Terpenes and terpenoids as main bioactive compounds of essential oils, their roles in human health and potential application as natural food preservatives

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Terpenes and terpenoids are the main bioactive compounds of essential oils (EOs).

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EOs and their major constituents confer several biological activities.

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EOs are potential as natural food preservatives.

Essential oils (EOs) are volatile and concentrated liquids extracted from different parts of plants. Bioactive compounds found in EOs, especially terpenes and terpenoids possess a wide range of biological activities including anticancer, antimicrobial, anti-inflammatory, antioxidant, and antiallergic. Available literature confirms that EOs exhibit antimicrobial and food preservative properties that are considered as a real potential application in food industry. Hence, the purpose of this review is to present an overview of current knowledge of EOs for application in pharmaceutical and medical industries as well as their potential as food preservatives in food industry.

Ethnobotanical survey of medicinal plants used in the Maseru district of Lesotho

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnobotanical knowledge in Lesotho is passed on orally from one generation to another. As a result it has not been well documented. Existing publications have relied on previous literature and are limited either in terms of scope or coverage. Furthermore, some of them are out of print. Therefore, there are gaps in the documentation of medicinal plants used in Lesotho.

AIM OF THE STUDY

The purpose of the current study is to investigate common ailments in Lesotho's traditional medicine and document plants that are used in treating such ailments.

MATERIALS AND METHODS

Interviews were conducted in five urban and four rural areas of the capital town of Maseru, by means of questionnaires to elicit information on medicinal plant use to cure common ailments. The informants were 20 males and seven females comprising 15 traditional healers, 11 herbalists and one pharmacist.

RESULTS

Reproductive ailments were found to be the most commonly treated, followed by respiratory, degenerative and digestive problems. A list of the 80 plants used for treating the common ailments is given. A total of 44 families is represented, with Asteraceae, Fabaceae, Asphodelaceae and Poaceae families having the highest number of species used for medicinal purposes. The most frequently mentioned medicinal plants in interviews include; Elephantorrhiza elephantina, Pentanisia prunelloides, Hypoxis hermerocallidea, Eriocephalus sp., Salvia runcinata, Scabiosa columbaria, Dicoma anomala, Morella serrata, Xysmalobium undulatum, and Leobordea lanceolata. Due to the high demand of medicinal plants, some species such as L. lanceolata, Tephrosia capensis, E. elephantina, D. anomala and P. prunelloides were reported as over-harvested. In some cases animal products are added to the medicinal plants to enhance their curative abilities.

CONCLUSIONS

A total of 80 plants were recorded in the study as treating 38 common ailments in the Maseru district of Lesotho. Records of eight medicinal plants and 146 new medicinal uses of 34 plants that were not recorded elsewhere in literature are reported in the current study for the first time. The new records of medicinal plants used in traditional healing practices in Lesotho clearly show the need to document these practices, and the wealth of new knowledge gained with the current study reinforces the importance of extending the study to other parts of Lesotho.