Flavonoids as a scaffold for development of novel anti-angiogenic agents: An experimental and computational enquiry.

Relationship between structural diversity and biological activities of flavonoids has remained an important discourse in the mainstream of flavonoid research. In the current study anti-angiogenic, cytotoxic, antioxidant and cyclooxygenase (COX) inhibitory activities of diverse class of flavonoids including hydroxyl and methoxy substituted flavones, flavonones and flavonols have been evaluated in the light of developing flavonoids as a potential scaffold for designing novel anti-antiangiogenic agents. We demonstrate anti-angiogenic potential of flavonoids using in vivo chorioallantoic membrane model (CAM) and further elaborate the possible structural reasoning behind observed anti-angiogenic effect using in silico methods. Additionally, we report antioxidant potential and kinetics of free radical scavenging activity using DPPH and SOR scavenging assays. Current study indicates that selected flavonoids possess considerable COX inhibition potential. Furthermore, we describe cytotoxicity of flavonoids against selected cancer cell lines using MTT cell viability assay. Structural analysis of in silico docking poses and predicted binding free energy values are not only in accordance with the experimental anti-angiogenic CAM values from this study but also are in agreement with the previously reported literature on crystallographic data concerning EGFR and VEGFR inhibition.

First Report of Leaf Spot Caused by Phoma costarricensis on Delphinium malabaricum in Western Ghats of India.

Delphinium L. is a genus of more than 300 species of perennial flowering plants belonging to the family Ranunculaceae and is native throughout the Northern Hemisphere. In India, 24 species are found mainly in the Himalayan regions. Delphinium malabaricum (Huth) Munz is the only species of the genus endemic to northern Western Ghats. Its mediumsized violet-to-metallic blue spurred flowers have considerable ornamental value as a floriculture crop (3). There is no report of serious diseases of this genus in India. Since 2008, a severe foliar disease was observed each year on D. malabaricum cultivated on the experimental plots located at Shivaji University, Kolhapur, India. Symptoms were small, necrotic spots on the abaxial and adaxial sides of infected leaves, with spots enlarging to form round areas that were 6 to 9 mm in diameter and well defined by a dark black margin. Severely infected leaves wilted without abscising. No symptoms were observed on other plant parts. From infected leaves, a fungus was isolated on Czapek Dox agar (CDA) amended with 25 mg/liter of streptomycin sulfate. The fungus was grown on CDA and cultures were maintained at 4°C for further studies. After 6 days, black pycnidia developed, which were variable in size, releasing abundant hyaline, elliptical conidia measuring from 3 to 4 × 1.5 to 2 µm. On the basis of cultural and morphological characteristics, the fungus was identified as Phoma costarricensis (1,2). The identification was verified by sequencing a region of 28S ribosomal RNA with the geneOmbio LSU gene sequencing primers and ABI BigDye Terminator v3.1 Cycle Sequencing Reaction Kit (Applied Biosystems, Carlsbad, CA). The sequence was deposited as Accession No. HE608244 in EMBL-Bank. Blast analysis of the sequence obtained showed a 99% homology with several isolates of P. costarricensis in the GenBank database (Accession No. GU238058.1). Pathogenicity tests were performed by spraying leaves of 10 healthy plants with spores (~10,000 spores or mycelial fragments per ml) on the abaxial and adaxial surface of leaves. Noninoculated plants served as control. Symptoms identical to those on field samples developed on all inoculated plants 1 week after inoculation but controls remained asymptomatic during the observation period. P. costarricensis was reisolated from inoculated symptomatic plants and the identity was confirmed, which completed Koch's postulates. This experiment was repeated three times in a greenhouse, confirming the pathogenicity of P. costarricensis on D. malabaricum. P. ajacis (Thum.) Aa & Boerema, P. delphinii (Rabenh.) Cooke, P. aquilegiicola M. Petrov, and P. xanthina Sacc. are reported to cause leaf spot and stem rot in Delphinium spp. (1). However, to our knowledge, there are no previous reports of leaf spot of D. malabaricum caused by P. costarricensis. Leaf spot severity induced premature defoliation, leading to reduction in flower setting and ultimately the yield. The disease could lead to an economic crisis in the farmer community of western India. The only other known host of P. costarricensis is Coffea arabica (2). References: (1) G. H. Boerema et al. Phoma Identification Manual. CABI Publishing, Wallingford, UK and Cambridge, MA, 2004. (2) E. Echandi. Rev. Biol. Trop. 5:83, 1957. (3) S. R. Pai et al. Cytologia 72:319, 2007.

First Report of Aspergillus niger as a Plant Pathogen on Zingiber officinale from India.

Zingiber officinale Rosc., belonging to the Zingiberaceae family, is medicinally important. It is commonly known as ginger and has been extensively cultivated for many centuries for use as a spice and traditional medicine in India. During a survey in September of 2007, leaves of Z. officinale showed a necrotic leaf spot disease on a plant growing in Kolhapur, India. Symptoms of the disease appeared as small (10 to 15 mm), rectangular to irregular, yellow spots on the leaves that covered a major area of the leaf when severe. The infection caused defoliation. Symptomatic leaves were collected and isolations from infected leaves were made on Czapek's Dox agar supplemented with streptomycin sulfate (30 mg/l). Plates were incubated at 28 to 30°C for 6 to 7 days. The fungal colonies were colorless to pale on the reverse side and covered with a dense layer of dark brown-to-black conidial heads. Conidia were globose to subglobose (3.5 to 5.0 µm in diameter), dark brown to black, and rough walled. 16S rRNA of isolates was amplified and sequenced (EMBL Accession No. AM941157) and compared with sequences of known Aspergillus species obtained from GenBank. The closest matches (99% identity) were with A. niger. On the basis of morphological and molecular approaches, the pathogen was confirmed as A. niger. Of five isolates, AN-5 was used for pathogenicity study. Koch's postulates were satisfied after reisolating the fungus from leaves inoculated with a conidial suspension that showed symptoms (6 days after inoculation) similar to the lesions observed on the leaves collected from Z. officinale. The tests were repeated three times in the greenhouse. Healthy, potted Z. officinale plants were grown in isolation after artificial inoculation with a suspension of spores (10,000 conidia per ml), which was prepared in 100 ml of sterile distilled water and then sprayed on the abaxial and adaxial surface of leaves. Noninoculated plants served as controls. These results confirmed the pathogenicity of A. niger on Z. officinale. To our knowledge, this is the first report of A. niger causing a disease on ginger (1). Reference: (1) G. N. Dake. J. Spices Aromatic Crops. 4:40, 1995.

Evidence for high prevalence & rapid transmission of HIV among individuals attending STD clinics in Pune, India.

Prevalence and incidence of HIV-1 infection among persons attending two STD clinics in Pune between May 1993 and October 1995 are reported. On screening 5321 persons, the overall prevalence of HIV-1 infection was found to be 21.2 per cent, being higher in females (32.3%) than in males (19.3%). Analysis of behavioural and biological factors showed that old age, sex work, lifetime number of sexual partners, receptive anal sex, lack of circumcision, genital diseases and lack of formal education were related to a higher HIV-1 seroprevalence. The observed incidence rate of 10.2 per cent per year was very high, much higher in women than in men (14.2% and 9.5% per year respectively) and over three times higher among the sex workers. Females in sex work, males having recent contacts with female sex workers (FSWs) and living away from the family and persons with previous or present genital diseases had a higher risk of seroconversion. Condom usage was shown to have a protective effect in seroprevalence and seroincidence analysis. With limited available resources and lack of a suitable vaccine or a drug, long-term prevention policy of creating awareness in the community must be supplemented by strengthening STD control measures and promotion of condom use and safe sex. Factors related to availability and utilization of condoms must be carefully investigated.