In vitro studies of the dry fruit of Chinese fan palm Livistona chinensis

The hot water extract of the dry fruit of Chinese fan palm Livistona chinensis R Br. (LC) has been used in folklore medicine in Southern China for treating various tumors. Our in vitro study showed that the ethanolic extract (LCET) and the hot water extract (LCWE) of LC inhibited HL60 cell growth, with 50% inhibition (IC50) estimated at a 1150 dilution for both preparations. LCET showed mild activity in inducing HL60 cell differentiation into granulocyte lineage. However, at 1/100 and 1/200 dilutions, it respectively induced 314 +/- 12.6% and 16.3 +/- 6.1% of HL60 cells into monocyte/macrophage lineage, compared to 4.4 +/- 1.3% in the control. In contrast, LCWE did not demonstrate a significant differentiation-inducing, capacity on HL60 cells. Cell-free Trolox equivalent antioxidant capacity hydroxyl radical scavenging assay estimated that a 1/10 dilution of LCET and LCWE has a similar activity, equivalent to 13.0 and 12.7 mu M of Trolox activity respectively. At a 1/100 dilution, neither extract affected nitric oxide production in both non-stimulated and lipopolysaccharide (LPS) stimulated RAW 264.7 cells. RTPCR analyses of mRNA expression showed that treatment of RAW 264.7 cells with either extract at a 1/100 dilution did not affect tumor necrosis factor-alpha (TNF alpha), interleukin-16 (IL-1 beta), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA expression in these cells compared to the untreated control. Neither extract affected TNF alpha and iNOS mRNA expression in LPS-stimulated cells, but at a 1/100 dilution they both reduced IL-1 beta mRNA expression in LPS-stimulated cells (p<0.01). Only a 1/100 dilution of LCET reduced COX-2 mRNA expression in LPS-stimulated RAW 264.7 cells (p<0.01). The dry fruit of Livistona chinensis warrants further investigation.