Orobanche crenata Forsk. (Broomrape) is an obligate holoparasitic weed that attacks legume crops, such as faba bean, lentil, pea, and vetch, but also affects a large number of wild legume species. Broomrape can cause severe damage to the most important crops in the Mediterranean region and the Middle East. As a holoparasite plant, it is able to accumulate special metabolites that enable it to obtain its food from the host plant. It lacks in chlorophyll; the host phloem and xylem are its principal sources of carbohydrates and minerals, respectively. It has also some interest as an edible plant because of the high content of antioxidant phenols of its tender shoots, the edible portion of the plant. Orobanche was used historically by some North American tribes for externally treating ulcers and cancergrowth, and internally for treating some bowel disorders. California Broomrape or cancer root (O. californica) is used externally to treat skin infections caused by Streptococcus, as a poultice or wash for wounds, ulcers and herpes lesions. Gatto et al. performed chemical characterization of O. crenata phenolic extract: verbascoside and isoverbascoside were quantitatively extracted, purified and characterized:. These compounds proved to be effective in reducing the growth of some important fungi responsible for the decay of fresh fruit and vegetables in postharvest. In addition antioxidant capacity of O. crenataextract was investigated and it was found that methanolic extract showed the highest activity in DPPH and ABTS free radical scavenging assays. Despite the large amount of research on screening for active compounds from plants in different parts of the world, to date little is known about active compounds from Orobanche. The current study aimed to investigate antimicrobial and antioxidant activities of O. crenata Forsk. acetonic leaf extract. Antibacterial effect on Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecium, Enterococcus faecalis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) pathogenic bacteria and antifungal activity against Candidaspp. clinical isolates were evaluated. Antimicrobial activities were compared to standard drugs. Total phenolic and flavonoidcontents of the extract were evaluated by spectrophotometric assay; antiradical activity of O. crenataForsk. extract was performed by DPPH test and by superoxide anion scavenging capacity. Moreover ex vivo antioxidant assay was performed using percentage of hemolysis induced by APPH in red blood cells.Results obtained showed that the extract has both antioxidant in vitro activity and antimicrobial ability against Gram-positive strains but with different effectiveness probably due to active compounds present in the extract. O. crenataForsk. extract demonstrated also a good antifungal potential against some tested clinical isolates of yeast. This study allowed us to enhance the knowledge of O. crenata Forsk., its chemical composition and biological activities in order to explore other possible applications of this extract.
In vitro evidence for biological activities of sicilian Orobanche crenata Forskk. leaf extract
Genovese C
2017-01-01
Abstract
Orobanche crenata Forsk. (Broomrape) is an obligate holoparasitic weed that attacks legume crops, such as faba bean, lentil, pea, and vetch, but also affects a large number of wild legume species. Broomrape can cause severe damage to the most important crops in the Mediterranean region and the Middle East. As a holoparasite plant, it is able to accumulate special metabolites that enable it to obtain its food from the host plant. It lacks in chlorophyll; the host phloem and xylem are its principal sources of carbohydrates and minerals, respectively. It has also some interest as an edible plant because of the high content of antioxidant phenols of its tender shoots, the edible portion of the plant. Orobanche was used historically by some North American tribes for externally treating ulcers and cancergrowth, and internally for treating some bowel disorders. California Broomrape or cancer root (O. californica) is used externally to treat skin infections caused by Streptococcus, as a poultice or wash for wounds, ulcers and herpes lesions. Gatto et al. performed chemical characterization of O. crenata phenolic extract: verbascoside and isoverbascoside were quantitatively extracted, purified and characterized:. These compounds proved to be effective in reducing the growth of some important fungi responsible for the decay of fresh fruit and vegetables in postharvest. In addition antioxidant capacity of O. crenataextract was investigated and it was found that methanolic extract showed the highest activity in DPPH and ABTS free radical scavenging assays. Despite the large amount of research on screening for active compounds from plants in different parts of the world, to date little is known about active compounds from Orobanche. The current study aimed to investigate antimicrobial and antioxidant activities of O. crenata Forsk. acetonic leaf extract. Antibacterial effect on Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecium, Enterococcus faecalis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) pathogenic bacteria and antifungal activity against Candidaspp. clinical isolates were evaluated. Antimicrobial activities were compared to standard drugs. Total phenolic and flavonoidcontents of the extract were evaluated by spectrophotometric assay; antiradical activity of O. crenataForsk. extract was performed by DPPH test and by superoxide anion scavenging capacity. Moreover ex vivo antioxidant assay was performed using percentage of hemolysis induced by APPH in red blood cells.Results obtained showed that the extract has both antioxidant in vitro activity and antimicrobial ability against Gram-positive strains but with different effectiveness probably due to active compounds present in the extract. O. crenataForsk. extract demonstrated also a good antifungal potential against some tested clinical isolates of yeast. This study allowed us to enhance the knowledge of O. crenata Forsk., its chemical composition and biological activities in order to explore other possible applications of this extract.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
