Browsing by Author "Samarakoon, S.R."

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Anti-hepatocarcinogenic and anti-oxidant effects of mangrove plant scyphiphora hydrophyllace
(Medknow Publications and Media, 2017) Samarakoon, S.R.; Shanmuganathan, C.; Ediriweera, M.K.; Piyathilaka, P.; Tennekoon, K.H.; Thabrew, I.; Galhena, P.; de Silva, E.D.
CONTEXT: Scyphiphora hydrophyllacea is a shrub mangrove plant of the family Rubiaceae and not yet been studied for anti-hepatocarcinogenic effects. OBJECTIVES: We investigated possible in vitro anti-hepatocarcinogenic and antioxidant properties of S. hydrophyllacea. MATERIALS AND METHODS: Dried leaves of S. hydrophyllacea were sequentially extracted into hexane, chloroform, ethyl acetate, and methanol and tested for cytotoxicity on HepG2 cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and sulforhodamine B assays, and for antioxidant activities by the free radical 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) assays. Total phenolic and flavonoid contents were estimated in all four extracts. The hexane and chloroform extracts were tested for pro-apoptotic properties in HepG2 cells, and bioactive components were identified by gas chromatography-mass spectrometry (GC-MS) analysis. RESULTS: The hexane and chloroform extracts showed dose-dependent and time-dependent cytotoxic effects. Morphological changes observed under fluorescence microscope related to apoptosis, and significant (P < 0.001) increases in caspase 3 and 9 levels were observed in hexane and chloroform extract-treated cells. Slight DNA fragmentation was observed only in response to the chloroform extract. mRNA expressions of p53 and Bax were significantly upregulated by low doses of hexane and chloroform extracts. Highest antioxidant activity was observed in the methanol extract. GC-MS profiles identified 24 and four major compounds in the hexane and chloroform extracts, respectively. These included some known anticancer compounds such as lupeol. CONCLUSION: Cytotoxicity, antioxidant effects, and apoptosis-related changes exerted by hexane and chloroform extracts of S. hydrophyllacea concluded that these two extracts are good source for isolation of possible anticarcinogenic compounds. SUMMARY: The hexane and chloroform extracts of Scyphiphora hydrophyllacea showed dose-dependent and time-dependent cytotoxic effects.Morphological changes related to apoptosis and significant (P < 0.001) increases in caspase 3 and 9 levels were observed in hexane and chloroform extract-treated cells.mRNA expressions of p53 and Bax were significantly upregulated by low doses of hexane and chloroform extracts.Highest antioxidant activity was observed in the methanol extract.GC-MS profiles identified 24 and four major compounds in the hexane and chloroform extracts, respectively. Abbreviation used: DPPH: 1,1-diphenyl-2-picryl-hydrazyl, ABTS: 2,2'-azinobis-3-ethylbenzthiazoline-6-sulfonic acid, GC-MS: gas chromatography-mass spectrometry, DNA: deoxyribonucleic acid, HCC: Hepatocellular carcinoma, GAE: gallic acid equivalents, SRB: sulforhodamine B, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, AO/EB: acridine orange/ethidium bromide, GAPDH: Glyceraldehyde 3-phosphate dehydrogenase, IC50: half maximal inhibitory concentration; QE: quercetin equivalents, HE: hexane extract, CE: chloroform extract, EAE: ethyl acetate extract, ME: methanolic extract, TPC: total polyphenol content, TFC: total flavonoid content, ANOVA: Analysis of variance.
Anti-Inflammatory activity is a possible mechanism by which the polyherbal formulation comprised of Nigella sativa (Seeds), Hemidesmus indicus (Root), and Smilax glabra (Rhizome) mediates its antihepatocarcinogenic effects
(Hindawi Pub, 2012) Galhena, P.B.; Samarakoon, S.R.; Thabrew, M.I.; Weerasinghe, G.A.; Thammitiyagodage, M.G.; Ratnasooriya, W.; Tennekoon, K.H.
The present study investigated the anti-inflammatory effects of a polyherbal decoction comprised of Nigella sativa, Hemidesmus indicus, and Smilax glabra in order to justify its claimed antihepatocarcinogenic activity. Activation of hepatic nuclear factor-kappa B (NF-κB), IκB kinase (IKK α/β) proteins, and TNFα and IL-6 expression was investigated in diethylnitrosamine- (DEN-) induced C3H mice-bearing early hepatocarcinogenic changes. Acute phase inflammatory response was evaluated by carrageenan-induced rat paw edema formation. Anti-inflammatory mechanisms were also assessed by determining effect on (a) membrane stabilization, (b) nitric oxide (NO) inhibitory activity, and (c) inhibition of leukocyte migration. A significant inhibition of the paw edema formation was observed in healthy rats as well as in rats bearing early hepatocarcinogenic changes with oral administration of the decoction. As with the positive control, indomethacin (10 mg/kg b.w.) the inhibitory effect was pronounced at 3rd and 4th h after carrageenan injection. A notable IKK α/β mediated hepatic NF-κB inactivation was associated with a significant hepatic TNFα down regulation among mice-bearing hepatocarcinogenic changes subjected to decoction treatment. Inhibition of NO production, leukocyte migration, and membrane stabilization are possible mechanisms by which anti-inflammatory effect is mediated by the decoction. Overall findings imply that anti-inflammatory activity could
A Comparison of the cytotoxic potential of standardized aqueous and ethanolic extracts of a polyherbal mixture comprised of Nigella sativa (seeds), Hemidesmus indicus (roots) and Smilax glabra (rhizome)
(Medknow Publications, 2010) Samarakoon, S.R.; Thabrew, I.; Galhena, P.B.; de Silva, D.; Tennekoon, K.H.
BACKGROUND: A decoction (hot-water extract) comprised of Nigella sativa (seeds), Hemidesmus indicus (roots), and Smilax glabra (rhizome) has been reported to prevent chemically-induced hepatocarcinogenic changes in rats and to exert significant cytotoxic effects on human hepatoma (HepG2) cells. However, the decoction used in previous studies to determine cytotoxicity was not standardized. Further, during preparation of pharmaceuticals for clinical use, it is more convenient to use an ethanolic extract. Therefore this study was carried out to (a) develop standardizedaqueous and ethanolic extracts of the plant mixture (N. sativa, H. indicus, and S. glabra) used in the preparation of the original decoction, and (b) compare the cytotoxic effects of these two extracts by evaluating cytotoxicity to the human hepatoma (HepG2) cell line. METHODS: Aqueous and ethanolic extracts have been standardized by evaluating organoleptic characters, physicochemical properties, qualitative and quantitative analysis of chemical constituents, and analysis of High Performance Liquid Chromatography (HPLC) and Thin Layer Chromatography (TLC) profiles. Cytotoxic potentials of the above standardized extracts were compared by evaluating their effects on the survival and overall cell activity of HepG2 cells by use of the 3-(4, 5-dimethylthiazol-2yl) -2, 5 - biphenyl tetrazolium bromide (MTT) and Sulphorhodamine B (SRB) assays. RESULTS: Results from MTT and SRB assays demonstrated that both extracts exerted strong dose-dependent in vitro cytotoxicity to HepG2 cells. The standardized aqueous extract showed a marginally (though significantly, P<0.05) higher cyotoxic potential than the ethanolic extract. Thymoquinone, an already known cytotoxic compound isolated from N. sativa seeds was only observed in the standardized ethanolic extract. Thus, compounds other than thymoquinone appear to mediate the cytotoxicity of the standardized aqueous extract of this poly-herbal preparation. CONCLUSION: It may be concluded that results obtained in the present study could be used as a diagnostic tool for the correct identification of these aqueous or ethanolic extracts and would be useful for the preparation of a standardized pharmaceutical product that may be used in the future for clinical therapy of hepatocellular carcinoma.
Cytotoxic and apoptotic effect of the decoction of the aerial parts of Flueggea leucopyrus on human endometrial carcinoma (AN3CA) cells
(Pharmacotherapy Group, University of Benin, Nigeria, 2014) Samarakoon, S.R.; Kotigala, S.B.; Gammana-Liyanage, I.; Thabrew, I.; Tennekoon, K.H.; Siriwardana, A.; Galhena, P.B.
PURPOSE: To evaluate the anti-cancer potentials of a decoction of Flueggea. leucopyrus (Willd.) on human endometrial carcinoma (AN3CA) cells. METHODS: Decoction was prepared by boiling 60 g of the ground plant material in 1.6 L of distilled water for about 3 h to reduce the volume to 200 mL and then freeze dried. The effect of the decoction on AN3CA cells was determined by evaluating its cytotoxicity by 3-(4, 5-dimethylthiazol-2yl) -2, 5-biphenyl tetrazolium bromide (MTT) and sulphorhodamine B (SRB) assays, as well as its ability to modulate apoptosis (microscopic observation of morphological changes, DNA fragmentation and caspase activity). The antioxidant activity of the decoction was also determined by DPPH assay, and its total polyphenolic and flavonoid content. RESULTS: The decoction exerted a significant dose-dependent cytotoxicity on AN3CA cells as evident from MTT assay IC50 values of 22.09 and 14.60 µg/mL at 24 and 48 h post-incubation, respectively; and SRB assay IC50 values of 28.60 and 15.09 µg/mL at 24 and 48 h post-incubation, respectively. The decoction also enhanced apoptosis as shown by enhanced DNA fragmentation, microscopic observation of nuclear condensation, fragmentation and apoptotic bodies and enhanced caspase 3 and 9 activities, as well as moderately increased radical scavenging activity. CONCLUSION: The cytotoxic and apoptotic effects demonstrated by F. leucopyrus (Willd.) decoction provide supportive evidence for the ethnomedicinal use of this plant for cancer therapy. Copyright of Tropical Journal of Pharmaceutical Research
Effect of standardized decoction of Nigella sativa seed, Hemidesmus indicus root and smilax glabra rhizome on the expression of p53 and p21 genes in human hepatoma cells (HepG2) and mouse liver with chemically-induced hepatocarcinogenesis
(University of Benin, 2012) Samarakoon, S.R.; Thabrew, I.; Galhena, P.B.; Tennekoon, K.H.
PURPOSE: To evaluate in vitro (using human hepatoma HepG2 cells) and in vivo (using mouse liver with diethlynitrosamine (DEN)-induced hepatocarcinogenesis) effect of a standardized decoction on the expression of p53 (tumour suppressor) and p21 (cyclin kinase inhibitor) genes with the long-term goal of developing the formulation into a globally acceptable therapy for hepatocellular carcinoma (HCC). METHODS: The effect of the decoction on (a) mRNA and (b) protein expression of p53 and p21 genes in HepG2 cells and mouse livers with DEN-induced early hepatocarcinogenesis were evaluated by (a) reverse transcription PCR (RT-PCR) and (b) immunohistochemical and Western blot analysis, respectively. RESULTS: The results demonstrated that the decoction significantly (p < 0.001) enhanced the expression of p53 and p21 genes in a time-and dose-dependent manner in HepG2 cells. A dose of 75 μg/ml significantly increased p53 mRNA at 24 and 48 h and p21 mRNA at 12, 24, 48 h of incubation with the decoction (p < 0.01). Induction of hepatocarcinogenesis in mice significantly increased hepatic expression of both p53 and p21 compared to distilled water control (p < 0.001), while treatment with the decoction further enhanced expression of both genes in DEN-induced hepatocarcinogenesis (p < 0.01). CONCLUSION: Overall, the findings demonstrate that the decoction may mediate its reported antihepatocarcinogenic effect, at least in part, through the modulating activities of genes involved in tumour suppression and cell cycle arrest. All rights reserved. © Pharmacotherapy Group. All rights reserved.
Effect of standardized decoction of Nigella sativa seed, Hemidesmusindicus root and Smilax glabra rhizome on the expression of p53 and p21 genes in human hepatoma cells (HepG2) and mouse liver with chemically-induced hepatocarcinogenesis
(Pharmacotherapy Group, University of Benin, Nigeria, 2012) Samarakoon, S.R.; Thabrew, I.; Galhena, P.B.; Tennekoon, K.H.
Purpose: To evaluate in vitro (using human hepatoma HepG2 cells) and in vivo (using mouse liver with diethlynitrosamine (DEN)-induced hepatocarcinogenesis) effect of a standardized decoction on the expression of p53 (tumour suppressor) and p21 (cyclin kinase inhibitor) genes with the long-term goal of developing the formulation into a globally acceptable therapy for hepatocellular carcinoma (HCC). Methods: The effect of the decoction on (a) mRNA and (b) protein expression of p53 and p21 genes in HepG2 cells and mouse livers with DEN-induced early hepatocarcinogenesis were evaluated by (a) reverse transcription PCR (RT-PCR) and (b) immunohistochemical and Western blot analysis, respectively. Results: The results demonstrated that the decoction significantly (p < 0.001) enhanced the expression of p53 and p21 genes in a time- and dose-dependent manner in HepG2 cells. A dose of 75 Âµg/ml significantly increased p53 mRNA at 24 and 48 h and p21 mRNA at 12, 24, 48 h of incubation with the decoction (p < 0.01). Induction of hepatocarcinogenesis in mice significantly increased hepatic expression of both p53 and p21 compared to distilled water control (p < 0.001), while treatment with the decoction further enhanced expression of both genes in DEN-induced hepatocarcinogenesis (p < 0.01). Conclusion: Overall, the findings demonstrate that the decoction may mediate its reported antihepatocarcinogenic effect, at least in part, through the modulating activities of genes involved in tumour suppression and cell cycle arrest.
In silico identification and in vitro validation of alpha-hederin as a potent inhibitor of Wnt/β-catenin signaling pathway in breast cancer stem cells.
(Springer-Verlag, GmbH, 2024) Saliu, T.P.; Seneviratne, N.N.; Faizan, M.; Rajagopalan, U.; Perera, D.C.; Adhikari, A.; Senathilake, K.S.; Galhena, P.B.; Tennekoon, K.H.; Samarakoon, S.R.
Cancer stem cells (CSCs) play a vital role in metastasis, recurrence and chemoresistance in breast cancer. β-catenin, which is a frequently over activated protein in CSCs, binds to T-cell factor/lymphoid enhancer factor (Tcf/Lef) family transcription factors leading to ectopic expression of Wnt pathway responsive genes necessary for the maintenance and action of CSCs. With the aim of identifying a small molecules that can effectively eliminate CSCs, molecular docking studies were performed against the Tcf/Lef binding hotspot on β-catenin using a library of 100 natural or synthetic small molecules. Small molecule ligands giving docking energy better than - 7 kcal/mol were further investigated by binding interactions analysis and molecular dynamics (MD) simulations. These compounds were then investigated in vitro, for cytotoxicity against CSCs isolated from MDA-MB-231 triple negative breast cancer cells. Alpha-hederin (AH) was identified as the only compound in the selected library that has cytotoxicity against breast CSCs. AH was further investigated for it's ability to regulate Wnt pathway target genes (Cyclin D1 and CD44)and the tumor suppressor p53by real-time quantitative PCR. Absorption, distribution, metabolism, excretion and toxicity properties of the AH was predicted in silico. AH significantly down regulated the transcription of Cyclin D1 and CD44 while up-regulating the transcription of p53. AH was predicted to have acceptable drug likeness. Although AH is currently known to inhibit the growth of various cancer cells in vitro, present study demonstrated for the first time that it is a potent inhibitor of Wnt/β-catenin signaling pathway and induce apoptosis in breast CSCs.
In vitro anticancer effect of gedunin on human teratocarcinomal (NTERA-2) cancer stem-like cells
(Hindawi, 2017) Tharmarajah, L.; Samarakoon, S.R.; Ediriweera, M.K.; Piyathilaka, P.; Thennakoon, K.H.; Senathilake, K.S.; Rajagopalan, U.; Galhena, P.B.; Thabrew, I.
Gedunin is one of the major compounds found in the neem tree (Azadirachta indica). In the present study, antiproliferative potential of gedunin was evaluated in human embryonal carcinoma cells (NTERA-2, a cancer stem cell model) and peripheral blood mononuclear cells (PBMCs), using Sulforhodamine (SRB) and WST-1 assays, respectively. The effects of gedunin on expression of heat shock protein 90 (HSP90), its cochaperone Cdc37, and HSP client proteins (AKT, ErbB2, and HSF1) were evaluated by real-time PCR. Effects of gedunin on apoptosis were evaluated by (a) apoptosis associated morphological changes, (b) caspase 3/7 expression, (c) DNA fragmentation, (d) TUNEL assay, and (e) real-time PCR of apoptosis related genes (Bax, p53, and survivin). Gedunin showed a promising antiproliferative effect in NTERA-2 cells with IC50 values of 14.59, 8.49, and 6.55 μg/mL at 24, 48, and 72 h after incubations, respectively, while exerting a minimal effect on PBMCs. Expression of HSP90, its client proteins, and survivin was inhibited and Bax and p53 were upregulated by gedunin. Apoptosis related morphological changes, DNA fragmentation, and increased caspase 3/7 activities confirmed the proapoptotic effects of gedunin. Collectively, results indicate that gedunin may be a good drug lead for treatment of chemo and radiotherapy resistant cancer stem cells.
Modulation of apoptosis in human hepatocellular carcinoma (HepG2 cells) by a standardized herbal decoction of Nigella sativa seeds, Hemidesmus indicus roots and Smilax glabra rhizomes with anti- hepatocarcinogenic effects
(BioMed Central, 2012) Samarakoon, S.R.; Thabrew, I.; Galhena, P.B.; Tennekoon, K.H.
BACKGROUND A standardized poly-herbal decoction of Nigella sativa seeds, Hemidesmus indicus roots and Smilax glabra rhizomes used traditionally in Sri Lanka for cancer therapy has been demonstrated previously, to have anti-hepatocarcinogenic potential. Cytotoxicity, antioxidant activity, anti-inflammatory activity, and up regulation of p53 and p21 activities are considered to be some of the possible mechanisms through which the above decoction may mediate its anti-hepatocarcinogenic action. The main aim of the present study was to determine whether apoptosis is also a major mechanism by which the decoction mediates its anti-hepatocarcinogenic action. METHODS Evaluation of apoptosis in HepG2 cells was carried out by (a) microscopic observations of cell morphology, (b) DNA fragmentation analysis, (c) activities of caspase 3 and 9, as well as by (d) analysis of the expression of pro-apoptotic (Bax) and anti-apoptotic (Bcl-2) proteins associated with cell death. RESULTS The results demonstrated that in HepG2 cells, the decoction can induce (a) DNA fragmentation and (b) characteristic morphological changes associated with apoptosis (nuclear condensation, membrane blebbing, nuclear fragmentation and apoptotic bodies). The decoction could also, in a time and dose dependent manner, up regulate the expression of the pro-apoptotic gene Bax and down regulate expression of anti-apoptotic Bcl-2 gene (as evident from RT-PCR analysis, immunohistochemistry and western blotting). Further, the decoction significantly (p < .001) enhanced the activities of caspase-3 and caspase-9 in a time and dose dependent manner. CONCLUSIONS Overall findings provide confirmatory evidence to demonstrate that the decoction may mediate its reported anti-hepatocarcinogenic effect, at least in part, through modulation of apoptosis.
Synthesis of C-11 and C-12 oxidized derivatives of3β-[(α-Larabinopyranosyl)oxy]olean-12-en-28-oic acid and evaluation of their cytotoxic activity in human non-small cell lung cancer (NCI-H292) cells using Sulforhodamine B assay
(Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Jayasundara, J.M.J.; Wickramasinghe, A.; Karunaratne, D.N.; Wickramaratne, N.S.; Samarakoon, S.R.; Jayasinghe, S.
The most common cancer, lung cancer is the foremost reason for cancer deaths in both males and females throughout the world. The two major categories of lung cancer which propagate differently are Non-small cell lung cancer (NSCLC) and Small cell lung cancer (SCLC). Among those NSCLCs are the most prevalent lung cancers, contributing 80% of all lung cancers. Natural products represent the bedrock of drug discovery, providing novel scaffold structures that serve as a starting point for developing novel therapeutic agents. A number of new drugs with improved therapeutic potential have been obtained from natural sources, by functional group modifications or by the synthesis of new compounds, following lead natural compounds as models. The recurrence of cancer due to the drug resistance and undesirable side effects which have limited the use of anticancer drugs, have increased the demand for novel alternative therapeutics with enhanced pharmacological activity and fewer side effects. Hence, the synthesis of natural product derived compound libraries in the discovery of novel drugs is still a key aspect of cancer therapy. 3β-[(α-L-arabinopyranosyl)oxy]olean-12-en-28-oic acid (APOA) is a triterpenoid saponin with the oleanolic acid aglycone linked to arabinopyranose sugar moiety and can be easily isolated from endemic plant extracts of genus Schumacheria. This compound exerts potent cytotoxic and apoptotic potential in human NSCLC cells (NCI-H292) with an IC50 value of 5.977 μgmL-1 while exhibiting a comparable toxicity value (IC50 = 5.702 μgmL-1 ) against normal lung (MRC-5) cells. The objective of this study was to synthesize oxidized structural analogues at C-11 and C-12 positions of the APOA and to evaluate their cytotoxic effect. Sulforhodamine B (SRB) assay is used to evaluate in-vitro cytotoxic efficacy of the synthesized analogues on NCI-H292 cells and MRC-5 cells. The methylene group at the C-11 and methine group at C-12 of the ethyl ester of acetylated APOA (Ee-Ac-APOA) was oxidized to afford respective ketones and followed by deacetylation of the afforded analogues resulted in the oxidized analogues with free sugar hydroxyls (Ee-APOA). Chemical structures of the synthesized analogues were confirmed with spectroscopic data and comparative cytotoxic effects of the synthesized analogues were assessed using SRB assay against APOA. GraphPad Prism 7.00 software was used for statistical analysis and the results indicated that the oxidized analogues of Ee-APOA exhibit higher cytotoxicity against NCI-H292 cells than the oxidized derivatives of Ee-Ac-APOA while exhibiting comparable toxicity values against normal lung (MRC-5) cells. However, the α, β-unsaturated derivative of Ee-Ac-APOA exhibited potent cytotoxic activity against NCI-H292 cells while being less toxic to normal MRC-5 cells compared to the parental saponin indicating better activity. These empirical data suggest that the oxidized compounds at C-11 and C-12 of APOA could be a lead to develop promising new anticancer agents.