Rhitajit Sarkar

Assessment of the Antioxidant and Reactive Oxygen Species Scavenging Activity of Methanolic Extract of Caesalpinia crista Leaf

“Oxidative stress” is initiated by reactive oxygen species (ROS), which are responsible for majority of the diseases. However, antioxidants with ROS scavenging ability may have great relevance in the prevention of oxidative stress. The present study was undertaken, using a 70% methanolic extract of Caesalpinia crista leaves, to examine different in vitro tests in diversified fields including total antioxidant activity, scavenging activities for various ROS, iron chelating activity and phenolic and flavonoid contents. Total antioxidant activity was evaluated as trolox equivalent antioxidant capacity value of 0.546 ± 0.014. The extract was investigated for different ROS scavenging activities and IC50 values were found to be 0.44 ± 0.1 mg/ml, 24.9 ± 0.98 μg/ml, 33.72 ± 0.85 μg/ml, 61.13 ± 3.24 μg/mL and 170.51 ± 4.68 μg/mL for hydroxyl, superoxide, nitric oxide, singlet oxygen and hypochlorous acid, respectively; however, no significant results were obtained in scavenging of hydrogen peroxide and peroxynitrite anion. The extract was found to be a potent iron chelator with IC50 = 279.85 ± 4.72 μg/mL. The plant extract (100 mg) yielded 50.23 ± 0.003 mg/mL gallic acid equivalent phenolic content and 106.83 ± 0.0003 mg/mL quercetin equivalent flavonoid content. In the in vivo experiments, the extract treatment showed significant increase in the level of superoxide dismutase, catalase, glutathione-S-transferase and reduced glutathione. In a word, it may be concluded that 70% methanol extract of C. crista leaves acts as an antioxidant and ROS scavenger; which may be due to the presence of phenolic and flavonoid compounds.

An antioxidant extract of tropical lichen, Parmotrema reticulatum, induces cell cycle arrest and apoptosis in breast carcinoma cell line MCF-7.

This report highlights the phytochemical analysis, antioxidant potential and anticancer activity against breast carcinoma of 70% methanolic extract of lichen, Parmotrema reticulatum (PRME). Phytochemical analysis of PRME confirms the presence of various phytoconstituents like alkaloids, carbohydrates, flavonoids, glycosides, phenols, saponins, tannins, anthraquinones, and ascorbic acid; among which alkaloids, phenols and flavonoids are found in abundant amount. High performance liquid chromatography (HPLC) analysis of PRME revealed the presence of catechin, purpurin, tannic acid and reserpine. Antioxidant activity was evaluated by nine separate methods. PRME showed excellent hydroxyl and hypochlorous radical scavenging as well as moderate DPPH, superoxide, singlet oxygen, nitric oxide and peroxynitrite scavenging activity. Cytotoxicity of PRME was tested against breast carcinoma (MCF-7), lung carcinoma (A549) and normal lung fibroblast (WI-38) using WST-1 method. PRME was found cytotoxic against MCF-7 cells with an IC50 value 130.03±3.11 µg/ml while negligible cytotoxicity was observed on A549 and WI-38 cells. Further flow cytometric study showed that PRME halted the MCF-7 cells in S and G2/M phases and induces apoptosis in dose as well as time dependent manner. Cell cycle arrest was associated with downregulation of cyclin B1, Cdk-2 and Cdc25C as well as slight decrease in the expression of Cdk-1 and cyclin A1 with subsequent upregulation of p53 and p21. Moreover PRME induced Bax and inhibited Bcl-2 expression, which results in increasing Bax/Bcl-2 ratio and activation of caspase cascade. This ultimately leads to PARP degradation and induces apoptosis in MCF-7 cells. It can be hypothesised from the current study that the antioxidant and anticancer potential of the PRME may reside in the phytoconstitutents present in it and therefore, PRME may be used as a possible source of natural antioxidant that may be developed to an anticancer agent.

Reducing power and iron chelating property of Terminalia chebula (Retz.) alleviates iron induced liver toxicity in mice

BackgroundThe 70% methanol extract of Terminalia chebula Retz. fruit (TCME) was investigated for its in vitro iron chelating property and in vivo ameliorating effect on hepatic injury of iron overloaded mice.MethodsThe effect of fruit extract on Fe2+-ferrozine complex formation and Fe2+ mediated pUC-18 DNA breakdown was studied in order to find the in vitro iron chelating activity. Thirty-six Swiss Albino mice were divided into six groups of: blank, patient control and treated with 50, 100, 200 mg/kg b.w. of TCME and desirox (standard iron chelator drug with Deferasirox as parent compound). Evaluations were made for serum markers of hepatic damage, antioxidant enzyme, lipid per oxidation and liver fibrosis levels. The reductive release of ferritin iron by the extract was further studied.ResultsIn vitro results showed considerable iron chelation with IC50 of 27.19 ± 2.80 μg/ml, and a significant DNA protection with [P]50 of 1.07 ± 0.03 μg/ml along with about 86% retention of supercoiled DNA. Iron-dextran injection (i.p.) caused significant increase in the levels of the serum enzymes, viz., alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), alkaline phosphatase (ALP) and Bilirubin, which were subsequently lowered by oral administration of 200 mg/kg b.w. dose of the fruit extract by 81.5%, 105.88%, 188.08% and 128.31%, respectively. Similarly, treatment with the same dose of the extract was shown to alleviate the reduced levels of liver antioxidant enzyme superoxide dismutase, catalase, glutathione S-transferase and non-enzymatic reduced glutathione, by 49.8%, 53.5%, 35.4% and 11% respectively, in comparison to the iron overloaded mice. At the same time, the fruit extract effectively lowered the iron-overload induced raised levels of lipid per oxidation, protein carbonyl, hydroxyproline and liver iron by 49%, 67%, 67% and 26%, respectively, with oral treatment of 200 mg/kg b.w. dose of TCME. The fruit extract also showed potential activity for reductive release of ferritin iron.ConclusionsThese findings suggest that Terminalia chebula extract may contain active substances capable of lessening iron overload induced toxicity, and hence possibly be useful as iron chelating drug for iron overload diseases.

Assessment of in Vitro Antioxidant and Free Radical Scavenging Activity of Cajanus cajan

The present study was undertaken to evaluate the antioxidant and free radical scavenging activities of 70% methanolic extract of Cajanus cajan leaves using various in vitro assays. The TEAC value 0.84 ± 0.05 for the extract indicates it is an antioxidant. The extract had shown its scavenging activity for different free radicals and 175.73 ± 7.50 ?g/ml, 27.17 ± 0.9 ?g/ml, 60.78 ± 5.15 ?g/ml and 250.29 ± 5.70 ?g/ml were determined as the IC50 values for hydroxyl, superoxide, nitric oxide and singlet oxygen radicals, respectively. The sample showed reasonable chelation of Fe2+ ion and inhibition of lipid peroxidation. The phenolic and flavonoid contents of the extract were also determined to be 51.33 ± 0.002 mg/ml gallic acid equivalent and 143.0 ± 0.003 mg/ml quercetin equivalent, respectively. The results showed that 70% methanol extract of C. cajan leaves possesses antioxidant and free radical scavenging properties.

Heartwood extract of Acacia catechu induces apoptosis in human breast carcinoma by altering bax/bcl-2 ratio

Background: The heartwood extract of A. catechu, called pale catechu or “Katha” in Hindi has been widely used in traditional Indian medicinal system. Although various pharmacological properties of this plant had been reported previously, only a few were concerned with the anticancer activity of this plant. Objective: The objective was to assess the in vitro anticancer and apoptosis inducing effect of 70% methanolic extract of “Katha” (ACME) on human breast adenocarcinoma cell line (MCF-7). Materials and Methods: MCF-7 cell line was treated with increasing concentrations of ACME and cell viability was calculated. Flow cytometric methods were used to confirm the apoptosis promoting role of ACME. Morphological changes were then analysed using confocal microscopy. Western blotting was then performed to investigate the expression of apoptogenic proteins and to analyse the activation of caspases. Results: ACME showed significant cytotoxicity to MCF-7 cells with an IC50 value of 288.85 ± 25.79 μg/ml. Flow cytometric analysis and morphological studies confirmed that ACME is able to induce apoptosis in MCF-7 cells. Furthermore, immunoblot results suggested the pathway of apoptosis induction by increasing Bax/Bcl-2 ratio which results in the activation of caspase-cascade and ultimately leads to the cleavage of Poly adeno ribose polymerase (PARP). Conclusion: These results provide the evidence that ACME is able to inhibit the proliferation of MCF-7 cells by inducing apoptosis through intrinsic pathway.

Hepatoprotective Potential of Caesalpinia crista against Iron-Overload-Induced Liver Toxicity in Mice.

The present study was carried out to evaluate the ameliorating effect of Caesalpinia crista Linn. (CCME) extract on iron-overload-induced liver injury. Iron overload was induced by intraperitoneal administration of iron dextran into mice. CCME attenuated the percentage increase in liver iron and serum ferritin levels when compared to control group. CCME also showed a dose-dependent inhibition of lipid peroxidation, protein oxidation, and liver fibrosis. The serum enzyme markers were found to be less, whereas enhanced levels of liver antioxidant enzymes were detected in CCME-treated group. In presence of CCME, the reductive release of ferritin iron was increased significantly. Furthermore, CCME exhibited DPPH radical scavenging and protection against Fe2+-mediated oxidative DNA damage. The current study confirmed the hepatoprotective effect of CCME against the model hepatotoxicant iron overload and the activity is likely related to its potent antioxidant and iron-chelating property.

Amelioration of iron overload-induced liver toxicity by a potent antioxidant and iron chelator, Emblica officinalis Gaertn

In liver, the major site of iron storage, iron overload is associated with oxidative damage of protein, lipid, and DNA and causes protein oxidation, lipid peroxidation, and rupture of hepatocytes, leading to cell death. Serum ferritin and liver iron content are the main forecasters of moderate to severe iron overload in the liver. The sequels of excess iron deposition in the liver are fibrosis and enhanced levels of serum enzymes and bilirubin markers. Emblica officinalis (EO) fruit extract was found efficient in lessening intraperitoneally injected iron dextran-induced liver toxicity in Swiss albino mice. Mice administered with different doses of 70% methanol extract of EO (50, 100, and 200 mg kg−1 body weight) showed significant decrease in liver iron, serum ferritin, and serum enzyme levels, along with the decrease in lipid peroxidation, protein oxidation, and collagen content. The activity was further supported by its considerable iron chelation with half-maximal inhibitory concentration of 70.24 ± 2.74 μg ml−1 and the protection on ferrous ion-mediated DNA breakdown with 50% protection ([P]50) of 1.04 ± 0.01 μg ml−1. Simultaneously, the extract effectively induced the antioxidant enzyme levels and also exhibited the potential activity of reductive release of ferritin iron. These findings suggest that the EO extract may be used as a potent drug for the treatment of pathological sequences arisen in the iron overload-induced liver damage.

Hydroalcoholic extracts of Indian medicinal plants can help in amelioration from oxidative stress through antioxidant properties

The in vitro study of the antioxidant properties of the hydroalcoholic extracts of various Indian medicinal plants can logically help to develop a better and safer way of amelioration from oxidative stress. As aimed, the present study has been done to estimate and thereby conclude regarding the antioxidant activities of a few Indian medicinal plants, viz., Terminalia chebula, Terminalia belerica, Emblica officinalis, Caesalpinia crista, Cajanus cajan, and Tinospora cordifolia. The extracts of the plants have been subjected to the evaluation of antioxidant properties through scavenging assays for reactive oxygen species like superoxide, nitric oxide, peroxynitrite, hypochlorous acid, singlet oxygen, etc. and measurement of TEAC values and other phytochemical parameters. The phenolic and flavonoid contents of each plant have been found to be correlated to their individual antioxidant activity. The results showed the hydroalcoholic extracts of the plants were efficient indicators of their antioxidant capacity thus concreting their basis to be used as natural antioxidant.

Plants of Indian Traditional Medicine with Antioxidant Activity

Oxidative stress is associated with increased production of reactive oxygen species (ROS) that can pose a threat to cells by causing lipid peroxidation, protein oxidation, nucleic acid damage, enzyme inhibition and activation of cell death pathways. An uncontrollable production of ROS may lead to organ dysfunction and diseases. It has been well documented in the last few decades that antioxidant compounds are the major agents that eliminate/scavenge ROS hence inhibiting oxidative stress and hindering the onset and development of non communicable chronic diseases (NCDs). Naturally occurring antioxidant compounds in plants may contribute to their potential dietary, nutritious and curative activities against ROS-induced oxidative cellular damage and NCDs. India is endowed with a variety of natural resources and flora with antioxidant principles that can be used in traditional medicine aimed at maintaining health and curing NCDs. Indian plants are important sources of alkaloids and phenolic compounds with potential antioxidant activities. Ancient texts of Ayurveda and Charaka Samhita mention innumerable herbal formulations in the treatment of NCDs that we know are caused due to oxidative stress and free-radical damage. Scientists around the world have shown interest in the Indian system of medicine and have realized the potential of Indian plants against ROS-induced cellular damage and NCDs. Plants mentioned in the texts of Indian traditional medicine are discussed here so as to project a picture of Indian flora as potential sources of antioxidants in the prevention and management of human NCDs.