Medicinal herbs and multiple sclerosis: Overview on the hard balance between new therapeutic strategy and occupational health risk

Multiple sclerosis (MS) is an autoimmune disease characterized by demyelination and axonal loss of the central nervous system (CNS). Despite its spread throughout the world, the mechanisms that determine its onset are still to be defined. Immunological, genetic, viral, and environmental factors and exposure to chemicals may trigger MS. Many studies have highlighted the anti-inflammatory and anti-oxidant effects of medicinal herbs, which make them a natural and complementary treatment for neurodegenerative diseases. A severe reduction of several MS symptoms occurs with herbal therapy. Thus, the request for medicinal plants with potential beneficial effects, for MS patients, is constantly increasing. Consequently, a production increase needs. Unfortunately, many medicinal herbs were untested and their action mechanism, possible adverse effects, contraindications, or interactions with other drugs, are poorly or not investigated. Keeping in mind the pathological mechanisms of MS and the oxidative damages and mitochondrial dysfunctions induced by pesticides, it is important to understand if pesticides used to increase agricultural productivity and their residues in medicinal plants, may increase the risk of developing MS in both workers and consumers. Studies providing some indication about the relationship between environmental exposure to pesticides and MS disease incidence are few, fragmentary, and discordant. The aim of this article is to provide a glance at the therapeutic potential of medicinal plants and at the risk for MS onset of pesticides used by medicinal plant growers and present in medicinal herbs.

The Safe Use of Pesticides: A Risk Assessment Procedure for the Enhancement of Occupational Health and Safety (OHS) Management

The attention paid to the use of pesticides has increased notably in recent years as demonstrated by the issue of laws and regulations requiring their safe and environmentally-conscious use (e.g. Directive 2009/128/EC and Regulation (EC) no. 1272/2008). Despite the benefits that can be achieved by pursuing the targets of stricter legislative framework, the difficulties for farmers in complying with it are remarkable, especially for small-sized companies. In fact, in contrast to other occupational health and safety (OHS) contexts, in the case of pesticides even a preliminary analysis on the relationship between pesticide use and the consequent exposure risks for the workers is a complex task. In order to reduce the above-mentioned gap, the present study is focused on the development of an easy-to-use tool for carrying out occupational risk assessment of agricultural activities related to the use of pesticides. The procedure was developed by starting from the Agricultural Health Study (AHS) approach and its improvements, and continuing to the thorough development of a tool for preliminary risk assessment, providing a simplified model for its practical application by farmers. A case study concerning olive cultivation was used for its first verification. The results achieved should be considered as an initial step for the promotion of safer practices when using pesticides, providing a consistent base for their further validation.

[Epigenetics and environmental exposure to xenobiotics]

Environmental pollution, together with predisposing genetic factors, plays a key role in determining short and long-term adverse effects on human health. In the industrialized countries the identification of etiology related to diseases of environmental origin has then become a research of priority interest. With regard to this, it has been widely demonstrated that different chemical compounds, such as endocrine disruptors, are able to modify the epigenetic characteristics of a human being. According to recent studies, the paradigm "genotype is strongly correlated with a phenotype" is changing in favor of the concept that a phenotype is defined by a "genotype and by an epigenome". Thus, there is a genotype identical for all cells associated to the epigenome that causes changes in gene expression without modifying the nucleotide sequence of the genome, through alterations in DNA methylation, histone modifications and the pathway of small non-coding RNAs. The epigenome is easily affected by different factors, such as aberrations of normal epigenetic processes that can be caused by environmental factors as exposure to xenobiotics, social behavior and nutritional deficiencies. Epigenetic changes are thus a biological response to environmental stress factors and may be transmitted to the offspring. As the elimination of the environmental factor determines the possible reversion of epigenetic modifications, it seems not to play a role in the natural selection process. However, epigenetic aberrations affect gene expression by interfering with the stability and survival of cells and with the inactivation of onco-suppressor genes. Thus, it is of considerable interest to investigate about the possible elements of induction of epigenetic processes in order to implement prevention protocols. Moreover, the gene expression screening through high through-put techniques like microarray, represent a new tool for the identification of new epigenetic indicators in order to monitor the early biological effects on the population exposed to xenobiotics.