Rhus verniciflua stokes against advanced cancer: a perspective from the Korean Integrative Cancer Center

Abstract

Active anticancer molecules have been searched from natural products; many drugs were developed from either natural products or their derivatives following the conventional pharmaceutical paradigm of drug discovery. However, the advances in the knowledge of cancer biology have led to personalized medicine using molecular-targeted agents which create new paradigm. Clinical benefit is dependent on individual biomarker and overall survival is prolonged through cytostatic rather than cytotoxic effects to cancer cell. Therefore, a different approach is needed from the single lead compound screening model based on cytotoxicity. In our experience, the Rhus verniciflua stoke (RVS) extract traditionally used for cancer treatment is beneficial to some advanced cancer patients though it is herbal extract not single compound, and low cytotoxic in vitro. The standardized RVS extract's action mechanisms as well as clinical outcomes are reviewed here. We hope that these preliminary results would stimulate different investigation in natural products from conventional chemicals.

Figure 1

Effects of the standardized RVS extract on the migratory activity of VEGF-stimulated HUVEC (Wound-healing test). (a) The migrated cells in window-scraped field after scratching the cell monolayer; Control. (b) The wounds closed by cell migration from the wound edge after VEGF alone. (c) VEGF plus RVS (50 μg/mL). (d) VEGF plus RVS (100 μg/mL) showing inhibitory effect on migration compared to only VEGF-treated control.

Figure 2

Effects of the standardized RVS extract on the tube formation in VEGF-stimulated HUVECs. (a) HUVECs seeding in Matrigel form capillary networks; Control. (b) The robust and complete tube network formation after VEGF alone. (c) VEGF plus RVS (50 μg/mL). (d) VEGF plus RVS (100 μg/mL) showing inhibitory effect on tube network formation compared to only VEGF-treated control.

Figure 3

The effect of the standardized RVS extract on the invasiveness of human fibrosarcoma HT1080 cells using Boyden chamber assay. (a) Control. (b) RVS 50 μg/mL. (c) RVS 100 μg/mL. (d) RVS 200 μg/mL showing inhibitory effect on invasion compared to the control.

Figure 4

The effect of the standardized RVS extract on matrix metalloproteinase (MMP) activities by spectrofluorometric method. The IC₅₀ of the standardized RVS extract for MMP-2 and MMP-9 was 1.01 ± 0.07 μg/mL and 1.94 ± 0.11 μg/mL respectively. *P < 0.05 versus respective controls.