Pharmacognostical and Biological Studies of Delonix regia growing in Egypt: HPLC Profiles

Background: Delonix regia (Hook.) Raf. (Fabaceae) is an ornamental tree with flamboyant flowers. Objective: to carry out pharmacognostical studies to evaluate the features of different D. regia organs, quantification and HPLC profiling of phenolics and flavonoids of leaf extract, also to evaluate possible hepatoprotective activities of the leaf hydroalcoholic extract and its fractions. Materials and Methods: Total phenolic content (TPC) as gallic acid equivalent /100 g dried extract (GAE/100 g DE), and total flavo- noid content (TFC) as catechin equivalent /100 g (CE/100 g DE) of the leaves were carried out using Folin–Ciocalteu’s and aluminum chloride assays, respectively. Hepatoprotective activity was determined against CCl4 induced hepatotoxicity in rats. Results: TPC and TFC were 5.5 g GAE/100 g DE and 53.3 g CE/100 g DE respectively, with identification of 13 flavonoids, and 17 phenolics. Hesperidin was present as the highest flavonoid content (48622.5 mg/100 g DE), followed by quercetrin (711.5 mg/100 g DE), whilst hydroxytyrosol was the major identified phenolic compound (1111.2 mg/100g DE) followed by catechin (1026.1 mg/100 g DE). The ethyl acetate fraction showed significant protection against the elevation in the levels of serum biochemical parameters, normal hepatocytes with minimum fatty changes, portal vain congestion and mild inflammatory cell infiltration around the portal vain comparable to CCl4 group (P< 0.001). The potent and significant hepatoprotective activity of the ethyl acetate fraction may be attributed to its high content of antioxidant phenolic compounds. Thus, the present study may be the first to test the hepatoprotective effect of Delonix regia fractions. Conclusion: This study recommends the use of D. regia as a natural chemopreventive agent against liver damage and liver toxicity caused by chlorinated agents.