From a biopharmaceutical standpoint, the skin is recognized as an interesting route for drug delivery. In general, small molecules are able to penetrate the stratum corneum, the outermost layer of ...

Mosquito-borne diseases such as malaria, filariasis, chikunguniya, yellow fever, dengue and Japanese encephalitis are the major cause of remarkable morbidity and mortality in livestock and humans worldwide. Since ancient times, aromatic plants are used for their medicinal value. Essential oils derived from these plants may be used as effective alternatives/adjuvants in pharmaceuticals, biomedical, cosmetic, food, veterinary and agriculture applications. These oils have also gained popularity and interest for prevention and treatment of various disorders. However, several reports on adverse effects including skin eruption, contact artricaria or toxic encephalopathy in children are available for synthetic repellent in the literature. Thus, natural insect repellents like essential oils have been explored recently as an alternative. One such essential oil studied widely, is citronella oil, extracted mainly from Cymbopogon nardus. This essential oil has exhibited good efficacy against mosquitoes. It is a mixture of components including citronellal, citronellol, geraniol as major constituents contributing to various activities (antimicrobial, anthelmintic, antioxidant, anticonvulsant antitrypanosomal and wound healing), besides mosquito repellent action. Citronella essential oil is registered in US EPA (Environmental protection agency) as insect repellent due to its high efficacy, low toxicity and customer satisfaction. However, poor stability in the presence of air and high temperature limits its practical applications. Since specific knowledge on properties and chemical composition of oil is fundamental for its effective application, the present review compiles and discusses biological properties of citronella oil. It also sheds light on various formulations and applications of this essential oil.

Alzheimer’s disease (AD) is a gradually growing irreversible illness of the brain that almost affects every fifth person (aged > 80 years) in the world. World Health Organization (WHO) also revealed that the prevalence of this disease will enhance (upto double) significantly upto 2030. The poor cholinergic transmission at the synapse is considered to be one of the main reasons behind the progression and occurrence of this disorder. Natural inhibitors of acetylcholine (ACh) such as galanthamine and rivastigmine are used commercially in the treatmentof AD. The biomolecules such assesquiterpenes, possess a great structural diversity and are responsible for a plethora of pharmacological properties. The potential of various sesquiterpenes as anticholinesterase has been reviewed in this article. For this purpose, the various databases, mainly PubMed, Scopus, and Web of Science were investigatedwith different keywords such as “sesquiterpenes+acetylcholinesterase” and “sesquiterpenes+cholinesterase+inhibitors” in the surveyed time frame (2010–2020). A vast literature was evident in the last decade, which affirms the potential of various sesquiterpenes in the improvement of cholinergic transmission by inhibiting the AChE. After data analysis, it was found that 12 compounds out of a total of 58 sesquiterpenes were reported to possess IC₅₀ < 9 μM and can be considered as potential candidates for the improvement of learning and memory. Sesquiterpene is an important category of terpenoids, found to possess a large spectrum of biological activities. The outcome of the review clearly states that sesquiterpenes (such as amberboin, lipidiol, etc.) from herbs could offer fresh, functional compounds for possible prevention and treatment of AD.