V. Rajkumar

Bio: V. Rajkumar is an academic researcher from VIT University. The author has contributed to research in topics: DPPH & Lipid peroxidation. The author has an hindex of 13, co-authored 15 publications receiving 575 citations.

Quantitative assessment of the relative antineoplastic potential of the n-butanolic leaf extract of Annona muricata Linn. in normal and immortalized human cell lines.

Abstract: Natural products have been the target for cancer therapy for several years but there is still a dearth of information on potent compounds that may protect normal cells and selectively destroy cancerous cells. The present study was aimed to evaluate the cytotoxic potential of n-butanolic leaf extract of Annona muricata L. on WRL-68 (normal human hepatic cells), MDA-MB-435S (human breast carcinoma cells) and HaCaT (human immortalized keratinocyte cells) lines by XTT assay. Prior to cytotoxicity testing, the extract was subjected to phytochemical screening for detecting the presence of compounds with therapeutic potential. Their relative antioxidant properties were evaluated using the reducing power and DPPH * radical scavenging assay. Since most of the observed chemo-preventive potential invariably correlated with the amount of total phenolics present in the extract, their levels were quantified and identified by HPLC analysis. Correlation studies indicated a strong and significant (P <0.05) positive correlation of phenolic compounds with free radical scavenging potential. The results revealed that the extract was moderately cytotoxic to normal cells with a mean IC50 value of 52.4 µg when compared with those obtained for cancerous cells (IC50 values of 29.2 µg for MDA-MB-435S and 30.1 µg for HaCaT respectively). The study confirms the presence of therapeutically active antineoplastic compounds in the n-butanolic leaf extract of Annona muricata. Isolation of the active metabolites from the extract is in prospect.

Antioxidant and anti-neoplastic activities of Picrorhiza kurroa extracts.

Abstract: Picrorhizakurroa Royle ex Benth., a well-known traditional herb from the Scrophulariaceae family has a remarkable reputation among the indigenous medical practitioners. The antioxidant and anti-neoplastic activities of methanolic and aqueous extracts of P. kurroa rhizome were investigated in the present study. The total phenolic content was determined by a spectrophotometric method. The antioxidant efficacies of the extracts were studied employing radical scavenging assays (DPPH· and ·OH), ferric reducing antioxidant property (FRAP) and thiobarbituric acid (TBA) assay for testing inhibition of lipid peroxidation. Furthermore, the cytotoxicity of the extracts was tested by XTT assay in MDA-MB-435S (human breast carcinoma), Hep3B (human hepatocellular carcinoma) and PC-3 (human prostate cancer) cell lines. The ability of the extracts to induce apoptosis was also investigated. Both extracts exhibited promising antioxidant potentials. The extracts were also observed to be cytotoxic at the tested dosage and were able to target cells towards apoptosis. The study concludes that P. kurroa possess diverse therapeutic potentials which might be useful in development of drugs or their precursors.

Antioxidant and Anti-Cancer Potentials of Rheum emodi Rhizome Extracts

Abstract: The objective of this study was to determine antioxidant and cytotoxic efficacies of methanolic and aqueous extracts of Rheum emodi Wall. ex Meissn. rhizome. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical scavenging activities, inhibitory effect on lipid peroxidation and Fe3+ reducing antioxidant property have been used to investigate antioxidant properties of the extracts. Cytotoxicity of the extracts was tested on MDA-MB-435S and Hep3B cell lines. Both extracts displayed extensive cytotoxicity to the tested cell lines. The extracts were studied for their ability to protect pBR322 DNA from damage by UV induced photolysis of H2O2. The aqueous extract, though inferior to methanolic extract in its antioxidant potential exhibited efficiency in DNA protection, while the methanolic extract failed to protect the DNA. The amount of total polyphenolics in the extracts was measured by spectrophotometric method. The methanolic extract contained higher polyphenolic contents than aqueous extract. Significant positive correlations were observed (P < .05) between results of phenolic content estimation and that of antioxidant assays. Hence, high-performance liquid chromatography analysis was performed to identify few major phenolic compounds that might be responsible for these therapeutic properties. These results indicate that rhizome of R. emodi possesses antioxidant and cytotoxic activities and therefore have therapeutic potential.

Aqueous extract of Phyllanthus amarus inhibits chromium(VI)-induced toxicity in MDA-MB-435S cells.

Abstract: Cr(VI) (hexavalent) is a very strong oxidant which causes high cytotoxicity through oxidative stress in tissue systems. Its abundance in groundwater and drinking water in several parts of the world has been noted to cause severe toxicity to both flora and fauna. This study evaluated the effects of aqueous extract of Phyllanthus amarus Schum. & Thon. against Cr(VI)-induced oxidative toxicity in vitro in MDA-MB-435S human breast carcinoma cells, along with an estimation of its antioxidant potential, inhibition of lipid peroxidation and determination of its polyphenolic composition. The extract showed significant (P<0.05) potential in scavenging free radicals (DPPH() and ABTS()(+)) and Fe(+3), and in inhibiting lipid peroxidation. A distinct decline in Cr(VI)-induced cytotoxicity was noticed in MDA-MB-435S cells with an increase in extract dosage. Furthermore, the extract proved to contain a high content of phenolic compounds which were found to have strong and significant (P<0.05) positive correlations to free-radical scavenging potential, lipid peroxidation inhibition capacity and cyto-protective efficiency against Cr(VI)-induced oxidative cellular damage. HPLC analysis identified some of the major phenolic compounds in it. It was concluded that P. amarus aqueous extract has high antioxidant potential (by virtue of its phenolic constituents) which simultaneously inhibits Cr(VI)-induced oxidative toxicity to MDA-MB-435S cells.

The antioxidant and DNA protection potential of Indian tribal medicinal plants

Abstract: Prevention and treatment of various degenerative diseases using traditional medicines is increasingly generating interest, especially in geriatric clinical research. This study aimed to evaluate the free-radical scavenging properties and potential to prevent DNA damage (from oxidative stress) of 56 extracts (polar and non-polar) from 14 medicinal plants (from 12 families) used by diverse Indian tribes and ethnic groups. Although widely known for traditional uses, these plants have not been extensively used for clinical purposes. Scavenging of DPPH radical by all the extracts was evaluated to estimate their antioxidant potential and rank them accordingly. Extracts occupying the top 10 ranks were further evaluated and extensively screened for their antioxidant potential by estimation of their ABTS

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Annona muricata (Annonaceae): A Review of Its Traditional Uses, Isolated Acetogenins and Biological Activities

Abstract: Annona muricata is a member of the Annonaceae family and is a fruit tree with a long history of traditional use. A. muricata, also known as soursop, graviola and guanabana, is an evergreen plant that is mostly distributed in tropical and subtropical regions of the world. The fruits of A. muricata are extensively used to prepare syrups, candies, beverages, ice creams and shakes. A wide array of ethnomedicinal activities is contributed to different parts of A. muricata, and indigenous communities in Africa and South America extensively use this plant in their folk medicine. Numerous investigations have substantiated these activities, including anticancer, anticonvulsant, anti-arthritic, antiparasitic, antimalarial, hepatoprotective and antidiabetic activities. Phytochemical studies reveal that annonaceous acetogenins are the major constituents of A. muricata. More than 100 annonaceous acetogenins have been isolated from leaves, barks, seeds, roots and fruits of A. muricata. In view of the immense studies on A. muricata, this review strives to unite available information regarding its phytochemistry, traditional uses and biological activities.

Phyllanthus amarus: Ethnomedicinal uses, phytochemistry and pharmacology: A review

Abstract: Ethnopharmacological relevance Phyllanthus amarus Schum. & Thonn. belongs to the family Euphorbiaceae is a small herb well known for its medicinal properties and widely used worldwide. P. amarus is an important plant of Indian Ayurvedic system of medicine which is used in the problems of stomach, genitourinary system, liver, kidney and spleen. It is bitter, astringent, stomachic, diuretic, febrifuge and antiseptic. The whole plant is used in gonorrhea, menorrhagia and other genital affections. It is useful in gastropathy, diarrhoea, dysentery, intermittent fevers, ophthalmopathy, scabies, ulcers and wounds. Materials and methods The present review covers a literature across from 1980 to 2011. Some information collected from traditional Ayurvedic texts and published literature on ethanomedicinal uses of Phyllanthus amarus in different countries worldwide. Results Phytochemical studies have shown the presence of many valuable compounds such as lignans, flavonoids, hydrolysable tannins (ellagitannins), polyphenols, triterpenes, sterols and alkaloids. The extracts and the compounds isolated from P. amarus show a wide spectrum of pharmacological activities including antiviral, antibacterial, antiplasmodial, anti-inflammatory, antimalarial, antimicrobial, anticancer, antidiabetic, hypolipidemic, antioxidant, hepatoprotective nephroprotective and diurectic properties. Conclusion The present review summarizes information concerning the morphology, ecology, ethnopharmacology, phytochemistry, biological activities, clinical applications and toxicological reports of P. amarus . This review aims at gathering the research work undertaken till date on this plant in order to provide sufficient baseline information for future works and commercial exploitation.

Annona muricata: A comprehensive review on its traditional medicinal uses, phytochemicals, pharmacological activities, mechanisms of action and toxicity

Abstract: Annona muricata L. (Magnoliales: Annonaceae) is a tropical plant species known for its edible fruit which has some medicinal merits, but also some toxicological effects. This review focuses on the phytochemicals contents, bioactivity, biological actions and toxicological aspects of extracts and isolated compounds, as well as medicinal uses of A. muricata, with the objective of stimulating further studies on extracts and fruit pulp used for human consumption. Traditional medicinal uses of A. muricata have been identified in tropical regions to treat diverse ailments such as fever, pain, respiratory and skin illness, internal and external parasites, bacterial infections, hypertension, inflammation, diabetes and cancer. More than 200 chemical compounds have been identified and isolated from this plant; the most important being alkaloids, phenols and acetogenins. Using in vitro studies, extracts and phytochemicals of A. muricata have been characterized as an antimicrobial, anti-inflammatory, anti-protozoan, antioxidant, insecticide, larvicide, and cytotoxic to tumor cells. In vivo studies of the crude extracts and isolated compounds of A. muricata were shown to possess anxiolytic, anti-stress, anti-inflammatory, contraceptive, anti-tumoral, antiulceric, wound healing, hepato-protective, anti-icteric and hypoglycemic activities. In addition, clinical studies support the hypoglycemic activity of the ethanolic extracts of A. muricata leaves. Mechanisms of action of some pharmacological activities have been elucidated, such as cytotoxic, antioxidant, antimicrobial, antinociception and hypotensive activities. However, some phytochemical compounds isolated from A. muricata have shown a neurotoxic effect in vitro and in vivo, and therefore, these crude extracts and isolated compounds need to be further investigated to define the magnitude of the effects, optimal dosage, mechanisms of action, long-term safety, and potential side effects. Additionally, clinical studies are necessary to support the therapeutic potential of this plant.

Anticancer Potential of Plants and Natural Products: A Review

Abstract: Cancer is one of the leading causes of death and globally the numbers of cases of cancer are increasing gradually. There are several medicines available in the market to treat the various types of cancer but no drug is found to be fully effective and safe. The major problem in the cancer chemotherapy is the toxicity of the established drugs. However plants and plant derived products have proved effective and safe in the treatment and management of cancers. These days most of the research work on cancer drugs is targeted on plants and plants derived natural products. Many natural products and their analogues have been identified as potent anti-cancer agents and day by day the anti-cancer property of various plants is being identified. Here an attempt is being made through this review to highlights the natural products and their analogues established as anti-cancer agents and the new plant species identified with anti-cancer properties either in vivo or in vitro.