Displaying publications 81 - 100 of 238 in total

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  1. Mollataghi A, Hadi AH, Awang K, Mohamad J, Litaudon M, Mukhtar MR
    Molecules, 2011 Aug 04;16(8):6582-90.
    PMID: 21818061 DOI: 10.3390/molecules16086582
    A new neolignan, 3,4-dimethoxy-3',4'-methylenedioxy-2,9-epoxy-6,7-cyclo-1,8-neolign-11-en-5(5H)-one, which has been named (+)-kunstlerone (1), together with six known alkaloids: (+)-norboldine (2), (+)-N-methylisococlaurine (3), (+)-cassythicine (4), (+)-laurotetanine (5), (+)-boldine (6) and (-)-pallidine (7), were isolated from the leaves of Beilschmiedia kunstleri. The structures were established through various spectroscopic methods notably 1D- and 2D-NMR, UV, IR and LCMS-IT-TOF. (+)- Kunstlerone (1) showed a strong antioxidant activity, with an SC(50) of 20.0 µg/mL.
  2. Nugroho AE, Wong CP, Hirasawa Y, Kaneda T, Tougan T, Horii T, et al.
    J Nat Med, 2023 Jun;77(3):596-603.
    PMID: 37162697 DOI: 10.1007/s11418-023-01706-w
    Ceramicines are a series of limonoids that were isolated from the bark of Malaysian Chisocheton ceramicus (Meliaceae) and were known to show various biological activity. Four new limonoids, ceramicines Q-T (1-4) were isolated from the barks of C. ceramicus, and their structures were determined on the basis of the 1D and 2D NMR analyses in combination with calculated 13C chemical shift data. Ceramicines Q-T (1-4) were established to be new limonoids with a cyclopentanone[α]phenanthren ring system with a β-furyl ring at C-17, and without a tetrahydrofuran ring like ceramicine B, which is characteristic of known ceramicines. Ceramicine R (2) exhibited potent antimalarial activity against Plasmodium falciparum 3D7 strain with IC50 value of 2.8 µM.
  3. Hasan SS, Kow CS, Hadi MA, Zaidi STR, Merchant HA
    Am J Cardiovasc Drugs, 2020 Dec;20(6):571-590.
    PMID: 32918209 DOI: 10.1007/s40256-020-00439-5
    INTRODUCTION: The use of renin-angiotensin system (RAS) inhibitors, including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), was alleged to cause a more severe course of novel coronavirus disease 2019 (COVID-19).

    METHODS: We systematically reviewed the published studies to assess the association of RAS inhibitors with mortality as well as disease severity in COVID-19 patients. A systematic literature search was performed to retrieve relevant original studies investigating mortality and severity (severe/critical disease) in COVID-19 patients with and without exposure to RAS inhibitors.

    RESULTS: A total of 59 original studies were included for qualitative synthesis. Twenty-four studies that reported adjusted effect sizes (24 studies reported mortality outcomes and 16 studies reported disease severity outcomes), conducted in RAS inhibitor-exposed and unexposed groups, were pooled in random-effects models to estimate overall risk. Quality assessment of studies revealed that most of the studies included were of fair quality. The use of an ACEI/ARB in COVID-19 patients was significantly associated with lower odds (odds ratio [OR] = 0.73, 95% confidence interval [CI] 0.56-0.95; n = 18,749) or hazard (hazard ratio [HR] = 0.75, 95% CI 0.60-0.95; n = 26,598) of mortality compared with non-use of ACEI/ARB. However, the use of an ACEI/ARB was non-significantly associated with lower odds (OR = 0.91, 95% CI 0.75-1.10; n = 7446) or hazard (HR = 0.73, 95% CI 0.33-1.66; n = 6325) of developing severe/critical disease compared with non-use of an ACEI/ARB.

    DISCUSSION: Since there was no increased risk of harm, the use of RAS inhibitors for hypertension and other established clinical indications can be maintained in COVID-19 patients.

  4. Golbabapour S, Majid NA, Hassandarvish P, Hajrezaie M, Abdulla MA, Hadi AH
    OMICS, 2013 Jun;17(6):283-96.
    PMID: 23692361 DOI: 10.1089/omi.2012.0105
    DNA methylation, histone modifications, and chromatin configuration are crucially important in the regulation of gene expression. Among these epigenetic mechanisms, silencing the expression of certain genes depending on developmental stage and tissue specificity is a key repressive system in genome programming. Polycomb (Pc) proteins play roles in gene silencing through different mechanisms. These proteins act in complexes and govern the histone methylation profiles of a large number of genes that regulate various cellular pathways. This review focuses on two main Pc complexes, Pc repressive complexes 1 and 2, and their phylogenetic relationship, structures, and function. The dynamic roles of these complexes in silencing will be discussed herein, with a focus on the recruitment of Pc complexes to target genes and the key factors involved in their recruitment.
  5. Amin ZA, Bilgen M, Alshawsh MA, Ali HM, Hadi AH, Abdulla MA
    PMID: 22649471 DOI: 10.1155/2012/241583
    A preclinical study was performed to determine if the extract from Phyllanthus niruri (PN) plays a protective role against liver cirrhosis induced by thioacetamide (TAA) in rats. Initially, acute toxicity was tested and the results showed that the extract was benign when applied to healthy rats. Next, the therapeutic effect of the extract was investigated using five groups of rats: control, TAA, silymarin, and PN high dose and low dose groups. Significant differences were observed between the TAA group and the other groups regarding body and liver weights, liver biochemical parameters, total antioxidant capacity, lipid peroxidation, and oxidative stress enzyme levels. Gross visualization indicated coarse granules on the surface of the hepatotoxic rats' livers, in contrast to the smoother surface in the livers of the silymarin and PN-treated rats. Histopathological analysis revealed necrosis, lymphocytes infiltration in the centrilobular region, and fibrous connective tissue proliferation in the livers of the hepatotoxic rats. But, the livers of the treated rats had comparatively minimal inflammation and normal lobular architecture. Silymarin and PN treatments effectively restored these measurements closer to their normal levels. Progression of liver cirrhosis induced by TAA in rats can be intervened using the PN extract and these effects are comparable to those of silymarin.
  6. Rabeea SA, Merchant HA, Khan MU, Kow CS, Hasan SS
    Daru, 2021 Jun;29(1):217-221.
    PMID: 33715138 DOI: 10.1007/s40199-021-00390-z
    The social restrictions amid coronavirus disease 2019 (COVID-19) pandemic have posed a serious threat to mental health and have implications in the use of medications for mental health including antidepressants (ADs). This study investigated the trends in prescriptions and costs of various ADs in England during COVID-19 pandemic. National prescribing rates and net ingredient costs (NIC) of all ADs prescriptions during 2016 to 2020 were analyed. The total number of ADs prescriptions dispensed during COVID-19 pandemic (January to December 2020) were 78 million, 4 million more than in 2019 that costed NHS England £ 139 million more than in 2019. Sertraline, an SSRI antidepressant drug, alone accounted for an extra £113 million during 2020 than in 2019. The peak dispensing for ADs was observed in March 2020 while the total costs for AD drugs peaked in April 2020. The rising prescription costs for ADs during COVID-19 pandemic is a potential cause of concern, in particular the increasing use in adolescents and younger adults needs attention, who are at a higher risk of life-threatening adverse drug reactions.
  7. Saadi S, Saari N, Anwar F, Abdul Hamid A, Ghazali HM
    Biotechnol Adv, 2014 12 12;33(1):80-116.
    PMID: 25499177 DOI: 10.1016/j.biotechadv.2014.12.003
    The growing momentum of several common life-style diseases such as myocardial infarction, cardiovascular disorders, stroke, hypertension, diabetes, and atherosclerosis has become a serious global concern. Recent developments in the field of proteomics offering promising solutions to solving such health problems stimulates the uses of biopeptides as one of the therapeutic agents to alleviate disease-related risk factors. Functional peptides are typically produced from protein via enzymatic hydrolysis under in vitro or in vivo conditions using different kinds of proteolytic enzymes. An array of biological activities, including antioxidative, antihypertensive, antidiabetic and immunomodulating has been ascribed to different types of biopeptides derived from various food sources. In fact, biopeptides are nutritionally and functionally important for regulating some physiological functions in the body; however, these are yet to be extensively addressed with regard to their production through advance strategies, mechanisms of action and multiple biological functionalities. This review mainly focuses on recent biotechnological advances that are being made in the field of production in addition to covering the mode of action and biological activities, medicinal health functions and therapeutic applications of biopeptides. State-of-the-art strategies that can ameliorate the efficacy, bioavailability, and functionality of biopeptides along with their future prospects are likewise discussed.
  8. Zarei M, Ebrahimpour A, Abdul-Hamid A, Anwar F, Saari N
    Int J Mol Sci, 2012;13(7):8097-111.
    PMID: 22942692 DOI: 10.3390/ijms13078097
    The aim of this study was to produce a valuable protein hydrolysate from palm kernel cake (PKC) for the development of natural antioxidants. Extracted PKC protein was hydrolyzed using different proteases (alcalase, chymotrypsin, papain, pepsin, trypsin, flavourzyme, and bromelain). Subsequently, antioxidant activity and degree of hydrolysis (DH) of each hydrolysate were evaluated using DPPH• radical scavenging activity and O-phthaldialdehyde spectrophotometric assay, respectively. The results revealed a strong correlation between DH and radical scavenging activity of the hydrolysates, where among these, protein hydrolysates produced by papain after 38 h hydrolysis exhibited the highest DH (91 ± 0.1%) and DPPH• radical scavenging activity (73.5 ± 0.25%) compared to the other hydrolysates. In addition, fractionation of the most effective (potent) hydrolysate by reverse phase high performance liquid chromatography indicated a direct association between hydrophobicity and radical scavenging activity of the hydrolysates. Isoelectric focusing tests also revealed that protein hydrolysates with basic and neutral isoelectric point (pI) have the highest radical scavenging activity, although few fractions in the acidic range also exhibited good antioxidant potential.
  9. Hamid K, Yusoff A, Rahman M, Mohamad M, Hamid A
    Biomed Imaging Interv J, 2012 Apr;8(2):e13.
    PMID: 22970069 MyJurnal DOI: 10.2349/biij.8.2.e13
    This fMRI study is about modelling the effective connectivity between Heschl's gyrus (HG) and the superior temporal gyrus (STG) in human primary auditory cortices. MATERIALS #ENTITYSTARTX00026;
  10. Hussin M, Hamid AA, Mohamad S, Saari N, Bakar F, Dek SP
    J Food Sci, 2009 Mar;74(2):H72-8.
    PMID: 19323754 DOI: 10.1111/j.1750-3841.2009.01045.x
    A study was carried out to investigate the effects of Centella asiatica leaf on lipid metabolism of oxidative stress rats. The rats were fed 0.1% hydrogen peroxide (H(2)O(2)) with either 0.3% (w/w) C. asiatica extract, 5%C. asiatica powder (w/w), or 0.3% (w/w) alpha-tocopherol for 25 wk. Results of the study showed that C. asiatica powder significantly (P < 0.05) lowered serum low-density lipoprotein compared to that of control rats (rats fed H(2)O(2) only). At the end of the study C. asiatica-fed rats were also found to have significantly (P < 0.05) higher high-density lipoprotein and lower triglyceride level compared to rats fed only normal diet. However, cholesterol level of rats fed both C. asiatica extract and powder was found to be significantly (P < 0.05) higher compared to that of control rats. It was interesting to note that consumption of C. asiatica significantly decreased body and liver weights of the rats. Histological examinations revealed no obvious changes in all rats studied. Quantitative analysis of C. asiatica leaf revealed high concentration of total phenolic compounds, in particular, catechin, quercetin, and rutin.
  11. Pak-Dek MS, Abdul-Hamid A, Osman A, Soh CS
    J Food Sci, 2008 Oct;73(8):C595-8.
    PMID: 19019102 DOI: 10.1111/j.1750-3841.2008.00929.x
    Efficacy of Morinda citrifolia L. leaf (MLE) and fruit extracts (MFE) in inhibiting lipoprotein lipase (LPL) was determined in vitro. The result of the study showed that the highest inhibition on the LPL activity was exhibited by MLE (66%+/- 2.1%), which is significantly higher than that demonstrated by MFE (54.5%+/- 2.5%), green tea extract (GTE) (54.5%+/- 2.6%), and catechin (43.6%+/- 6.1%). Percent of LPL inhibition increase with concentration of the extracts. Quantitative analysis of the extracts revealed the presence of high levels of (+)-catechin at 63.5 +/- 17 and 53.7 +/- 5.7 mg/g in MLE and MFE, respectively, although not as high as that found in GTE (530.6 +/- 42 mg/g). Appreciable amount of epicatechin was found in all extracts tested, while rutin was only found in MLE and MFE. The study suggested that both leaf and fruit of M. citrifolia may be used as antiobesity agents in body weight management.
  12. Ghanbari R, Ebrahimpour A, Abdul-Hamid A, Ismail A, Saari N
    Int J Mol Sci, 2012;13(12):16796-811.
    PMID: 23222684 DOI: 10.3390/ijms131216796
    Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH) were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp.) were evaluated. Papain hydrolysis showed the highest DH value (89.44%), followed by alcalase hydrolysis (83.35%). Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions.
  13. Kazemi M, Karim R, Mirhosseini H, Abdul Hamid A
    Food Chem, 2016 Sep 1;206:156-66.
    PMID: 27041311 DOI: 10.1016/j.foodchem.2016.03.017
    Pomegranate peel is a rich source of phenolic compounds (such as punicalagin and hydroxybenzoic acids). However, the content of such bioactive compounds in the peel extract can be affected by extraction type and condition. It was hypothesized that the optimization of a pulsed ultrasound-assisted extraction (PUAE) technique could result in the pomegranate peel extract with higher yield and antioxidant activity. The main goal was to optimize PUAE condition resulting in the highest yield and antioxidant activity as well as the highest contents of punicalagin and hydroxybenzoic acids. The operation at the intensity level of 105W/cm(2) and duty cycle of 50% for a short time (10min) had a high efficiency for extraction of phenolics from pomegranate peel. The application of such short extraction can save the energy and cost of the production. Punicalagin and ellagic acid were the most predominant phenolic compounds quantified in the pomegranate peel extract (PPE) from Malas variety. PPE contained a minor content of gallic acid.
  14. Mohammad Naim N, Abdullah H, Umar AA, Abdul Hamid A, Shaari S
    ScientificWorldJournal, 2015;2015:696521.
    PMID: 26078996 DOI: 10.1155/2015/696521
    PANI-Ag-Fe nanocomposite thin films based electrochemical E. coli sensor was developed with thermal annealing. PANI-Ag-Fe nanocomposite thin films were prepared by oxidative polymerization of aniline and the reduction process of Ag-Fe bimetallic compound with the presence of nitric acid and PVA. The films were deposited on glass substrate using spin-coating technique before they were annealed at 300 °C. The films were characterized using XRD, UV-Vis spectroscopy, and FESEM to study the structural and morphological properties. The electrochemical sensor performance was conducted using I-V measurement electrochemical impedance spectroscopy (EIS). The sensitivity upon the presence of E. coli was measured in clean water and E. coli solution. From XRD analysis, the crystallite sizes were found to become larger for the samples after annealing. UV-Vis absorption bands for samples before and after annealing show maximum absorbance peaks at around 422 nm-424 nm and 426 nm-464 nm, respectively. FESEM images show the diameter size for nanospherical Ag-Fe alloy particles increases after annealing. The sensor performance of PANI-Ag-Fe nanocomposite thin films upon E. coli cells in liquid medium indicates the sensitivity increases after annealing.
  15. Alam MA, Juraimi AS, Rafii MY, Abdul Hamid A
    Biomed Res Int, 2015;2015:105695.
    PMID: 25802833 DOI: 10.1155/2015/105695
    13 selected purslane accessions were subjected to five salinity levels 0, 8, 16, 24, and 32 dS m(-1). Salinity effect was evaluated on the basis of biomass yield reduction, physiological attributes, and stem-root anatomical changes. Aggravated salinity stress caused significant (P < 0.05) reduction in all measured parameters and the highest salinity showed more detrimental effect compared to control as well as lower salinity levels. The fresh and dry matter production was found to increase in Ac1, Ac9, and Ac13 from lower to higher salinity levels but others were badly affected. Considering salinity effect on purslane physiology, increase in chlorophyll content was seen in Ac2, Ac4, Ac6, and Ac8 at 16 dS m(-1) salinity, whereas Ac4, Ac9, and Ac12 showed increased photosynthesis at the same salinity levels compared to control. Anatomically, stem cortical tissues of Ac5, Ac9, and Ac12 were unaffected at control and 8 dS m(-1) salinity but root cortical tissues did not show any significant damage except a bit enlargement in Ac12 and Ac13. A dendrogram was constructed by UPGMA based on biomass yield and physiological traits where all 13 accessions were grouped into 5 clusters proving greater diversity among them. The 3-dimensional principal component analysis (PCA) has also confirmed the output of grouping from cluster analysis. Overall, salinity stressed among all 13 purslane accessions considering biomass production, physiological growth, and anatomical development Ac9 was the best salt-tolerant purslane accession and Ac13 was the most affected accession.
  16. Nwe KH, Morat PB, Hamid A, Fadzilah S, Khalid BA
    Exp. Clin. Endocrinol. Diabetes, 1999;107(5):288-94.
    PMID: 10482040
    The 11beta-hydroxysteroid dehydrogenase (11beta-HSD) protects the testis from the inhibitory effects of corticosterone on testosterone (T) production. The objectives of the present studies were to determine the effects of deoxycorticosterone (DOC) and its mechanism of actions on testicular 11beta-HSD activity and plasma T levels after 7 days of treatment. The results revealed that at the end of 7 days treatment, DOC significantly increased testicular 11beta-HSD activity and plasma T levels in normal rats. However, the time course showed that high plasma T levels lowered 11beta-HSD activity on day 14 and by 21 days both the levels normalized. In adrenalectomized (ADX) rats, only the enzyme activity increased significantly but not plasma T levels. Spironolactone, a competitive inhibitor of mineralocorticoid receptor (MR), did not change testicular 11beta-HSD activity in both normal and DOC treated rats suggesting that DOC did not act through MR in increasing 11beta-HSD activity. On the other hand, spironolactone significantly decreased plasma T levels in DOC treated rats. Progesterone (P), a competitive inhibitor of glucocorticoid receptors (GR) or corticosterone significantly suppressed testicular enzyme activity and plasma T levels in DOC treated normal rats. Carbenoxolone which is an inhibitor of 11beta-HSD activity significantly depressed testicular 11beta-HSD activity and plasma T levels in DOC treated normal rats. This paper suggests that DOC increased testicular 11beta-HSD activity through GR; whilst increase in plasma T levels required functioning adrenal glands. The testicular 11beta-HSD is one of the regulators of T levels and vice versa.
  17. Raj SM, Yap K, Haq JA, Singh S, Hamid A
    Trans R Soc Trop Med Hyg, 2001 3 31;95(1):24-7.
    PMID: 11280057
    The Helicobacter pylori infection rate was determined in 124 consecutive patients with duodenal ulcers (DU), gastric ulcers (GU), duodenal erosions or gastric erosions diagnosed by endoscopy at a single institution in north-eastern peninsular Malaysia in 1996-97. Biopsies of the gastric antrum and body were subjected to the urease test, Gram staining of impression smears, culture and histopathological examination. Serology was undertaken on all patients using a locally validated commercial kit. Infection was defined as a positive result in at least one test. The infection rates were 20% (10/50), 21.2% (7/33), 16.7% (1/6) and 17.1% (6/35) in DU, GU, duodenal erosion and gastric erosion patients, respectively. The infection rate among Malays [7.0%, (6/86)] was lower than in non-Malays [47.4% (18/38)] (P < 0.001). There was a higher infection rate among males, who constituted 62.1% (77/124) of the sample. Seventy-eight patients (62.9%) were receiving non-steroidal anti-inflammatory drugs (NSAIDs) and 33 patients (26.6%) were neither receiving NSAIDs nor were infected with H. pylori. The H. pylori infection rate among peptic ulcer patients in this predominantly Malay rural population appears to be the lowest reported in the world thus far. Empirical H. pylori eradication therapy in peptic ulcer patients is clearly not indicated in this community. The possible reasons for the low prevalence of H. pylori infection are discussed.
  18. Sakai S, Momose K, Yumoto T, Nagamitsu T, Nagamasu H, Hamid AA, et al.
    Am J Bot, 1999 Oct;86(10):1414-36.
    PMID: 10523283
    The first systematic observation of a general flowering, a phenomenon unique to lowland mixed-dipterocarp forests in Southeast Asia, is presented. During general flowering, which occurs at irregular intervals of 3-10 yr, nearly all dipterocarp species together with species of other families come heavily into flower. We monitored reproductive phenology of 576 individual plants representing 305 species in 56 families in Sarawak, Malaysia. Observations continued for 53 mo from August 1992 and covered one episode of a general flowering cycle. Among 527 effective reproductive events during 43 mo, 57% were concentrated in the general flowering period (GFP) of 10 mo in 1996. We classified 257 species into flowering types based on timing and frequency of flowering. The most abundant type was "general flowering" (35%), which flowered only during GFP. The others were "supra-annual" (19%), "annual" (13%), and "sub-annual" (5%) types. General flowering type and temporal aggregation in reproductive events were commonly found among species in various categories of taxonomic groups, life forms, pollination systems, and fruit types. Possible causes for general flowering, such as promotion of pollination brought about by interspecific synchronization and paucity of climatic cues suitable for flowering trigger, are proposed, in addition to the predator satiation hypothesis of Janzen (1974).
  19. Nwe KH, Norhazlina AW, Hamid A, Morat PB, Khalid BA
    Exp. Clin. Endocrinol. Diabetes, 2000;108(5):369-77.
    PMID: 10989957
    The effects of stress and corticosterone on testicular 11beta-hydroxysteroid dehydrogenase (11beta-HSD) oxidative activity have been controversial, whilst that of adrenocorticotrophic hormone (ACTH) have not been investigated before. Hence, the aim of the present study was to determine the in vivo effects of stress due to injection and sham operation, ACTH and corticosterone on testicular and hepatic 11beta-HSD oxidative activity and plasma testosterone levels in normal and adrenalectomized (ADX) rats and their possible mechanism of actions. Adrenalectomy reduced both testicular 11beta-HSD oxidative activity and plasma testosterone levels. The effects of injection and sham operation significantly increased plasma corticosterone levels with decreased testicular 11beta-HSD oxidative activity and plasma testosterone levels in normal but not in ADX rats. Likewise. ACTH or corticosterone treatment for 7 days decreased both testicular 11beta-HSD oxidative activity in a dose dependent manner and plasma testosterone levels in normal rats; but the values in ADX rats remained unchanged. However, none of the above values were significantly lower than that of the ADX levels. Corticosterone seems to maintain testicular 11beta-HSD oxidative activity within the range between normal and ADX rats. These changes are not attributable to diurnal rhythms, as the time of sacrifice has been fixed between 8:30 and 10:30 am. In the liver, no significant change in 11beta-HSD oxidative activity was observed with sham operation, ACTH or corticosterone treatment; but adrenalectomy significantly decreased it. In conclusion, in the intact normal rats, stress, ACTH or corticosterone modulates testicular (but not hepatic) 11beta-HSD oxidative activity indirectly through the adrenal glands and the physiological level of corticosterone is ideal for normal reproductive functions.
  20. Nwe KH, Hamid A, Morat PB, Khalid BA
    Steroids, 2000 Jan;65(1):40-5.
    PMID: 10624835
    11Beta-hydroxysteroid dehydrogenase (11beta-HSD) Type I enzyme is found in testis and liver. In Leydig cell cultures, 11beta-HSD activity is reported to be primarily oxidative while another report concluded that is primarily reductive. Hepatic 11beta-HSD preferentially catalyzes reduction and the reaction direction is unaffected by the external factors. Recent analysis of testicular 11beta-HSD revealed two kinetically distinct components. In the present study, various steroid hormones or glycyrrhizic acid (GCA), given for 1 week, or thyroxine given for 5 weeks to normal intact rats had different effects on the 11beta-HSD oxidative activity in testis and liver. Deoxycorticosterone, dexamethasone, progesterone, thyroxine, and clomiphene citrate increased testicular 11beta-HSD oxidative activity, but decreased hepatic enzyme activity except for deoxycorticosterone (unchanged). Corticosterone and testosterone decreased 11beta-HSD oxidative activity in testis but not that of liver (which was unchanged). Estradiol, GCA and adrenalectomy lowered oxidative activity of 11beta-HSD in testis and liver, but the degrees of reduction were different. The in vivo effects of glucocorticoids too were different, even in the same organ. Dexamethasone, a pure glucocorticoid, has greater affinity for glucocorticoid receptors (GR) than corticosterone. The direct effects of dexamethasone via GR in increasing testicular 11beta-HSD oxidative activity may override its indirect effects. Possibly, the reverse occurs with corticosterone treatment, as it has both glucocorticoid and mineralocorticoid effects. Because both organs have Type I isoenzyme, the difference in 11beta-HSD oxidative activities of these two organs could be attributable to the presence of an additional isozyme in testis or differences in tissue-specific regulatory mechanisms.
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