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  1. Kaharudin FA, Zohdi RM, Mukhtar SM, Sidek HM, Bihud NV, Rasol NE, et al.
    J Ethnopharmacol, 2020 May 23;254:112657.
    PMID: 32045683 DOI: 10.1016/j.jep.2020.112657
    ETHNOPHARMACOLOGICAL RELEVANCE: Malaria, a devastating infectious disease which was initially recognized as episodic fever, is caused by parasitic protozoan of the genus Plasmodium. Medicinal plants with ethnobotanical information to treat fever and/or malaria has been the key element in identifying potential plant candidates for antimalarial screening. Goniothalamus lanceolatus Miq. (Annonaceae) is used as a folk remedy, particularly to treat fever and skin diseases.

    AIM OF THE STUDY: In this context, supported with previous preliminary data of its antiplasmodial activity, this study was undertaken to determine the in vitro antiplasmodial and cytotoxicity activities of G. lanceolatus crude extracts and its major compounds.

    MATERIALS AND METHODS: The in vitro antiplasmodial activity was determined by parasite lactate dehydrogenase (pLDH) assay on chloroquine-sensitive (3D7) and chloroquine-resistant (K1) strains of Plasmodium falciparum. The cytotoxicity activity was evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on hepatocellular carcinoma (HepG2) and normal liver (WRL-68) cell lines.

    RESULTS: The root methanol extract possessed potent antiplasmodial activity against both P. falciparum 3D7 and K1 strains (IC50 = 2.7 μg/ml, SI = 140; IC50 = 1.7 μg/ml, SI = 236). Apart from the DCM extract of stem bark and root that were found to be inactive (IC50 > 50 μg/ml) against 3D7 strain, all other tested crude extracts exhibited promising (5< IC50  30 µg/ml, CC50 > 10 µM, respectively), except for the hexane and DCM extracts of root, which exerted mild cytotoxicity on HepG2 cell line (IC50 

    Matched MeSH terms: Dose-Response Relationship, Drug
  2. Alalaf SK, Al Tawil NG, Jawad AK, Mahmoud MB, Muhamad BQ, Abdul Rahman KH, et al.
    J Obstet Gynaecol Res, 2020 May;46(5):727-735.
    PMID: 32157797 DOI: 10.1111/jog.14232
    AIMS: This trial was conducted to determine the efficacy of umbilical vein injection of 400 versus 800 μg misoprostol to deliver retained placenta and to compare both regimens regarding the time of placental delivery and amount of vaginal blood loss.

    METHODS: A double-blind, multicenter randomized clinical trial was undertaken in four teaching hospitals in the North of Iraq and Al-Azhar University Hospital in Egypt, from March 2016 to May 2019. Group I (274 women) received 400 μg misoprostol and group II (249 women) received 800 μg misoprostol. Data regarding the time of placental separation and amount of vaginal blood loss were analyzed and proportions were compared between groups using Chi-squared test. Mean values were compared using the Student's t-test. The Mann-Whitney test was used to determine the median of vaginal blood loss.

    RESULTS: The proportion of placental separation was 84.3% among women in group I and 86.7% of women in group II. The mean time of placental separation was 18.86 ± 234.2 and 17.86 ± 213.09 min in groups I and II, respectively (P

    Matched MeSH terms: Dose-Response Relationship, Drug
  3. Ooi TC, Chan KM, Sharif R
    Free Radic Res, 2020 May;54(5):330-340.
    PMID: 32366187 DOI: 10.1080/10715762.2020.1763333
    Zinc L-carnosine (ZnC) is a chelated compound of zinc and L-carnosine. The present study aims to determine the protective effects of ZnC against hydrogen peroxide (H2O2)-induced oxidative stress and genomic damage in CCD-18co human normal colon fibroblast cells. Generally, cells were pretreated with ZnC (0-100 µM) for 24 h before challenged with 20 µM of H2O2 for 1 h to induce oxidative damage. Results showed that pretreatment with ZnC was able to reduce the intracellular ROS level in CCD-18co cells after being challenged with H2O2. Moreover, pretreatment with ZnC demonstrated protection from H2O2-induced DNA strand breaks and micronucleus formation. Our current findings revealed that pretreatment with ZnC could induce the activation of MTF-1 signaling pathway and expression of metallothionein (MT) in a dose-dependent manner. However, ZnC did not have any effects on Nrf2 signaling pathway and the expression of glutathione, superoxide dismutase 1, and glutamate-cysteine ligase catalytic subunit (GCLC). Furthermore, pretreatment with ZnC did not induce the expression of OGG1 and PARP-1 in CCD-18co cells, suggesting that these two DNA repairing enzymes are not related to the genoprotective effects of ZnC. Since the expression of MT has been demonstrated to protect cells from oxidative DNA damage induced by various genotoxic agents, the genoprotective effects of ZnC might be due to the ability of ZnC to induce the expression of MT. In conclusion, ZnC pretreatment was able to protect CCD-18co cells from H2O2-induced genomic damage via the activation of the MTF-1 signalling pathway and the induction of MT expression.
    Matched MeSH terms: Dose-Response Relationship, Drug
  4. Leong SW, Chia SL, Abas F, Yusoff K
    Bioorg Med Chem Lett, 2020 04 15;30(8):127065.
    PMID: 32127259 DOI: 10.1016/j.bmcl.2020.127065
    In the present study, a series of nine stable 3,4,5-methoxylphenyl-containing asymmetrical diarylpentanoids, derivatives of curcuminoids, have been synthesized, characterized and evaluated for their in-vitro anti-cancer potential against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, LoVo and SW620, HT29, RKO and NCI-H508, respectively. Structure-activity relationship study on cytotoxicity of tested compounds suggested that the presence of meta-hydroxyl and adjacent dimethoxyl groups are crucial for enhanced cytotoxicity of diarylpentanoids. Among the evaluated analogs, 8 has been identified as the lead compound due to its highest chemotherapeutic index of 9.9 and nano molar scale cytotoxicity against SW620 and RKO. Colonies formation and cell cycle analyses on 8-treated RKO cells showed that 8 exhibits strong anti-proliferative activity by inducing G2/M-phase cell arrest. Subsequent flow cytometry based annexin-V and DCFHDA studies suggested that 8 could induce apoptosis through intracellular ROS-dependent pathway. Further Western blot studies confirmed that 8 has induced intrinsic apoptosis in RKO cells through the up-regulations of Bad and Bax pro-apoptotic proteins and down-regulations of Bcl-2 and Bcl-xL pro-survival proteins. In all, the present results suggest that 8 could be a potent lead which deserves further modification and investigation in the development of small molecule-based anti-colorectal cancer agents.
    Matched MeSH terms: Dose-Response Relationship, Drug
  5. Paudel YN, Kumari Y, Abidin SAZ, Othman I, Shaikh MF
    Int J Mol Sci, 2020 Apr 03;21(7).
    PMID: 32260203 DOI: 10.3390/ijms21072492
    Epilepsy is a devastating neurological condition exhibited by repeated spontaneous and unpredictable seizures afflicting around 70 million people globally. The basic pathophysiology of epileptic seizures is still elusive, reflecting an extensive need for further research. Developing a novel animal model is crucial in understanding disease mechanisms as well as in assessing the therapeutic target. Most of the pre-clinical epilepsy research has been focused on rodents. Nevertheless, zebrafish disease models are relevant to human disease pathophysiology hence are gaining increased attention nowadays. The current study for the very first time developed a pilocarpine-induced chronic seizure-like condition in adult zebrafish and investigated the modulation in several neuroinflammatory genes and neurotransmitters after pilocarpine exposures. Seizure score analysis suggests that compared to a single dose, repeated dose pilocarpine produces chronic seizure-like effects maintaining an average seizure score of above 2 each day for a minimum of 10 days. Compared to the single dose pilocarpine treated group, there was increased mRNA expression of HMGB1, TLR4, TNF-α, IL-1, BDNF, CREB-1, and NPY; whereas decreased expression of NF-κB was upon the repeated dose of pilocarpine administration. In addition, the epileptic group demonstrates modulation in neurotransmitters levels such as GABA, Glutamate, and Acetylcholine. Moreover, proteomic profiling of the zebrafish brain from the normal and epileptic groups from LCMS/MS quantification detected 77 and 13 proteins in the normal and epileptic group respectively. Summing up, the current investigation depicted that chemically induced seizures in zebrafish demonstrated behavioral and molecular alterations similar to classical rodent seizure models suggesting the usability of adult zebrafish as a robust model to investigate epileptic seizures.
    Matched MeSH terms: Dose-Response Relationship, Drug
  6. Suppan VKL, Tew MM, Wong BC, Chan HK, Chew YW, Tan CS, et al.
    J Orthop Surg (Hong Kong), 2020 3 5;28(1):2309499019895029.
    PMID: 32129141 DOI: 10.1177/2309499019895029
    PURPOSE: A recent 3-month randomized, open-label controlled trial found that the intra-articular hyaluronic acid injection (GO-ON®) given as a single dose of 5 mL is as effective and safe as three repeated doses of 2.5 mL in patients with knee osteoarthritis. However, the information on the long-term efficacy and economic implications of the single-dose regimen is still limited. Hence, this follow-up study was designed to compare the effectiveness and costs of the two regimens 12 months following the treatment.

    METHODS: All the 127 patients, who received either three repeated doses (n = 64) or a single dose (n = 63) of GO-ON in the previous trial, were followed up in month 12 following the treatment. The effectiveness of both the regimens was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the mean WOMAC scores were compared with those recorded at the baseline and in month 3. Additionally, the total treatment costs of the two regimens, taking account of both direct and indirect costs, were computed and compared.

    RESULTS: A total of 125 patients (98.4%) completed the assessment. Despite the reduction of the overall mean WOMAC score from 39.24 to 19.93 (p < 0.001) in the first 3 months following the treatment with GO-ON, no further changes were observed up to month 12 (p > 0.95). In the meantime, the two regimens did not differ in the mean WOMAC scores (p = 0.749) and in the subscale scores for pain (p = 0.970), stiffness (p = 0.526), and physical functioning (p = 0.667) in month 12. The cost for single-dose injection was found to be approximately 30% lower compared to the repeated doses.

    CONCLUSION: These findings indicate that the single larger dose of GO-ON is as effective as the repeated doses over 12 months, and yet the total treatment cost is lowered.

    Matched MeSH terms: Dose-Response Relationship, Drug
  7. Wu J, Pistolozzi M, Liu S, Tan W
    Bioorg Med Chem, 2020 03 01;28(5):115324.
    PMID: 32008882 DOI: 10.1016/j.bmc.2020.115324
    Rivastigmine, a dual inhibitor of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), has been approved by U.S. Food and Drug Administration to treat Alzheimer's disease (AD) and Parkinson's disease (PD) dementia. In the current work, a bambuterol derivative lacking one of the carbamoyloxy groups on the benzene ring (BMC-1) and its analogues were synthesized using 1-(3-hydroxyphenyl) ethan-1-one and 1-(4-hydroxyphenyl) ethan-1-one as starting materials. In-vitro cholinesterase assay established that nine compounds were more potent to inhibit both electric eel AChE and equine serum BChE than rivastigmine under the same experimental conditions. Further study confirmed that among the nine carbamates, BMC-3 (IC50(AChE) = 792 nM, IC50(BChE) = 2.2 nM) and BMC-16 (IC50(AChE) = 266 nM, IC50(BChE) = 10.6 nM) were excellent cholinesterase inhibitors with potential of permeating through the blood-brain barrier. These carbamates could be used as potential dual inhibitors of AChE and BChE and to discover novel drugs for the treatment of AD and PD dementia.
    Matched MeSH terms: Dose-Response Relationship, Drug
  8. Chan ZCK, Leong KH, Kareem HS, Norazit A, Noor SM, Ariffin A
    Naunyn Schmiedebergs Arch Pharmacol, 2020 03;393(3):405-417.
    PMID: 31641820 DOI: 10.1007/s00210-019-01730-2
    The rationale of designing compounds containing a (3,4,5-trimethoxybenzyloxy) phenyl moiety is largely due to its potential antioxidant and cytotoxic activities. A previous study focused on its antioxidant mechanism, whereas in this study, we investigated the cytotoxicity of a series of 28 analogues and the mechanism of apoptosis of the most cytotoxic compound against wild-type (HCT-116) and p53 mutant (HT-29) colorectal cancer cell lines. The series of analogues comprise of different families, namely hydrazone, oxadiazole, thiosemicarbazides and triazoles. In the initial cytotoxicity screening, N-(3,4,5-trimethoxybenzylidene)-4-(3,4,5-trimethoxybenzyloxy) benzohydrazide, henceforth known as, P5H, was found to be most cytotoxic against human colorectal cancer cell lines (IC50 for HCT-116 = 11.79 μM and HT-29 = 18.52 μM). Additionally, P5H was found to have some degree of selectivity towards cancer cells compared to normal human colon cells (CCD-112 CoN). Subsequent investigation had brought insight on P5H ability to induce apoptosis in both HCT-116 and HT-29 cell lines. Cell cycle analysis showed both cell lines were arrested at the G2/M phase upon treatment. Our study concluded that P5H induced the death receptor, DR5 in HCT-116 and mitochondria-mediated apoptosis pathway in HT-29. Therefore, P5H may be a promising candidate as a chemotherapy agent against colon cancer. Graphical abstract The apoptotic pathways induced in HT-29 and HCT-116 cells upon P5H treatment.
    Matched MeSH terms: Dose-Response Relationship, Drug
  9. Harun N, Johari IS, Mansor SM, Shoaib M
    Psychopharmacology (Berl), 2020 Mar;237(3):855-867.
    PMID: 31832720 DOI: 10.1007/s00213-019-05418-6
    RATIONALE: Kratom is proposed to exhibit therapeutic potential as an opium substitute, but little is known about its dependence-producing profile, particularly of its main psychoactive compound, mitragynine (MG).

    OBJECTIVES: This study examined the dependence-producing effects of MG using operant-scheduled behaviour in rats and investigated the potential therapeutic effect of MG by comparing effects to buprenorphine in morphine-dependent rats using the same schedule-controlled behavioural task.

    METHODS: The effects of acutely administered MG and morphine were determined in rats trained to respond under fixed-ratio (FR) 10 schedule of food reinforcement. Next, the rats were administered MG and morphine twice daily for 14 consecutive days to determine if physiological dependence would develop by examining cessation of drug treatment and following antagonist-precipitated withdrawal. The study then examined the effects of MG substitution to suppress naloxone-precipitated morphine withdrawal effects on scheduled responding.

    RESULTS: Acute doses of MG did not produce dose-related decreases on FR schedules of responding compared to morphine. Unlike morphine, MG-treated rats showed no suppression of response rates following cessation of MG treatment. However, withdrawal effects were evident for MG after precipitation by either naloxone or SR141716A (rimonabant), similar to morphine-treated rats. MG in higher doses (10 and 30 mg/kg) attenuated the naloxone-precipitated morphine withdrawal effects while smaller doses of buprenorphine (0.3 and 1.0 mg/kg) were necessary to alleviate these effects.

    CONCLUSION: The findings suggest that MG does not induce physiological dependence but can alleviate the physical symptoms associated with morphine withdrawal which represent the desired characteristics of novel pharmacotherapeutic interventions for managing opioid use disorder (OUD).

    Matched MeSH terms: Dose-Response Relationship, Drug
  10. Hitora Y, Takada K, Ise Y, Woo SP, Inoue S, Mori N, et al.
    Bioorg Med Chem, 2020 01 15;28(2):115233.
    PMID: 31848114 DOI: 10.1016/j.bmc.2019.115233
    New sesquiterpene quinones, metachromins X (1) and Y (2), together with the known metachromins C (3), J (4), and T (5), were isolated as inhibitors of cell cycle progression in the HeLa/Fucci2 cells. The structure of 1 was assigned by spectroscopic data and confirmed by a total synthesis. The planar structure of 2 was determined by interpretation of spectroscopic data, whereas its absolute configuration was analyzed by a combination of chiral HPLC and CD spectroscopy. Metachromins X (1) and C (3) arrested the cell cycle progression of HeLa/Fucci2 cells at S/G2/M phase.
    Matched MeSH terms: Dose-Response Relationship, Drug
  11. Naaz F, Ahmad F, Lone BA, Pokharel YR, Fuloria NK, Fuloria S, et al.
    Bioorg Chem, 2020 01;95:103519.
    PMID: 31884140 DOI: 10.1016/j.bioorg.2019.103519
    A set of two series of 1,3,4-oxadiazole (11a-n) and 1,2,4-Triazole (12a, c, e, g, h, j-n) based topsentin analogues were prepared by replacing imizadole moiety of topsentin through a multistep synthesis starting from indole. All the compounds synthesized were submitted for single dose (10 µM) screening against a NCI panel of 60-human cancer cell lines. Among all cancer cell lines, colon (HCC-2998) and Breast (MCF-7, T-47D) cancer cell lines were found to be more susceptible for this class of compounds. Among the compounds tested, compounds 11a, 11d, 11f, 12e and 12h, were exhibited good anti-proliferative activity against various cancer cell lines. Compounds 11d, 12e and 12h demonstrated better activity with IC50 2.42 µM, 3.06 µM, and 3.30 µM respectively against MCF-7 human cancer cell line than that of the standard drug doxorubicin IC50 6.31 µM. Furthermore, 11d induced cell cycle arrest at G0/G1 phase and also disrupted mitochondrial membrane potential with reducing cell migration potential of MCF-7 cells in dose dependent manner. In vitro microtubule polymerization assays found that compound 11d disrupt tubulin dynamics by inhibiting tubulin polymerization with IC50 3.89 μM compared with standard nocodazole (IC50 2.49 μM). In silico docking studies represented that 11d was binding at colchicine binding site of β-tubulin. Compound 11d emerged as lead molecule from the library of compounds tested and this may serve as a template for further drug discovery.
    Matched MeSH terms: Dose-Response Relationship, Drug
  12. Mohd Faudzi SM, Abdullah MA, Abdull Manap MR, Ismail AZ, Rullah K, Mohd Aluwi MFF, et al.
    Bioorg Chem, 2020 01;94:103376.
    PMID: 31677861 DOI: 10.1016/j.bioorg.2019.103376
    In search of potent anti-inflammatory agents, twenty-four chalcone derivatives including seven new compounds (13 - 17, 21 and 23) containing pyrrole moiety were designed, synthesized, and assessed for their nitric oxide (NO) and prostaglandin E2 (PGE2) suppression ability on IFN-γ/LPS-induced RAW 264.7 macrophage cells. Results showed that none of the synthesized compounds were PAINS-associated molecules, with 3-(2,5-dimethoxyphenyl)-1-(1H-pyrrol-2-yl)-prop-2-en-1-one (compound 16) exhibiting remarkable inhibition activity towards PGE2 and NO production with IC50 values of 0.5 ± 1.5 µM and 12.1 ± 1.5 µM, respectively. Physicochemical and ADMET studies showed that majority of the compounds obey to Lipinski's rule of five (RO5) having high blood brain barrier (BBB) penetration, human intestinal absorption (HIA), P- glycoprotein (PgP) inhibition and plasma binding protein (PPB) inhibition. The obtained atomic coordinates for the single-crystal XRD of 16 were then applied in a molecular docking simulation, and compound 16 was found to participate in a number of important binding interactions in the binding sites of ERK and mPGES-1. Based on these results, we have observed the potential of compound 16 as a new hit anti-inflammatory agent, and these findings could serve as a basis for further studies on its mechanism of action.
    Matched MeSH terms: Dose-Response Relationship, Drug
  13. Lasing T, Phumee A, Siriyasatien P, Chitchak K, Vanalabhpatana P, Mak KK, et al.
    Bioorg Med Chem, 2020 01 01;28(1):115187.
    PMID: 31761725 DOI: 10.1016/j.bmc.2019.115187
    In a search for potent antileishmanial drug candidates, eighteen rhodacyanine analogues bearing fluorine or perfluoroalkyl substituents at various positions were synthesized. These compounds were tested for their inhibitory activities against Leishmania martiniquensis and L. orientalis. This 'fluorine-walk' analysis revealed that the introduction of fluorine atom at C-5, 6, 5', or 6' on the benzothiazole units led to significant enhancement of the activity, correlating with the less negative reduction potentials of the fluorinated analogues confirmed by the electrochemical study. On the other hand, CF3 and OCF3 groups were found to have detrimental effects, which agreed with the poor aqueous solubility predicted by the in silico ADMET analysis. In addition, some of the analogues including the difluorinated species showed exceptional potency against the promastigote and axenic amastigote stages (IC50 = 40-85 nM), with the activities surpassing both amphotericin B and miltefosine.
    Matched MeSH terms: Dose-Response Relationship, Drug
  14. Yang X, Kord-Varkaneh H, Talaei S, Clark CCT, Zanghelini F, Tan SC, et al.
    Pharmacol Res, 2020 01;151:104588.
    PMID: 31816435 DOI: 10.1016/j.phrs.2019.104588
    BACKGROUND: A meta-analysis is needed to comprehensively consolidate findings from the influence of metformin on IGF-1 levels. The present study was conducted with the objective to accurately evaluate the influence of metformin intake on IGF-1 levels via a meta-analysis of randomized controlled trials.

    METHODS: A comprehensive systematic search was carried out in PubMed/MEDLINE, Web of Science, SCOPUS and Embase from inception until June 2019. Weighted mean difference (WMD) with the 95 % CI were applied for estimating the effects of metformin on serum IGF-1 levels.

    RESULTS: 11 studies involving a total of 569 individuals reported changes in IGF-1 plasma concentrations as an outcome measure. Pooled results demonstrated an overall non-significant decline in IGF-1 following metformin intake (WMD: -8.292 ng/ml, 95 % CI: -20.248, 3.664, p = 0.174) with heterogeneity among (p = 0.000,I2 = 87.1 %). The subgroup analyses displayed that intervention duration <12 weeks on children (WMD:-55.402 ng/ml, 95 % CI: -79.845, -30.960, I2 = 0.0 %) significantly reduced IGF-1. Moreover, in age 18 < years older metformin intake (WMD: 15.125 ng/ml, 95 % CI: 5.522, 24.729, I2 = 92.5 %) significantly increased IGF-1 than 18 ≤ years older (WMD:-1.038 ng/ml, 95 % CI: -3.578,1.502,I2 = 78.0 %). Following dose-response evaluation, metformin intake reduced IGF-1 (coefficient for dose-response analysis= -13.14, P = 0.041 and coefficient for liner analysis= -0.066, P = 0.038) significantly based on treatment duration.

    CONCLUSION: We found in children, intervention duration <12 weeks yielded significant reductions in IGF-1, whilst paradoxically, in participants >18 years old, metformin intake significantly increased IGF-1. We suggest that caution be taken when interpreting the findings of this review, particularly given the discordant supplementation practices between children and adults.

    Matched MeSH terms: Dose-Response Relationship, Drug
  15. Fairus S, Cheng HM, Sundram K
    J Integr Med, 2020 Jan;18(1):68-79.
    PMID: 31812339 DOI: 10.1016/j.joim.2019.11.005
    OBJECTIVE: Tocotrienols (T3s) have been hypothesized to have greater antioxidant capacity than tocopherols (Ts) due to differences in biokinetics that affect their absorption and function. The present trial compares the antioxidant effectiveness following postprandial challenge of two different doses of α-T or palm T3-rich fraction (TRF) treatments and evaluates their dose-response effects on antioxidant status.

    METHODS: Ten healthy volunteers were given four different doses of vitamin E formulations (268 mg α-T, 537 mg α-T, 263 mg TRF or 526 mg TRF) in a cross-over postprandial trial. Blood was sampled at 0, 2, 4, 5, 6 and 8 hours after meal consumption and plasma antioxidant status including total glutathione, superoxide dismutase, malondialdehyde (MDA), ferric reducing antioxidant potential and trolox-equivalent antioxidant capacity, was analyzed.

    RESULTS: Supplementation with the different doses of either α-T or TRF did not significantly improve overall antioxidant status. There was no significant difference in overall antioxidant status among treatments at the different doses compared. However, a significant dose-response effect was observed for plasma MDA throughout the 8-hour postprandial period. MDA was significantly lower after the 537 mg α-T treatment, compared to the 268 mg α-T treatment; it was also lower after the 526 mg TRF treatment compared to the 263 mg TRF treatment (P 

    Matched MeSH terms: Dose-Response Relationship, Drug
  16. Arulnathan SB, Leong KH, Ariffin A, Kareem HS, Cheah KKH
    Anticancer Agents Med Chem, 2020;20(9):1072-1086.
    PMID: 32188392 DOI: 10.2174/1871520620666200318100051
    BACKGROUND: Oxadiazoles, triazoles, and their respective precursors have been shown to exhibit various pharmacological properties, namely antitumour activities. Cytotoxic activity was reported for these compounds in various cancer cell lines.

    AIM AND OBJECTIVES: In this study, we aim at investigating the mechanism of apoptosis by N-(4-chlorophenyl)-2-(4- (3,4,5-trimethoxybenzyloxy)benzoyl)-hydrazinecarbothioamide, a triazole precursor, henceforth termed compound P7a, in breast cancer cell line, MCF-7. We first screen a series of analogues containing (3,4,5-trimethoxybenzyloxy) phenyl moiety in breast cancer cell lines (MCF-7 and MDA-MB-231) to select the most cytotoxic compound and demonstrate a dose- and time-dependent cytotoxicity. Then, we unravel the mechanism of apoptosis of P7a in MCF-7 as well as its ability to cause cell cycle arrest.

    METHODS: Synthesis was performed as previously described by Kareem and co-workers. Cytotoxicity of analogues containing (3,4,5-trimethoxybenzyloxy)phenyl moiety against MCF-7 and MDA-MB-231 cell lines was evaluated using the MTS assay. Flow cytometric analyses was done using Annexin V/PI staining, JC-1 staining and ROS assay. The activity of caspases using a chemoluminescence assay and western blot analysis was conducted to study the apoptotic pathway induced by the compound in MCF-7 cells. Lastly, cell cycle analysis was conducted using flow cytometry.

    RESULTS: Upon 48 hours of treatment, compound P7a inhibited the proliferation of human breast cancer cells with IC50 values of 178.92 ± 12.51μM and 33.75 ± 1.20μM for MDA-MB-231 and MCF-7, respectively. Additionally, compound P7a showed selectivity towards the cancer cell line, MCF-7 compared to the normal breast cell line, hTERT-HME1, an advantage against current anticancer drugs (tamoxifen and vinblastine). Flow cytometric analyses using different assays indicated that compound P7a significantly increased the proportion of apoptotic cells, increased mitochondria membrane permeabilisation and caused generation of ROS in MCF-7. In addition, cell cycle analysis showed that cell proliferation was arrested at the G1 phase in the MCF-7 cell line. Furthermore, upon treatment, the MCF-7 cell line showed increased activity of caspase-3/7, and caspase-9. Lastly, the western blot analysis showed the up-regulation of pro-apoptotic proteins along with up-regulation of caspase-7 and caspase-9, indicating that an intrinsic pathway of apoptosis was induced.

    CONCLUSION: The results suggest that compound P7a could be a potential chemotherapeutic agent for breast cancer.

    Matched MeSH terms: Dose-Response Relationship, Drug
  17. Jeyamogan S, Khan NA, Sagathevan K, Siddiqui R
    Anticancer Agents Med Chem, 2020;20(13):1558-1570.
    PMID: 32364082 DOI: 10.2174/1871520620666200504103056
    BACKGROUND: Cancer contributes to significant morbidity and mortality despite advances in treatment and supportive care. There is a need for the identification of effective anticancer agents. Reptiles such as tortoise, python, and water monitor lizards are exposed to heavy metals, tolerate high levels of radiation, feed on rotten/germ-infested feed, thrive in unsanitary habitat and yet have prolonged lifespans. Such species are rarely reported to develop cancer, suggesting the presence of anticancer molecules/mechanisms.

    METHODS: Here, we tested effects from sera of Asian water monitor lizard (Varanus salvator), python (Malayopython reticulatus) and tortoise (Cuora kamaroma amboinensis) against cancer cells. Sera were collected and cytotoxicity assays were performed using prostate cancer cells (PC3), Henrietta Lacks cervical adenocarcinoma cells (HeLa) and human breast adenocarcinoma cells (MCF7), as well as human keratinized skin cells (Hacat), by measuring lactate dehydrogenase release as an indicator for cell death. Growth inhibition assays were performed to determine the effects on cancer cell proliferation. Liquid chromatography mass spectrometry was performed for molecular identification.

    RESULTS: The findings revealed that reptilian sera, but not bovine serum, abolished viability of Hela, PC3 and MCF7 cells. Samples were subjected to liquid chromatography mass spectrometry, which detected 57 molecules from V. salvator, 81 molecules from Malayopython reticulatus and 33 molecules from C. kamaroma amboinensis and putatively identified 9 molecules from V. salvator, 20 molecules from Malayopython reticulatus and 9 molecules from C. kamaroma amboinensis when matched against METLIN database. Based on peptide amino acid composition, binary profile, dipeptide composition and pseudo-amino acid composition, 123 potential Anticancer Peptides (ACPs) were identified from 883 peptides from V. salvator, 306 potential ACPs from 1074 peptides from Malayopython reticulatus and 235 potential ACPs from 885 peptides from C. kamaroma amboinensis.

    CONCLUSION: To our knowledge, for the first time, we reported comprehensive analyses of selected reptiles' sera using liquid chromatography mass spectrometry, leading to the identification of potentially novel anticancer agents. We hope that the discovery of molecules from these animals will pave the way for the rational development of new anticancer agents.

    Matched MeSH terms: Dose-Response Relationship, Drug
  18. Anwar A, Siddiqui R, Hameed A, Shah MR, Khan NA
    Med Chem, 2020;16(7):841-847.
    PMID: 31544702 DOI: 10.2174/1573406415666190722113412
    BACKGROUND: Acanthamoeba is an opportunistic pathogen widely spread in the environment. Acanthamoeba causes excruciating keratitis which can lead to blindness. The lack of effective drugs and its ability to form highly resistant cyst are one of the foremost limitations against successful prognosis. Current treatment involves mixture of drugs at high doses but still recurrence of infection can occur due to ineffectiveness of drugs against the cyst form. Pyridine and its natural and synthetic derivatives are potential chemotherapeutic agents due to their diverse biological activities.

    OBJECTIVE: To study the antiamoebic effects of four novel synthetic dihydropyridine (DHP) compounds against Acanthamoeba castellanii belonging to the T4 genotype. Furthermore, to evaluate their activity against amoeba-mediated host cells cytopathogenicity as well as their cytotoxicity against human cells.

    METHODS: Dihydropyridines were synthesized by cyclic dimerization of alkylidene malononitrile derivatives. Four analogues of functionally diverse DHPs were tested against Acanthamoeba castellanii by using amoebicidal, encystation and excystation assays. Moreover, Lactate dehydrogenase assays were carried out to study cytopathogenicity and cytotoxicity against human cells.

    RESULTS: These compounds showed significant amoebicidal and cysticidal effects at 50 μM concentration, whereas, two of the DHP derivatives also significantly reduced Acanthamoebamediated host cell cytotoxicity. Moreover, these DHPs were found to have low cytotoxicity against human cells suggesting a good safety profile.

    CONCLUSION: The results suggest that DHPs have potential against Acanthamoeba especially against the more resistant cyst stage and can be assessed further for drug development.

    Matched MeSH terms: Dose-Response Relationship, Drug
  19. Abuelizz HA, Anouar EH, Marzouk M, Hasan MH, Saleh SR, Ahudhaif A, et al.
    Anticancer Agents Med Chem, 2020;20(14):1714-1721.
    PMID: 32593283 DOI: 10.2174/1871520620666200627212128
    BACKGROUND: The use of tyrosinase has confirmed to be the best means of recognizing safe, effective, and potent tyrosinase inhibitors for whitening skin. Twenty-four 2-phenoxy(thiomethyl)pyridotriazolopyrimidines were synthesized and characterized in our previous studies.

    OBJECTIVE: The present work aimed to evaluate their cytotoxicity against HepG2 (hepatocellular carcinoma), A549 (pulmonary adenocarcinoma), MCF-7 (breast adenocarcinoma) and WRL 68 (embryonic liver) cell lines.

    METHODS: MTT assay was employed to investigate the cytotoxicity, and a tyrosinase inhibitor screening kit was used to evaluate the Tyrosinase (TYR) inhibitory activity of the targets.

    RESULTS: The tested compounds exhibited no considerable cytotoxicity, and nine of them were selected for a tyrosinase inhibitory test. Compounds 2b, 2m, and 5a showed good inhibitory percentages against TYR compared to that of kojic acid (reference substance). Molecular docking was performed to rationalize the Structure-Activity Relationship (SAR) of the target pyridotriazolopyrimidines and analyze the binding between the docked-selected compounds and the amino acid residues in the active site of tyrosinase.

    CONCLUSION: The target pyridotriazolopyrimidines were identified as a new class of tyrosinase inhibitors.

    Matched MeSH terms: Dose-Response Relationship, Drug
  20. Wan Hasan WN, Chin KY, Abd Ghafar N, Soelaiman IN
    Drug Des Devel Ther, 2020;14:969-976.
    PMID: 32184566 DOI: 10.2147/DDDT.S224941
    PURPOSE: Annatto-derived tocotrienol (AnTT) has been shown to improve bone formation in animal models of osteoporosis and promote differentiation of pre-osteoblastic cells. However, the mechanism of action of AnTT in achieving these effects is unclear. This study aims to investigate the mechanism of action of AnTT on MC3T3-E1 pre-osteoblasts via the mevalonate pathway.

    METHODS: Murine pre-osteoblastic cells, MC3T3-E1, were cultured with the density of 1 × 104 cells/mL and treated with 4 concentrations of AnTT (0.001-1 µg/mL). Expression of HMG-CoA reductase (HMGR) gene was carried out using qPCR after treatment with AnTT for 21 days. RhoA activation and bone morphogenetic protein-2 (BMP-2) were measured using immunoassay after 9 and 15 days of AnTT treatment. Lovastatin was used as the positive control. Mineralized nodules were detected using Von Kossa staining after 21 days of AnTT treatment.

    RESULTS: The results showed that HMGR was up-regulated in the lovastatin group on day 9 and 21 compared to the control. Lovastatin also inhibited RhoA activation (day 9 and 15) and increased BMP-2 protein (day 15). On the other hand, AnTT at 0.001 μg/mL (day 3) and 0.1 μg/mL (day 21) significantly down-regulated HMGR gene expression compared to the control. On day 21, HMGR gene expression was significantly reduced in all groups compared to day 15. AnTT at 0.1 μg/mL significantly decreased RhoA activation on day 9 compared to the control. AnTT at 1 μg/mL significantly increased BMP-2 protein on day 15 compared to the control (P<0.05). Mineralized calcium nodules were more abundant in AnTT treated groups compared to the control on day 21.

    CONCLUSION: AnTT suppresses the mevalonate pathway by downregulating HMGR gene expression and inhibiting RhoA activation, leading to increased BMP-2 protein in MC3T3-E1 cells. This explains the stimulating effects of AnTT on osteoblast mineralization.

    Matched MeSH terms: Dose-Response Relationship, Drug
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