scholarly journals A COMPARlTlVE STUDY ON THE IN VlTRO HEPATIC METABOLISM OF RETlNOlC ACID USING DIFFERENT SPECIES

2004 ◽  
Vol 72 (4) ◽  
pp. 265-274
Author(s):  
MOBASHER AHMAD ◽  
O.A. AL-SHABANAH

All trans retinoic acid (RA), derived from the oxidative metabolism of dietary retinol (vitamin A) and β carotene, contributes to the growth and differentiation of mammalian epithelial tissues. RA is rapidly cleared from the plasma and sudenly metabolized in tissues. The increase of its biological potency through inhibition of its oxidative metabolism is consistent with this.This research is part of a study to develop novel compounds as inhibitors of retinoic acid metabolism that could have potential value as anticancer agent. The investigation was done to compare the in vitro metabolism of [3H]RA by hepatic m icrosomes from several common laboratory animal species. Also, the ability of ketaconazole to inhibit RA metabolism was examined. The species studied were male rat, male New Zealand white rabbit, male albino mouse, male Syrian hamster, male Dunkin hartley guinea pig and male nude mouse. The results revealed that km and Vmax were species dependent. Among the animals, rat liver appeared to be the most active in metabolizing RA. Inhibition of RA metbolism by ketoconazole (100 µM) was very similar in the hepatic microsomes of all the species examine. Overall the results indicate that male rat hepatic microsomes represent a useful enzyme source for screening novel compounds as inhibitors of RA metabolism.

2020 ◽  
Vol 8 (6) ◽  
pp. 495-510
Author(s):  
Manoj Kumar ◽  
Garima Sharma ◽  
Dinesh Singla ◽  
Sukhjeet Singh ◽  
Vandita Kakkar ◽  
...  

Background:: All-trans retinoic acid (ATRA) is widely employed in the treatment of various proliferative and inflammatory diseases. However, its therapeutic efficacy is imperiled due to its poor solubility and stability. Latter was surmounted by its incorporation into a solid matrix of lipidic nanoparticles (SLNs). Methods:: ATRA loaded SLNs (ATRA-SLNs) were prepared using a novel microemulsification technique (USPTO 9907758) and an optimal composition and were characterized in terms of morphology, differential scanning calorimetry (DSC), and powder X-ray diffraction studies (PXRD). In vitro release, oral plasma pharmacokinetics (in rats) and stability studies were also done. Results:: Rod-shaped ATRA-SLNs could successfully incorporate 3.7 mg/mL of ATRA, increasing its solubility (from 4.7 μg/mL) by 787 times, having an average particle size of 131.30 ± 5.0 nm and polydispersibility of 0.283. PXRD, DSC, and FTIR studies confirmed the formation of SLNs. Assay/total drug content and entrapment efficiency of ATRA-SLNs was 92.50 ± 2.10% and 84.60 ± 3.20% (n=6), respectively, which was maintained even on storage for one year under refrigerated conditions as an aqueous dispersion. In vitro release in 0.01 M phosphate buffer (pH 7.4) with 3% tween 80 was extended 12 times from 2h for free ATRA to 24 h for ATRA-SLNs depicting Korsmeyer Peppas release. Oral administration in rats showed 35.03 times enhanced bioavailability for ATRA-SLNs. Conclusion:: Present work reports preparation and evaluation of bioenhanced ATRA-SLNs containing a high concentration of ATRA (>15 times than that reported by others). Latter is attributed to the novel preparation process and intelligent selection of components. Lay Summary: All-trans retinoic acid (ATRA) shows an array of pharmacological activities but its efficacy is limited due to poor solubility, stability and side effects. In present study its solubility and efficacy is improved by 787 and 35.5 times, respectively upon incorporation into solid lipid nanoparticles (ATRA-SLNs). Latter extended its release by 12 times and provided stability for at least a year under refrigeration. A controlled and sustained release will reduce dose related side effects. ATRA-SLNs reported presently can thus be used in treatment /prophylaxis of disorders like cancers, tuberculosis, age related macular degeneration and acne and as an immune-booster.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1202
Author(s):  
Bojjibabu Chidipi ◽  
Syed Islamuddin Shah ◽  
Michelle Reiser ◽  
Manasa Kanithi ◽  
Amanda Garces ◽  
...  

In the heart, mitochondrial homeostasis is critical for sustaining normal function and optimal responses to metabolic and environmental stressors. Mitochondrial fusion and fission are thought to be necessary for maintaining a robust population of mitochondria, and disruptions in mitochondrial fission and/or fusion can lead to cellular dysfunction. The dynamin-related protein (DRP1) is an important mediator of mitochondrial fission. In this study, we investigated the direct effects of the micronutrient retinoid all-trans retinoic acid (ATRA) on the mitochondrial structure in vivo and in vitro using Western blot, confocal, and transmission electron microscopy, as well as mitochondrial network quantification using stochastic modeling. Our results showed that ATRA increases DRP1 protein levels, increases the localization of DRP1 to mitochondria in isolated mitochondrial preparations. Our results also suggested that ATRA remodels the mitochondrial ultrastructure where the mitochondrial area and perimeter were decreased and the circularity was increased. Microscopically, mitochondrial network remodeling is driven by an increased rate of fission over fusion events in ATRA, as suggested by our numerical modeling. In conclusion, ATRA results in a pharmacologically mediated increase in the DRP1 protein. It also results in the modulation of cardiac mitochondria by promoting fission events, altering the mitochondrial network, and modifying the ultrastructure of mitochondria in the heart.


1996 ◽  
Vol 93 (2) ◽  
pp. 392-393 ◽  
Author(s):  
R. DI NOTO ◽  
E. M. SCHIAVONE ◽  
C. LO PARDO ◽  
F. FERRARA ◽  
C. MANZO ◽  
...  

Blood ◽  
1998 ◽  
Vol 91 (7) ◽  
pp. 2452-2458 ◽  
Author(s):  
Hiromichi Matsushita ◽  
Masahiro Kizaki ◽  
Hiroyuki Kobayashi ◽  
Hironori Ueno ◽  
Akihiro Muto ◽  
...  

Complete remission is achieved in a high proportion of patients with acute promyelocytic leukemia (APL) after all-trans retinoic acid (RA) treatment, but most patients relapse and develop RA-resistant APL. We have previously reported that both RA-resistant HL-60 (HL-60R) and APL cells express P-glycoprotein and MDR1 transcripts; and these cells differentiate to mature granulocytes after culture with RA and P-glycoprotein antagonist. Ribozymes have been shown to be able to intercept a target RNA by catalytic activity. To address the role of MDR1 in overcoming RA-resistance in APL cells, we investigated the biologic effects of ribozymes against the MDR1 transcript in HL-60R cells. These ribozymes efficiently cleaved MDR1 mRNA at a specific site in vitro. The 196 MDR1 ribozyme was cloned into an expression vector, and stably transfected (HL-60R/196Rz) cells were obtained. Expression of MDR1 transcripts was decreased in HL-60R/196Rz cells compared with parental HL-60R and empty vector-transfected (HL-60R/neo) cells. Interestingly, RA inhibited cellular proliferation and induced differentiation of HL-60R/196Rz cells in a dose-dependent manner, suggesting reversal of drug resistance in HL-60R cells by the MDR1 ribozyme. These data are direct evidence that P-glycoprotein/MDR1 is responsible in part for acquired resistance to RA in myeloid leukemic cells. The MDR1 ribozyme may be a useful tool for investigating the biology of retinoid resistance and may have therapeutic potential for patients with RA-resistant APL.


Oncotarget ◽  
2016 ◽  
Vol 7 (29) ◽  
pp. 46028-46041 ◽  
Author(s):  
Farzaneh Atashrazm ◽  
Ray M. Lowenthal ◽  
Joanne L. Dickinson ◽  
Adele F. Holloway ◽  
Gregory M. Woods

2015 ◽  
Vol 26 (7) ◽  
pp. 763-773
Author(s):  
Muhammad N. Aslam ◽  
Shannon McClintock ◽  
Shazli P. Khan ◽  
Patricia Perone ◽  
Ronald Allen ◽  
...  

Development ◽  
1993 ◽  
Vol 117 (3) ◽  
pp. 835-845 ◽  
Author(s):  
K. Kawamura ◽  
K. Hara ◽  
S. Fujiwara

We have extracted retinoids from the budding tunicate Polyandrocarpa misakiensis and, using HPLC, identified some major peaks as cis-retinal, all-trans-retinal and all-trans-retinoic acid, of which cis-retinal was most abundant (~2 micromolar). In developing buds, the amount of cis-retinal was about one-fifth that of the adult animals. In those buds, aldehyde dehydrogenase, which could metabolize retinal in vitro, was expressed in epithelial cells and then in mesenchymal cells at the proximal extremity, that is, the future developmental field of the bud. Exogenous retinoic acid comparable to the endogenous level could induce an additional field at the distal end of the bud, resulting in a double monster. The induction always accompanied an ectopic expression of aldehyde dehydrogenase. The results of this work suggest that retinoic acid or related molecule(s) act as an endogenous trigger of morphallactic development of Polyandrocarpa buds.


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