Biological and antioxidant activities, extraction methodology and prospects of essential oil from Hyptis suaveolens (L.): A review

Conventional chemicals and synthetic inputs have been identified with numerous environmental and human health hazards. These challenges have created increase in the search for better alternatives from different sources. In this paper, essential oil was studied as a prominent alternative with high levels of microbiological and antioxidant activities, and the potential to meet the replacement needs, since they are considered eco-friendly, cheaper, safer and healthier. Essential oils (EOs) have been identified for their vital relevance and uses in many areas ranging from pharmaceutical, medicinal, food flavoring and preservation. The potency of EOs and their viability for various applications are attributed to the constituent bioactive compounds, which constitute their active agents. EOs are mainly isolated and recovered from plant substrates by adopting different methods of extraction. This study presents a critical overview of the relevant and current trends in available literature concerning extraction methods for EOs. In this study, the methods for extracting essential oils, vis-`a-vis their influence on production yields, qualities, compositions and bioactivities of products were reviewed. The study focused on the perspectives and prospects of Hyptis suaveolens, a renewable resource, with a view of bringing it to the limelight as a viable biological source of essential oil. It was found that extraction methods, as well as edaphic factors and geographical locations, have significant effects on the yields, qualities and chemical compositions of the essential oils obtained. The study further revealed that essential oil from Hyptis suaveolens exhibits strong bioactivities, which serve as the basis for its use to effectively check and control pests, insects, and other pathogenic organisms and for treatment of ailments like diarrhea, and stomach disorders. Therefore, it is recommended that viable, improved methods and processes for extracting essential oil from Hyptis suaveolens be successfully developed and deployed to access its accruing potential advantages, ranging from high production yields, economic gains (low cost and low energy consumption), high product quality and low environmental impact. This is expected to create a reliable alternative biological input, with the potential to replace the conventional synthetic chemicals in current use and thereby avoid the negative side effects of synthetics on nontargeted organisms, the environment and the economy. It would also contribute immensely to better control of carbon cycle and green and sustainable technology.