Molecular Size Fractions of Bay Leaf(Laurus nobilis)Exhibit Differentiated Regulation of Colorectal Cancer Cell Growth In Vitro

Abstract

Numerous in vitro studies using solvent or aqueous extracts of raw dietary plant material have demonstrated modulation of colon cancer cell growth and apoptosis and effects on immune and nonimmune pathways of inflammation. We have developed a generic, 3-staged food-compatible process involving heating for conversion of dietary plants into food ingredients and report results on potential colon cancer-regulating properties of processed forms of Bay leaf (Laurus nobilis). In vitro studies demonstrated inhibition of cancer cell growth by processed Bay leaf products in HT-29, HCT-116, Caco-2, and SW-480 human cancer cell lines, which were accompanied by variable levels of elevated apoptosis. Bay leaf also exerted moderate inhibition of cycloxygenase 2 and 5 lipoxygenase enzymatic activity. In addition, these extracts significantly downregulated interferon-γ production in T helper Type 1-stimulated whole blood from healthy donors. Furthermore, size fractionation of the extracts revealed that antiproliferative and proapoptotic activities were associated with low mass (primarily polyphenolics and essential oils) and high mass (primarily proteins including polyphenol oxidase) chemical classes, respectively. Bay leaf exerted in vitro bioactivity that might be relevant to protecting against early events in sporadic colorectal cancer, with potential for further optimization of bioactivity by size-based fractionation.

Inhibitory Effects of Culinary Herbs and Spices on the Growth of HCA-7 Colorectal Cancer Cells and Their COX-2 Expression

“…The growth inhibition results are in line with other studies that demonstrated that CHS possess anti-proliferative activity against various cancer cell lines including CRC [ 22 , 23 , 36 , 40 , 41 , 42 ]. However, to our knowledge, none of the above-cited studies investigated the effect of the CHS used in the present study (individually or in combination) on the HCA-7 CRC cell line.…”

“…In the present study, bay leaf, specifically BLE, proved to be almost as potent as that of TE. Bay leaf is a less studied herb, a small number of studies have reported its ability to decrease COX-2 expression (in macrophages) [ 60 , 61 ] and also to moderately inhibit COX-2 activity [ 42 ]. However, in the latter study, processed bay leaf (cooked and enzymatically treated) was used and the inhibition of cellular COX-2 expression and activity was not investigated.…”

RNA sequencing supports distinct reactive oxygen species-mediated pathways of apoptosis by high and low size mass fractions of Bay leaf (Lauris nobilis) in HT-29 cells

“…The Stage 1 product was the same as that used and characterised in ref. 26 but it was the Stage 1 and not the Stage 2 product that was fractionated and used in the current study. Previously, the supernatant was fractionated using preparative gel filtration chromatography (PD-10 column, Amersham Biosciences, GE Healthcare, Uppsala, Sweden) with 6 successive 1.75 ml aliquots of water and finally 3.5 ml of methanol (fraction 7), under gravity-based elution.…”

Lipid nanocarriers based on natural oils with high activity against oxygen free radicals and tumor cell proliferation

“…The antiproliferative activity of laurel volatile oil against human breast adenocarcinoma was proved by Jelnar et al [7]. Other in vitro study demonstrated inhibition of cancer cell growth by laurel leaf oil in HT-29, HCT-116, Caco-2, and SW-480 human cancer cell lines, which were accompanied by variable levels of elevated apoptosis [8]. Both seed and leaf essential oils from laurel plant exhibited a scavenging effect on DPPH radical and inhibited proliferation of the K562 tumor cell line [9].…”