Polysaccharide from Spirulina platensis Evokes Antitumor Activity in Gastric Cancer Cells via Modulation of Galectin-3 and Exhibited Cyto/DNA Protection: Structure-Function Study.

Polysaccharides play significant role in the management of different cancer types including gastric cancer. Here, we report the effect of spirulina polysaccharide (Sp) on galectin-3 modulatory activity in gastric cancer cells (AGS). The isolated Sp possessed an average molecular weight of 1457 kDa and galactose (42%) as a major sugar consisting of (ß1-4d) units with a galactoarabinorhamnoglycan backbone. The Sp inhibited the proliferation of AGS cells by 48% without affecting normal NIH/3T3 cells as compared to doxorubicin, a known anticancer drug. Also, Sp exhibited significant (p < 0.05) galectin-3 mediated hemeagglutination inhibition with MIC of 9.37 µg/mL compared to galactose (6.25 µg/mL), a sugar specific to galectin-3. Galactose showed the highest molecular interaction with galectin-3 in the in silico study. In addition, Sp exhibited the cytoprotection in RBCs, buccal cells, and DNA exposed to oxidants. These findings suggest that Sp offers a promising therapeutic tool in the management of gastric cancer.

Gastro-protective potentials of Spirulina: role of vitamin B12.

Gastric ulcer is a chronic health problem world over. Spirulina is known to contain significant amounts of vitamin B12 hence Spirulina was evaluated for gastroprotective properties against gastric ulcerations. Spirulina biomass (SB) and Spirulina extract (SE) were evaluated in swim stress induced gastric ulcers in adult male albino rats. Both SB and SE inhibited 45% and 60% of ulcers formation induced by swim stress respectively. Gastroprotection has been elucidated to be due to inhibition of (a) upregulated H+, K+-ATPase activity that induced ulcer condition; (b) lipid peroxidation and (c) altered antioxidant enzyme levels. The data highlighted the importance of vitamin B12 in protecting the gut against gastric ulcerations and suggested that both Spirulina biomass and Spirulina extract contain bioavailable B12. Spirulina based product/food can be used as alternatives to gastroprotective agents that are known to cause acidity themselves upon long term use.

Disruption of galectin-3 and galectin-3 binding protein (G3BP) interaction by dietary pectic polysaccharides (DPP) - Arrest of metastasis, inhibition of proliferation and induction of apoptosis.

Galectin-3 and galectin-3 binding proteins (G3BP) are implicated as key players in metastasis. In the current study, we evaluated the effect of pectic polysaccharides on galectin-3 and G3BP mediated metastasis in vitro (cells) and in vivo (tissues). In vitro study (double immunostaining) confirms the presence of galectin-3 on the cell surface and G3BP in the interlinking region of the cells confirming the role of G3BP in bridging galectin-3 molecules. Dietary carrot (Daucus carota) pectic polysaccharide (CRPP) blocked the expression of galectin-3 and G3BP more effectively (80%), whereas the expressions were reduced to 60% upon treatment with swallow root (Decalepis hamiltonii) pectic polysaccharide (SRPP), ß­carotene and deferoxamine (antiproliferative drug). Ginger (Gingiber officinale) pectic polysaccharide (GRPP) showed only 20% reduction. CRPP reduced 80% of tumor incidence followed by cyclophosphamide - a chemotherapeutic drug (77%), SRPP (67%) and GRPP (45%). Further 3-5 folds reduction in galectin-3/G3BP expression followed by infiltration of macrophages into the deeper layer of the skin by CRPP and SRPP suggested the anticancer property via immunomodulation. Surface Plasmon Resonance (SPR) studies confirm galectin-3 and G3BP interaction, which are disrupted during the treatment with dietary pectic polysaccharides (DPP) (Supplementary Scheme-1). Overall data demonstrate the role of DPPs as potential anticancer alternatives.

Antioxidant and anti-inflammatory properties of marmelosin from Bael (Aegle marmelos L.); Inhibition of TNF-α mediated inflammatory/tumor markers.

Oxidative stress and inflammation are important critical factors that are implicated in almost all life style disorders such as diabetes, cardiovascular disease, ulcer and cancer. Current study aimed at isolation and characterization of a furanocoumarin from Bael (Aegle marmelos L.) fruit that can modulate both oxidative stress and inflammation effectively. Ethyl acetate extract of Bael fruit (EAFB) was subjected to HPLC for identification, purified and characterized using FTIR, NMR and ESI-MS analysis. Predominant peak of EAFB at RT 12.54 min on HPLC was identified as marmelosin with molecular weight of m/z ∼ 271.2. Marmelosin was evaluated for antioxidant, antiproliferative, apoptotic, cancer (Tyrosinase & Galectin-3) and immunomodulatory (NO, TNF-α) potentials employing standard assay systems. Marmelosin possessed potent antioxidant activity with IC50 of ∼ 15.4 ±â€¯0.32 µM as opposed to standard - gallic acid (IC50 1.1 ±â€¯0.08 µM), antiproliferative activity with IC50 of ∼ 6.24 ±â€¯0.16 µM as opposed to deferoxamine (∼10.8 ±â€¯0.28 µM) and protected cells against cellular/DNA damage. Anti-inflammatory property was evident with significant reduction in the release of NO (∼3.9 fold) and TNF-α (∼3.4 fold), a pro-inflammatory cytokine, in addition to the inhibition of NFκB (∼2.7 fold), a transcription factor in Raw 264.7 cells. Marked down regulation of galectin-3 (∼5.5 folds) and tyrosinase (∼11.1 folds) by gene expression analysis substantiated by tyrosinase inhibition (IC50 - 20.3 ±â€¯1.26 µM Vs. Kojic acid - IC50 - 24.1 ±â€¯1.41 µM) and molecular docking studies strengthened the cancer modulatory property of marmelosin. In addition, marmelosin induced apoptotic bodies, chromatin condensation and nulcear blebbing in Raw 264.7 cells commending the apoptotic effect of marmelosin. Marmelosin thus displayed potential multi-potent antioxidant, anti-inflammatory and anticancer properties via TNF-α mediated Akt signaling pathway.

Swallow root (Decalepis hamiltonii) pectic oligosaccharide (SRO1) induces cancer cell death via modulation of galectin-3 and survivin.

Swallow root pectic oligosaccharide fraction (SRO1) from swallow root pectic polysaccharide (SRPP) possessed a molecular size of 831 Da. Structural analysis revealed that it is a rhamnogalacturonan I type, bearing arabinogalactan side chain with ß-d-(1→4) galactose along with α-l-Araf (1→5)-α-l-Araf (1→3) structure on α-d-GalA-OAc-(1→2)-α-l-Rha-(1→4)- linear backbone. ß-d (1→4) linked galactose being the specific sugar for galectin-3, SRO1 had potentials in inhibiting galectin-3 mediated cancer progression. SRO1 inhibited galectin-3 mediated agglutination, in vitro, effectively with MIC of 1.08 µg/ mL and down regulated mRNA levels of galectin-3 (∼92%) along with its downstream key protein that inhibits apoptosis - survivin (∼78%) suggesting the capability of SRO1 in inhibiting galectin-3 mediated cancer promoting pathway. This is the first report, which highlights the inhibition of interplay of galectin-3 and survivin by a dietary pectic oligosaccharide.

Antimetastatic pectic polysaccharide from Decalepis hamiltonii; galectin-3 inhibition and immune-modulation.

Melanoma is a malignant neoplasm of major concern because of its high mortality rate and failure of chemotherapy. Previously we have shown that galectin-3, a galactose specific lectin, plays a pivotal role in the initiation of metastasis. It was hypothesized that blocking galectin-3 with galactose rich dietary pectic polymer would inhibit metastasis. The current study analyzes the preventive effect and mode of action of a pectic polymer from Swallow Root (Decalepis hamiltonii) in a preventative study of B16F10 cells lung colonization. Matrix metalloproteinase (MMPs) activity was assayed by zymography. Apoptotic/proliferative markers and cytokines were analyzed by immunoassay. Results indicated ~88% inhibition of lung colonization by SRPP as compared to 60% by CPP and only 7% by GRPP. Further molecular analysis revealed that galectin-3 blockade was associated with down regulation of MMPs and NFκB. Activation of caspases supported the apoptotic effect of SRPP. Infiltration of inflammatory cells into the lung was evidenced by presence of CD11b+ cells and release of the pro-inflammatory cytokine-IL-17, indicating inflammation during the cancer cell colonization process. SRPP enhanced the release of IL-12 that enables the reduction of inflammation. Our data for the first time indicate the effective anti-metastatic effect of SRPP due to both galectin-3 blockade and immunomodulation.

Pectic Oligosaccharide from tomato exhibiting anticancer potential on a gastric cancer cell line: Structure-function relationship.

Pectic Polysaccharide (PP) from dietary sources has been known to prevent cancer growth and hence impede cancer progression. We evaluated anticancer effect of Pectic-Oligosaccharide isolated from Sour Raw Tomato (SrTPO); its bioavailability and structure elucidated from purified fraction (SrTPO1). SrTPO1 inhibited galectin-3 activity with MIC of 0.25 ug/mL (100 fold better than standard galactose), inhibited the growth of AGS cells (IC50 3.4µg/mL) and induced apoptosis (70% inhibition at 30µg/mL concentration). Normal- NIH 3T3 cells were not affected by SrTPO as opposed to doxorubicin, a known anticancer drug, which reduced 76% viability at equivalent dose. SrTPO1 was identified as RhamnogalacturonanI-arabinogalactan (RGI-AG), where repeated alternative rhamnose and galacturonic acid residues were observed while arabinose in the branch point and ß-1,4 linked galactose in the linear chain form. SrTPO was found to be bioavailable as evaluated by FITC labelled oligos inside the cell, which was in reciprocal proportion with apoptosis.

Antioxidant and cyto/DNA protective properties of apple pomace enriched bakery products.

Apple pomace (AP), the residue that remains after the extraction of juice from apple accounts for ~25 % of total apple weight. Current study is aimed at identification of phytochemicals and utilization of Dehydrated apple pomace (DAP) in the preparation of bakery products with potential health benefits. DAP was prepared by drying the pomace obtained by crushing peeled apple fruits. DAP was incorporated into bakery products such as bun, muffin and cookies for value addition. Bioactivity such as free radical scavenging, cyto/DNA protectivity was evaluated in these products. DAP contained 17 g/100 g starch, 49.86 g/100 g fructose and 37 g/100 g dietary fibre. The phenolics and flavonoids content was 1.5 mg/g and 3.92 mg/g, respectively. Increase in DAP resulted in decreased volume and enhanced firmness of buns and muffins. DAP at 15 % in buns, 30 % in muffins and 20 % in cookies were found to be acceptable. DAP blended products exhibited better free radical scavenging as well as cyto/DNA protective properties suggesting the retention of bioactivity after baking. Addition of DAP potentially enhanced the bioactivity of the products evaluated.

A novel ß-carotene-associated carrot (Daucus carota L.) pectic polysaccharide.

OBJECTIVE: Carrot (Daucus carota L.) is a nutritional source with enriched ß-carotene (0.01%) and pectins (0.8%). Although studies have highlighted the association between ß-carotene and carrot pectic polysaccharide (CRPP), the precise binding of ß-carotene to CRPP and its biological implications were not yet clearly understood. The aim of the present study is to report for the first time a natural carbohydrate polymer-CRPP-with associated ß-carotene. METHODS: The presence of ß-carotene in CRPP and its binding is demonstrated by various studies including differential extraction followed by liquid chromatography (LC), liquid chromatography mass spectrometry (LC MS), and Fourier transform infrared spectroscopy (FTIR). Further, we show the binding via its release from CRPP using LC, fermentation studies and scanning electron microscopy (SEM) studies. The role of ß-carotene in induction of apoptosis and the galactic-3 inhibitory property was also studied. RESULTS: The presence of ß-carotene in CRPP was demonstrated, as well as an association between ß-carotene and CRPP, apoptotic and galectin-3 inhibitory properties of CRPP, and upregulation of connexin 43 by CRPP. CONCLUSION: The data highlights that with the combination of ß-carotene with CRPP, the prooxidant effect of ß-carotene may be reduced, an apoptotic effect may be enhanced, and the anticancer potential of CRPP thus may be strengthened via galectin-3 inhibition.

Physiologically induced changes in bound phenolics and antioxidants, DNA/cytoprotective potentials in pectic poly/oligosaccharides of tomato (Solanum lycopersicum).

BACKGROUND: Antioxidant, cyto/DNA protective potentials are known to offer significant protection against free radical induced injury to cells or tissues and cellular damages that are envisaged in various diseases including chronic diseases like cancer, diabetes, etc, while galectin-3 inhibitory potentials are known to block or delay the process of metastasis in cancer. Antioxidant, cyto/DNA protection and galectin-3 inhibitory potentials were examined in pectic polysaccharides (PPs) and pectic oligosaccharides (POs) from four types of two varieties of tomatoes such as Sour (Mallika local variety) raw (SrRT-SrRTPP, SrRTPO), Sour ripe (SrRIT-SrRITPP, SrRITPO), Sweet (Rashmi local variety) raw (SwRT-SwRTPP, SwRTPO) and Sweet ripe (SwRIT-SwRITPP and SwRITPO). RESULTS: Results indicate that unripe PPs and POs show approximately four- to five-fold better galectin-3 inhibitory property than ripe ones. An approximately nine- to 10-fold increase in galectin-3 inhibitory activity in sour variety was observed. The IC50 as determined by free radical scavenging (FRS), red blood cell (RBC) and DNA protection assays revealed reduction in FRS and RBC protective potencies in pectic oligosaccharides (POs) than pectic polysaccharides (PPs), supporting the fact that phenolics contribute towards these activities. Loss of activity could be attributed to the hydrolysis of certain phenolics during the ripening process as well as during conversion of PPs to POs. CONCLUSION: This study, for the first time, showed changes in bioactivity profiling in unripened and ripened conditions in tomato. Precise alterations in biomolecular components, such as bound cinnamyl/ferulyl and vanillic acid derivatives, along with alterations in sugar composition that reflect changes in antioxidants, cyto/DNA protective and antimetastatic potentials, have been delineated. © 2016 Society of Chemical Industry.

Modified pectic polysaccharide from turmeric (Curcuma longa): A potent dietary component against gastric ulcer.

Native, intact (TrPP) and modified, low-molecular-weight (MTrPP) forms of pectic polysaccharides isolated from turmeric were evaluated for ulcer-preventive potentials in in vitro and in vivo models. Data indicated that MTrPP possessed significantly better ulcer-preventive property than TrPP; inhibiting ulcer scores up to 85%. Results were substantiated by effective muco-protection, H(+),K(+)-ATPase down-regulation, inhibition of H. pylori growth/adherence, higher antioxidant/cytoprotective mechanisms. Structural data indicated TrPP and MTrPP differ in their molecular weights and structural characteristics with different sugar compositions and side chain ratios. MTrPP was rich in galacturonic acid (687mg/g; TrPP-544mg/g) and galactose (52.9%; TrPP-21.7%). Results were substantiated by NMR/FTIR data indicating the presence of homogalacturonan and rhamnogalacturonam-I containing galactans. By virtue of binding to inflammatory marker (galectin-3), galactans may reduce inflammation induced ulcerations. The low molecular weight of MTrPP (155kDa; TrPP-13kDa) may increase its bioavailability than TrPP, thus MTrPP may possess higher antiulcer potential.

Pectic polysaccharide from corn (Zea mays L.) effectively inhibited multi-step mediated cancer cell growth and metastasis.

Corn pectic polysaccharide (COPP) inhibited galectin-3 mediated hemagglutination at Minimum Inhibitory Concentration (MIC) of 4.08 µg/mL as opposed to citrus pectin (25 µg/mL), a well known galectin-3 inhibitor and lactose (4.16 µg/mL)--sugar specific to galectin-3. COPP effectively (72%) inhibited invasion and metastasis in experimental animals. In vivo results were substantiated by modulation of cancer specific markers such as galectin-3, which is a key molecule for initiation of metastatic cascade, vascular endothelial growth factor (VEGF) that enhances angiogenesis, matrix metalloproteinases 2 and 9 that are required for invasion, NF-κB, a transcription factor for proliferative potency of tumor cells and a phosphoglucoisomerase (PGI), the activity of which favors cancer cell growth. Structural characterization studies indicate the active component (relatively less acidic, 0.05 M ammonium carbonate, 160 kDa fraction) which showed antimetastatic potency in vitro with MIC of 0.09 µg/mL, and ∼ 45 fold increase in the activity when compared to that of COPP. Gas liquid chromatographic analysis indicated the presence of rhamnose (1%), arabinose (20%), xylose (3%), mannose (4%), galactose (54%) and uronic acid (10%) in different proportions. However, correlative data attributed galectin-3 inhibitory activity to enhanced levels of arabinose and galactose. FTIR, HPLC and NMR spectroscopic analysis further highlights that COPP is an arabinogalactan with methyl/ethyl esters. It is therefore suggested that the blockade of galectin-3 mediated lung metastasis appears to be a result of an inhibition of mixed functions induced during metastasis. The data signifies the importance of dietary carbohydrate as cancer-preventive agent. Although pectin digestibility and absorption are issues of concern, promising in vivo data provides evidence for the cancer preventive property of corn. The present study reveals for the first time a new component of corn, i.e.,--corn pectin with cancer preventive activity apart from corn starch that has been in wide use for multipurpose health benefits.

REMOVED: Protective effect of Daucus carota against UV-DMBA induced skin cancer in mice.

This article has been removed: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been removed at the request of "Due to a processing error during the review process, this paper was erroneously published online prematurely. The Publisher apologizes to readers and the authors for any inconvenience caused."

Effective inhibition of skin cancer, tyrosinase, and antioxidative properties by astaxanthin and astaxanthin esters from the green alga Haematococcus pluvialis.

Astaxanthin mono- (AXME) and diesters (AXDE) were characterized and examined for anticancer potency with total carotenoids (TC) and astaxanthin (AX) against UV-7,12-dimethylbenz(a)anthracene (DMBA)-induced skin cancer model in rat. At 200 µg/kg bw, AXDE and AXME reduced UV-DMBA-induced tumor incidences up to 96 and 88%, respectively, when compared to AX (66%) and TC (85%). UV-DMBA has been known to generate high levels of free radicals and tyrosinase enzyme, leading to characteristic symptoms of skin pigmentation and tumor initiation. Intriguingly, ~7-fold increase in tyrosinase and 10-fold decrease in antioxidant levels were normalized by AXDE and AXME as opposed to only ~1.4-2.2-fold by AX and TC, respectively. This result together with the appearance of 72 and 58 ng/mL of retinol in the serum of respective AXE-treated (AXDE + AXME) and AX-treated animals suggested that better anticancer potency of AXEs could be due to increased bioavailability.

Structural elucidation of possible lutein oxidation products mediated through peroxyl radical inducer 2,2'-Azobis (2-methylpropionamidine) dihydrochloride: antioxidant and cytotoxic influence of oxidized lutein in HeLa cells.

Aim of this study was to elucidate lutein oxidation products mediated through peroxyl radical inducer 2,2'-Azobis (2-methylpropionamidine) dihydrochloride (AAPH) and to study antioxidant and cytotoxic effects of oxidized lutein using liposome and HeLa cells. Lutein (20 µmol) with AAPH (5 mM) in liposome's was incubated at 37 °C in dark for 3 h, oxidized lutein products were characterized by LC-MS (APCI(+)) and studied for their free radical scavenging activity and cytotoxic effects in terms of cell viability, cellular glutathione, and malondialdehyde levels. AAPH mediated lutein fragmented ions were identified as 551 (M(+)+H(+)-H(2)O), 391 (M(+)+H(+)+O(2)-C(22)H(32)O) and 276 (M(+)+H(+)+O(2)-C(12)H(20)O) and its isomers as 13-Z lutein, 13-Z zeaxanthin, 13'-Z zeaxanthin and all-E zeaxanthin. Free radical scavenging activity of oxidized lutein was higher by 32.7% (IC(50), 2.64 µg) than lutein (IC(50), 5.28 µg). Oxidized lutein lowered the lipid peroxidation (21%), HeLa cells viability (22%) and glutathione levels (32%) than lutein. To conclude, the oxidized lutein may be highly reactive, since oxidation by AAPH results in peroxyl radical ions, which can react with conjugated polyene chain of lutein that could lead to higher antioxidant and cytotoxic effects on HeLa cells.

Gastroprotective Properties of Karanjin from Karanja (Pongamia pinnata) Seeds; Role as Antioxidant and H, K-ATPase Inhibitor.

Plant extracts are the most attractive sources of newer drugs and have been shown to produce promising results for the treatment of gastric ulcers. Karanjin, a furano-flavonoid has been evaluated for anti-ulcerogenic property by employing adult male albino rats. Karanjin (>95% pure) was administered to these rats in two different concentrations, that is, 10 and 20 mg kg(-1) b.w. Ulcers were induced in the experimental animals by swim and ethanol stress. Serum, stomach and liver-tissue homogenates were assessed for biochemical parameters. Karanjin inhibited 50 and 74% of ulcers induced by swim stress at 10 and 20 mg kg(-1) b.w., respectively. Gastric mucin was protected up to 85% in case of swim stress, whereas only 47% mucin recovery was seen in ethanol stress induced ulcers. H(+), K(+)-ATPase activity, which was increased 2-fold in ulcer conditions, was normalized by Karanjin in both swim/ethanol stress-induced ulcer models. Karanjin could inhibit oxidative stress as evidenced by the normalization of lipid peroxidation and antioxidant enzyme (i.e., catalase, peroxidase and superoxide dismutase) levels. Karanjin at concentrations of 20 mg kg(-1) b.w., when administered orally for 14 days, did not indicate any lethal effects. There were no significant differences in total protein, serum glutamate pyruvate transaminase, serum glutamate oxaloacetate transaminase and alkaline phosphatase between normal and Karanjin-treated rats indicating no adverse effect on major organs. During treatment schedule, animals remained as healthy as control animals with normal food and water intake and body weight gain.

Gastroprotective Effect of Ginger Rhizome (Zingiber officinale) Extract: Role of Gallic Acid and Cinnamic Acid in H(+), K(+)-ATPase/H. pylori Inhibition and Anti-Oxidative Mechanism.

Zinger officinale has been used as a traditional source against gastric disturbances from time immemorial. The ulcer-preventive properties of aqueous extract of ginger rhizome (GRAE) belonging to the family Zingiberaceae is reported in the present study. GRAE at 200 mg kg(-1) b.w. protected up to 86% and 77% for the swim stress-/ethanol stress-induced ulcers with an ulcer index (UI) of 50 ± 4.0/46 ± 4.0, respectively, similar to that of lansoprazole (80%) at 30 mg kg(-1) b.w. Increased H(+), K(+)-ATPase activity and thiobarbituric acid reactive substances (TBARS) were observed in ulcer-induced rats, while GRAE fed rats showed normalized levels and GRAE also normalized depleted/amplified anti-oxidant enzymes in swim stress and ethanol stress-induced animals. Gastric mucin damage was recovered up to 77% and 74% in swim stress and ethanol stress, respectively after GRAE treatment. GRAE also inhibited the growth of H. pylori with MIC of 300 ± 38 µg and also possessed reducing power, free radical scavenging ability with an IC(50) of 6.8 ± 0.4 µg mL(-1) gallic acid equivalent (GAE). DNA protection up to 90% at 0.4 µg was also observed. Toxicity studies indicated no lethal effects in rats fed up to 5 g kg(-1) b.w. Compositional analysis favored by determination of the efficacy of individual phenolic acids towards their potential ulcer-preventive ability revealed that between cinnamic (50%) and gallic (46%) phenolic acids, cinnamic acid appear to contribute to better H(+), K(+)-ATPase and Helicobacter pylori inhibitory activity, while gallic acid contributes significantly to anti-oxidant activity.

Inhibition of Helicobacter pylori growth and its cytotoxicity by 2-hydroxy 4-methoxy benzaldehyde of Decalepis hamiltonii (Wight & Arn); a new functional attribute.

Helicobacter pylori mediated gastric ulcer and cancers are common global problems since it was found to colonize in ∼50% of gastric ulcer/cancer patients. Decalepis hamiltonii, (Asclepiadaceae family) extracts have been depicted with medicinal properties supporting the traditional knowledge of health beneficial attributes of D. hamiltonii. Previously we have shown that both aqueous as well as methanol extracts of D. hamiltonii containing abundant phenolics with predominant levels (20-40% of total phenolics) of 2-hydroxy-4-methoxy benzaldehyde (HMBA). Despite higher levels, HMBA contributed very little to the antioxidant activity (<10%) when compared to other phenolic compounds in the extract. In the current study we attempted to explore antimicrobial property, particularly anti-H. pylori activity, since traditional users document D. hamiltonii as a fighter of microbial infections. HMBA was isolated from the roots of D. hamiltonii by hydrodistillation and cold crystallization method; identified by HPLC and characterized using ESI-MS and confirmed by NMR studies as a compound of molecular mass 152 Da. Isolated HMBA was found to inhibit the growth of H. pylori, a potential ulcerogen in a dose dependent manner with MIC of ∼39 µg/mL as apposed to that of amoxicillin (MIC - 26 µg/mL) for which H. pylori is susceptible. Results were further substantiated by the lysis of H. pylori by electron microscopy and electrophoretic studies. Studies on the mechanism of action indicated the counteracting effect of vacuolating toxin (VacA) of H. pylori which otherwise would lead to host cell cytotoxicity. Further the increased binding ability of HMBA to DNA and protein offered an impact on DNA protectivity and bioavailability. Results for the first time provide a direct evidence for anti-microbial attribute of HMBA. Insignificant antioxidant attribute of HMBA also reveals the anti-H. pylori activity via mechanisms other than antioxidative routes.

Assessment of antioxidant potentials of free and bound phenolics of Hemidesmus indicus (L) R.Br against oxidative damage.

BACKGROUND: Hemidesmus indicus R.Br. is a twining shrub commonly found in India, which was known to have wide pharmacological actions. 2-hydroxy-4-methoxy-benzoic acid (HMBA) and a number of pregnane glycosides were believed to be responsible for its various bioactivities. Until now, there are no reports regarding the antioxidant properties of phenolics from H. indicus OBJECTIVE: To establish the role of phenolics in the properties of H.indicus. MATERIALS AND METHODS: Hemidesmus free phenolic fraction (HDFP) and Hemidesmus bound phenolic fraction (HDBP) have been isolated from H. indicus, and the antioxidant activity was evaluated for inhibition of lipid peroxidation, DNA protection, free radical scavenging (FRS), reducing power and cytoprotective activities. RESULTS: HDFP and HDBP exhibited potent inhibition of lipid peroxidation (IC(50) - 19.5 ±0.5 and 21.7 ±0.5 µg gallic acid equivalent - GAE/mL), FRS (IC(50) - 7 ± 0.2 and 8.6 ± 0.2 µgGAE/mL), reducing power (110.3 ± 2 and 33.5 ± 1 U/g) and red blood cell protection (14.8 ± 0.4 and 14.5 ± 0.5 mg GAE/mL). HDFP is constituted by gallic (18%), caffeic (17%), ferulic acids (16%) and HDBP by syringic acid (35%) as major phenolic acids. Besides, both HDFP and HDBP contained significant levels of HMBA; in HDFP (10%) and HDBP (57%), respectively. Results indicated a 34-and 27-folds better contribution to the antioxidant activity by HDFP and HDBP, respectively, than that of HMBA. CONCLUSION: Potent antioxidant activities of phenolics may be one of the mechanisms by which H.indicus is effective against several health disorders as encountered in traditional medicines.

Antioxidant and cytotoxic effect of oxidized lutein in human cervical carcinoma cells (HeLa).

This study investigated the antioxidant and cytotoxic effect of oxidized lutein using human cervical carcinoma cell lines (HeLa). Liposome contained phosphatidylcholine (20 micromol) in Tris-HCl buffer and lutein (200 micromol) was exposed to sunlight for 100 min. Photo-oxidized lutein products were characterized by LC-MS (APCI(+)) and studied for their antioxidant property and apoptosis in terms of cell viability, glutathione and malondialdehyde (MDA) levels. Photo-oxidized lutein fragmented ions were identified as 523 (M+ + H+-3CH3), 476 (M+ + H+-6CH3), 551 (M+ + H+-H2O) and its isomers as 13-Z lutein, 13'-Z lutein, 13-Z zeaxanthin, all-E zeaxanthin, 9-Z lutein, 9'-Z lutein. Free radical scavenging activity of oxidized lutein was higher by 45.9% (IC(50), 3.71 microg) than lutein (IC(50), 5.28 microg). Oxidized lutein lowered the lipid peroxidation by 20.7% than lutein. The viability of HeLa cells, glutathione and MDA levels were decreased by 64%, 40% and 18% than lutein. To conclude, oxidized lutein may be highly reactive, since oxidation results in radical ions, which can combine with similar reactive oxidative species that could lead to higher antioxidant effect. This may be true in this study that antioxidant property of oxidized lutein was higher than lutein that correlates with free radical scavenging activity and cytotoxic effects on HeLa cells.