eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2015-08-15 12 2 1209 1222 2500 article Ammar Bader 1 Mohamed I. S. Abdelhady 1,3 Usama Shaheen 1,4 Yasser El-Malah 2,5 M.A.S Abourehab 2,6 Mohamed F. Barghash 7 Departments of 1Pharmacognosy, Umm Al-Qura University, Makkah 21955, Saudi Arabia. Pharmaceutics, Faculty of Pharmacy, Umm Al-Qura University, Makkah 21955, Saudi Arabia. Department of Pharmacognosy, Faculty of Pharmacy, Helwan University, Cairo 11795, Egypt Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt Department of Pharmaceutics, College of Pharmacy, Mansoura University, Mansoura, Egypt Pharmaceutics Department, Faculty of Pharmacy, Minia Universuty, Egypt. Cancer is a life threatening malignant tumor, caused by many factors including the oxidative stress. Medicinal plants containing phenolic compounds represent an important source of antioxidant and anticancer drugs. Azadirachta indica Family: Meliaceae contains variety of bioactive components of numerous biological and pharmacological properties. This study explored the constitutive polyphenols of Azadirachta indica (A. indica) growing in KSA and evaluated its antioxidant and cytotoxic activity. Chemical structures of the isolated compounds from the leaves of A. indica were established by spectral techniques (UV, MS, 1H, and ¹³C NMR, and two dimentional NMR). The colourimetric assay (SRB) used to evaluate the cytotoxicity against HCT₁₁₆, MCF₇ and Hep-G₂ cell lines. Chromatographic separation of 80% Ethanol extract of the leaves of A. indica have resulted in seven polyphenolic compounds three of them isolated for the first time from this species (2,3-(S)-hexahydroxydiphenoyl-(α/β)-D-glucopyranose, Avicularin and Castalagin) and four known previously isolated compounds (Gallic acid, Ellagic acid, Quercetin and Quercetin-3-O-glucoside). The 80% Ethanol extract exhibited higher antioxidant activity than the ethyl acetate and butanol extracts, which is correlated with its phenolic content. The ethanolic extract, compounds 4 and 6 exhibited cytotoxic activity against HCT₁₁₆, MCF₇ and Hep-G₂. These findings revealed that the leaves of A. indica contains a considerable amount of polyphenolic compounds with significant antioxidant and cytotoxic activity, consequently it could be considered as a great potential source for natural health products.   https://www.biotech-asia.org/vol12no2/azadirachta-indica-as-a-source-for-antioxidant-and-cytotoxic-polyphenolic-compounds/ Neem; polyphenolic compounds; cytotoxic; antioxidant activities