUC and C_max values of 741.583 ± 33.557 μg/mL × min and 6.950 ± 0.45 μg/mL compared to 364.536 ± 45.215 μg/mL × min and 2.650 ± 0.55 μg/mL for the oral FLT suspension. With these promising findings, we conclude that encapsulation of FLT in cholesterol-loaded nanovesicles enhanced its anticancer activity and oral bioavailability which endorse its use in the management of prostate cancer.

Curcumin and trans- cinnamaldehyde are acrolein-based Michael acceptor compounds that are commonly found in domestic condiments, and known to cause cancer cell death via redox mechanisms. Based on the structural features of these compounds we designed and synthesized several 2-cinnamamido-N-substituted-cinnamamide (bis-cinnamamide) compounds. One of the derivatives, ( Z )-2-[( E )-cinnamamido]-3-phenyl-N-propylacrylamide ( 1512) showed a moderate antiproliferative potency (HT116 cell line inhibition of 32.0 µM ± 2.6) with proven cellular activities leading to apoptosis. Importantly, 1512 exhibited good selectivity toxicity on cancer cells over noncancerous cells (IC ₅₀ of C-166 cell lines >100 µM), and low cancer cell resistance at 100 µM dose (growth rate 10.1±1.1%). We subsequently carried out structure activity relationship studies with 1512 . Derivatives with electron rich moiety at the aryl ring of the 2-aminocinnamaide moiety exhibited strong antiproliferative action while electron withdrawing groups caused loss of activity. Our most promising compound, 4112 [( Z )-3-(1 H -indol-3-yl)- N -propyl-2-[( E )-3-(thien-2-yl)propenamido)propenamide] killed cancer cells at IC ₅₀ = 0.89 ± 0.04 µM (Caco-2), 2.85 ± 1.5 (HCT-116) and 1.65 ± 0.07 (HT-29), while exhibiting much weaker potency on C-166 and BHK normal cell lines (IC ₅₀ = 71 ± 5.12 and 77.6 ± 6.2 µM, respectively). Cellular studies towards identifying the compounds mechanism of cytotoxic activities revealed that apoptotic induction occurs in part due to oxidative stress. Importantly, the compounds showed inhibition of cancer stem cells that are critical for maintaining the potential for self-renewal and stemness. The results presented here show discovery of Michael addition compounds that potently kill cancer cells by a defined mechanism, with minimal effect on normal noncancerous cell.

Cisplatin (CP) is one of the most effective chemotherapeutic agents. Unfortunately, CP‐induced nephrotoxicity hampered its use. This study aims to investigate the effect of vitamin E (Vit E) on CP‐induced nephrotoxicity. Male white albino rats were divided to four group's six rats each and received either, 1% tween 80 in normal saline or Vit E (75 mg/kg) per day for 14 consecutive days or a single injection of CP (6 mg/kg) alone or CP (6 mg/kg) together with Vit E (75 mg/kg per day for 14 consecutive days). Five days after the CP injection, rats were euthanized; blood samples were collected; kidneys were dissected; and biochemical, immunohistochemical, and histological examinations were performed. Our results revealed that CP treatment significantly increased serum levels of creatinine and urea. Moreover, reduced glutathione (GSH) content as well as superoxide dismutase (SOD) and catalase (CAT) activities were significantly reduced with concurrent increase in kidney malondialdehyde (MDA) content following CP treatment. Vit E successfully lowered serum levels of urea and creatinine, enhanced creatinine clearance and diuresis, and normalized relative kidney/body weight. Furthermore, Vit E successfully normalized renal MDA and nitrite concentrations, elevated GSH level, and restored CAT and SOD activities in renal tissues. Histopathological examination of rat kidney revealed that Vit E significantly mitigated CP‐induced renal damage. Importantly, administration of Vit E reduced kidney total platinum concentration indicating a role of platinum renal accumulation on the ability of Vit E to protect against CP nephrotoxicity.

Cisplatin (cis-diammine dichloroplatinum (II), CDDP) is a widely used drug for treatment of various types of cancers. However, CDDP-induced nephrotoxicity remains the main dose-limiting side effect. Retinoids are a group of vitamin A-related compounds that exert their effects through retinoid receptors activation. In this study, we investigated the effect of CDDP treatment on retinoic acid receptor-α (RAR-α) and retinoid X receptor-α (RXR-α) expression. In addition, we investigated the possible modulatory effects of RAR agonist, all-trans retinoic acid (ATRA), on CDDP-induced nephrotoxicity. Rats were treated with saline, DMSO, CDDP, ATRA, or CDDP/ATRA. Twenty-four hours after the last ATRA injection, rats were killed; blood samples were collected; kidneys were dissected; and biochemical, immunohistochemical, and histological examinations were performed. Our results revealed that CDDP treatment significantly increased serum levels of creatinine and urea, with concomitant decrease in serum albumin. Moreover, reduced glutathione (GSH) content as well as superoxide dismutase (SOD) and catalase (CAT) activities were significantly reduced with concurrent increase in kidney malondialdehyde (MDA) content following CDDP treatment. Furthermore, CDDP markedly upregulated tubular RAR-α, RXR-α, fibrin, and inducible nitric oxide synthase (iNOS) protein expression. Although administration of ATRA to control rats did not produce marked alterations in kidney function parameters, administration of ATRA to CDDP-treated rats significantly exacerbated CDDP-induced nephrotoxicity. In addition, CDDP/ATRA co-treatment significantly increased RAR-α, RXR-α, fibrin, and iNOS protein expression compared to CDDP alone. In conclusion, we report, for the first time, the crucial role of retinoid receptors in CDDP-induced nephrotoxicity. Moreover, our findings indicate that co-administration of ATRA with CDDP, although beneficial on the therapeutic effects, their deleterious effects on the kidney may limit their clinical use.

Methotrexate (MTX) is a widely used drug for treatment of rheumatic and autoimmune diseases as well as different types of cancer. One of the major side effects of MTX is hepatotoxicity. Retinoid receptors, including retinoid X receptor (RXR), and retinoic acid receptor (RAR) are vitamin A receptors that are highly expressed in the liver and regulate important physiological processes through regulation of different genes. In this study, we investigated the effect of MTX on RXR-α and RAR-α expression in the liver and the potential protective effects of all-trans retinoic acid (ATRA) in MTX-induced hepatotoxicity. Rats were randomly divided into five groups: The rates were treated with saline, DMSO, MTX (20 mg/kg/IP; single dose), ATRA (7.5 mg/kg/day, I.P), or MTX and ATRA. Rats were killed 24 h after the last ATRA injection. The liver tissues were dissected out, weighed, and subjected to histological, immunohistochemical, and biochemical examinations. Our results demonstrated that treatment with MTX resulted in significant decrease in reduced glutathione (GSH) content and superoxide dismutase (SOD) activity, with concomitant increase in ALT, AST, and MDA levels. In addition, MTX markedly downregulated the expression of both RXR-α and RAR-α, and changed the appearance of RXR-α to be very small speckled droplets. Treatment with ATRA significantly ameliorated MTX-induced effects on GSH, ALT, and MDA. Moreover, ATRA administration increased the expression and nuclear translocation of RXR-α in rat hepatocytes. In conclusion, our study revealed, for the first time, that retinoid receptors may play an important role in the MTX-induced hepatotoxicity.