Croton oblongus Burm.f. Bark

Aziz, Ahmad Nazif, Ismail, Nor Hadiani, Halim, Siti Nadiah Abdul, Looi, Chung Yeng, Anouar, El Hassane, Langat, Moses K., Mulholland, Dulcie & Awang, Khalijah, 2018, Laevifins A-G, clerodane diterpenoids from the Bark of Croton oblongus Burm. f., Phytochemistry 156, pp. 193-200 : 197

2.1. Biological activities of Croton oblongus Burm.f. Bark

It is known that inflammation is closely linked to tumour promotion and almost all tumours have inflammatory cells reside in them regardless of the underlying cause of the tumour ( Rosenberg et al., 1991; Medzhitov, 2008). Hence, extracts and selected pure compounds from the bark of C. oblongus were evaluated for their cytotoxicity and the closely related anti-inflammatory activity via inhibition of LPS-induced NF-κB translocation in RAW 264.7 cells evaluation.

Crude extracts of C. oblongus were screened against a panel of cell lines consisted of normal liver cell line (WRL-68), lung cancer cell line (A549), prostate cancer cell line (PC-3), melanoma cell line (A375), colon cancer cell line (HT-29) and human breast cancer cell lines (MCF-7). IC 50 values of the hexane extract against these cell lines ranged between 35.0 and 66.1 μ g/mL while no activity recorded against HT-29 cell line. The CH 2 Cl 2 extract showed more selective activity, affecting only A549 (IC 50 57.6 μ g/mL) and A375 (IC 50 63.6 μ g/mL) cell lines. The methanol extract did not show activity.

All purified compounds were isolated from hexane and CH 2 Cl 2 extracts, which in the initial screen had shown potential cytotoxicity. However, most compounds were found to have very weak activity with IC 50> 100 μ M. Only β -amyrone and β -sitostenone exhibited IC 50 <100 μ M, 73 and 94 μ M respectively. Compounds 1, 3, β -amyrin and acetyl aleuritolic acid were also tested in the LPS-induced NF-κB translocation inhibition in RAW 264.7 cells assay. Compounds 1 and 3 showed no activity while β -amyrin and acetyl aleuritolic acid showed good anti-inflammatory activity with IC 50 values of 23.5 and 35.4 μ g/ mL respectively.