Asian Journal of Applied Sciences1996-3343xxxx-xxxxKnowledgia Review10.3923/ajaps.2019.71.75Polysiphonia and Laurencia Collected from the Arabian Gulf]]>Al-AmroAbir Abdullah Al-MutlaqMoudhi Abdullah Al-MoautherSara Al-TukhaifiNouf OthaimeenRawan Bin Al-MutairiNada Al-RashedSarah Al-MalkiFouziah HaqSamina Hyder 22019122Background and Objective: Seaweeds are considered as a potential source of antioxidant which reduces the risk of some diseases and a good source of new drugs with lower side effect and toxicity. This study aimed to estimate the antioxidant activity of Rhodophyta algae genus Polysiphonia and Laurencia (Rhodomelaceae, Ceramiales). Materials and Methods: Samples were collected from different regions of the Arabian Gulf. Antioxidant activity represented by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, total flavonoid, phenolic and tannin content were quantified in ethanolic and aqueous extract of these two red algal genera. Results: Ethanolic and aqueous extracts of Polysiphonia and Laurencia were compared for their antioxidant properties. Polysiphonia showed higher flavonoid, phenolic and tannins content. While the DPPH radical scavenging activity of ethanolic and aqueous extract of Laurencia showed higher antioxidant activity with IC50 (5.64±0.68 and 6.34±0.41 mg mL1, respectively) as compared to Polysiphonia which has IC50 (9.30±0.18 and 9.57±0.46 mg mL1, respectively). Conclusion: These results showed that red algae are high in antioxidants activity and support its use in dietary supplements, cosmetics and food industry.]]>Moubayed, N.M.S., H.J. Al Houri, M.M. Al Khulaifi and D.A. Al Farraj,201724162169Ismail, M.M., G.M. El Zokm and A.A.M. El-Sayed,20172017Hossain, M.F., R.R. Ratnayake, K. Meerajini and K.L.W. Kumara,20164753758Boopathy, N.S. and K. Kathiresan,20102010Baba, S.A. and S.A. Malik,2015Arisaema jacquemontii blume.]]>9449454Zhishen, J., T. Mengcheng and W. Jianming,199964555559Senguttuvan, J., S. Paulsamy and K. Karthika,2014Hypochaeris radicata L. for in vitro antioxidant activities.]]>4S359S367Prior, R.L., X. Wu and K. Schaich,20055342904302Siddhuraju, P. and S. Manian,2007Macrotyloma uniflorum (Lam.) Verdc.) seeds.]]>105950958Blois, M.S.,195818111991200Adams, L.S., Y. Zhang, N.P. Seeram, D. Heber and S. Chen,2010in vitro.]]>3108113Huang, W.Y., Y.Z. Cai and Y. Zhang,200962120Sinha, N. and P.K. Dabla,201511132142Wang, P., K. Xie, C. Wang and J. Bi,201472249254Pohanka, M.,201421356364Bains, S. and C.A. Shaw,199725335358Miazek, K., L. Kratky, R. Sulc, T. Jirout, M. Aguedo, A. Richel and D. Goffin,20172017Ganesan, K., K.S. Kumar and P.V.S. Rao,2011127378Cornish, M.L. and D.J. Garbary,201025155171