Angiogenesis is defined as the physiological process by which new blood vessels develop from pre-existing vessels; either by sprouting or intussusception. Inhibition of angiogenesis is one of the most encouraging strategies to manage the growth and metastasis of cancers. The functional and proliferative status of blood vessels is regulated by the balance between various key molecules that either stimulate or inhibit angiogenesis. During quiescence, the “angiogenic switch” is “off”. However, during tumour development pro-angiogenic factors such as vascular endothelial growth factor (VEGF), basic and acidic fibroblast growth factor, tumour necrosis factor-α and interleukin-1 are pathologically enhanced. Persistent growth of tumour directed capillary networks creates a favourable microenvironment, promoting cancer growth, progression and metastasis. VEGF, particularly VEGF-A, is a key angiogenic factor. Targeting VEGF, its receptors and the downstream signaling cascade, is a viable strategy to prevent tumour growth and metastasis. The present review discusses the role of VEGF in tumour angiogenesis and the current understanding of anti-VEGF therapies as well as refractoriness of anti-angiogenesis cancer therapy.
As part of an International Cooperative Biodiversity Groups (ICBG) program to study Jordan's biodiversity, the relative levels of antioxidant activity and the total phenolic content of aqueous and methanolic extracts of a total of 95 plant species, all of Jordanian origin and those collected at random, have been measured. The total phenolic content of aqueous and methanolic extracts of the investigated plant species ranged from 4.4 to 78.3 mg and from 2.1 to 52.8 mg gallic acid equivalents g−1 dry weight, respectively, while the total antioxidant capacity ranged from 20.0 to 916.7 and from 15.1 to 915.6 μmol Trolox equivalents g−1 dry weight, respectively. Based on this collection, approximately 5% of assayed plants showed high levels of antioxidant activity. There was a significant linear correlation between antioxidant activity and total phenolic content for aqueous and methanolic extracts, suggesting that phenolic compounds were the predominant antioxidant components in the investigated plant species. Interestingly, a few of the collected plants had high-antioxidant activity yet “low” phenolic content includes Ceratonia siliqua and Viscum cruciatum. These plants may serve as sources of antioxidants with new chemotypes.
1 May 2009 in Applied and Environmental Microbiology
Anecdotes, both historical and recent, recount the curing of skin infections, including diaper rash, by using red soils from the Hashemite Kingdom of Jordan. Following inoculation of red soils isolated from geographically separate areas of Jordan,Micrococcus luteusandStaphylococcus aureuswere rapidly killed. Over the 3-week incubation period, the number of specific types of antibiotic-producing bacteria increased, and high antimicrobial activity (MIC, ∼10 μg/ml) was observed in methanol extracts of the inoculated red soils. Antibiotic-producing microorganisms whose numbers increased during incubation included actinomycetes,Lysobacterspp., andBacillusspp. The actinomycetes produced actinomycin C2and actinomycin C3. No myxobacteria or lytic bacteriophages with activity against eitherM. luteusorS. aureuswere detected in either soil before or after inoculation and incubation. Although protozoa and amoebae were detected in the soils, the numbers were low and did not increase over the incubation period. These results suggest that the antibiotic activity of Jordan's red soils is due to the proliferation of antibiotic-producing bacteria.