Shashank Kumar

Chemistry and Biological Activities of Flavonoids: An Overview

There has been increasing interest in the research on flavonoids from plant sources because of their versatile health benefits reported in various epidemiological studies. Since flavonoids are directly associated with human dietary ingredients and health, there is need to evaluate structure and function relationship. The bioavailability, metabolism, and biological activity of flavonoids depend upon the configuration, total number of hydroxyl groups, and substitution of functional groups about their nuclear structure. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. Most recent researches have focused on the health aspects of flavonoids for humans. Many flavonoids are shown to have antioxidative activity, free radical scavenging capacity, coronary heart disease prevention, hepatoprotective, anti-inflammatory, and anticancer activities, while some flavonoids exhibit potential antiviral activities. In plant systems, flavonoids help in combating oxidative stress and act as growth regulators. For pharmaceutical purposes cost-effective bulk production of different types of flavonoids has been made possible with the help of microbial biotechnology. This review highlights the structural features of flavonoids, their beneficial roles in human health, and significance in plants as well as their microbial production.

Antioxidant mediated protective effect of Parthenium hysterophorus against oxidative damage using in vitro models

BackgroundParthenium hysterophorus L. (Asteraceae) is a common weed occurring throughout the globe. In traditional medicine its decoction has been used for treatment of many infectious and degenerative diseases. This work was therefore designed to assess the phytochemical constitution of P. hysterophorus flower and root extracts and to evaluate their reducing power, radical scavenging activity as well as protective efficacy against membrane lipid damage.MethodsDried flower and root samples were sequentially extracted with non-polar and polar solvents using Soxhlet apparatus. The phytochemical screening was done using standard chemical methods and thin layer chromatography. Total phenolic content was determined spectrophotometrically. Reducing power and hydroxyl radical scavenging activity assays were used to measure antioxidant activity. Protection against membrane damage was evaluated by inhibition of lipid peroxidation (TBARS assay) in rat kidney homogenate.ResultsFlavonoids, terpenoids, alkaloids and cardiac glycosides were present in all the extract. The total phenol contents in flower and root extracts were found to be in the range 86.69-320.17 mg propyl gallate equivalent (PGE)/g and 55.47-253.84 mg PGE/g, respectively. Comparatively better reducing power was observed in hexane fractions of flower (0.405) and root (0.282). Benzene extract of flower and ethyl acetate fraction of root accounted for appreciable hydroxyl radical scavenging activity (75-77%). Maximum protection against membrane lipid peroxidative damage among flower and root extracts was provided by ethanol (55.26%) and ethyl acetate (48.95%) fractions, respectively. Total phenolic content showed positive correlations with reducing power and lipid peroxidation inhibition (LPOI) % in floral extracts as well as with hydroxyl radical scavenging activity and LPOI % in root extracts.ConclusionStudy established that phytochemicals present in P. hysterophorus extracts have considerable antioxidant potential as well as lipo-protective activity against membrane damage.

Bauhinia variegata leaf extracts exhibit considerable antibacterial, antioxidant, and anticancer activities.

The present study reports the phytochemical profiling, antimicrobial, antioxidant, and anticancer activities of Bauhinia variegata leaf extracts. The reducing sugar, anthraquinone, and saponins were observed in polar extracts, while terpenoids and alkaloids were present in nonpolar and ethanol extracts. Total flavonoid contents in various extracts were found in the range of 11–222.67 mg QE/g. In disc diffusion assays, petroleum ether and chloroform fractions exhibited considerable inhibition against Klebsiella pneumoniae. Several other extracts also showed antibacterial activity against pathogenic strains of E. coli, Proteus spp. and Pseudomonas spp. Minimum bactericidal concentration (MBC) values of potential extracts were found between 3.5 and 28.40 mg/mL. The lowest MBC (3.5 mg/mL) was recorded for ethanol extract against Pseudomonas spp. The antioxidant activity of the extracts was compared with standard antioxidants. Dose dependent response was observed in reducing power of extracts. Polar extracts demonstrated appreciable metal ion chelating activity at lower concentrations (10–40 μg/mL). Many extracts showed significant antioxidant response in beta carotene bleaching assay. AQ fraction of B. variegata showed pronounced cytotoxic effect against DU-145, HOP-62, IGR-OV-1, MCF-7, and THP-1 human cancer cell lines with 90–99% cell growth inhibitory activity. Ethyl acetate fraction also produced considerable cytotoxicity against MCF-7 and THP-1 cell lines. The study demonstrates notable antibacterial, antioxidant, and anticancer activities in B. variegata leaf extracts.

Scientific Validation of the Medicinal Efficacy of Tinospora cordifolia

Present communication reports the scientific evaluation of Tinospora cordifolia for its medicinal efficacy which includes phytochemical screening, antimicrobial, antioxidant, and anticancer activities of the plant. Secondary metabolites including anthraquinones, terpenoids, and saponins were present in many extracts in addition to phenolics. Total phenol contents in various extracts were found in the range of 8.75–52.50 catechol equivalent per gram (CE/g). In disc diffusion assays, polar extracts exhibited considerable inhibition against Klebsiella pneumoniae. Several other extracts also showed antibacterial activity against pathogenic strains of E. coli, Pseudomonas spp., and Proteus spp. Minimum bactericidal concentration (MBC) values of potential extracts were found between 1.29 and 22.73 mg/mL. The lowest MBC (1.29 mg/mL) was recorded for acetone and ethyl acetate extracts against K. pneumoniae and Pseudomonas spp., respectively. The antioxidant activity of the extracts was comparable to that of standard antioxidants and concentration-dependent response was shown in reducing power assay. Aqueous extracts demonstrated substantial metal ion chelating activity (67–95%) at lower concentrations (10–40 μg/mL). Other extracts also exhibited considerable metal chelating response. Most of the extracts revealed considerable inhibition of MCF-7 cancer cell line. The study established remarkable antibacterial, antioxidant, and anticancer potential in T. cordifolia stem extracts.

Calotropis procera Root Extract Has the Capability to Combat Free Radical Mediated Damage.

The present study reports the antioxidant and membrane protective activities of Calotropis procera aqueous root extract using several in vitro assays along with the determination of phenolic as well as flavonoid contents. Total phenol and flavonoid contents in extract were 15.67 ± 1.52 mg propyl gallate equivalent/g and 1.62 ± 0.05 mg quercetin equivalent/g, respectively. UV-visual spectroscopic scanning of the extract indicated the presence of glycoside-linked tannins or flavonoids. The extract exhibited appreciable reducing power signifying hydrogen donating potential. DPPH radical scavenging assay revealed substantial free radical scavenging activity (42–90%) in the extracts. Concentration dependent response was observed in the metal ion chelating activity (16–95%). Extracts also provided protection against iron induced lipid peroxidation in rat tissue (liver, brain, and kidney) homogenates. Comparatively better protective efficacy against peroxidative damage was observed in liver (71%) followed by kidney (65%) and brain (60%) tissues. Positive correlation (r 2 = 0.756) was observed between DPPH free radical scavenging activity and reducing power of extract. Similarly strong positive correlation (r 2 ≈ 0.756) was observed between metal ion chelating ability and percentage lipid peroxidation inhibition in different tissues. The study demonstrated considerable protective efficacy in C. procera root aqueous extracts against free radical and metal ion mediated oxidative damage.

Parthenium hysterophorus: A Probable Source of Anticancer, Antioxidant and Anti-HIV Agents

The present work reports the anticancer, antioxidant, lipo-protective, and anti-HIV activities of phytoconstituents present in P. hysterophorus leaf. Dried leaf samples were sequentially extracted with nonpolar and polar solvents. Ethanol fraction showed noticeable cytotoxic activity (81–85%) in SRB assay against MCF-7 and THP-1 cancer cell lines at 100 μg/ml concentration, while lower activity was observed with DU-145 cell line. The same extract exhibited 17–98% growth inhibition of HL-60 cancer cell lines in MTT assay, showing concentration dependent response. Ethanol extract caused 12% reduction in mitochondrial membrane potential and 10% increment in sub G1 population of HL-60 cell lines. Several leaf fractions, namely, ethyl acetate, ethanol, and aqueous fractions exhibited considerable reducing capability at higher concentrations. Most of the extracts demonstrated appreciable (>75%) metal ion chelating and hydroxyl radical scavenging activities at 200 µg/ml. All the extracts except aqueous fraction accounted for about 70–80% inhibition of lipid peroxidation in rat liver homogenate indicating protective response against membrane damage. About 40% inhibition of reverse transcriptase (RT) activity was observed in hexane fraction in anti-HIV assay at 6.0 µg/ml concentration. The study showed that phytochemicals present in P. hysterophorus leaf have considerable potential as cytotoxic and antioxidant agents with low to moderate anti-HIV activity.

In Vitro Antibacterial, Antioxidant, and Cytotoxic Activities of Parthenium hysterophorus and Characterization of Extracts by LC-MS Analysis

Present work reports the biological activities of P. hysterophorus leaf, stem, flower, and root. Dried samples were sequentially extracted with many solvents. Hexane (HX), benzene (BZ), and chloroform (CH) extracts of leaf showed considerable antibacterial activity against Streptococcus mutans (MTCC 497), Proteus vulgaris (MTCC 7299), and Salmonella typhi (MTCC 3917). Flower extracts exhibited presence of higher amount of flavonoids (13.9–59.6 μgQE/mg) followed by leaf, stem, and root. Stem (HX, BZ, and CH), leaf ethanol (ET), and root (HX, BZ, and CH) fractions showed noticeable antioxidant capacity in phosphomolybdate assay. Most of the extracts demonstrated beta carotene bleaching inhibition capability. BZ, ethyl acetate (EA), and ET fractions of leaves, stem aqueous (AQ), and flower EA extracts showed membrane protective activities (40–55%). Middle fractions of the plant parts displayed moderate antihemolytic potential. Most of the flower extracts exhibited cytotoxic activity (80–100%) against lung and colon cancer cell lines. Root (HX and ET) and leaf ET extracts showed considerable inhibition (90–99%) of colon and ovary cancer cell lines. The LC-MS scan demonstrated presence of different compounds showing 3–20 min retention time. The study revealed considerable antibacterial, antioxidant, lipo-protective, antihemolytic, and anticancer potential in all parts of P. hysterophorus.

In vitro antioxidant, antibacterial, and cytotoxic activity and in vivo effect of Syngonium podophyllum and Eichhornia crassipes leaf extracts on isoniazid induced oxidative stress and hepatic markers.

The present study reports the in vitro antioxidant, antibacterial, and cytotoxic potential of Syngonium podophyllum (SP) and Eichhornia crassipes (EC) leaf aqueous extracts as well as their in vivo effect on oxidative stress and hepatic biomarkers in isoniazid induced rats. Phytochemical screening of extracts revealed the presence of flavonoids, terpenoids, reducing sugars, alkaloids, and saponins. Phenolic content in SP and EC extracts was 5.36 ± 0.32 and 10.63 ± 0.13 mg PGE/g, respectively, while flavonoid content was 1.26 ± 0.03 and 0.51 ± 0.03 μg QE/mg, respectively. EC extract exhibited comparatively better antioxidant activity as indicated by reducing power (0.197–0.775), DPPH radical scavenging potential (11%–96%), and metal ion chelating ability (42%–93%). Both the extracts provided 13%–65% protection against lipid peroxidation in rat tissue (liver, kidney, and brain) homogenate. SP and EC extracts exhibited 51% and 43% cytotoxicity against lung cancer (NCI-H322) cell line, respectively. Both extracts demonstrated considerable antibacterial activity against Proteus vulgaris, Salmonella typhi, and Bordetella bronchiseptica. Coadministration of E. crassipes extract with isoniazid in rats accounted for 46% decrease in malondialdehyde content and 21% increase in FRAP value of plasma. It also mitigated the isoniazid induced alterations in serum enzymes (SGOT, SGPT, and ALP), total bilirubin, creatinine, and hemoglobin contents. S. podophyllum extract was found to be hepatotoxic.

Drug Targets for Cancer Treatment: An Overview

Cancer is one of the major causes of the death worldwide.Malignant cells display metabolic changes, when compared to normal cells, because of both genetic and epigenetic alterations. Number of drugs being used for the cancer treatment follows different mechanisms of action. Therapeutic strategies include targeting of drugs at specific genes or proteins/enzymes found in cancer cells or the internal tissueenvironment which contributes to growth and survival of these cells. Targeted therapy is often used along with chemotherapy and other treatments to restrict the growth and spread of cancer cells. During the past few decades, targeted therapy has emerged as a promising approach for the development of selective anticancer agents. There is a class of targeted therapy drugs called angiogenesis inhibitors which focus on blocking the development of new blood vesselsin tumor tissues. In addition, anticancer drugs also include DNA intercalators, DNA synthesis inhibitors, transcription regulators, enzyme inhibitors etc. This review focuses on major classes of anticancer drug targets and their therapeutic importance.

Association of MTHFR (C677T) Gene Polymorphism With Breast Cancer in North India

Background Breast cancer is one of the most common malignancies in women and is associated with a variety of risk factors. The functional single-nucleotide polymorphism (SNP) C677T in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) may lead to decreased enzyme activity and affect the chemosensitivity of tumor cells. This study was designed to investigate the association of MTHFR gene polymorphism (SNP) in the pathogenesis of breast cancer among the North Indian women population. Materials and Methods Genotyping was performed by polymerase chain reaction (PCR) using genomic DNA, extracted from the peripheral blood of subjects with (275 cases) or without (275 controls) breast cancer. Restriction fragment length polymorphism was used to study C677T polymorphism in the study groups. Results The distribution of MTHFR (C677T) genotype frequencies, ie, CC, TT, and CT, among the patients was 64.7%, 2.18%, and 33.09%, respectively. In the healthy control group, the CC, TT, and CT frequencies were 78.91%, 1.09%, and 20.1%, respectively. The frequencies of C and T alleles were 81.2% and 18.7%, respectively, in the patient subjects, while they were 88.9% and 11.09%, respectively, among the healthy control group. Frequencies of the CT genotype and the T allele were significantly different (P = 0.007 and P = 0.005, respectively) between the control and the case subjects. Conclusion This study shows an association of the CT genotype and the T allele of the MTHFR (C667T) gene with increased genetic risk for breast cancer among Indian women.