OBJECTIVES: This study aims (i) to investigate the effects of EGCG on nadolol pharmacokinetics (maximum plasma concentration, time to achieve maximum concentration, area under the time-plasma concentration curve, plasma half-life and total clearance) and subsequently its impact on blood pressure control; and (ii) to identify transcriptional regulatory roles of EGCG on the nadolol intestinal and hepatic drug-transporters in SHR.
METHODS: Male SHR were pre-treated with a daily dose of EGCG (10 mg/kg body weight, i.g.) for 13 days. On day-14, a single dose of nadolol (10 mg/kg body weight) was given to the rats 30 min after the last dose of EGCG administration. Systolic blood pressure (SBP) was measured at 6-h and 22-h post-nadolol administration. Plasma and urinary nadolol concentrations were quantified using high-performance liquid chromatography, and pharmacokinetic parameters were analyzed by using non-compartmental analysis. Hepatic and ileal Oatp1a5, P-gp, and Oct1 mRNA expressions were determined by real-time PCR.
RESULTS: SBP of SHR pre-treated with EGCG and received nadolol was significantly higher than those which were not pre-treated with EGCG but received nadolol. Pre-treatment of EGCG resulted in a marked reduction of plasma nadolol maximum concentration (Cmax) and area under the time-plasma concentration curve (AUC) by 53% and 51% compared to its control. The 14-day treatment with oral EGCG led to a significant downregulation of mRNA levels of ileal Oatp1a5, P-gp, and Oct1 genes by 4.03-, 8.01- and 4.03-fold; and hepatic P-gp, and Oct1 genes by 2.61- and 2.66-fold.
CONCLUSION: These data concluded that exposure to EGCG could lead to reduced nadolol bioavailability and therefore, uncontrolled raised blood pressure and higher risks of cardiovascular events. Our data suggest that the reduced nadolol bioavailability is associated with the downregulation of ileal Oatp1a5 and Oct1 mRNA levels that subsequently lead to poor absorption of nadolol to the systemic circulation.
METHODS: An analytical cross-sectional study using purposive sampling method was conducted at eight thalassemia societies in Peninsular Malaysia. 260 respondents comprised of patients and caregivers were assessed with two separate sets of questionnaires.
RESULTS: Knowledge on dietary iron among the respondents was unsatisfactory, despite them having good knowledge on thalassemia disorder. Female patients were found to have better dietary knowledge, attitude and practice compared to males. The percentage of caregivers with good attitude and good practice were significantly higher compared to adult patients. Caregivers with children on iron chelators were noted to have better dietary attitude and practice. Thalassemia knowledge and children on vitamins were found to be the predictors of dietary knowledge among the patients and caregivers respectively.
CONCLUSION: The level of knowledge on dietary iron among the patients and caregivers was unsatisfactory in spite of their attitude and practice towards dietary iron were good. Effective delivery of dietary information to the patients and caregivers is essential to enable them to choose a healthy diet for their condition.
OBJECTIVE: Formulation of methacrylic acid-methyl methacrylate copolymer-coated capsules filled with chitosan nanoparticles loaded with rHuKGF for oral delivery.
METHODS: We report on chitosan nanoparticles (CNPs) with diameter < 200 nm, prepared by ionic gelation, loaded with rHuKGF and filled in methacrylic acid-methyl methacrylate copolymercoated capsules for oral delivery. The pharmacokinetic parameters were determined based on the serum levels of rHuKGF, following a single intravenous (IV) or oral dosages using a rabbit model. Furthermore, fluorescent microscope imaging was conducted to investigate the cellular uptake of the rhodamine-labelled rHuKGF-loaded nanoparticles. The proliferation effect of the formulation on FHs 74 Int cells was studied as well by MTT assay.
RESULTS: The mucoadhesive and absorption enhancement properties of chitosan and the protective effect of methacrylic acid-methyl methacrylate copolymer against rHuKGF release at the stomach, low pH, were combined to promote and ensure rHuKGF intestinal delivery and increase serum levels of rHuKGF. In addition, in-vitro studies revealed the protein bioactivity since rHuKGFloaded CNPs significantly increased the proliferation of FHs 74 Int cells.
CONCLUSION: The study revealed that oral administration of rHuKGF-loaded CNPs in methacrylic acid-methyl methacrylate copolymer-coated capsules is practically alternative to the IV administration since the absolute bioavailability of the orally administered rHuKGF-loaded CNPs, using the rabbit as animal model, was 69%. Fluorescent microscope imaging revealed that rhodaminelabelled rHuKGF-loaded CNPs were taken up by FHs 74 Int cells, after 6 hours' incubation time, followed by increase in the proliferation rate.