Crateva adansonii DC, an African ethnomedicinal plant, exerts cytotoxicity in vitro and prevents experimental mammary tumorigenesis in vivo

Abstract

Ethnopharmacological relevance: Crateva adansonii DC is a plant traditionally used in Cameroon to treat constipation, asthma, snakebites, postmenopausal complaints and cancers.

Aim: The anticancer potential of the dichloromethane/methanol extract of C. adansonii stem barks was investigated using human breast cancer cell and 7,12 dimethylbenz(a)anththracene (DMBA)-induced mammary tumorigenesis model in rats.

Material and methods: The cytotoxicity of C. adansonii extract was assessed in vitro towards breast carcinoma (MCF-7 and MDA-MB-231) and non-tumoral cell lines (NIH/3T3 and HUVEC) by Alamar Blue assay. Furthermore, in vivo studies were performed on female Wistar rats treated either with C. adansonii extract at a dose of 75 or 300mg/kg body weight or with tamoxifen (3.3mg/kg body weight), starting 1 week prior DMBA treatment and lasted 12 weeks. The investigation focused on tumour burden, tumour DNA fingerprint, morphological, histological, hematological, and biochemical parameters.

Results: CC50 values for the in vitro assays were 289µg/mL against MCF-7 cells and >500µg/mL in others cells, leading to a selectivity index ≥1.73. C. adansonii extract significantly (p<0.001) revealed in vivo the reduction of the cumulative tumour yield (87.23%), total tumour burden (88.64%), average tumour weight (71.11%) and tumour volume (78.07%) at the dose of 75mg/kg as compared to DMBA control group. A weak effect was also observed at 300mg/kg. This extract showed a moderate hyperplasia at the dose of 75mg/kg while at 300mg/kg no significant change was noted as compared to DMBA group. It protected rats from the DNA alteration induced by DMBA and increased antioxydant enzymes activities in mammary gland tissue homogenates. In addition, Ultra-High Performance Liquid Chromatography/ESI-QTOF-Mass Spectrometry analysis of C. adansonii extract detected structure-related of many well-known anticancer agents such as flavane gallate, flavonol, phenylpropanoïds, sesquiterpene derivatives, gallotannins and lignans. The LD50 of C. adansonii was estimated to be greater than 5000mg/kg.

Conclusions: These aforementioned results suggest that the C. adansonii extract may possess antitumor constituents, which could combat breast cancer and prevent chemically-induced breast cancer in rats.

Keywords: Antioxidant activity; Breast cancer; Chemoprevention; Crateva adansonii; Cytotoxicty; Dmba.