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Naturally occurring carcinogens of plant origin: Toxicology, pathology and biochemistry
297
Book reviews Naturally Occurring Carcinogens of Plant Origin: Toxicology, Pathology and Biochem!stry, e d i t e d by I. H i r o n o , Elsevier, A m s t e r d a m , 1987, pp. 240, U S $ 93.25, Dfl 210.00 "It can't hurt you: it's natural[" If you still hear this said, refer the soothsayer to the present book, or rather to the two volumes already published in this series (the first one dealt with mycotoxins and phycotoxins, and the series deals with 'Bioactive molecules'). Naturally occurring carcinogens are of course very important in any attempt not to cure, but to avoid cancer. And it is quite remarkable that while chemical additives are strictly controlled, many traditional foods, or spices, are used (even in the wise East) despite their proved or suspected carcinogenicity, it is true that harmful effects are additive, and that nobody, even fond offern fronds as a Japanese delicacy, consumes them as a staple food. The present book is concise, precise and critical. Its authors are all Japanese chemists or physicians. They describe plants for which a carcinogenic activity has been reported, but then proceed to review all their published biological activities, useful as well as harmful. For instance, in the chapter devoted to flavonoid plants, quite rightly more space is devoted to their anti-inflammatory effects than to their mutagenicity. Judging from the first books of this series, it will be a very useful one, at the interface between chemistry, r,~,-,~,gy,...,.,,.,and ,,,,.,.,,.,,,~.~:~:-^ I have only one reservation to express: no reference seems to be more recent than 1984. Why is publication not a faster process? G. Ourisson
Secondary Metabolism in Plant Cell Cultures, e d i t e d by P. Morris, A.H. Scragg, A. Stafford a n d M . W . F o w l e r . C a m b r i d g e U n i v e r s i t y Press, C a m b r i d g e , 1986, pp. 262, U S $ 37.50 The possibility ofusing plant cell culture on an induslriai scale for natural product synthesis has given rise to energetic studies throughout the world for the past three decades. Despite the extremely encouraging development of the shikonin process up to commercialization in Japan, fundamental knowledge of the subject s t i l l remains wretchedly inadequate and keeps the technology for industrial purposes at the immature stage.
This book regroups the contributions presented at the ! APTC meeting, held in Sheffield in the summer of 1985, which focused on this very problem o f t h e status ofplant cell culture and natural product synthesis= Surveying the wide range of research relevant to the development of plant technology, this book is an excellent review of the studies available at the time of the conference. Section by section the main problems of the art are presented, including investigations on natural product accumulation (section l) and biosynthesis pathways (section 3), relationship between growth and secondary metabolite-related differentiation (section 2), management of in vitro variability (section 5) and, more downstream in the technology, studies on mass cell culture and immobilized plant cells (section 4). The book does not escape the defects of this type of publication whose heterogeneity reflects differences in the appoaches to the problem used by the various contributors. Each section is a collection ofsample studies and does not include a synthetic approach to the topic of the section. Some coniributions, however, are review articles which complement those restricted to very specific results. The fifth part ofthe book, for example, which is devoted to the crucial problem of stability of cell lines and of variation arising when plant cells are passed through in vitro culture, begins with two excellent reviews by S. Mantell and A. Stafford on possible genetic, epigenetic or ontogenic bases of variability. Underlying mechanisms are poorly understood. It is obviously of the greatest importance for selection and improvement programs, and how to limit this instability when stable cloning is desired for production purposes. Process development possibilities ar/e now limited by a lack of information on the synthetic pathways for the formation of secondary metabolites, the control of its expression, the properties and regulation ofkey enzymes. Much of t h e work on process development undertaken until now has had a strongly empirical approach. Halfof the contributions of this book (sections 1-3) attempt to fill the gap in our knowledge and describe a wide spectrum of particular studies on specific secondary metabolites in plant cell culture. Even so, there are a number of contributors (as well as the editors, in their preface) to conclude that, if there is to be commercial exploitation of plant cell cultures for the production of useful substances, it remains essential that these basic areas of research receive further sustained investigation. In spite ofthe large range of approaches presented, one remarks the absence of non-islander European researchers at this conference (all ofthe presentations came from the U.K.) in light of the excellent teams working in this domain in France and Germany, even without mention-
Book reviews Naturally Occurring Carcinogens of Plant Origin: Toxicology, Pathology and Biochem!stry, e d i t e d by I. H i r o n o , Elsevier, A m s t e r d a m , 1987, pp. 240, U S $ 93.25, Dfl 210.00 "It can't hurt you: it's natural[" If you still hear this said, refer the soothsayer to the present book, or rather to the two volumes already published in this series (the first one dealt with mycotoxins and phycotoxins, and the series deals with 'Bioactive molecules'). Naturally occurring carcinogens are of course very important in any attempt not to cure, but to avoid cancer. And it is quite remarkable that while chemical additives are strictly controlled, many traditional foods, or spices, are used (even in the wise East) despite their proved or suspected carcinogenicity, it is true that harmful effects are additive, and that nobody, even fond offern fronds as a Japanese delicacy, consumes them as a staple food. The present book is concise, precise and critical. Its authors are all Japanese chemists or physicians. They describe plants for which a carcinogenic activity has been reported, but then proceed to review all their published biological activities, useful as well as harmful. For instance, in the chapter devoted to flavonoid plants, quite rightly more space is devoted to their anti-inflammatory effects than to their mutagenicity. Judging from the first books of this series, it will be a very useful one, at the interface between chemistry, r,~,-,~,gy,...,.,,.,and ,,,,.,.,,.,,,~.~:~:-^ I have only one reservation to express: no reference seems to be more recent than 1984. Why is publication not a faster process? G. Ourisson
Secondary Metabolism in Plant Cell Cultures, e d i t e d by P. Morris, A.H. Scragg, A. Stafford a n d M . W . F o w l e r . C a m b r i d g e U n i v e r s i t y Press, C a m b r i d g e , 1986, pp. 262, U S $ 37.50 The possibility ofusing plant cell culture on an induslriai scale for natural product synthesis has given rise to energetic studies throughout the world for the past three decades. Despite the extremely encouraging development of the shikonin process up to commercialization in Japan, fundamental knowledge of the subject s t i l l remains wretchedly inadequate and keeps the technology for industrial purposes at the immature stage.
This book regroups the contributions presented at the ! APTC meeting, held in Sheffield in the summer of 1985, which focused on this very problem o f t h e status ofplant cell culture and natural product synthesis= Surveying the wide range of research relevant to the development of plant technology, this book is an excellent review of the studies available at the time of the conference. Section by section the main problems of the art are presented, including investigations on natural product accumulation (section l) and biosynthesis pathways (section 3), relationship between growth and secondary metabolite-related differentiation (section 2), management of in vitro variability (section 5) and, more downstream in the technology, studies on mass cell culture and immobilized plant cells (section 4). The book does not escape the defects of this type of publication whose heterogeneity reflects differences in the appoaches to the problem used by the various contributors. Each section is a collection ofsample studies and does not include a synthetic approach to the topic of the section. Some coniributions, however, are review articles which complement those restricted to very specific results. The fifth part ofthe book, for example, which is devoted to the crucial problem of stability of cell lines and of variation arising when plant cells are passed through in vitro culture, begins with two excellent reviews by S. Mantell and A. Stafford on possible genetic, epigenetic or ontogenic bases of variability. Underlying mechanisms are poorly understood. It is obviously of the greatest importance for selection and improvement programs, and how to limit this instability when stable cloning is desired for production purposes. Process development possibilities ar/e now limited by a lack of information on the synthetic pathways for the formation of secondary metabolites, the control of its expression, the properties and regulation ofkey enzymes. Much of t h e work on process development undertaken until now has had a strongly empirical approach. Halfof the contributions of this book (sections 1-3) attempt to fill the gap in our knowledge and describe a wide spectrum of particular studies on specific secondary metabolites in plant cell culture. Even so, there are a number of contributors (as well as the editors, in their preface) to conclude that, if there is to be commercial exploitation of plant cell cultures for the production of useful substances, it remains essential that these basic areas of research receive further sustained investigation. In spite ofthe large range of approaches presented, one remarks the absence of non-islander European researchers at this conference (all ofthe presentations came from the U.K.) in light of the excellent teams working in this domain in France and Germany, even without mention-