Mitigation of oxidative stress with dihydroactinidiolide, a natural product against scopolamine-induced amnesia in Swiss albino mice.

The present work describes the neuroprotective efficacy of DHAc under escalated oxidative stress condition in scopolamine-induced amnesic mice. During the toxicity test of DHAc in mice, the acute dose (LD50) is found to be 3.468 mg/kg bw and the sub-acute dose is 0.68 mg/kg bw. Improved cognitive and learning abilities are observed in Morris water maze and Y-maze test in 10 days DHAc (0.68 mg/kg bw) treated scopolamine-induced male Swiss albino mice. In the molecular level these changes are monitored as reduced oxidative load followed by significantly lower lipid peroxidation and protein carbonylation, increased superoxide dismutase, catalase, acetylcholinesterase, caspase-3 activity and glutathione content followed by higher expression of anti apoptotic protein bcl-2 in mice brain as compared to scopolamine (1 mg/kg bw) treated mice. Meanwhile real time PCR shows higher expression of brain derived neurotrophic factor (BDNF) and synaptophysin in DHAc pretreated scopolamine treated mice brain. HPLC analysis suggested its possible blood brain barrier crossing ability. Overall DHAc reversed behavioral anomalies in the scopolamine treated mice via oxidative stress quenching, enhancing antioxidative enzyme activity, enhancing BDNF and synaptophysin mRNA levels and reducing expression of apoptotic protein Bax.

Molecular targets of curcumin for cancer therapy: an updated review.

In recent years, natural edible products have been found to be important therapeutic agents for the treatment of chronic human diseases including cancer, cardiovascular disease, and neurodegeneration. Curcumin is a well-known diarylheptanoid constituent of turmeric which possesses anticancer effects under both pre-clinical and clinical conditions. Moreover, it is well known that the anticancer effects of curcumin are primarily due to the activation of apoptotic pathways in the cancer cells as well as inhibition of tumor microenvironments like inflammation, angiogenesis, and tumor metastasis. In particular, extensive studies have demonstrated that curcumin targets numerous therapeutically important cancer signaling pathways such as p53, Ras, PI3K, AKT, Wnt-ß catenin, mTOR and so on. Clinical studies also suggested that either curcumin alone or as combination with other drugs possess promising anticancer effect in cancer patients without causing any adverse effects. In this article, we critically review the available scientific evidence on the molecular targets of curcumin for the treatment of different types of cancer. In addition, we also discuss its chemistry, sources, bioavailability, and future research directions.

Targeting mTOR signaling by polyphenols: A new therapeutic target for ageing.

Current ageing research is aimed not only at the promotion of longevity, but also at improving health span through the discovery and development of new therapeutic strategies by investigating molecular and cellular pathways involved in cellular senescence. Understanding the mechanism of action of polyphenolic compounds targeting mTOR (mechanistic target of rapamycin) and related pathways opens up new directions to revolutionize ways to slow down the onset and development of age-dependent degeneration. Herein, we will discuss the mechanisms by which polyphenols can delay the molecular pathogenesis of ageing via manipulation or more specifically inhibition of mTOR-signaling pathways. We will also discuss the implications of polyphenols in targeting mTOR and its related pathways on health life span extension and longevity. .

Neuroprotective effect of the marine macroalga Gelidiella acerosa: identification of active compounds through bioactivity-guided fractionation.

Context Gelidiella acerosa (Forsskål) Feldmann & G. Hamel (Rhodophyta-Gelidiales) is a marine red macroalga. Our previous work found that a benzene extract of G. acerosa possesses noticeable neuroprotective activity, when evaluated through in vitro and in vivo systems. Objective Bioactive-guided fractionation and identification of active compounds by column chromatography using solvents of varying polarity. Materials and methods Fractionation was done by column chromatography, antioxidant and anticholinesterase activity was assessed by DPPH and cholinesterase inhibition assays (50-200 µg/ml), compound identification was done by LC-MS analysis, the mode of interaction of active compound was analyzed through docking studies and quantification was done by high-performance thin-layer chromatography (HPTLC) analysis. Results The results suggest that fractions F9-F13 exhibited significant (p < 0.05) antioxidant and anticholinesterase activities. Hence, these fractions were pooled together and verified for neuroprotective activity. The pooled fraction was subjected to LC-MS analysis and among all the compounds, phytol was previously reported to possess excellent neuroprotective potential. Hence, the neuroprotective potential of phytol was assessed. The results suggest that phytol showed significant (p < 0.05) antioxidant activities (25-125 µg/ml) with an IC50 value of 95.27 ± 1.65 µg/ml and cholinesterase inhibitory potential (5-25 µg/ml) with IC50 values of 2.704 ± 0.07 and 5.798 ± 0.72 µg/ml for AChE and BuChE, respectively. Molecular docking studies suggest that phytol interacts with cholinesterase through the arginine residue of the enzyme. HPTLC quantification showed that about 6.266 µg of phytol was present per mg of pooled fraction. Conclusion The study suggests that phytol might act as the key compound in contributing to the neuroprotective potential of G. acerosa.

2,3,7,8-TCDD-mediated toxicity in peripheral blood mononuclear cells is alleviated by the antioxidants present in Gelidiella acerosa: an in vitro study.

Seaweeds have been used as a source of traditional medicine worldwide for the treatment of various ailments, mainly due to their ability to quench the free radicals. The present study aims at evaluating the protective effect of methanolic extract of Gelidiella acerosa, an edible red seaweed against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced toxicity in peripheral blood mononuclear cells (PBMC). For evaluating the protective effect of G. acerosa, PBMC were divided into four groups: vehicle control, TCDD (10 nM), TCDD + G. acerosa (300 µg/ml), and G. acerosa alone treated. Scavenging of intracellular reactive oxygen species (ROS) induced by TCDD was assessed by the dichloro-dihydro-fluorescein diacetate (DCFH-DA) method. Alterations at macromolecular level were quantified through lipid peroxidation (LPO) level, protein carbonyl content (PCC) level, and comet assay. The cellular morphology upon TCDD toxicity and G. acerosa treatment was obtained by light microscopy and histopathological studies. The chemical composition present in the methanolic extract of G. acerosa was determined by gas chromatography-mass spectrometry (GC-MS) analysis. The results reveal that 10 nM TCDD caused significant (P < 0.05) reduction in cell viability (94.10 ± 0.99), and treatment with 300 µg/ml extract increased the cell viability (99.24 ± 0.69). TCDD treatment resulted in a significant increase in the production of ROS, LPO (114 ± 0.09), and PCC (15.13 ± 1.53) compared to the control, whereas co-treatment with G. acerosa significantly (P < 0.05) mitigated the effects. Further, G. acerosa significantly (P < 0.05) prevented TCDD-induced genotoxicity and cell damage. GC-MS analysis showed the presence of n-hexadecanoic acid (retention time (RT) 13.15), cholesterol (RT 28.80), α-D-glucopyranose, 4-O-α-D-galactopyranosyl (RT 20.01), and azulene (RT 4.20). The findings suggest that G. acerosa has a strong protective ability against TCDD-induced cytotoxicity, oxidative stress, and DNA damage.

Olive oil and its phenolic compounds (hydroxytyrosol and tyrosol) ameliorated TCDD-induced heptotoxicity in rats via inhibition of oxidative stress and apoptosis.

CONTEXT: Naturally occurring polyphenols including olive oil (OO) and its constituents hydroxytyrosol (HT) and tyrosol (TY), consumed in the Mediterranean diet, have shown to treat various ailments due to their remarkable antioxidant properties. OBJECTIVE: The present study investigates the hepatoprotective effects of OO and its phenolic compounds HT and TY against TCDD-induced hepatotoxicity in male Wistar rats. MATERIALS AND METHODS: TCDD was administered at a dose of 100 ng/kg p.o. for 20 d. Administration of OO (10 ml/kg; oral), HT (0.5 mg/kg; oral), and TY (30 mg/kg; i.p) was started 5 d prior to TCDD administration, and continued for 25 d with or without TCDD administration. At the end of the experiment (25 d), blood was taken for biochemical analyses and liver for the measurement of macromolecular damages, antioxidant status, expressions of CYP1A1, and apoptotic factors. RESULTS: TCDD administration resulted in significant (p < 0.05) increase in the level of hepatic stress markers ALT (101.6 ± 3.07 IU/l), AST (295.0 ± 3.0 IU/l), and ALP (266.66 ± 3.7 IU/l). Also, biochemical analyses of liver reported elevation in nitrite and protein carbonyl content and depletion of NQO1 and HO. However, OO, HT, and TY restored the antioxidant status. Protein expressions by Western Blot technique showed an increase in the level of CYP1A1 and Bax and a decreased level of Bcl-2 on TCDD treatment, and vice versa on OO, HT, and TY treatment. DISCUSSION AND CONCLUSION: Our work concludes that dietary supplementation of OO, HT, and TY could serve as a potential preventive drug for TCDD-induced hepatotoxicity.

Understanding genistein in cancer: The "good" and the "bad" effects: A review.

Nowadays, diet and specific dietary supplements are seen as potential adjuvants to prevent different chronic diseases, including cancer, or to ameliorate pharmacological therapies. Soybean is one of the most important food components in Asian diet. A plethora of evidence supports the in vitro and in vivo anticancer effects of genistein, a soybean isoflavone. Major tumors affected by genistein here reviewed are breast, prostate, colon, liver, ovarian, bladder, gastric, brain cancers, neuroblastoma and chronic lymphocytic leukemia. However, it is not always clear if and when genistein is beneficial against tumors (the "good" effects), or the opposite, when the same molecule exerts adverse effects (the "bad" effects), favouring cancer cell proliferation. This review will critically evaluate this concept in the light of the different molecular mechanisms of genistein which occur when the molecule is administered at low doses (chemopreventive effects), or at high doses (pharmacological effects).

Evaluation of in vitro and in vivo safety profile of the Indian traditional medicinal plant Grewia tiliaefolia.

Grewia tiliaefolia Vahl., is a subtropical tree used in Ayurvedic formulations and also by tribal communities in India for treatment of wounds, urinary infection and skin diseases. Despite of its medicinal use, the plant has not been previously tested for its safety. This study evaluated the toxicological profile of the methanolic extract of G. tiliaefolia leaves (MEGT) through in vitro (cytotoxic, mutagenic, genotoxic) and in vivo (acute and sub-acute) studies. In vitro assays conclude that there is no significant (p<0.05) level of cytotoxicity and genotoxicity at the tested concentrations (250-2000 µg/ml) in peripheral blood mononuclear cells. Ames assay in the tested Salmonella typhimurium strains revealed no significant (p<0.05) increase in the mutagenic index both in the presence and absence of metabolic activation. Alternatively, no change in mortality, physiological, behavioural, haematological and biochemical parameters were observed under in vivo acute (250, 500, 1000, 2000 mg/kg b.w) and sub-acute (100, 200, 1000 mg/kg b.w) toxicity studies in Wistar rats. Histopathological examinations of the animals did not reveal any treatment related changes and showed normal architecture, even at the highest concentration (1000 mg/kg b.w) following 28 days treatment. Overall, the results show that MEGT is non-toxic at the tested concentrations and is safe to be used as herbal medicine.

Olive oil and its phenolic constituent tyrosol attenuates dioxin-induced toxicity in peripheral blood mononuclear cells via an antioxidant-dependent mechanism.

Olive oil (OO) and its phenolic compounds are reported to possess many potential biological effects, which are ascribed to its powerful antioxidant property. In this study, we have assessed whether OO and its phenolic compound tyrosol (TY) could mitigate 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced oxidative damages in peripheral blood mononuclear cells (PBMC). The results showed that exposure of PBMC to 10 nM TCDD caused significant cell death and elevated cellular concentrations of reactive oxygen species and lipid peroxidation. Comet assay indicated that OO and TY protected DNA damage against dioxin toxicity. In addition, alterations in levels of antioxidant enzymes were substantially prevented by OO and TY. TCDD-induced CYP1A1 activity and loss of mitochondrial membrane potential were significantly reduced by the administration of OO and TY. The results suggested that dietary modifications incorporating diets rich in OO and associated phenolics could prove beneficial in protecting individuals against toxicity induced by dioxins.

Assessment of mutagenic effect of G. acerosa and S. wightii in S. typhimurium (TA 98, TA 100, and TA 1538 strains) and evaluation of their cytotoxic and genotoxic effect in human mononuclear cells: a non-clinical study.

The marine red algae (Gelidiella acerosa and Sargassum wightii) possessing excellent antioxidant and anticholinesterase activity were subjected to toxicity evaluation for a deeper understanding of other bioprotective properties of seaweeds. Cytotoxic evaluation was done by trypan blue exclusion, and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays using human PBMC (peripheral blood mononuclear cells) and RBC (red blood cells) lysis assay using human erythrocytes. Mutagenicity of the seaweeds was analyzed by Ames salmonella mutagenicity test with the histidine dependent mutant strains TA 98, TA100 and TA 1538. Genotoxic activity was verified in PBMC by comet assay. The results suggest that benzene extract of G. acerosa (BEGA) and dichloromethane extract of S. wightii (DMESW) did not show cytotoxic effect both in PBMC and erythrocytes. Evaluation of mutagenic activity suggests that the seaweeds did not cause any mutagenic effects both in the absence and the presence of S9 microsomal fraction in all the three Salmonella mutant strains. Results of genotoxic study showed that PBMC treated with seaweed extracts (1 mg/mL) exhibit less or no damage to cells, thus proving the non-genotoxic effect of the extract. Since these in vitro non-clinical studies clearly demonstrate the non-toxic nature of the seaweeds, they could be exploited for further characterization, which would result in development of novel and safe therapeutic entities.

Antioxidant and anti-cholinesterase activity of Sargassum wightii.

CONTEXT: Sargassum has been used in traditional Chinese medicine since the eighth century AD to treat goiter. Sargassum wightii Greville (Sargassaceae) is a major source of alginic acid used widely in food and drug industries. OBJECTIVE: To evaluate the anti-Alzheimer potential of S. wightii through evaluation of antioxidant and cholinesterase inhibitory activities. MATERIALS AND METHODS: Successive extraction was done using solvents of varying polarity. Solvent extracts (100-500 µg/mL) were employed for all the antioxidant assays. Free radical scavenging activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl, OH•, H2O2 radical scavenging assay. The reducing power of the seaweed was evaluated by ferric reducing antioxidant power and reducing power assay. Cholinesterase (ChE) inhibitory activity was evaluated and the Km, Vmax and Ki were calculated. Further, compound characterization was done by GC-MS analysis. RESULTS: The non-polar extracts were found to possess significant antioxidant activity. At 100 µg/mL, petroleum ether, hexane, benzene and dichloromethane extracts showed significant ChE inhibitory activity with IC50 values of 19.33 ± 0.56, 46.81 ± 1.62, 27.24 ± 0.90, 50.56 ± 0.90 µg/mL, respectively, for AChE, and 17.91 ± 0.65, 32.75 ± 1.00, 12.98 ± 0.31, 36.16 ± 0.64 µg/mL, respectively, for BuChE. GC-MS reveals that 1,2-benzenedicarboxylic acid, diisooctyl ester is the major compound present in dichloromethane extract of S. wightii. The mode of inhibition exhibited by dichloromethane extract against the cholinesterases was found to be competitive type. DISCUSSION AND CONCLUSION: The presence of high amount of terpenoids could be the possible reason for its potential antioxidant and ChE inhibitory activity.

Plants traditionally used in age-related brain disorders (dementia): an ethanopharmacological survey.

CONTEXT: Epidemiological studies have shown that despite mortality due to communicable diseases, poverty and human conflicts, the incidence of dementia increases in the developing world in tandem with the ageing population. Although some FDA approved drugs are available for the treatment of dementia, the outcomes are often unsatisfactory. In traditional practices of medicine, numerous plants have been used to treat cognitive disorders, including neurodegenerative diseases such as Alzheimer's disease (AD) and other memory-related disorders. In western medicine most of the drugs used for the treatment of neurodegenerative disorders are derived from plant sources. OBJECTIVE: This article reviews plants and their active constituents that have been used for their reputed cognitive-enhancing and antidementia effects. METHODS: A literature survey in Science Direct, Pubmed, and Google Scholar was performed to gather information regarding drug discovery from plants sources for the treatment of congnitive disorders and dementia. RESULTS: More than forty herbal remedies were identified with cholinesterase inhibitory, anti-inflammatory, or antioxidant activities. Bioactive compounds include alkaloids, flavonoids, steroids, saponins, terpenoids, and essential oils. About eleven herbal plants with multipotent activity against AD are discussed. CONCLUSION: Literature surveys show that most of the research has been conducted on herbal remedies effect on cholinesterase inhibitory and antioxidant activities. Studies regarding the effect of herbal drugs on ß-secretase inhibitory activity and antiaggregation property are lacking. This review provides leads for identifying potential new drugs from plant sources for the treatment of neurodegenerative disorders.

Silymarin attenuates benzo(a)pyrene induced toxicity by mitigating ROS production, DNA damage and calcium mediated apoptosis in peripheral blood mononuclear cells (PBMC).

Benzo(a)pyrene (B(a)P), which is the most studied member of PAH family is released into the environment (air, water and soil) from natural and man-made sources including industrial and automobile exhaust fumes. Since B(a)P is an omnipresent environmental pollutant and is believed to be a risk factor for human chemical carcinogenesis, it is important to identify potent naturally occurring/synthetic agents that could modulate B(a)P-induced toxicity. The present study explores the effect of the flavonoid silymarin (2.4mg/ml) in counteracting the toxicity of B(a)P (1µM) in PBMC. Flourimetry and Confocal Laser Scanning Microscopy results showed that silymarin reduces the B(a)P induced ROS production and DNA damage. Atomic Absorption Spectroscopy analysis and fluorescent microscopic pictures proved that silymarin reduces the increased intracellular calcium and apoptosis induction during B(a)P treatment. Furthermore, silymarin did not show any inhibition for CYP1B1 activity at transcriptional level by semiquantitative RT PCR but it affects the catalytic activity of Phase I CYP1A1/CYP1B1 enzyme (EROD assay) during B(a)P treatment. The findings reveal that silymarin possesses substantial protective effect against B(a)P induced DNA damage and calcium mediated apoptosis by inhibiting the catalytic activity of CYP1B1 and maintaining the intracellular calcium dysregulation; hence, it could be considered as a potential protective agent for environmental contaminant induced immunotoxicity.

p53 exon 4 (codon 72) polymorphism and exon 7 (codon 249) mutation in breast cancer patients in southern region (Madurai) of Tamil Nadu.

BACKGROUND: We investigated the association between polymorphisms in the p53 tumor suppressor gene and breast cancer risk in women especially in the Southern part of India. METHODS: Genotyping was performed for 50 breast cancer women and 50 controls to determine the status of p53 exon 4 codon 72 polymorphism and exon 7 codon 249 mutation and their possible role in breast cancer risk. RESULTS: Frequency of Arg/Arg at codon 72 was 18% in controls and 28% in patients, Arg/Pro frequency was 56% and 66%, Pro/Pro genotype was 8% in controls and 8% in patients. No significance was observed for breast cancer risk with either Arg/Arg or Pro/Pro genotype in codon 72 polymorphism. Similarly, mutation analysis of exon 7 codon 249 revealed that 72% of breast cancer patients have mutation, which is not statistically significant. However, there is a strong association between increase in exon 7 codon 249 mutation and exposure to pollution. CONCLUSION: The results suggested that there is no risk for exon 4 with Arg/Arg or Pro/Pro polymorphisms in the p53 gene and there is no strong correlation between breast cancer patients and mutation in exon 7 codon 249 in South Indian women.

Assessment of Anticholinesterase Activity of Gelidiella acerosa: Implications for Its Therapeutic Potential against Alzheimer's Disease.

The effect of various solvent extracts of Gelidiella acerosa on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities was investigated. AChE and BuChE inhibitory activities were analyzed by spectrophotometric method. Phytochemical screening of the compounds present in the solvent extracts was done qualitatively. Characterization of the compounds present in the benzene extract of G. acerosa was done by GC-MS analysis. The results showed that, at 487.80 µg/mL, benzene extract showed significant (P < 0.05) inhibitory activity against both AChE and BuChE with the percentage of inhibition 54.18 ± 5.65 % (IC(50) = 434.61 ± 26.53 µg/mL) and 78.43 ± 0% (IC(50) = 163.01 ± 85.35 µg/mL), respectively. The mode of inhibition exhibited by benzene extract against the AChE and BuChE was found to be competitive and uncompetitive type of inhibition, respectively. Preliminary phytochemical analysis coupled with GC-MS illustrates that the benzene extract possesses high amount of terpenoids, which could be the reason for potential cholinesterase inhibitory activity.

Cholinesterase inhibitors from Sargassum and Gracilaria gracilis: seaweeds inhabiting South Indian coastal areas (Hare Island, Gulf of Mannar).

Dementia is a chronic progressive mental disorder, which adversely affects memory, thinking, comprehension, calculation and language. Some of the commonest forms of dementia are Alzheimer's disease, Parkinsonism, Dementia with Lewy Bodies and Myasthenia gravis. All these disorders are related to abnormalities in the central cholinergic system, which shows a decline in acetylcholine level. Cholinesterase (ChE) inhibitors are one of the novel strategies used for the symptomatic treatment of neurological disorders like dementia. In the course of screening new ChE inhibitors from marine sources, about 11 seaweeds, which have wide pharmaceutical applications, were collected from Hare Island, Gulf of Mannar, Tamilnadu, India. Methanolic extracts of the seaweeds were assessed for ChE inhibitory activity under in vitro conditions. Kinetic parameters IC(50), K(i) and V(max) were also analysed. The results showed that 3/11 seaweeds showed 50% inhibition for both ChEs (using acetylthiocholine iodide and butyrylthiocholine iodide as substrate) at concentrations of 2 mg mL(-1) (Gracilaria gracilis, Sargassum, Cladophora fasicularis for ChE with acetylthiocholine iodide as substrate and Gracilaria gracilis, Gracilaria edulis, Sargassum for ChE with butyrylthiocholine iodide as substrate) and 4/11 showed no inhibitory activity. Inhibitory activity of seaweed extracts was compared with standard drug donepezil. Enzyme kinetic analysis showed that algal extracts exhibited mixed type inhibition (partially non-competitive inhibition).