Abstract
The fatty acids (FAs), amino acids (AAs), phenolic and polysaccharides fromCymodocea serrulata,Halodule uninervis,Halophila stipulaceaandThalassia hemprichiiwere studied, their antioxidant and anticancer activities were also investigated. The results showed thatT. hemprichiiandC. serrulatawere rich in gallic acid and protocatechuic acid with values of 45.26 and 25.26 mg/g, respectively. The polysaccharides ofT. hemprichiiandH. stipulaceawere mainly composed of galactose (similar to 21%), mannose (similar to 14.5%) and glucose (similar to 12.5%). The protein contents ranged from 3.06% (H. stipulacea) to 9.56% (T. hemprichii). Palmitic acid (C16:0) percentage was more than half of the total FAs content ofH. uninervisandT. hemprichii, while linoleic acid (C18:2) was 35.7 and 28.6%, respectively, in both seagrasses. The highest steroid content was found inC. serrulataat 92.67%, and triterpenes lupeol (15.51%) and beta-amyrin (16.59%) inH. stipulaceaas the major oxygenated-unsaponifiable matters.T. hemprichiiextract demonstrated the highest effective antioxidant activity with IC50 value of 1.2 mu g/ml, whileH. uninervisextract displayed potential cytotoxic effect against human SKOV-3 ovarian and MCF-7 breast carcinoma cells with IC50 values of 0.52 and 2.3 mu g/ml, respectively.