Survey of aliphatic glucosinolates in Sicilian wild and cultivated Brassicaceae
Glucosinolates, found widely in plants of the family Brassicaceae, have been implicated as anti-cancerous. The genetic variability of glucosinolate profiles found in the Sicilian wild and cultivated Brassicaceae is summarized.
Introduction
In the frame of the activities carried out to characterize Sicilian local cultivars of brassicas (Branca and Iapichino, 1997), we focused our attention on the content of potentially health-inducing compounds, which could improve the value of the produce. Our objective was to evaluate local cultivars with the goal of improving genotypes for developing functional foods aimed at the prevention of human diseases. Kohlmeier and Su (1997) reported that consumption of B. oleracea vegetables results in lower probability of acquiring colon and rectal cancers. Similarly, Michaud et al. (1999) observed reduction of incidence of cancer to the bladder, and Cohen et al. (2000) for prostate cancer. In this context, we surveyed local cultivars of broccoli, cauliflower, kale and a few Brassica wild species for aliphatic glucosinolates (GSL).
Glucosinolates are a diverse class of compounds found mostly in the Brassicaceae. The glucosinolate molecule consists of two parts, a common glycone moiety and a variable aglycone side chain (Fenwick et al., 1983, Rosa et al., 1997). The aglycone part may contain aliphatic, indolyl, or aromatic side chains derived from a corresponding α-amino acid. Glucosinolates are hydrolyzed into isothiocyanates by the enzyme myrosinase, which is present in both plant cells and in human gut microflora (Shapiro et al., 1998). Many isothiocyanates have been shown to inhibit tumor formation when induced by chemical carcinogens in several animal systems (Zhang and Talalay, 1994, Hecht, 1995). One of these isothiocynantes is sulforaphane, resulting from the hydrolysis of glucoraphanin (GR=4-methylsulfinyl-butyl glucosinolate), which is a potent inducer of phase II enzymes involved in carcinogen detoxification. Zhang et al., 1992, Zhang et al., 1994 demonstrated that sulforaphane protects rats against tumorigenesis after treatment with dimethyl benzanthracene, a carcinogenic agent. For the purpose of our study, we collected local cultivars both in east and west Sicily whereas the wild species analyzed came mostly from west Sicily, where they occur naturally. Two of these wild species, B. macrocarpa and B. rupestris, form part of the primary gene pool of B. oleracea, which occurs in Sicily and is maintained by local growers (Branca and Iapichino, 1997, Gomez-Campo and Gustafsson, 1991). More specifically speaking, the aim of the present study was to determine primarily the variability of aliphatic GSL profiles in local cultivars compared with those from the related wild species. Although certain GSL derivatives have a protective effect against cancer (Rosa et al., 1997), there are some that may have detrimental effects, such as progoitrin and others derived from alkenyl GSL. These compounds mostly reported in rapeseed meal act as antinutrients affecting not only animal growth and development, but also lowering food intake. Additionally, modified isothiocyanates derived from progoitrin may have goitrogenic effects in animals (Rosa et al., 1997). Therefore, among the GSL surveyed in the present study, of particular interest are glucoraphanin because of its role as a cancer protecting agent, sinigrin, which has been reported as an inhibitor of fungi and nematodes (Rosa et al., 1997), and progoitrin, which is considered an antinutrient for its possible involvement in goiter.
Section snippets
Results and discussion
Glucosinolate quantity varied extensively among species and crops, with a global mean of 1.00 μM−g FW leaves (Fig. 1). All local and commercial broccoli and kale accessions showed higher amounts of total GSL, with means of approximately 1.20 and 1.32 μM−g FW leaves respectively, than cauliflower, which on the average all accessions contained 0.77 μM−g FW leaves.
Local cultivars showed on average twice the amount of GSL than that observed for the commercial cultivars; with the exception
Conclusions
Our results disclosed a great level of variability in GSL content in the Sicilian Brassica germplasm tested, including related wild species.
GSL profiles differed, above all between local and commercial cultivars of cauliflower, especially for glucoraphanin. For this crop the local colored cultivars seem to show a more desirable profile for beneficial GSL than the commercial ones. For broccoli and kale we found the same GSL as those reported by other authors. The wild Brassica screened had
Experimental
A total of 37 accessions were included in the present study. Out of these, 21 have been maintained at the Dipartimento di OrtoFloroArboricoltura e Tecnologie Agroalimentari of Catania University (DOFATA), representing a core collection of Sicilian local cultivars of kale (Brassica oleracea convar. acephala), cauliflower (B. oleracea convar. botrytis) and broccoli (B. oleracea convar. italica), and one each for B. macrocarpa (MA) and B. rupestris (RU). Eleven commercial cultivars (CO),
Acknowledgements
This work was funded in part by a contribution of the University of Catania for scientific updating of researchers in countries abroad, and by the research project: “Exploitation of agroecological specificity of inland areas by vegetable crops” funded by Sicilian Region of Italy.
References (21)
- et al.
Some wild and cultivated Brassicaceae exploited in Sicily as vegetables
FAO/IPGRI Plant Genetic Resources Newsletter
(1997) - et al.
Fruit and vegetable intakes and prostate cancer risk
J. Natl. Cancer Inst.
(2000) - Crisp, P., 1989. The evolution of Brassica under domestication. Advisory group meeting on the possible use of mutation...
- et al.
The capacity of broccoli to induce a mammalian chemoprotective enzyme varies among inbred lines
J. Am. Soc. Hort. Sci.
(2000) - et al.
Glucosinolates and their breakdown products in food and food plants
Crit. Rev. Food Sci. Nutr.
(1983) - et al.
Germplasm of wild n=9 Mediterranean species of Brassica
Bot. Chron.
(1991) Taxonomy and evolution of broccolis and cauliflowers
Baileya
(1989)Chemoprevention by isothiocyanates
J. Cell. Biochem. (Suppl.)
(1995)- et al.
Cruciferous vegetable consumption and colorectal cancer risk: meta-analysis of the epidemiological evidence
FASEB J.
(1997) - Kop, E., Smith, L., McClenagham, R., Teakle, G., King, G., 2000. Characterization of MADS-box gene expression in the...
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