Madhu Chandel

Modulatory role of alizarin from Rubia cordifolia L. against genotoxicity of mutagens.

Rubia cordifolia L. (Rubiaceae) is an important medicinal plant used in the Ayurvedic medicinal system. Its use as a traditional therapeutic has been related to the treatment of skin disorders and cancer. Besides its medicinal value, anthraquinones from this plant are used as natural food colourants and as natural hair dyes. Dyes derived from natural sources have emerged as important alternatives to synthetic dyes. Alizarin (1,2-dihydroxyanthraquinone) was isolated and characterized from R. cordifolia L. and evaluated for its antigenotoxic potential against a battery of mutagens viz. 4-nitro-o-phenylenediamine (NPD) and 2-aminofluorene (2-AF) in Ames assay using TA98 tester strain of Salmonella typhimurium; hydrogen peroxide (H(2)O(2)) and 4-nitroquinoline-1-oxide (4NQO) in SOS chromotest using PQ37 strain of Escherichia coli and in Comet assay using human blood lymphocytes. Our results showed that alizarin possessed significant modulatory role against the genotoxicity of mutagens.

Antioxidant activity and identification of bioactive compounds from leaves of Anthocephalus cadamba by ultra–performance liquid chromatography/electrospray ionization quadrupole time of flight mass spectrometry

OBJECTIVE To evaluate the antioxidant potential of different extract/fractions of Anthocephalus cadamba (A. cadamba) (Roxb.) Miq. (Rubiaceae) and study the tentative identification of their active constituents. METHODS The extract/fractions were screened for antioxidant activity using various in vitro assays viz. DPPH assay, ABTS assay, superoxide anion radical scavenging assay, reducing power assay and plasmid DNA nicking assay. Total phenolic content of extract/fractions was determined by colorimetric method. An ultra-performance LC-electrospray-quadrupole-time of flight mass spectrometry method was used to analyse the active constituents of extract/fractions of A. cadamba. RESULTS The ethyl acetate fraction was found to be most active fraction in all the assays as compared to other extract/fractions. The IC(50) value of ethyl acetate fraction (ETAC fraction) was 21.24 μg/mL, 1.12 μg/mL, 9.68 μg/mL and 57.81 μg/mL in DPPH assay, ABTS assay, reducing power assay and superoxide scavenging assay respectively. All the extract/fractions also showed the potential to protect the plasmid DNA (pBR322) against the attack of hydroxyl radicals generated by Fentońs reagent. The bioactive compounds were identified by UPLC-ESI-QTOF-MS, by comparing the mass and λ(max) with literature values. CONCLUSIONS The potential of the extract/fractions to scavenge different free radicals in different systems indicated that they may be useful therapeutic agents for treating radical-related pathologic damage.

Amelioration of oxidative stress by anthraquinones in various in vitro assays

Objective The use of natural phytoconstituents for food and as nutritional supplements is an easiest way to be healthier. Anthraquinone pigments have been traditionally used for various purposes viz. food colorants, textile staining, color paints and medicines. Rubia cordifolia L. is a perennial, herbaceous climbing plant belonging to family Rubiaceae. This plant contain substantial amounts of anthraquinones, especially in the roots. The present study deals with the bioactivity evaluation of phytoconstituents viz. alizarin and purpurin from Rubia cordifolia.

In Vitro Studies on the Antioxidant/Antigenotoxic Potential of Aqueous Fraction from Anthocephalus cadamba Bark

Cancer is a major public health problem in all parts of the world. With the increasing number of cancer cases worldwide, considerable attention is now being given to natural products for their possible cancer-preventing properties. Increasing evidence suggests that oxidative stress-mediated cardiovascular diseases and cancer-causing oxidation of the DNA molecule can be counteracted by natural antioxidants. The present study was conducted to evaluate the antioxidant/antigenotoxic potential of aqueous fraction from the bark of Anthocephalus cadamba, an important Ayurvedic medicinal plant. The antioxidant activity was assessed by in vitro assays, namely, DPPH (2,2-diphenyl-2-picrylhydrazyl), ABTS 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) assay, reducing power assay, superoxide anion radical scavenging assay and plasmid DNA nicking assay. The antigenotoxicity was studied against 4NQO-induced DNA damage in E. coli PQ37 tester strain using SOS chromotest. The fraction exhibited potent antioxidant activity in all the antioxidant assays. The fraction exhibited 90.77 % activity in DPPH and 97.46 % in ABTS assay at highest tested concentration (200 μg/ml). The fraction showed 67.13 % reduction potential and percent inhibition of 81.00 % in superoxide anion radical scavenging assay at 1,000 μg/ml. The fraction at a concentration of 1,000 μg/ml decreased the SOS-inducing potency(SOSIP) of 4NQO (20 μg/ml) by 21.86 %. Phytochemical analysis of aqueous fraction (AQAB) by UPLC-ESI-QTOF-MS revealed the fraction to be rich in alkaloids.

Investigations on Antioxidant, Antiproliferative and COX-2 Inhibitory Potential of Alkaloids from Anthocephalus cadamba (Roxb.) Miq. Leaves

In the present study, an ayurvedic medicinal plant, Anthocephalus cadamba (Roxb.) Miq. commonly known as ‘Kadamb’ was explored for its potential against oxidative stress and cancer. The fractions namely AC‐4 and ACALK (alkaloid rich fraction) were isolated from A. cadamba leaves by employing two different isolation methods and evaluated for their in vitro antioxidant and antiproliferative activity. The structure of the isolated AC‐4 was characterized tentatively as dihydrocadambine by using various spectroscopic techniques such as ESI‐QTOF‐MS, 1H‐ and 13C‐NMR, DEPT, COSY, HMQC, and HMBC. Results of various antioxidant assays viz. 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), ABTS cation radical, superoxide anion radical scavenging, and plasmid nicking assay demonstrated that both the fractions viz. AC‐4 and ACALK possess ability to scavenge DPPH, ABTS radicals and effectively protected plasmid pBR322 DNA from damage caused by hydroxyl radicals. Further, when both fractions were evaluated for their potential to suppress growth of HeLa and COLO 205 cells, only ACALK fraction showed antiproliferative effects. ACALK exhibited GI50 of 205.98 and 99.54 μg/ml in HeLa and COLO 205 cell lines, respectively. Results of Hoechst staining in cervical carcinoma (HeLa) cells confirmed that ACALK induced cell death in HeLa cells via apoptotic mode. Both the fractions also inhibited COX‐2 enzyme activity.

Efficacy of golden rain tree against free radicals and H2O2-induced damage to pUC18/calf thymus DNA

Abstract Objective To investigate the antioxidant and genoprotective potential of the methanol extract (METH–KP) along with its hexane fraction (HEX–KP) from the leaves of Koelreuteria paniculata ( K. paniculata ) Laxm. Methods The antioxidant potential was checked using metal chelation assay, ABTS, DPPH (2,2–diphenyl–2–picryl–hydrazyl), reducing power and superoxide anion radical scavenging assay, Folin–Ciocalteu reducing capacity (FCR assay), Total flavonoid content (TFC assay) and genoprotective activity against the DNA damage induced by Fentons reagent using pUC18/calf thymus. Results Results showed that radical scavenging activities of the both test extract/fraction revealed a concentration-dependent antiradical activity in all the assays. In Metal chelation assay, METH–KP and HEX–KP showed 39.04% and 32.51% of scavenging at highest tested concentrations. The METH–KP exhibited IC 50 of 54.54 μg/mL in ABTS, 115 μg/mL in DPPH, 110 μg/mL in reducing power and 135 μg/mL in superoxide anion radical scavenging assay while that HEX–KP was found to be very poor in radical scavenging in all the above assays. The phytochemical analysis showed good amount of phenolic and flavonoid compounds in METH–KP while the HEX–KP fraction lacks phenols. The METH–KP extract and HEX–KP fraction both showed DNA protective effect in Calf thymus/pUC18 DNA protection studies. Conclusions The activity of METH–KP may be attributed to its polyphenolic constituents which needs further isolation of its active constituents which may lead to the development of novel drugs to combat cancer.