Aptamer-Based Biosensor for Detection of Mycotoxins

Mycotoxins are a large type of secondary metabolites produced by fungi that pose a great hazard to and cause toxic reactions in humans and animals. A majority of countries and regulators, such as the European Union, have established a series of requirements for their use, and they have also set maximum tolerance levels. The development of high sensitivity and a specific analytical platform for mycotoxins is much in demand to address new challenges for food safety worldwide. Due to the superiority of simple, rapid, and low-cost characteristics, aptamer-based biosensors have successfully been developed for the detection of various mycotoxins with high sensitivity and selectivity compared with traditional instrumental methods and immunological approaches. In this article, we discuss and analyze the development of aptasensors for mycotoxins determination in food and agricultural products over the last 11 years and cover the literatures from the first report in 2008 until the present time. In addition, challenges and future trends for the selection of aptamers toward various mycotoxins and aptasensors for multi-mycotoxins analyses are summarized. Given the promising development and potential application of aptasensors, future research studies made will witness the great practicality of using aptamer-based biosensors within the field of food safety.Project of risk assessment on raw milk (GJFP2019026

Influence of climate variation on phenolic composition and antioxidant capacity of Medicago minima populations

peer reviewedMedicago minima is a pasture legume that grows almost all over the world. In Tunisia, it occupies various climatic environments and is considered the most abundant annual Medicago plant. However, this species is unconsumed and unused by humans. This study aimed to explore the phytochemical characteristics of Medicago minima selected from diferent provenances in Tunisia and subsequently investigate the infuence of environmental factors on their phenolic composition and antioxidant activity. Therefore, a calorimetric method and DPPH tests provided the total phenolic and totalfavonoid contents and antioxidant potential in roots, stems, leaves and seeds. High performance liquid chromatography (HPLC) identifed and quantifed four phenolic acids and three favonoids in the studied organs. Roots and leaves showed the greatest phenolic compound content and had high antioxidant activity. Rutin and syringic acid (leaves) represent a characteristic for this species. For each organ, principal component analysis of phenolic profles showed that the root’s phenolic composition could be an indication of the plant adaptation to even small changes in its environments. Plants originating from a cold climate, higher altitude or semi-arid environment had the highest phenolic compound contents in their organs. Our fndings provide useful information for the exploitation of the phenolic compounds in these weeds for the development of environmental sustainability

Etude phytochimique de plantes utilisées en cosmétique et médecine traditionnelle à Mayotte.

The Indian ocean is one of the biggest source of botanical diversity in the world, 25% of the world’s flora can be found in those islands. In addition, people living in that area, have been using what nature has to offer to treat themselves for centuries. In this work we focused on the Comoros archipelago and more precisely on the island of Mayotte. The socio-economic situation of the area has been precarious since the end of the Ylang-ylang (Cananga odorata (Lam.) Hook.f. & Thomson) industry. The aim of this thesis is to provide the inhabitants with an analysis of plant species with the potential for the development of local cosmetic products. Through the analysis of the traditional knowledge we were hoping to find the ideal species for this project. First, a preliminary study was conducted leading to the identification of more than 200 different species which could be useful. Following this first work, an infield ethnobotanical study was conducted allowing for the identification of 69 species which were interesting. By cross referencing the previously gathered information 21 different species were identified for collection and the analysis so as to validate their real biological activity: the lipoxygenase inhibition potential, the tyrosinase inhibition potential and the DPPH (2,2-diphenyl-1-picrylhydrazyl) reduction potential. The most active species then underwent a selection process based on current knowledge-to-date and availability. Following this selection, we focused on the roots of the litchi plant (Litchi chinensis Sonn.). The last step of this work consisted of the identification of the compound responsible for the observed activities. This was achieved by submitting the crude extract of L. chinensis to a bio-guided fractionation until only a single compound remained. The purified compound then went through the following molecular identification process: UV, IR, MS, RMN and colorimetric analysis. Finally, these process allowed us to identify a compound from the polyphenol family: cinnamtannin D2 (CAS number : 97233-47-1)

Screening of mahoran plants for cosmetic application

This study's main aim is to identify plant species showing anti-oxidant, anti-inflammatory and skin whitening properties. A selection of samples from previous infield studies on the traditional uses of plants in Mayotte were analyzed. The anti-oxidant activity was assessed using the ¿, ¿-diphenyl-ß-picrylhydrazyl (DPPH) method developed by Blois [1]. The anti-inflammatory activity and the skin whitening activity were both assessed through the study of inhibition kinetics from specific enzymes.The IC50 value for each sample and for each activity was obtained using UV/Vis spectrophotometric technics. They were then compared with the ones obtained from known molecules found in the literature. The most effective anti-oxidant activity was observed in fresh leaves from Acalypha wilkesiana Müll.Arg. (IC50 = 0,381 g/L) and Leea guineensis G. Don. (IC50 = 0,225 g/L) as well as in dried roots from Litchi chinensis Sonn. (IC50 = 0,346 g/L). The analysis for the two other activities are currently showing promising results.Etude phytochimique de plantes d'intérêt cosmétique à Mayott

Etude phytochimique de molécules d'intérêt cosmétique à Mayotte

This study takes place in a bigger project aiming to identify and to make an inventory of the French Pharmacopeia. Its aim is to identify plants or plant families regularly used in traditional cosmetics in Mayotte. In order to give a direction to the research, two technics where used. At first, the plants and their families used in the pharmacopeia of neighboring regions were inventoried using the literature. The resulting inventory was then compared with the flora of the Mahoran territory. The second technique was the realization of a semi-structured survey with people known for their plant-use knowledge in Mayotte. In order to have significant results, the ethnobotanical survey was done following Trotter & Logan’s protocol. (1986) According to that protocol, the gathered data has to be the following: common name, place of harvest, part used and the posology. Moreover the number of informant has to be big enough in order to integrate the data in several indicators such as: The informant agreement ration (IAR), the fidelity level (FL) and use value (UV). The number of informant was determined based on the population density of the different communes of the island. Another critical factor for this study is the correct identification of each sample. To achieve that when a sample was realized, it was taken twice. One for the analysis, the second sample was pressed and dried so as to enter a herbarium for identification. The last important step of this part of the study is the development of fast technics to establish the samples’ physiological activity. These test will give us qualitative information in order the isolate the plants that show a true potential. The targeted activities and tests being: - Anti-tyrosinase activity through an inhibition of tyrosinase test. - Anti-free-radicals activity through the DPPH test. - Anti-inflammatory activity through an inhibition of lipoxygenase an cyclooxygenase test The following steps of the study is the complete analysis of the physiologically active plants extracts in order to identify the active molecules. The end of the study will result in the creation of cosmetics originating from Mayotte’s flora. The way the cosmetics will be developed is thought so as it can be easily and durably done in Mayotte allowing this study to have a positive impact on the development of the island.Etude phytochimique de molécule d'intérêt cosmétique à mayott

Criblage de plantes mahoraise pour une utilisation cosmétique.

audience: researcher, student, popularizationThis study’s main aim is to identify plant species showing anti-oxidant, anti-inflammatory and skin whitening properties. A selection of 89 samples from previous infield studies on the traditional uses of plants in Mayotte were analyzed. The anti-oxidant activity was assessed using the α, α-diphenyl-β-picrylhydrazyl (DPPH) method developed by Blois [1]. The anti-inflammatory activity and the skin whitening activity were both assessed through the study of inhibition kinetics from specific enzymes: respectively, lipoxygenase (EC 1.13.11.12) due to its important role in the leukotriene pathway and tyrosinase (EC. 1.14.18.1) as it takes part in the melanogenesis pathway. The IC 50 value for each sample and for each activity was obtained using UV/Vis spectrophotometric technics. These IC 50 were then compared with the ones obtained from known molecules found in the literature: namely, (±)-6-Hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (IC50 = 4,388 µM) for the anti-oxidant activity, nordihydroguaiaretic acid (IC50 = 3,5µM) for the anti-inflammatory activity and kojic acid (IC50 = 722 µM) for the anti-tyrosinase activity. The most effective anti-oxidant activity was observed in fresh leaves from Acalypha wilkesiana Müll.Arg. (IC50 = 0,381 g/L) and Leea guineensis G. Don. (IC50 = 0,225 g/L) as well as in dried roots from Litchi chinensis Sonn. (IC50 = 0,346 g/L). All results are expressed in grams of fresh matter. According to the preliminary tests for the-anti-inflammatory and skin whitening activities, the crude extracts from Kalanchoe pinnata Lam. Pers., Litchi chinensis Sonn., Zingiber zerumbet (L.) Sm., Leea guineensis G. Don. and Paullinia pinnata L. are likely to show promising activities

Plants used in traditional medicine and cosmetics in Mayotte Island (France): An ethnobotanical study

Mayotte is a small island located in the Mozambique canal and due to this location it has long been an important cultural and botanical crossroad. Species from Madagascar, China, India and the African continent as well as some endemic species are found on this small island. Semi structured interviews were carried out throughout the island with 29 informants wkown for their knowledge of the traditional uses of plants. We based our work on the hypothesis that the more a plant was mentioned by the interviewees, the higher the chances would be to find an effective biological activity. In the en 69 species of interest were identified through the interviews. Flowers of Jacminum nummularifolium Baker, wood of Carizza spinarum L., roots of Curcuma longa L., leaves of Lawsonia inermis L., and wood of Santalum album L. tend to be the most known and the most used in Mayotte for traditional medicine and cosmetics. In the end, those plants are used for medicine or for cosmetics, however, when it comes to medicinal uses, the traditional doctors are not looking for the cause of the disease and will orient their treatment towards the curing of the symptoms. On another hand, it is clear that the locals have a strong cultural bond with the use of traditional cosmectics in addition to traditional medicine

Plants used in traditional medicine and cosmetics in Mayotte Island (France): An ethnobotanical study

645-653Mayotte is a small island located in the Mozambique canal and due to this location it has long been an important cultural and botanical crossroad. Species from Madagascar, China, India and the African continent, as well as some endemic species are found on this small island. Semi structured interviews were carried out throughout the island with 29 informants known for their knowledge of the traditional uses of plants. We based our work on the hypothesis that the more a plant was mentioned by the interviewees, the higher the chances would be to find an effective biological activity. In the end 69 species of interest were identified through the interviews. Flowers of Jasminum nummularifolium Baker, wood of Carissa spinarum L., roots of Curcuma longa L., leaves of Lawsonia inermis L., and wood of Santalum album L. tend to be the most known and the most used in Mayotte for traditional medicine and cosmetics. In the end those plants are used for medicine or for cosmetics, however, when it comes to medicinal uses, the traditional doctors are not looking for the cause of the disease and will orient their treatment towards the curing of the symptoms. On another hand, it is clear that the locals have a strong cultural bond with the use of traditional cosmetics in addition to traditional medicine

Plants used in traditional medicine in the Comoros archipelago: a review

peer reviewedIn the Comoros archipelago, as in many places in Africa, traditional medicine is the first reflex people have when it comes to finding a cure. This work illustrates the diversity of remedies found in this group of islands. The plant species potentially effective from a pharmaceutical point of view can be targeted through the comparison of different databases. At the same time, the present study also illustrates the importance of preventing the loss of traditional knowledge based on hundreds of years of observations. Literature: The gathered information in this paper originates from data bases built by ethnobotanists as well as peer reviewed scientific articles. In addition, some information also comes from work done by locals working with recognized organisms. Conclusion: The scientific literature cites 207 different species that are used for traditional practices in the Comoros Archipelago, among which 9 are endemic. These species were compared to the pharmacopoeias of other islands and surroundings from the Indian Ocean in terms of similarities and differences between targeted ailments. Only 3% of the cited species present similarities in use among the islands of the Indian Ocean and surroundings. Most species mentioned in this work have many different uses throughout the Indian Ocean and surroundings. In addition, the importance of defining each physical area of study in a precise way in order to have the most significant results was emphasized. Other important aspects of ethnopharmacology were highlighted, such as the safekeeping of traditional knowledge, as well as the ecological impact an intensive use of some species of interest might cause. Clearly, plants are a rich resource that should be studied and used with an environmentally orientated way of thinking