In rural areas of Nepal, where it is difficult to get access to Government health care facilities, people depend on medicinal plants and local healers for health problems. This study concerns an ethnobotanical survey of the Kavrepalanchok District, reporting some unusual uses of medicinal plants and original recipes. A total of 32 informants were interviewed, 24 of them being key informants. Ethnobotanical uses concerned 116 taxa, of which 101 were medicinal plants, with the most representative species belonging to Asteraceae, Fabaceae, Lamiaceae, and Zingiberaceae. Ethnobotanical indexes were used to evaluate the ethnopharmacological importance of each plant species and the degree of agreement among the informants’ knowledge. Informant consensus factor (Fic) showed that the fever category had the greatest agreement. Highest fidelity level (FL) values were found for Calotropis gigantea used for dermatological diseases, Drymaria cordata for fever, Mangifera indica and Wrightia arborea for gastrointestinal disorders. Data document the richness of the local flora and the traditional knowledge on medicinal plant species used by ethnic communities in rural areas. The active involvement of local populations in the conservation and management of medicinal plant species will encourage future projects for the sustainable development of the biological and cultural diversity of these rural areas of Nepal.

The essential oils (EOs) of three Caprifoliaceae species, the Eurasiatic Valeriana officinalis (Vo), the Himalayan Valeriana jatamansi (Vj) and Nardostachys jatamansi (Nj), are traditionally used to treat neurological disorders. Roots/rhizomes micromorphology, DNA barcoding and EOs phytochemical characterization were carried out, while biological effects on the nervous system were assessed by acetylcholinesterase (AChE) inhibitory activity and microelectrode arrays (MEA). Nj showed the highest inhibitory activity on AChE (IC₅₀ 67.15 μg/mL) followed by Vo (IC₅₀ 127.30 μg/mL) and Vj (IC₅₀ 246.84 μg/mL). MEA analyses on rat cortical neurons, carried out by recording mean firing rate (MFR) and mean bursting rate (MBR), revealed stronger inhibition by Nj (IC₅₀ 18.8 and 11.1 μg/mL) and Vo (16.5 and 22.5 μg/mL), compared with Vj (68.5 and 89.3 μg/mL). These results could be related to different EO compositions, since sesquiterpenes and monoterpenes significantly contribute to the observed effects, but the presence of oxygenated compounds such as aldehydes and ketones is a discriminating factor in determining the order of potency. Our multidisciplinary approach represents an important tool to avoid the adulteration of herbal drugs and permits the evaluation of the effectiveness of EOs that could be used for a wide range of therapeutic applications.

The essential oils (EOs) of the Eurasiatic Valeriana officinalis (Vo), the Himalayan Valeriana jatamansi (Vj) and Nardostachys jatamansi (Nj), are traditionally used to treat neurological disorders. A multidisciplinary approach based on micromorphology, DNA barcoding, EOs characterization as well as evaluation of the biological effects on the nervous system was carried out. Nj showed the highest inhibitory activity on acetylcholinesterase (IC₅₀ 67.15 μg/mL), followed by Vo (IC₅₀ 127.30 μg/mL) and Vj (IC₅₀ 246.84 μg/mL). Microelectrode arrays analyses on rat cortical neurons revealed stronger inhibition by Nj (IC₅₀ 18.8 and 11.1 μg/mL) and Vo (16.5 and 22.5 μg/mL), compared with Vj (68.5 and 89.3 μg/mL). These results could be related to the different EOs composition and in particular to the different content of oxygenated compounds such as aldehydes and ketones, which represents a discriminating factor in determining the order of potency. In conclusion, this multidisciplinary approach could be a useful tool to quickly discriminate these three plant species and avoid adulterations.