The healthy effects of L. barbarum on in vitro cell models

Abstract

Cancer is a group of diseases characterized by the over proliferation of the cells. Epidemiological studies indicate that about 30-40% types of cancers are directly or indirectly linked to improper diet and related factors. Morover, several reports demonstrate an association between intake of fruits and vegetables and reduced mortality from degenerative diseases, including cancer.

Plants possess a variety of bioactive substances like phenols, flavonoids, carotenes and organo sulphur compounds having anti proliferative activities.

Goji is a native Chinese deciduous shrub with bright red berries. Goji has been utilized in traditional chinese medicine since the first century AD to promote longevity, to sustain the liver and improve the eyesight.

To date, several studies indicate beneficial effects of Goji berries for diabetes, high blood pressure, poor circulation, fever, malaria, inlammatory diseases, eye disorders and cancer.

Goji polysaccharide was shown to inhibit the growth of human leukemia HL-60 and human breast cancer MCF-7 cell lines. In vivo, it could enhance the anti-cancer effect of a chemotherapy on patients with various neoplasias, such as malignant melanoma, renal cell carcinoma, colorectal carcinoma, and lung cancer.

Besides the great variety of association studies, there is a need of studies to unravel its therapeutic effects at the biochemical level.

In our study, we demonstrate that Goji dry extracts do not induce in vitro tumor cell death and do not determine reduction of proliferation, using several tumor cell lines and fibroblasts and lymphocytes as normal cell controls.

Goji dry extract has shown in vitro excellent anti-inflammatory properties in a bidimensional monolayer of differentiated Caco-2 cells, as a model of the intestinal barrier. TNF-alpha-induced increase in intestinal epithelial tight junction (TJ) permeability, proposed as one of the proinflammatory mechanisms contributing to the intestinal inflammation, has been drastically reduced by Goji treatment; moreover, after 24 h incubation with the cytokine, MTT showed a beneficial protective effect when epithelial cells were treated with the Goji extract.

In our study, we have also evaluated the cellular effects by the fecal water (aqueous phase of human feces, FW), a useful biomarker approach to study cancer risks and protective activities of food.

Faecal waters from 5 healthy volunteers consuming their habitual diet were screened for genotoxicity by the single-cell gel electrophoresis (comet) assay and citotoxicity by the MTT assay, using a human cell line models, as target; goji berries supplementation increased the vitality of FW-treated cells and reduced genotoxic damages, confirming the antioxidative properities of goji.

The results showed remarkable biological activity of goji berries and dry extract and qualify it as a potential resource for food/pharmaceutical applications.