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Fulltext Subditine, a new monoterpenoid indole alkaloid from bark of Nauclea subdita (Korth.) Steud. induces apoptosis in human prostate cancer cells

Liew SY, Looi CY, Paydar M, Cheah FK, Leong KH, Wong WF, et al.

PLoS One, 2014;9(2):e87286.
PMID: 24551054 DOI: 10.1371/journal.pone.0087286

In this study, a new apoptotic monoterpenoid indole alkaloid, subditine (1), and four known compounds were isolated from the bark of Nauclea subdita. Complete (1)H- and (13)C- NMR data of the new compound were reported. The structures of isolated compounds were elucidated with various spectroscopic methods such as 1D- and 2D- NMR, IR, UV and LCMS. All five compounds were screened for cytotoxic activities on LNCaP and PC-3 human prostate cancer cell-lines. Among the five compounds, the new alkaloid, subditine (1), demonstrated the most potent cell growth inhibition activity and selective against LNCaP with an IC50 of 12.24±0.19 µM and PC-3 with an IC50 of 13.97±0.32 µM, compared to RWPE human normal epithelial cell line (IC50 = 30.48±0.08 µM). Subditine (1) treatment induced apoptosis in LNCaP and PC-3 as evidenced by increased cell permeability, disruption of cytoskeletal structures and increased nuclear fragmentation. In addition, subditine (1) enhanced intracellular reactive oxygen species (ROS) production, as reflected by increased expression of glutathione reductase (GR) to scavenge damaging free radicals in both prostate cancer cell-lines. Excessive ROS could lead to disruption of mitochondrial membrane potential (MMP), release of cytochrome c and subsequent caspase 9, 3/7 activation. Further Western blot analyses showed subditine (1) induced down-regulation of Bcl-2 and Bcl-xl expression, whereas p53 was up-regulated in LNCaP (p53-wild-type), but not in PC-3 (p53-null). Overall, our data demonstrated that the new compound subditine (1) exerts anti-proliferative effect on LNCaP and PC-3 human prostate cancer cells through induction of apoptosis.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Inhibition of mitochondrial cytochrome c release and suppression of caspases by gamma-tocotrienol prevent apoptosis and delay aging in stress-induced premature senescence of skin fibroblasts

Makpol S, Abdul Rahim N, Hui CK, Ngah WZ

Oxid Med Cell Longev, 2012;2012:785743.
PMID: 22919441 DOI: 10.1155/2012/785743

In this study, we determined the molecular mechanism of γ-tocotrienol (GTT) in preventing cellular aging by focusing on its anti-apoptotic effect in stress-induced premature senescence (SIPS) model of human diploid fibroblasts (HDFs). Results obtained showed that SIPS exhibited senescent-phenotypic characteristic, increased expression of senescence-associated β-galactosidase (SA β-gal) and promoted G(0)/G(1) cell cycle arrest accompanied by shortening of telomere length with decreased telomerase activity. Both SIPS and senescent HDFs shared similar apoptotic changes such as increased Annexin V-FITC positive cells, increased cytochrome c release and increased activation of caspase-9 and caspase-3 (P < 0.05). GTT treatment resulted in a significant reduction of Annexin V-FITC positive cells, inhibited cytochrome c release and decreased activation of caspase-9 and caspase-3 (P < 0.05). Gene expression analysis showed that GTT treatment down regulated BAX mRNA, up-regulated BCL2A1 mRNA and decreased the ratio of Bax/Bcl-2 protein expression (P < 0.05) in SIPS. These findings suggested that GTT inhibits apoptosis by modulating the upstream apoptosis cascade, causing the inhibition of cytochrome c release from the mitochondria with concomitant suppression of caspase-9 and caspase-3 activation. In conclusion, GTT delays cellular senescence of human diploid fibroblasts through the inhibition of intrinsic mitochondria-mediated pathway which involved the regulation of pro- and anti-apoptotic genes and proteins.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Artonin E Induces Apoptosis via Mitochondrial Dysregulation in SKOV-3 Ovarian Cancer Cells

Rahman MA, Ramli F, Karimian H, Dehghan F, Nordin N, Ali HM, et al.

PLoS One, 2016;11(3):e0151466.
PMID: 27019365 DOI: 10.1371/journal.pone.0151466

Artonin E is a prenylated flavonoid isolated from the stem bark of Artocarpus elasticus Reinw.(Moraceae). This study aimed to investigate the apoptotic mechanisms induced by artonin E in a metastatic human ovarian cancer cell line SKOV-3 in vitro. MTT assay, clonogenic assay, acridine orange and propidium iodide double staining, cell cycle and annexin V analyses were performed to explore the mode of artonin E-induced cell death at different time points. DNA laddering, activation of caspases-3, -8, and -9, multi-parametric cytotoxicity-3 analysis by high-content screening, measurement of reactive oxygen species generation, and Western blot were employed to study the pathways involved in the apoptosis. MTT results showed that artonin E inhibited the growth of SKOV-3 cells, with IC50 values of 6.5±0.5 μg/mL after 72 h treatment, and showed less toxicity toward a normal human ovarian cell line T1074, with IC50 value of 32.5±0.5 μg/mL. Results showed that artonin E induced apoptosis and cell cycle arrest at the S phase. This compound also promoted the activation of caspases-3, -8, and -9. Further investigation into the depletion of mitochondrial membrane potential and release of cytochrome c revealed that artonin E treatment induced apoptosis via regulation of the expression of pro-survival and pro-apoptotic Bcl-2 family members. The expression levels of survivin and HSP70 proteins were also down regulated in SKOV-3 cells treated with artonin E. We propose that artonin E induced an antiproliferative effect that led to S phase cell cycle arrest and apoptosis through dysregulation of mitochondrial pathways, particularly the pro- and anti-apoptosis signaling pathways.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Synthesis, characterization, and anticancer activity of new quinazoline derivatives against MCF-7 cells

Faraj FL, Zahedifard M, Paydar M, Looi CY, Abdul Majid N, Ali HM, et al.

ScientificWorldJournal, 2014;2014:212096.
PMID: 25548779 DOI: 10.1155/2014/212096

Two new synthesized and characterized quinazoline Schiff bases 1 and 2 were investigated for anticancer activity against MCF-7 human breast cancer cell line. Compounds 1 and 2 demonstrated a remarkable antiproliferative effect, with an IC50 value of 6.246×10(-6) mol/L and 5.910×10(-6) mol/L, respectively, after 72 hours of treatment. Most apoptosis morphological features in treated MCF-7 cells were observed by AO/PI staining. The results of cell cycle analysis indicate that compounds did not induce S and M phase arrest in cell after 24 hours of treatment. Furthermore, MCF-7 cells treated with 1 and 2 subjected to apoptosis death, as exhibited by perturbation of mitochondrial membrane potential and cytochrome c release as well as increase in ROS formation. We also found activation of caspases-3/7, -8, and -9 in compounds 1 and 2. Moreover, inhibition of NF-κB translocation in MCF-7 cells treated by compound 1 significantly exhibited the association of extrinsic apoptosis pathway. Acute toxicity results demonstrated the nontoxic nature of the compounds in mice. Our results showed significant activity towards MCF-7 cells via either intrinsic or extrinsic mitochondrial pathway and are potential candidate for further in vivo and clinical breast cancer studies.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Cancer-associated fibroblasts promote proliferation of endometrial cancer cells

Subramaniam KS, Tham ST, Mohamed Z, Woo YL, Mat Adenan NA, Chung I

PLoS One, 2013;8(7):e68923.
PMID: 23922669 DOI: 10.1371/journal.pone.0068923

Endometrial cancer is the most commonly diagnosed gynecologic malignancy worldwide; yet the tumor microenvironment, especially the fibroblast cells surrounding the cancer cells, is poorly understood. We established four primary cultures of fibroblasts from human endometrial cancer tissues (cancer-associated fibroblasts, CAFs) using antibody-conjugated magnetic bead isolation. These relatively homogenous fibroblast cultures expressed fibroblast markers (CD90, vimentin and alpha-smooth muscle actin) and hormonal (estrogen and progesterone) receptors. Conditioned media collected from CAFs induced a dose-dependent proliferation of both primary cultures and cell lines of endometrial cancer in vitro (175%) when compared to non-treated cells, in contrast to those from normal endometrial fibroblast cell line (51%) (P<0.0001). These effects were not observed in fibroblast culture derived from benign endometrial hyperplasia tissues, indicating the specificity of CAFs in affecting endometrial cancer cell proliferation. To determine the mechanism underlying the differential fibroblast effects, we compared the activation of PI3K/Akt and MAPK/Erk pathways in endometrial cancer cells following treatment with normal fibroblasts- and CAFs-conditioned media. Western blot analysis showed that the expression of both phosphorylated forms of Akt and Erk were significantly down-regulated in normal fibroblasts-treated cells, but were up-regulated/maintained in CAFs-treated cells. Treatment with specific inhibitors LY294002 and U0126 reversed the CAFs-mediated cell proliferation (P<0.0001), suggesting for a role of these pathways in modulating endometrial cancer cell proliferation. Rapamycin, which targets a downstream molecule in PI3K pathway (mTOR), also suppressed CAFs-induced cell proliferation by inducing apoptosis. Cytokine profiling analysis revealed that CAFs secrete higher levels of macrophage chemoattractant protein (MCP)-1, interleukin (IL)-6, IL-8, RANTES and vascular endothelial growth factor (VEGF) than normal fibroblasts. Our data suggests that in contrast to normal fibroblasts, CAFs may exhibit a pro-tumorigenic effect in the progression of endometrial cancer, and PI3K/Akt and MAPK/Erk signaling may represent critical regulators in how endometrial cancer cells respond to their microenvironment.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Alpha-tomatine induces apoptosis and inhibits nuclear factor-kappa B activation on human prostatic adenocarcinoma PC-3 cells

Lee ST, Wong PF, Cheah SC, Mustafa MR

PLoS One, 2011;6(4):e18915.
PMID: 21541327 DOI: 10.1371/journal.pone.0018915

Alpha-tomatine (α-tomatine) is the major saponin in tomato (Lycopersicon esculentum). This study investigates the chemopreventive potential of α-tomatine on androgen-independent human prostatic adenocarcinoma PC-3 cells.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Zerumbone-induced antinociception: involvement of the L-arginine-nitric oxide-cGMP -PKC-K+ ATP channel pathways

Perimal EK, Akhtar MN, Mohamad AS, Khalid MH, Ming OH, Khalid S, et al.

Basic Clin Pharmacol Toxicol, 2011 Mar;108(3):155-62.
PMID: 20955360 DOI: 10.1111/j.1742-7843.2010.00635.x

This study investigated the antinociceptive effects of zerumbone in chemical behavioural models of nociception in mice. Zerumbone given through intraperitoneal route (i.p.) produced dose-related antinociception when assessed on acetic acid-induced abdominal writhing test in mice. In addition, the i.p. administration of zerumbone exhibited significant inhibition of the neurogenic pain induced by intraplantar (i.pl.) injection of capsaicin and bradykinin. Likewise, zerumbone given by i.p. route reduced the nociception produced by i.pl. injection of glutamate and phorbol myristate acetate (PMA). The antinociception caused by zerumbone in the acetic acid test was significantly attenuated by i.p. pre-treatment of mice with l-arginine (nitric oxide precursor) and glibenclamide (ATP-sensitive K(+) channel inhibitor). However, the antinociception of zerumbone was enhanced by methylene blue (non-specific gyanylyl cyclase inhibitor). Together, these results indicate that zerumbone produces pronounced antinociception against chemical models of nociception in mice. It also strongly suggests that the l-arginine-nitric oxide-cGMP-PKC-K(+) ATP channel pathways, the TRPV1 and kinin B2 receptors play an important role in the zerumbone-induced antinociception.

Matched MeSH terms: Enzyme Activation/drug effects
Effects of glycyrrhizic acid on 11 β-hydroxysteroid dehydrogenase (11 βHSD1 and 2) activities and HOMA-IR in rats at different treatment periods

Chia YY, Yin YY, Ton SH, Kadir KB

Exp. Clin. Endocrinol. Diabetes, 2010 Oct;118(9):617-24.
PMID: 19998240 DOI: 10.1055/s-0029-1237703

Glycyrrhizic acid (GA) has been reported to inhibit postprandial blood glucose rise and 11 β-hydroxysteroid dehydrogenase 1 (11 βHSD1) activity. As not much work has been done on GA effects on 11 βHSD1 and 2 and HOMA-IR at different treatment periods, this work was conducted. 60 male Sprague Dawley rats fed AD LIBITUM were assigned into six groups of control and treated that were given GA at different duration namely 12, 24 and 48 h. Treated and control groups were intraperitoneally administered with GA (50 mgkg (-1)) and saline respectively. Blood and subcutaneous (ATS) and visceral adipose tissue (ATV), abdominal (MA) and quadriceps femoris muscle (MT), liver (L) and kidney (K) were examined. HOMA-IR in GA-treated rats decreased in all groups (P<0.05). In the 12-h and 24-h treated rats, 11 βHSD1 activities decreased in all tissues (P<0.05) except MA and MT (P>0.05) in the former and ATV (P>0.05) in the latter. However, 11 βHSD1 activities decreased significantly in all tissues ( P<0.05) in the 48-h treated rats. Significant decrease in 11 βHSD2 (P>0.05) activities were observed in the L of all treatment groups and K in the 24-h and 48-h treated rats (P<0.05). Histological analysis on ATS showed increase in the number of small-size adipocytes while ATV adipocytes showed shrinkage after GA administration. Increased glycogen deposition in the L was observed in the GA-administered rats in all the treatment periods. In conclusion, GA treatment showed a decrease in the HOMA-IR and both 11 βHSD1 and 2 activities in all tissues, with more profound decrease in the 48-h treated rats.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Antiproliferative property and apoptotic effect of xanthorrhizol on MDA-MB-231 breast cancer cells

Cheah YH, Nordin FJ, Tee TT, Azimahtol HL, Abdullah NR, Ismail Z

Anticancer Res, 2008 Nov-Dec;28(6A):3677-89.
PMID: 19189649

Xanthorrhizol is a natural sesquiterpenoid compound isolated from the rhizome of Curcuma xanthorrhizza Roxb (Zingerberaceae). Recent studies of xanthorrhizol in cell cultures strongly support the role of xanthorrhizol as an antiproliferative agent. In our study, we tested the antiproliferative effect of xanthorrhizol using different breast cancer cell lines. The invasive breast cancer cell line, MDA-MB-231, was then selected for further investigations. Treatment with xanthorrhizol caused 50% growth inhibition on MDA-MB-231 cells at 8.67 +/- 0.79 microg/ml as determined by sulforhodamine B (SRB) assay. Hoechst 33258 nuclear staining assay showed the rate of apoptosis of MDA-MB-231 cells to increase in response to xanthorrhizol treatment. Immunofluorescence staining using antibody MitoCapture and fluorescein isothiocyanate (FITC)-labeled cytochrome c revealed the possibility of altered mitochondrial transmembrane potential and the release of cytochrome c respectively. This was further confirmed by Western-blotting, where cytochrome c was showed to migrate from mitochondrial fraction to the cytosol fraction of treated MDA-MB-231 cells. Caspase activity assay showed the involvement of caspase-3 and caspase-9, but not caspase-6 or caspase-8 in MDA-MB-231 apoptotic cell death. Subsequently, cleavage of PARP-1 protein is suggested. These data suggest treatment with xanthorrhizol modulates MDA-MB-231 cell apoptosis through the mitochondria-mediated pathway subsequent to the disruption of mitochondrial transmembrane potential, release of cytochrome c, activation of caspase-3 and caspase-9, and the modulation of PARP-1 protein.

Matched MeSH terms: Enzyme Activation/drug effects
Regulation of p53-, Bcl-2- and caspase-dependent signaling pathway in xanthorrhizol-induced apoptosis of HepG2 hepatoma cells

Handayani T, Sakinah S, Nallappan M, Pihie AH

Anticancer Res, 2007 Mar-Apr;27(2):965-71.
PMID: 17465228

Xanthorrhizol is a sesquiterpenoid compound extracted from the rhizome of Curcuma xanthorrhiza. This study investigated the antiproliferative effect and the mechanism of action of xanthorrhizol on human hepatoma cells, HepG2, and the mode of cell death. An antiproliferative assay using methylene blue staining revealed that xanthorrhizol inhibited the proliferation of the HepG2 cells with a 50% inhibition of cell growth (IC50) value of 4.17 +/- 0.053 microg/ml. The antiproliferative activity of xanthorrhizol was due to apoptosis induced in the HepG2 cells and not necrosis, which was confirmed by the Tdt-mediated dUTP nick end labeling (TUNEL) assay. The xanthorrhizol-treated HepG2 cells showed typical apoptotic morphology such as DNA fragmentation, cell shrinkage and elongated lamellipodia. The apoptosis mediated by xanthorrhizol in the HepG2 cells was associated with the activation of tumor suppressor p53 and down-regulation of antiapoptotic Bcl-2 protein expression, but not Bax. The levels of Bcl-2 protein expression decreased 24-h after treatment with xanthorrhizol and remained lower than controls throughout the experiment, resulting in a shift in the Bax to Bcl-2 ratio thus favouring apoptosis. The processing of the initiator procaspase-9 was detected. Caspase-3 was also found to be activated, but not caspase-7. Xanthorrhizol exerts antiproliferative effects on HepG2 cells by inducing apoptosis via the mitochondrial pathway.

Matched MeSH terms: Enzyme Activation/drug effects
Arginase activity in a murine macrophage cell line (RAW264.7) stimulated with lipopolysaccharide from Actinobacillus actinomycetemcomitans

Sosroseno W, Musa M, Ravichandran M, Fikri Ibrahim M, Bird PS, Seymour GJ

Oral Microbiol. Immunol., 2006 Jun;21(3):145-50.
PMID: 16626370

The aim of the present study was to determine whether or not lipopolysaccharide from Actinobacillus actinomycetemcomitans could stimulate arginase activity in a murine macrophage cell line (RAW264.7 cells).

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Flavokawain C Inhibits Cell Cycle and Promotes Apoptosis, Associated with Endoplasmic Reticulum Stress and Regulation of MAPKs and Akt Signaling Pathways in HCT 116 Human Colon Carcinoma Cells

Phang CW, Karsani SA, Sethi G, Abd Malek SN

PLoS One, 2016;11(2):e0148775.
PMID: 26859847 DOI: 10.1371/journal.pone.0148775

Flavokawain C (FKC) is a naturally occurring chalcone which can be found in Kava (Piper methysticum Forst) root. The present study evaluated the effect of FKC on the growth of various human cancer cell lines and the underlying associated mechanisms. FKC showed higher cytotoxic activity against HCT 116 cells in a time- and dose-dependent manner in comparison to other cell lines (MCF-7, HT-29, A549 and CaSki), with minimal toxicity on normal human colon cells. The apoptosis-inducing capability of FKC on HCT 116 cells was evidenced by cell shrinkage, chromatin condensation, DNA fragmentation and increased phosphatidylserine externalization. FKC was found to disrupt mitochondrial membrane potential, resulting in the release of Smac/DIABLO, AIF and cytochrome c into the cytoplasm. Our results also revealed that FKC induced intrinsic and extrinsic apoptosis via upregulation of the levels of pro-apoptotic proteins (Bak) and death receptors (DR5), while downregulation of the levels of anti-apoptotic proteins (XIAP, cIAP-1, c-FlipL, Bcl-xL and survivin), resulting in the activation of caspase-3, -8 and -9 and cleavage of poly(ADP-ribose) polymerase (PARP). FKC was also found to cause endoplasmic reticulum (ER) stress, as suggested by the elevation of GADD153 protein after FKC treatment. After the cells were exposed to FKC (60μM) over 18hrs, there was a substantial increase in the phosphorylation of ERK 1/2. The expression of phosphorylated Akt was also reduced. FKC also caused cell cycle arrest in the S phase in HCT 116 cells in a time- and dose-dependent manner and with accumulation of cells in the sub-G1 phase. This was accompanied by the downregulation of cyclin-dependent kinases (CDK2 and CDK4), consistent with the upregulation of CDK inhibitors (p21Cip1 and p27Kip1), and hypophosphorylation of Rb.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Arctium lappa L. root extract induces cell death via mitochondrial-mediated caspase-dependent apoptosis in Jurkat human leukemic T cells

Gurunanselage Don RAS, Yap MKK

Biomed Pharmacother, 2019 Feb;110:918-929.
PMID: 30572196 DOI: 10.1016/j.biopha.2018.12.023

Arctium lappa L. is a perennial herb traditionally consumed to improve well-being. It has been widely reported for its antioxidant properties; however, very little is known for its exact mechanisms underlying the anticancer activity. This study aimed to investigate the mechanisms of anticancer action for different A. lappa root extracts. Arctium lappa root was extracted with ethanol, hexane and ethyl acetate, then examined for in vitro anticancer activity against cancerous HeLa, MCF-7, Jurkat cell lines and non-cancerous 3T3 cell lines. Induction of apoptosis was determined by cellular morphological changes, mitochondrial membrane potential (ΔΨm), caspase-3/7 activity and DNA fragmentation. The active compounds present in the most potent root extracts were identified by LC-ESI-MS. Among all the extracts, ethyl acetate root extract has the highest potency with IC50 of 102.2 ± 42.4 μg/ml, followed by ethanolic root extract in Jurkat T cells, at 24 h. None of the extracts were cytotoxic against 3T3 cells, suggesting that the extracts were selective against cancerous cells only. Both ethyl acetate and ethanolic root extracts exhibited significant morphological changes in Jurkat T cells, including the detachment from adjacent cells, appearance of apoptotic bodies and cells shrinkage. The extracts treated cells also displayed an increase in caspase-3/7 activity and alteration in mitochondrial membrane potential. Only ethyl acetate root extract at IC50 induced DNA fragmentation in Jurkat T cells. LC-ESI-MS analysis of the extract revealed the presence of 8 compounds, of which only 6 compounds with various biological activities reported. These findings suggest that the ethyl acetate extract of A. lappa had strong anticancer potential and induced intrinsic apoptosis via loss of ΔΨm and activation of caspase-3/7 This study can provide new insight to the discovery of new promising lead compound in chemopreventive and chemotherapeutic strategies.

Matched MeSH terms: Enzyme Activation/drug effects
Garlic flavonoids alleviate H2 O2 induced oxidative damage in L02 cells and induced apoptosis in HepG2 cells by Bcl-2/Caspase pathway

Gao X, Yanan J, Santhanam RK, Wang Y, Lu Y, Zhang M, et al.

J Food Sci, 2021 Feb;86(2):366-375.
PMID: 33448034 DOI: 10.1111/1750-3841.15599

Liver damage is a common liver disorder, which could induce liver cancer. Oral antioxidant is one of the effective treatments to prevent and alleviate liver damage. In this study, three flavonoids namely myricetin, isoquercitrin, and isorhamnetin were isolated and identified from Laba garlic. The isolated compounds were investigated on the protective effects against H2 O2 -induced oxidative damages in hepatic L02 cells and apoptosis inducing mechanism in hepatic cancer cells HepG2 by using MTT assay, flow cytometry and western blotting analysis. Myricetin, isoquercitrin, and isorhamnetin showed proliferation inhibition on HepG2 cells with IC50 value of 44.32 ± 0.213 µM, 49.68 ± 0.192 µM, and 54.32 ± 0.176 µM, respectively. While they showed low toxicity on normal cell lines L02. They could significantly alleviate the oxidative damage towards L02 cells (P < 0.05), via inhibiting the morphological changes in mitochondria and upholding the integrity of mitochondrial structure and function. The fluorescence intensity of L02 cells pre-treated with myricetin, isoquercitrin, and isorhamnetin (100 µM) was 89.23 ± 1.26%, 89.35 ± 1.43% and 88.97 ± 0.79%, respectively. Moreover, the flavonoids could induce apoptosis in HepG2 cells via Bcl-2/Caspase pathways, where it could up-regulate the expression of Bax and down-regulate the expression of Bcl-2, Bcl-xL, pro-Caspase-3, and pro-Caspase-9 proteins in a dose dependent manner. Overall, the results suggested that the flavonoids from Laba garlic might be a promising candidate for the treatment of various liver disorders. PRACTICAL APPLICATION: Flavonoids from Laba garlic showed selective toxicity towards HepG2 cells in comparison to L02 cells via regulating Bcl-2/caspase pathway. Additionally, the isolated flavonoids expressively barred the oxidative damage induced by H2 O2 in L02 cells. These results suggested that the flavonoids from laba garlic could be a promising agent towards the development of functional foods.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Cardioprotection by isosteviol derivate JC105: A unique drug property to activate ERK1/2 only when cells are exposed to hypoxia-reoxygenation

Mohammed Abdul KS, Rayadurgam J, Faiz N, Jovanović A, Tan W

J Cell Mol Med, 2020 09;24(18):10924-10934.
PMID: 32794652 DOI: 10.1111/jcmm.15721

In the present study, we have investigated potential cardioprotective properties of Isosteviol analogue we recently synthesized and named JC105. Treatment of heart embryonic H9c2 cells with JC105 (10 μM) significantly increased survival of cells exposed to hypoxia-reoxygenation. JC105 (10 μM) activated ERK1/2, DRP1 and increased levels of cardioprotective SUR2A in hypoxia-reoxygenation, but did not have any effects on ERK1/2, DRP1 and/or SUR2A in normoxia. U0126 (10 μM) inhibited JC105-mediated phosphorylation of ERK1/2 and DRP1 without affecting AKT or AMPK, which were also not regulated by JC105. Seahorse bioenergetic analysis demonstrated that JC105 (10 μM) did not affect mitochondria at rest, but it counteracted all mitochondrial effects of hypoxia-reoxygenation. Cytoprotection afforded by JC105 was inhibited by U0126 (10 μM). Taken all together, these demonstrate that (a) JC105 protects H9c2 cells against hypoxia-reoxygenation and that (b) this effect is mediated via ERK1/2. The unique property of JC105 is that selectively activates ERK1/2 in cells exposed to stress, but not in cells under non-stress conditions.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Sodium nitrite exerts an antihypertensive effect and improves endothelial function through activation of eNOS in the SHR

Ling WC, Murugan DD, Lau YS, Vanhoutte PM, Mustafa MR

Sci Rep, 2016 09 12;6:33048.
PMID: 27616322 DOI: 10.1038/srep33048

Sodium nitrite (NaNO2) induces relaxation in isolated arteries partly through an endothelium-dependent mechanism involving NO-eNOS-sGC-cGMP pathway. The present study was designed to investigate the effect of chronic NaNO2 administration on arterial systolic blood pressure (SBP) and vascular function in hypertensive rats. NaNO2 (150 mg L-1) was given in drinking water for four weeks to spontaneously (SHR) and Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) treated hypertensive SD rats. Arterial SBP and vascular function in isolated aortae were studied. Total plasma nitrate/nitrite and vascular cyclic guanosine monophosphate (cGMP) levels were measured using commercially available assay kits. Vascular nitric oxide (NO) levels were evaluated by DAF-FM fluorescence while the proteins involved in endothelial nitric oxide synthase (eNOS) activation was determined by Western blotting. NaNO2 treatment reduced SBP, improved the impaired endothelium-dependent relaxation, increased plasma total nitrate/nitrite level and vascular tissue NO and cGMP levels in SHR. Furthermore, increased presence of phosphorylated eNOS and Hsp-90 was observed in NaNO2-treated SHR. The beneficial effect of nitrite treatment was not observed in L-NAME treated hypertensive SD rats. The present study provides evidence that chronic treatment of genetically hypertensive rats with NaNO2 improves endothelium-dependent relaxation in addition to its antihypertensive effect, partly through mechanisms involving activation of eNOS.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext In vitro and in vivo anti-angiogenic activities of Panduratin A

Lai SL, Cheah SC, Wong PF, Noor SM, Mustafa MR

PLoS One, 2012;7(5):e38103.
PMID: 22666456 DOI: 10.1371/journal.pone.0038103

BACKGROUND: Targeting angiogenesis has emerged as an attractive and promising strategy in anti-cancer therapeutic development. The present study investigates the anti-angiogenic potential of Panduratin A (PA), a natural chalcone isolated from Boesenbergia rotunda by using both in vitro and in vivo assays.
METHODOLOGY/PRINCIPAL FINDINGS: PA exerted selective cytotoxicity on human umbilical vein endothelial cells (HUVECs) with IC(50) value of 6.91 ± 0.85 µM when compared to human normal fibroblast and normal liver epithelial cells. Assessment of the growth kinetics by cell impedance-based Real-Time Cell Analyzer showed that PA induced both cytotoxic and cytostatic effects on HUVECs, depending on the concentration used. Results also showed that PA suppressed VEGF-induced survival and proliferation of HUVECs. Furthermore, endothelial cell migration, invasion, and morphogenesis or tube formation demonstrated significant time- and dose-dependent inhibition by PA. PA also suppressed matrix metalloproteinase-2 (MMP-2) secretion and attenuated its activation to intermediate and active MMP-2. In addition, PA suppressed F-actin stress fiber formation to prevent migration of the endothelial cells. More importantly, anti-angiogenic potential of PA was also evidenced in two in vivo models. PA inhibited neo-vessels formation in murine Matrigel plugs, and angiogenesis in zebrafish embryos.
CONCLUSIONS/SIGNIFICANCE: Taken together, our study demonstrated the distinctive anti-angiogenic properties of PA, both in vitro and in vivo. This report thus reveals another biological activity of PA in addition to its reported anti-inflammatory and anti-cancer activities, suggestive of PA's potential for development as an anti-angiogenic agent for cancer therapy.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Aqueous fraction of Nephelium ramboutan-ake rind induces mitochondrial-mediated apoptosis in HT-29 human colorectal adenocarcinoma cells

Chan CK, Goh BH, Kamarudin MN, Kadir HA

Molecules, 2012 May 31;17(6):6633-57.
PMID: 22728359 DOI: 10.3390/molecules17066633

The aim of this study was to investigate the cytotoxic and apoptotic effects of Nephelium ramboutan-ake (pulasan) rind in selected human cancer cell lines. The crude ethanol extract and fractions (ethyl acetate and aqueous) of N. ramboutan-ake inhibited the growth of HT-29, HCT-116, MDA-MB-231, Ca Ski cells according to MTT assays. The N. ramboutan-ake aqueous fraction (NRAF) was found to exert the greatest cytotoxic effect against HT-29 in a dose-dependent manner. Evidence of apoptotic cell death was revealed by features such as chromatin condensation, nuclear fragmentation and apoptotic body formation. The result from a TUNEL assay strongly suggested that NRAF brings about DNA fragmentation in HT-29 cells. Phosphatidylserine (PS) externalization on the outer leaflet of plasma membranes was detected with annexin V-FITC/PI binding, confirming the early stage of apoptosis. The mitochondrial permeability transition is an important step in the induction of cellular apoptosis, and the results clearly suggested that NRAF led to collapse of mitochondrial transmembrane potential in HT-29 cells. This attenuation of mitochondrial membrane potential (Δψm) was accompanied by increased production of ROS and depletion of GSH, an increase of Bax protein expression, and induced-activation of caspase-3/7 and caspase-9. These combined results suggest that NRAF induces mitochondrial-mediated apoptosis.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext C-phycocyanin confers protection against oxalate-mediated oxidative stress and mitochondrial dysfunctions in MDCK cells

Farooq SM, Boppana NB, Devarajan A, Asokan D, Sekaran SD, Shankar EM, et al.

PLoS One, 2014;9(4):e93056.
PMID: 24691130 DOI: 10.1371/journal.pone.0093056

Oxalate toxicity is mediated through generation of reactive oxygen species (ROS) via a process that is partly dependent on mitochondrial dysfunction. Here, we investigated whether C-phycocyanin (CP) could protect against oxidative stress-mediated intracellular damage triggered by oxalate in MDCK cells. DCFDA, a fluorescence-based probe and hexanoyl-lysine adduct (HEL), an oxidative stress marker were used to investigate the effect of CP on oxalate-induced ROS production and membrane lipid peroxidation (LPO). The role of CP against oxalate-induced oxidative stress was studied by the evaluation of mitochondrial membrane potential by JC1 fluorescein staining, quantification of ATP synthesis and stress-induced MAP kinases (JNK/SAPK and ERK1/2). Our results revealed that oxalate-induced cells show markedly increased ROS levels and HEL protein expression that were significantly decreased following pre-treatment with CP. Further, JC1 staining showed that CP pre-treatment conferred significant protection from mitochondrial membrane permeability and increased ATP production in CP-treated cells than oxalate-alone-treated cells. In addition, CP treated cells significantly decreased the expression of phosphorylated JNK/SAPK and ERK1/2 as compared to oxalate-alone-treated cells. We concluded that CP could be used as a potential free radical-scavenging therapeutic strategy against oxidative stress-associated diseases including urolithiasis.

Matched MeSH terms: Enzyme Activation/drug effects
Fulltext Anti- and pro-lipase activity of selected medicinal, herbal and aquatic plants, and structure elucidation of an anti-lipase compound

Ado MA, Abas F, Mohammed AS, Ghazali HM

Molecules, 2013;18(12):14651-69.
PMID: 24287996 DOI: 10.3390/molecules181214651

Plants that help in slowing down the digestion of triacylglycerols (TAGs) in the pancreas and small intestine of humans play an important role in the reduction of obesity. On the other hand, there may be plants or plant parts that stimulate intestinal lipolytic activity, thus contributing to greater TAG assimilation. The aim of this study was to evaluate the aqueous methanolic extracts of ninety eight (98) medicinal, herbal and aquatic plant materials from Malaysia for their effect on porcine pancreatic lipase (PPL) activity and to identify the structure of an anti-lipase compound from one of the sources. The degree of inhibition was also quantified as relative to orlistat activity against PPL (orlistat equivalents). Results revealed that while 19.4% of the extracts were found to have anti-lipase activity ≥80%, 12% were actually found to promote PPL activity. Twenty two percent (22.4%) exhibited moderate inhibition (41%-80%) and 2% were neutral toward PPL activity. The ripe fruit of Averrhoa carambola and the leaves of Archidendron jiringa (Jack) I.C Nielsen L. (jering), Cynometra cauliflora (nam-nam) and Aleurites moluccana (L.) Willd (candle nut/buah keras) had the highest (100%) anti-lipase activity and are equivalent to 0.11 µg orlistat/mL. Plants that stimulated lipase activity included Pimpinella anisum L. (aniseed/jintan manis), activating the enzyme by 186.5%. Kaempferol 3-O-rhamnoside was isolated from the ethyl acetate fraction of C. cauliflora leaves and found to be an active lipase inhibitor. The structure was elucidated using 1H-NMR, 13C-NMR and 2D-NMR analyses.

Matched MeSH terms: Enzyme Activation/drug effects

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