Applications of Monoterpenic Essential Oils in Neglected Diseases : Nerol in a Prospection

Monoterpenes are the naturally occurred essential oils in various plant species having a wide range of biological activities. Attentions on the natural compounds, especially those are plant-derived is growing day by day. Nerol, a monoterpene having some important biological activities along with its other applications, may be a hopeful tool in this context. By considering the above circumstances, this study aimed to perform a scientific and technological prospective study on this charming monoterpene with an emphasis on the treatment of neglected diseases along with other monoterpenes. We conducted a comprehensive and systematic search for published articles, periodicals, magazines in the CAPES, ScienceDirect and Pubmed, while for patents we have gone through search in National Institute of Industrial Property of Brazil (INPI), European Patent Office (EPO), World Intellectual Property Organization (WIPO) and United States Patent and Trademark Office (USPTO). Results suggesting monoterpenes have therapeutic potentials against malaria, dengue, schistosomiasis, tuberculosis, leprosies, leishmaniasis and chagas diseases. Nerol has anti-tuberculosis potential. In conclusion, more researches are recommenced with nerol in a context of treatment of neglected diseases. Applications of Monoterpenic Essential Oils in Neglected Diseases: Nerol in a Prospection REVIEW


Introduction
Nowadays, natural products are in a great attention to the peoples for the treatment of various ailments [1].Having less adverse effects and promising therapeutic making them to consider as health promoting tools.Essential oils are one of them.Monoterpenes, a class of terpe-nes under the EOs are now evident to have a good number of biological activities [2,3].
However, naturally occurring substances reveals therapeutic alternatives for the neglected diseases (ND), which are a group of illnesses representing mortality in a race-independent manner of people worldwide [12].People from the remote rural areas, urban slums or conflict zones are the most susceptible in this context.RDs are not only directly affect health, but also represent a vicious cycle of socio-economic events that reinforce the feedback on the other [13].It is noteworthy that the existing therapies for the RDs are largely based on drugs having toxicity and prone to serious side effects, which leading to search new agents with more effectively and safety [12].
Therefore, this study aimed to carry out a systematic revision in a scientific and technological viewpoint on monoterpenes with the applications to NDs underlying a special attention to nerol.

Findings Scientific and technological
In the search for articles, periodicals and magazines, monoterpenes constitute 57 periodicals, and 98 articles in CAPES, PM and SD in which SD occupied 61.29% while CAPES and PM by 36.77% and 1.94%, respectively.Among the 213 evidences, 66.19% articles belong to the database, SD leaving 27.23% periodicals, and 6.57% articles behind the CAPES and PM, respectively.However, patents searched in the databases, demonstrating that WIPO constitutes 47.06% then followed by 41.18% and 11.76% in EPO and INPI, respectively for monoterpenes.No patents were found in the USPTO.Otherwise, nerol constitutes 76 patents, among which 98.68% belongs to USPTO leavig behind 1.32% of WIPP database.No patents were funded in INPI and EPO databases (Table 1).
Figure 1 telling that IL is the owner of 31.06% patents on NDs, which was then followed an order of AW> US> CA> MA=NL=PA> AT=IN=LU> BS=FG=GA=IT=JP=ML=NO=UY, respectively.
Patients were found from 1992 to 2014 suggest in 2004, 2009 and 2013 costitute 8 of each then followed by the order of 2010 ( 7

Findings on neglected diseases (NDs)
Antimalarial activity Terpenes are the potential sources of antimalarial activity [14].Choloroform extract of Couroupita guianensis fruit was found to act against a number of pathogenic microbes including mycobacteria.It also significantly inhibited the formation of biofilm of the pathogens [15].EOs in the leaf extract of Plinia cerrocampanensis was found to produce significant antimalarial activity [16].Kpo-     [17].EOs from Lippia multiflora is also evident to act against P. falciparum [18].The ethanol extract of Ocimum sanctum is also evident to have antimalarial capacity [19].An in vivo antimalarial activity was demonstrated with the allylic alcohol, geraniol by [20].Parshikov et al. also introduced few new terpenes with anti-malaria activity [14].
A number of EOs derived from plants, including monoterpenes were introduced having mosquito repellent potential by Pohlitet al. [21].Nanocapsules prepared with onopordopicrin, a sesquiterpene was suggested to have a significant antimalaria activity [22].

Activity against dengue
Conti et al. reported that the Aede salbopictus larvae are susceptible to the EOs of Achillea millefolium, Lavandula angustifolia, Helichrysum italicum, Foeniculum vulgare, Myrtus communis, and Rosmarinus officinalis [23].EOs of the leaves of Salvia dorisiana, S. longifolia, and S. sclarea under the family, Lamiaceae exhibited potent anti-A.albopictus activity [24].Additionally, EOs from Citrus sinensis, C. limon and C. paraíso shells and its components were found to exhibit larvicidal potential against a number of mosquito [25].Pohlit et al. did a revision demonstrating EOs to have promising mosquito repellent capacity [21].A research conducted by Pandey et al. of eugenyl acetate, linalyl acetate, terpinyl acetate, menthyl acetate, geranyl acetate along with the monoterpenes eugenol, linalool, terpineol, L-menthol and geraniol suggesting significant anti-A.aegypti activity with an LC 50 value range between 50.2 to 415 ppm [26].A research done by Nyasembe et al. suggests that volatile phytochemicals may be good options for to repeal mosquito [27].

Anti-tuberculosis potential
EOs from C. guianensis fruit was found to act Mycobacterium tuberculosis [15].Kumar et al. observed that the Plumeria bicolor extract significantly inhibited the growth of M. tuberculosis and multidrug resistant M. tuberculosis.Along with nerol, plumericin and isoplumericin were claimed as a potential candidate for antituberculosis activity.The antituberculosis activity of EOs was also observed by Kumar et al. with Plumeria bicolor extract [31].The meso-dihydroguaiaretic also exhibited a potential anti-M.tuberculosis [32].According to Chinsembu EOs may be one of the potential sources of antituberculosis activity [33].

Conclusion
Consistent with the obtained results, we observed a significant number of scientific papers and patent deposits involving monoterpenes and nerol.Although, there are links with neglected diseases, but found evidences in databases are firmly deficient with specific activities, despite of a number of essential oils are evident to have activity against neglected diseases.More research is requested in this field of study.
International Archives of Medicine is an open access journal publishing articles encompassing all aspects of medical science and clinical practice.IAM is considered a megajournal with independent sections on all areas of medicine.IAM is a really international journal with authors and board members from all around the world.The journal is widely indexed and classified Q1 in category Medicine.
; SD: ScienceDirect; INPI: National Institute of Industrial Property of Brazil; EPO: European Patent Office; WIPO: World Intellectual Property Organization; USPTO: United States Patent and Trademark Office.

Figure 1 :
Figure 1: Patients on neglected diseases belonging to the owners with percentage occupied.

Table 1 .
Databasic evidences of monoterpenes and nerol in neglected diseases (after sorting).PM: PubMed; SD: ScienceDirect; INPI: National Institute of Industrial Property of Brazil; EPO: European Patent Office; WIPO: World Intellectual Property Organization; USPTO: United States Patent and Trademark Office.