Hasnah Mohd Sirat

Combined xanthorrhizol-curcumin exhibits synergistic growth inhibitory activity via apoptosis induction in human breast cancer cells MDA-MB-231

BackgroundIt has been suggested that combined effect of natural products may improve the treatment effectiveness in combating proliferation of cancer cells. The present study was undertaken to evaluate the possibility that the combination of xanthorrhizol and curcumin might show synergistic growth inhibitory effect towards MDA-MB-231 human breast cancer cells via apoptosis induction. The effective dose that produced 50% growth inhibition (GI50) was calculated from the log dose-response curve of fixed-combinations of xanthorrhizol and curcumin generated from the sulforhodamine B (SRB) assay. The experimental GI50 value was used to determine the synergistic activity of the combination treatment by isobolographic analysis and combination-index method. Further investigation of mode of cell death induced by the combination treatment was conducted in the present study.ResultsIsobole analysis revealed that substances interaction was synergistic when xanthorrhizol and curcumin were added concurrently to the cultures but merely additive when they were added sequentially. The synergistic combination treatment was then applied to the cultures to investigate the mode of cell death induced by the treatment. Immunofluorescence staining using antibody MitoCapture™ revealed the possibility of altered mitochondrial transmembrane potential, which is one of the hallmark of apoptosis. Hoechst 33258 nuclear staining assay showed the rate of apoptosis of MDA-MB-231 cells to increase in response to the treatment. Apoptotic cell death was further confirmed by DNA fragmentation assay, where internucleosomal excision of DNA was induced upon treatment with xanthorrhizol-curcumin.ConclusionThis is the first time the combined cytotoxic effect of xanthorrhizol and curcumin on MDA-MB-231 cells has been documented and our findings provide experimental support to the hypothesis that combined xanthorrhizol-curcumin showed synergistic growth inhibitory activity on MDA-MB-231 cells via apoptosis induction.

Anti-inflammatory activities of cucurbitacin E isolated from Citrullus lanatus var. citroides: Role of reactive nitrogen species and cyclooxygenase enzyme inhibition

The in vivo and in vitro mechanistic anti-inflammatory actions of cucurbitacin E (CE) (Citrullus lanatus var. citroides) were examined. The results showed that LPS/INF-γ increased NO production in RAW264.7 macrophages, whereas L-NAME and CE curtailed it. CE did not reveal any cytotoxicity on RAW264.7 and WRL-68 cells. CE inhibited both COX enzymes with more selectivity toward COX-2. Intraperitoneal injection of CE significantly suppressed carrageenan-induced rats paw edema. ORAC and FRAP assays showed that CE is not a potent ROS scavenger. It could be concluded that CE is potentially useful in treating inflammation through the inhibition of COX and RNS but not ROS.

The distribution of labdane diterpenes in the zingiberaceae of Malaysia

Labda-8(17),12-diene-15,16-dial and coronarin E were isolated from the chloroform extract of the rhizomes of Alpinia javanica. The structures were elucidated spectroscopically. This is the first report of the isolation of coronarin E from Alpinia species. The distribution of these two labdane diterpenes within the Zingiberaceae is reported

Chemical compositions, antioxidant and antimicrobial activities of essential oils of Piper caninum Blume.

Chemical composition, antioxidant and antimicrobial activities of the fresh leaves and stems oils of Piper caninum were investigated. A total of forty eight constituents were identified in the leaves (77.9%) and stems (87.0%) oil which were characterized by high proportions of phenylpropanoid, safrole with 17.1% for leaves and 25.5% for stems oil. Antioxidant activities were evaluated by using β-carotene/linoleic acid bleaching, DPPH radical scavenging and total phenolic content. Stems oil showed the highest inhibitory activity towards lipid peroxidation (114.9 ± 0.9%), compared to BHT (95.5 ± 0.5%), while leaves oil showed significant total phenolic content (27.4 ± 0.5 mg GA/g) equivalent to gallic acid. However, the essential oils showed weak activity towards DPPH free-radical scavenging. Evaluation of antimicrobial activity revealed that both oils exhibited strong activity against all bacteria strains with MIC values in the range 62.5 to 250 μg/mL, but weak activity against fungal strains. These findings suggest that the essential oils can be used as antioxidant and antimicrobial agents for therapeutic, nutraceutical industries and food manufactures.

A new prenylated dihydrochalcone from the leaves of Artocarpus lowii

A new prenylated dihydrochalcone, 2′,4′-dihydroxy-4-methoxy-3′-prenyldihydrochalcone (1), along with two known compounds, 2′,4′,4-trihydroxy-3′-prenylchalcone (2) and 2′,4-dihydroxy-3′,4′-(2,2-dimethylchromene)chalcone (3) were isolated from the leaves of Artocarpus lowii. The structures of 1–3 were elucidated by spectroscopic methods and by comparison with data reported in the literature. Compounds 1–3 showed strong free radical scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) measured by electron spin resonance (ESR) spectrometry.

Essential oil of Curcuma aeruginosa Roxb. from Malaysia

Abstract The essential oil of Curcuma aeruginosa Roxb. from Malaysia obtained by hydrodistillation of the rhizomes was analyzed by a combination of GC and GC/MS. Twenty-six components have been identified, of which the major constituents were found to be curzerenone (24.6%), 1,8-cineole (11.0%), camphor (10.6%), zedoarol (6.3%), isocurcumenol (5.8%), curcumenol (5.6%) and furanogermenone (5.5%). The structure elucidation of the sesquiterpenes were confirmed by IR, 1H- and 13C-NMR spectroscopies.

Isoflavones from root bark of gorse

Abstract Four novel complex isoflavones ulexones A, B, C and D, 5,7-dihydroxy-8-(3,3-dimethylallyl)-[6″,6″-dimethylpyrano (2″,3″:4′,3′)]-isoflavone, 5-hydroxy-[6″,6″-dimethylpyrano (2″,3″:4′,3′)] [6‴,6‴-dimethylpyrano (2‴,3‴:7,8)]-isoflavone, 5-hydroxy-[6″,6″-dimethylpyrano (2″,3″:4′,3′)] [1‴,2‴-dihydro-2‴-(1 -hydroxy-1 -methylethyl)-furano (4‴,5‴:7,8)]isoflavone, 5-hydroxy-[6″,6″-dimethylpyrano (2″,3″:4′,3′)] [6‴-methyl-6‴-(hydroxymethyl)-pyrano (2‴,3‴:7,8)]-isoflavone, have been isolated from the root bark of Ulex europaeus . Genistein and 5- O -methylgenistein were also present. Structures were established from the NMR spectra.

Chemical Composition of the Rhizome Oil of Alpinia conchigera Griff from Malaysia

ABSTRACT The essential oil isolated by hydrodistillation from the fresh rhizomes of Alpinia conchigera Griff was analyzed by capillary GC and GC/MS. More than 40 constituents were present in the oil, from which 34 components could be identified. The major components include β-sesquiphellandrene (20.5%), β-bisabolene (12.1%) and 1,8-cineole (11.6%).

Pharmacological Mechanisms Underlying Gastroprotective Activities of the Fractions Obtained from Polygonum minus in Sprague Dawley Rats

The leaves of Polygonum minus were fractionated using an eluting solvent to evaluate the pharmacological mechanisms underlying the anti-ulcerogenic activity of P. minus. Different P. minus fractions were obtained and evaluated for their ulcer preventing capabilities using the ethanol induction method. In this study, Sprague Dawley rats weighing 150–200 g were used. Different parameters were estimated to identify the active fraction underlying the mechanism of the gastroprotective action of P. minus: the gastric mucus barrier, as well as superoxide dismutase, total hexosamine, and prostaglandin synthesis. Amongst the five fractions from the ethanolic extract of P. minus, the ethyl acetate:methanol 1:1 v/v fraction (F2) significantly (p < 0.005) exhibited better inhibition of ulcer lesions in a dose-dependent manner. In addition, rats pre-treated with F2 showed a significant elevation in superoxide dismutase (SOD), hexosamine and PGE2 levels in the stomach wall mucosa in a dose-dependent matter. Based on these results, the ethyl acetate:methanol 1:1 v/v fraction was considered to be the best fraction for mucous protection in the ethanol induction model. The mechanisms underlying this protection were attributed to the synthesis of antioxidants and PGE2.

Chemical compositions of the rhizome oils of two Alpinia species of Malaysia

The essential oils obtained by hydrodistillation of the rhizomes of Alpinia aquatica Rosc. syn. Alpinia melanocarpa and Alpinia malaccensis Roscoe were analysed by capillary gas chromatography and gas chromatography–mass spectrometry. Eighteen compounds, representing 98.4% of the essential oil were identified in A. aquatica rhizome oil, with β-sesquiphellandrene in 36.5% being the major constituent, while 20 compounds representing 99.7% of the rhizome oil of A. malaccensis were identified, among which methyl (E)-cinnamate (78.2%) was the major constituent.