Baicalein, an enteric microbial metabolite, suppresses gut inflammation and cancer progression in ApcMin/+ mice.

OBJECTIVE: Chronic inflammation is recognized as a risk factor for colorectal cancer (CRC) development. Baicalin (BI), a major constituent in an anti-inflammatory herb Scutellaria baicalensis, can be biotransformed into baicalein (BE) by the intestinal microbiota. We evaluated the anti-inflammation and anti-CRC effects of the metabolite BE. METHODS: The in vitro biotransformation by human intestinal microbiota from BI into BE has been determined with HPLC. Using a gut-specific ApcMin/+ mouse model, the effects of oral BE on the life span, organ index, and tumor multiplicity were evaluated. The expressions of inflammatory cytokines were determined using ELISA. To verify the in vivo data, the anti-inflammatory and antiproliferative effects of BE were determined with an in vitro cell model. RESULTS: HPLC analysis showed that BI was quickly transformed into BE by the intestinal microbiota. Oral BE (30 mg/kg/day) significantly increased the life span, from 125.2 to 218.4 days (P < 0.01%). BE treatment also decreased intestine index and increased spleen index. Compared with the model group, following BE treatment, tumor numbers were significantly reduced in the small intestine and colon (P < 0.01, P < 0.05, respectively). In the gut tissues, BE treatment significantly reduced inflammatory cytokine levels such as IL-1ß, IL-2, IL-6, IL-10, G-CSF, and GM-CSF. In vitro data supported our in vivo results that the anti-CRC effects of BE were via the inhibition of gut inflammation and induction of cancer cell death. CONCLUSION: Our results suggest that the parent compound BI can be quickly converted into its microbial metabolite BE, which has stronger bioactive effects than BI. Baicalein is an active chemopreventive metabolite for inflammatory associated CRC.

Mutagenic effect, antioxidant and anticancer activities of six medicinal plants from Burkina Faso.

The antiproliferative activities of six medicinal plant extracts from Burkina Faso were evaluated in order to justify their traditional use for the treatment of cancer. The SOS chromotest method was used in vitro on Escherichia coli PQ37 to evaluate the mutagenic effect of the plant extracts. The DPPH method was used to evaluate the antioxidant activity of each plant. The antiproliferative activity was evaluated by MTS method on normal cells (Vero and MCR5) and cancer cells (KB) in contact with the extracts for 72 h. The results showed that the studied plants are not genotoxic. Lantana ukambensis and Acacia macrostachya induced a very significant antiproliferative effect against cancer cells with 94% and 95%, respectively. They also developed a strong antioxidant activity. The IC50 values were 5.96 ± 0.40 µg mL⁻¹ for L. ukambensis and 4.30 ± 0.26 µg mL⁻¹ for A. macrostachya. These two plants are therefore potential sources for isolating new antioxidant and anticancer molecules.

In vitro antileishmanial and antitrypanosomal activities of five medicinal plants from Burkina Faso.

After ethnobotanical surveys in central and western regions of Burkina Faso, five plants namely Lantana ukambensis (Verbenaceae), Xeoderris sthulmannii (Fabaceae), Parinari curatellifollia (Chrysobalanaceae), Ozoroa insignis (Anacardiaceae), and Ficus platyphylla (Moraceae) were selected for their traditional use in the treatment of parasitic diseases and cancer. Our previous studies have focused on the phytochemical, genotoxicity, antioxidant, and antiproliferative activities of these plants. In this study, the methanol extract of each plant was tested to reveal probable antileishmanial and antitrypanosomal activities. Colorimetric and spectrophotometric methods were used for the detection of antileishmanial and antitrypanosomal activities. Leishmania donovani (LV9 WT) and Trypanosoma brucei brucei GVR 35 were used to test the antileishmanial and antitrypanosomal activities, respectively. All extracts of tested plants showed a significant antitrypanosomal activity with minimum lethal concentrations between 1.5 and 25 µg/ml, the L. ukambensis extract being the most active. In the antileishmanial test, only the extract from L. ukambensis showed significant activity with an inhibitory concentration (IC(50)) of 6.9 µg/ml. The results of this study contribute to the promotion of traditional medicine products and are preliminary for the isolation of new natural molecules for the treatment of leishmaniasis and trypanosomiasis.