Antitumoral activity of 1,2,4-oxadiazoles compounds isolated from the Neowerdermannia vorwerkii in liver and colon human cancer cells

Two unknown 1,2,4-oxadiazoles (3-(pyridin-3-yl)-5-(thiophen-3-yl)-1,2,4-oxadiazole and 5-(3-hydroxyphenyl)-3-(pyridin-3-yl)-1,2,4-oxadiazole) and one known 1,2,4-oxadiazole (5-(3-methoxyphenyl)-3-(pyridin-3-yl)-1,2,4-oxadiazole) were isolated from tubers of Neowerdermannia vorwerkii, collected from the San Juan Huancollo, Ingavi province, La Paz, Bolivia. The chemical structures of these compounds were elucidated through NMR and HRMS spectroscopic analyses. All compounds showed apoptotic capacity against the SK-HEP-1 and Caco-2 tumour cells. 5-(3-methoxyphenyl)-3-(pyridin-3-yl)-1,2,4-oxadiazole and 5-(3-hydroxyphenyl)-3-(pyridin-3-yl)-1,2, 4-oxadiazole showed slight apoptotic capacities, with an IC₅₀ between 17.46 ± 0.75 to 15.91 ± 0.62 μM and 39.29 ± 0.98 to 34.81 ± 0.70 μM, respectively. 3-(pyridin-3-yl)-5-(thiophen-3-yl)-1,2,4-oxadiazole showed a higher apoptotic capacity with an IC₅₀ in the range of 0.98 ± 0.11 to 0.76 ± 0.03 μM, similar to that of the positive control (Dimethylenastron).

Anti-inflammatory properties of Neowerdermannia vorwerkii Frič 'Achacana' used in treating stomach-related ailments

ETHNO-PHARMACOLOGICAL RELEVANCE

The tuber of Neowerdermannia vorwerkii commonly known as 'Achacana' is used as an infusion in Andean countries to treat various gastrointestinal ailments, kidney and liver diseases.

AIM OF THE STUDY

This study determined the anti-inflammatory activity of the aqueous extract from Neowerdermannia vorwerkii and identified the compounds related to this activity.

MATERIALS AND METHODS

A bio-guided isolation of the active compounds of Neowerdermannia vorwerkii was carried out, selecting the sub-extracts and fractions depending on their anti-inflammatory activity in the Hs 738.St/Int, Hs 746T and NCI-N87 cells.

RESULTS

Three compounds were obtained and characterised by nuclear magnetic resonance and mass spectrometry. These compounds are (3-(pyridin-3-yl)-5-(tiophen-3-yl)-1,2,4-oxadiazole (1), 5-(3-methoxyphenyl)-3-(pyridin-3-yl)-1,2,4-oxadiazole (2) and 5-(3-hydroxyphenyl)-3-(pyridin-3-yl)-1,2,4-oxadiazole (3). Regarding their anti-inflammatory activity, the three compounds inhibited the production of cytokines (IL-1β, IL-6 and TNF-α), however, compound 1 was the most active, with an IC₅₀ of 0.87 μM in all cell lines.

CONCLUSION

In the present study, the anti-inflammatory activity of the aqueous extract of Neowerdermannia vorwerkii was tested and analysed, following the isolation of three 1,2,4-oxadiazoles type compounds with similar pharmacological properties.