RESUMO
Polyphenols constitute a distinct group of natural compounds of medicinal importance exhibiting wide range of physiological activities as antioxidant, immunestimulant, antitumor and antiparasitic. Yellow fever and dengue fever are mosquito-borne infectious diseases transmitted by Aedes aegyptii, the presence of yellow fever in Sudan and dengue fever in Saudi Arabia are threats to Egypt with the reemerging of Ae. aegyptii in Southern Egypt, larvae control is feasible than flying adults. This work was conducted targeting estimation of the relative levels of total phenolic content, antioxidant potential and larvicidal activity of 110 selected Egyptian plants. The highest total phenolic contents were estimated in aqueous extracts of Coronilla scorpioides L., Forsskaolea tenacissima L., Crataegus sinaica Boiss., Pistacia khinjuk Boiss. and Loranthus acacia Benth.; they were 916.70 +/- 4.80, 813.70 +/- 4.16, 744.90 +/- 4.93, 549.00 +/- 3.93& 460.80 +/- 4.02 mg% while those of methanol extracts were estimated in Coronilla scorpioides, Forsskaolea tenacissima, Crataegus sinaica, Loranthus acacia and Pistacia khinjuk, they were 915.60-4.86, 664.60 +/- 4.16, 659.30 +/- 4.80, 590.80 +/- 4.49 & 588.00 +/- 3.85 mg% respectively. Investigation of the antioxidant potentials revealed that the most potent plants were Co-ronilla scorpioides, Forsskaolea tenacissima, Crataegus sinaica, Pistacia khinjuk and Loranthus acacia with calculated values of 454.80 +/- 4.83, 418.4 +/- 4.16, 399.10 +/- 4.90, 342.5 +/- 2.72 & 239.7 +/- 2.91% for aqueous extracts and 452.9 +/- 4.94, 389.6 +/- 4.6, 378.48 +/- 3.84, 352.3 +/- 3.06 & 346.5 +/- 2.98% for methanol extracts respectively while screening of larvicidal activity proved that Coronilla scorpioides, Forsskaolea tenacissima, Crataegus sinaica, Pistacia khinjuk and Loranthus acacia exhibited highest potency calculated as 22.53 +/- 2.01, 23.85 +/- 2.07, 28.17 +/- 2.06, 31.60 +/- 2.93 & 39.73 +/- 4.58 mg% aqueous extracts and 18.53 +/- 1.95, 18.8 +/- 1.67, 20.17 +/- 1.85, 23.28 +/- 2.7 & 28.48 +/- 3.9 mg% methanol ones respectively.
