Kasi Pandima Devi

Bioprotective properties of seaweeds: In vitro evaluation of antioxidant activity and antimicrobial activity against food borne bacteria in relation to polyphenolic content

BackgroundFor many years chemical preservatives have been used in food, to act as either antimicrobials or antioxidants or both. In general, consumers regard additive-free foods as safer since preservatives can cause health hazards like asthma and cancer and are suspected to be mutagenic and neurotoxic. The present study was carried out to evaluate the antimicrobial and antioxidant activity of methanolic extracts of seaweeds, with a view to developing safer food preservatives.MethodsTen edible seaweeds, which have wide pharmaceutical application, were collected from Central Marine Fisheries Research Institute, Tamil Nadu, India and evaluated for antioxidant and antimicrobial activity against food borne pathogens.ResultsThe results indicate that Gelidiella acerosa has the highest antioxidant activity while Haligra sps exhibited antibacterial activity against Staphylococcus aureus (MTCC 96).ConclusionQuantitative analysis of the total phenolic content of the seaweeds indicated that Gelidella acerosa and Haligra sps have high phenolic contents, which correlated to their respective antioxidant and antimicrobial activity

Kaempferol and inflammation: From chemistry to medicine.

Inflammation is an important process of human healing response, wherein the tissues respond to injuries induced by many agents including pathogens. It is characterized by pain, redness and heat in the injured tissues. Chronic inflammation seems to be associated with different types of diseases such as arthritis, allergies, atherosclerosis, and even cancer. In recent years natural product based drugs are considered as the novel therapeutic strategy for prevention and treatment of inflammatory diseases. Among the different types of phyto-constituents present in natural products, flavonoids which occur in many vegetable foods and herbal medicines are considered as the most active constituent, which has the potency to ameliorate inflammation under both in vitro and in vivo conditions. Kaempferol is a natural flavonol present in different plant species, which has been described to possess potent anti-inflammatory properties. Despite the voluminous literature on the anti-inflammatory effects of kaempferol, only very limited review articles has been published on this topic. Hence the present review is aimed to provide a critical overview on the anti-inflammatory effects and the mechanisms of action of kaempferol, based on the current scientific literature. In addition, emphasis is also given on the chemistry, natural sources, bioavailability and toxicity of kaempferol.

Genistein and Cancer: Current Status, Challenges, and Future Directions

Primary prevention through lifestyle interventions is a cost-effective alternative for preventing a large burden of chronic and degenerative diseases, including cancer, which is one of the leading causes of morbidity and mortality worldwide. In the past decade, epidemiologic and preclinical evidence suggested that polyphenolic phytochemicals present in many plant foods possess chemopreventive properties against several cancer forms. Thus, there has been increasing interest in the potential cancer chemopreventive agents obtained from natural sources, such as polyphenols, that may represent a new, affordable approach to curb the increasing burden of cancer throughout the world. Several epidemiologic studies showed a relation between a soy-rich diet and cancer prevention, which was attributed to the presence of a phenolic compound, genistein, present in soy-based foods. Genistein acts as a chemotherapeutic agent against different types of cancer, mainly by altering apoptosis, the cell cycle, and angiogenesis and inhibiting metastasis. Targeting caspases, B cell lymphoma 2 (Bcl-2)-associated X protein (Bax), Bcl-2, kinesin-like protein 20A (KIF20A), extracellular signal-regulated kinase 1/2 (ERK1/2), nuclear transcription factor κB (NF-κB), mitogen-activated protein kinase (MAPK), inhibitor of NF-κB (IκB), Wingless and integration 1 β-catenin (Wnt/β-catenin), and phosphoinositide 3 kinase/Akt (PI3K/Akt) signaling pathways may act as the molecular mechanisms of the anticancer, therapeutic effects of genistein. Genistein also shows synergistic behavior with well-known anticancer drugs, such as adriamycin, docetaxel, and tamoxifen, suggesting a potential role in combination therapy. This review critically analyzes the available literature on the therapeutic role of genistein on different types of cancer, focusing on its chemical features, plant food sources, bioavailability, and safety.

Omega-3 polyunsaturated fatty acids and cancer: lessons learned from clinical trials

Over the past decades, extensive studies have addressed the therapeutic effects of omega-3 polyunsaturated fatty acids (omega-3 FAs) against different human diseases such as cardiovascular and neurodegenerative diseases, cancer, etc. A growing body of scientific research shows the pharmacokinetic information and safety of these natural occurring substances. Moreover, during recent years, a plethora of studies has demonstrated that omega-3 FAs possess therapeutic role against certain types of cancer. It is also known that omega-3 FAs can improve efficacy and tolerability of chemotherapy. Previous reports showed that suppression of nuclear factor-κB, activation of AMPK/SIRT1, modulation of cyclooxygenase (COX) activity, and up-regulation of novel anti-inflammatory lipid mediators such as protectins, maresins, and resolvins, are the main mechanisms of antineoplastic effect of omega-3 FAs. In this review, we have collected the available clinical data on the therapeutic role of omega-3 FAs against breast cancer, colorectal cancer, leukemia, gastric cancer, pancreatic cancer, esophageal cancer, prostate cancer, lung cancer, head and neck cancer, as well as cancer cachexia. We also discussed the chemistry, dietary source, and bioavailability of omega-3 FAs, and the potential molecular mechanisms of anticancer and adverse effects.

Hydroxytyrosol, the phenolic compound of olive oil protects human PBMC against oxidative stress and DNA damage mediated by 2,3,7,8-TCDD

The protective effect of hydroxytyrosol (HT), a strong antioxidant compound from extra virgin olive oil, against TCDD induced toxicity was investigated in human peripheral blood mononuclear cells (PBMC). PBMC (1 × 10(6)cellsmL(-1)) were divided into four groups and were incubated in a CO(2) incubator (5% CO(2)) for 12h with vehicle, TCDD (10 nM), TCDD+HT (10 nM+100 μM) and HT alone (100 μM) respectively. To clarify the role of HT against TCDD induced cytotoxicity, oxidative stress and the levels of antioxidant enzymes were assessed. Incubation of PBMC with TCDD significantly decreased cell viability, catalase (CAT) and glutathione peroxidase (GPx) and increased the levels of superoxide dismutase (SOD), glutathione reductase (GR) and oxidative stress markers such as lipid peroxidation products (LPO), protein carbonyl content (PCC) and reactive oxygen species (ROS). Whereas, HT had an effective antioxidant property as observed by the increased cell viability, normalization of antioxidant enzymes and decreased levels of LPO, PCC and ROS in PBMC co-treated with HT and TCDD. Apoptosis detection and comet assay results shows that HT, by acting as an antioxidant, prevents the damage to DNA induced by TCDD. In addition light microscopic and histopathological observations revealed that the cells are apoptotic and degenerated during TCDD treatment, whereas cells showed intact morphology during co-treatment with HT. On the whole, the results reveal that HT exerts a promising antioxidant potential in protecting the PBMC against TCDD induced oxidative stress, which might be due to the presence of catechol moiety in its structure.

Bioactive effects of quercetin in the central nervous system: Focusing on the mechanisms of actions

Quercetin, a ubiquitous flavonoid that is widely distributed in plants is classified as a cognitive enhancer in traditional and oriental medicine. The protective effects of quercetin for the treatment of neurodegenerative disorders and cerebrovascular diseases have been demonstrated in both in vitro and in vivo studies. The free radical scavenging activity of quercetin has been well-documented, wherein quercetin has been observed to exhibit protective effects against oxidative stress mediated neuronal damage by modulating the expression of NRF-2 dependent antioxidant responsive elements, and attenuation of neuroinflammation by suppressing NF-κB signal transducer and activator of transcription-1 (STAT-1). Several in vitro and in vivo studies have also shown that quercetin destabilizes and enhances the clearance of abnormal protein such as beta- amyloid peptide and hyperphosphorlyated tau, the key pathological hallmarks of Alzheimers disease. Quercetin enhances neurogenesis and neuronal longevity by modulating a broad number of kinase signaling cascades such as phophoinositide 3- kinase (P13-kinase), AKT/PKB tyrosine kinase and Protein kinase C (PKC). Quercetin has also been well reported for its ability to reverse cognitive impairment and memory enhancement during aging. The current review focuses on summarizing the recent findings on the neuroprotective effect of quercetin, its mechanism of action and its possible roles in the prevention of neurological disorders.

Molecular mechanisms underlying anticancer effects of myricetin.

Dietary guidelines published in the past two decades have acknowledged the beneficial effects of myricetin, an important and common type of herbal flavonoid, against several human diseases such as inflammation, cardiovascular pathologies, and cancer. An increasing number of studies have shown the beneficial effects of myricetin against different types of cancer by modifying several cancer hallmarks including aberrant cell proliferation, signaling pathways, apoptosis, angiogenesis, and tumor metastasis. Most importantly, myricetin interacts with oncoproteins such as protein kinase B (PKB) (Akt), Fyn, MEK1, and JAK1-STAT3 (Janus kinase-signal transducer and activator of transcription 3), and it attenuates the neoplastic transformation of cancer cells. In addition, myricetin exerts antimitotic effects by targeting the overexpression of cyclin-dependent kinase 1 (CDK1) in liver cancer. Moreover, it also targets the mitochondria and promotes different kinds of cell death in various cancer cells. In the present paper, a critical review of the available literature is presented to identify the molecular targets underlying the anticancer effects of myricetin.

Evaluation of physicochemical properties, proximate and nutritional composition of Gracilaria edulis collected from Palk Bay

Gracilaria edulis, a red alga present in southeast coast of India was evaluated for its nutritional composition. FT-IR analysis of soluble polysaccharides revealed the presence of galactans, 3,6-anhydro-α-L-galactopyranose, sulphated galactose and the gelling agent agar, with the sulphate content estimated as 51.01 μg/mg of polysaccharide. Results of physicochemical properties and nutritional profile reveal the presence of dietary fibre (8.9 ± 0.62% DW), carbohydrate (101.61 ± 1.8 mg/g DW), crude protein (6.68 ± 0.94 mg/g DW) and lipid content (8.3 ± 1.03 mg/g DW). G. edulis contains biologically important fatty acids like palmitic acid (2.06%), linolenic acid (2.56%), and oleic acid (1.98%). The other nutritional components present in high amounts are proline, chlorophyll A and B, all the essential amino acids and vitamin A, E and C. These findings suggest that G. edulis has potent nutritional value which might be used as a source of nutrients for human and animals.

Cholinesterase inhibitory effects of Rhizophora lamarckii, Avicennia officinalis, Sesuvium portulacastrum and Suaeda monica: Mangroves inhabiting an Indian coastal area (Vellar Estuary)

Alzheimers disease is a progressive neurodegenerative illness accounting for approximately 50% of all types of dementia in elderly people. The only symptomatic treatment proven effective to date is the use of cholinesterase inhibitors to augment surviving cholinergic activity. The purpose of this study is to investigate cholinesterase inhibitory activity of mangroves as an alternative medicine for the treatment of Alzheimers disease. About nine mangrove plants, which were used as folk medicine in tropical countries, were collected from Parangipettai, Vellar estuary, Tamilnadu, India. Nile Tilapia muscle homogenate was used as source of enzyme. Inhibitory effect of methanolic leaf extract was assessed under in vitro condition by incubating various concentration of the extract with total cholinesterase and butyryl cholinesterase and assessing their residual activities by Ellmans colorimetric method. The results showed that of the nine plants screened Rhizophora lamarckii, Suaeda monica, Avicennia officinalis and Sesuvium portulacastrum showed 50% inhibitory activity to both TChE and BChE at concentrations less than 2 mg/mL when compared to other plant extracts, which was comparable to the standard drug Donepezil. Phytochemical analysis showed the presence of alkaloids in high concentration which might be correlated to its cholinesterase inhibitory activity.

Mangrove Plant Extracts: Radical Scavenging Activity and the Battle against Food-Borne Pathogens

Aims: The present study was carried out to evaluate the radical scavenging and antibacterial activity of methanolic leaf extracts of mangrove plants. 8 mangrove plants, which are used as folk medicine in various tropical countries, were collected in Pichavaram and Thondi, Tamil Nadu, India. Methods: The antioxidant properties of methanolic leaf extracts were assessed under in vitro conditions using different antioxidant tests, including DPPH, nitric oxide, hydrogen peroxide, hydroxyl radical scavenging assay, reducing power, ferrous ion chelating, and lipid peroxidation inhibition assay. Results and Conclusion: Of the 8 mangrove plants screened, Rhizophora mucronata (100 μg/ml) showed significantly higher (p < 0.05) activities for all antioxidant assays, and its IC50 values were 43.17, 116, 60.06, and 46.76 μg/ml for DPPH, hydrogen peroxide, nitric oxide, and hydroxyl radical scavenging activity, respectively. Butylated hydroxytoluene, ascorbic acid and α-tocopherol were used as positive controls. Methanolic extracts of R. mucronata were also found to be effective in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals in a Fenton’s reaction mixture. Moreover, the total phenolic content of R. mucronata (720.79 mg/gm of dry leaves) was very high and a strong positive correlation was observed between its phenolic content and its antioxidant activity. Methanolic leaf extracts of mangrove plants exhibited no antibacterial activity against seven food-borne pathogens studied.