ABSTRACT
Polyphenols constitute a distinct group of natural compounds of medicinal importance exhibiting wide range of physiological activities as antioxidant, immune-stimulant, 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 re-emerging 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 and 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 and 588.00 +/- 3.85 mg% respectively. Investigation of the antioxidant potentials revealed that the most potent plants were Coronilla 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 and 239.7 +/- 2.91% for aqueous extracts and 452.9 +/- 4.94, 389.6 +/- 4.6, 378.48 +/- 3.84, 352.3 +/- 3.06 and 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 and 39.73 +/- 4.58 mg% aqueous extracts and 18.53 +/- 1.95, 18.8 +/- 1.67, 20.17 +/- 1.85, 23.28 +/- 2.7 and 28.48 +/- 3.9 mg% methanol ones respectively