Abstract

• Locally cultivated Schleichera oleosa(Lour.) Oken (Ceylon oak, Gyo) was chosen for the present study to investigate the phytochemicals and some biochemical properties of its bark.The preliminary phytochemical screening indicated that α-amino acids, carbohydrates, flavonoids, glycosides, phenolic compounds, reducing sugars, steroids, saponins, tannins and terpenoids were present while alkaloids was absent in the bark. The physico-chemical analysis revealed that the bark contained 2.14% of ash, 9.32% of moisture, 6.25% of protein, 22.78% crudefiber, 0.83% of crude fat and58.68% of carbohydrate. The elemental analysis carried out by EDXRF method showed some elements such as Ca, K, S, Fe, Sr, Mn and Cu were present in the sample. The extractable matters (% w/w)in different polarity of solvents such as methanol, ethanol, acetone, ethyl acetate and petroleum ether were respectively observed to be 5.8, 5.0, 2.0, 1.6, 1.0 % (w/w) and water soluble matter was 3.6 % (w/w) in the sample. The ethanol extract was found to have higher total phenol content (158.67±6.76 mg GAE /g of extract) and total flavonoid content (190.0 ± 8.5 mg QE/g of extract) than the watery extract containing 148.32 ± 4.73 mg GAE/g extract of total phenol content and 143.33±7.8 mg QE/g extract of total flavonoid content. Six different extracts (PE, EA, EtOH, MeOH, CHCl3 and H2O)exhibited mild antimicrobial activity against some microorganisms, determined by agar well diffusion method. The antioxidant activities of ethanol extract (IC50 = 0.56 μg/mL) and watery extracts (IC50 = 0.69 μg/mL) determined by DPPH radical scavenging assay were higher than that of standard gallic acid significantly. Some crude extracts such as MeOH, EtOH and watery extracts exhibited the inhibition of tumor formation at the dose of 0.2 g/disc, determined on tumor producing bacteria by using Potato Crown Gall test.The ethanol extract (LD50 = 2.69 μg/mL) and watery extract (LD50 = 8.85μg/mL) also showed significant cytotoxic effect against brine shrimp (24 h).Furthermore, ethanol extract possessedhigher antiproliferative activity than watery extract against Hela (cervical) and MCF-7 (breast) human cancer cell lines determined by using CCK-8 Assay (Cell Counting Kit-8).