Abstract 5677: Inhibition of Azoxymethane-induced aberrant crypt foci in C57BL/6 mice by the Chinese medicinal herb Scutellaria barbata

Abstract

Abstract Scutellaria barbata (SB) is a perennial herb of the mint family which has been used to treat appendicitis, hepatitis, pulmonary abscess, and cancers of the liver, lung, and colon in Chinese medicine. Our early studies showed that SB contained phytochemicals that inhibited mutagenesis, DNA binding, and metabolism of aflatoxin B1 (AFB1) and benzo[a]pyrene bioactivated by Arcoclor 1254-induced rat S9. It also inhibited the mutagenicity of AFB1 bioactivated by either non-induced or DXM-induced hepatic S9, suggesting its effect via an inhibition of CYP3-mediated metabolism of [3H]AFB1. Recent oral feeding data demonstrated that SB could delay prostate tumor development in TRAMP mice. Complementary in vitro data indicated that SB may exert this function via up-regulating the apoptotic pathway and down-regulating the survival pathway in murine (TRAMP-C1) and human (LNCaP) prostate cancer cells. Inhibitory effects of SB were also observed in inducing cell death in human (LoVo) colon cancer cells. This study investigated the effects of SB on azoxymethane (AOM)-induced aberrant crypt foci (AFC) formation in C57BL/6 mice. Thirty C57BL/6 mice of 9 wks old were randomized into three groups (N=10). Mice of the positive control and experimental groups were injected with AOM (5 mg/kg body wt) at the beginning and second wk of the 8-wk duration while the negative control group received no injection. Animals in the experimental group received daily oral feedings of 24 mg SB since day 1 while mice in the other two groups were given sterilized-water placebo. SB feeding significantly reduced the number of AOM-induced ACF in the proximal colon (25 mm) compared with the water-fed positive control AOM-induced group (8.35 ± 5.56 < 32.1 ± 9.86; P< 0.000047). The negative non-induced group had minimal ACF (2.0 ± 1.56) compared to the experimental and positive control groups (P< 0.0056; P< 0.0000034 respectively). The potency index of the herb was calculated as 3.84. Significant percent inhibition (74%) of AOM-induced ACF formation was obtained with SB treatment. Mice in all three groups had gained wt (% increase) in the course of the experiment (negative control, 16.2 ± 4.32 < experimental, 20.7 ± 10.39 < positive control, 35.78 ± 16.79). These in vivo data suggest the potential chemopreventive and treatment potential of SB. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5677.