The effect of ontogenetic factor on active agent content of Achillea collina

Wild yarrow (Achillea collina Becker) is popular medicinal plant which is applied in phytotherapy for its antiinflammatory, antispasmodic, digestive and cholagog effect. However, the quality of the drug is often variable. The effect of harvesting time on the essential oil and chamazulene content of yarrow was investigated by several authors, the results are contradictious while experiments focusing on other active compounds, such as flavonoids and phenolics are only sporadic.

In our trial the effect of plant development on essential oil, proazulene, total flavonoid and phenolic content of A. collina was investigated. The experiment was installed in Budapest during 2013 – 2014 using the cultivar 'Proa'. The flowering tops of the plants were harvested in five ontogenetical stages from early budding till late flowering. The essential oil, chamazulene and total flavonoid content was determined in the air-dried samples according to Ph. Eur. VII. [1]. The total phenolic content was measured by the modified method of Singleton and Rossi [2].

The results are summarised in the table below (mean of two years). These results shows that the main active compounds follow different dynamics during ontogenesis of yarrow, therefore harvesting should be optimised for reaching the desired quality according to market/processors' needs.

Plant development stage	Green bud	White bud	Beginning flowering	Full flowering	End of flowering
BBCH scale	55	59	61	65	69
Essential oil content (ml/100 g)	0.180	0.252	0.243	0.220	0.156
Proazulene content (%)	0.073	0.114	0.083	0.085	0.049
Total flavonoid content (%)	1.69	2.04	2.45	2.15	1.99
Total phenoloid content (mg GAE/g)	222.65	207.42	179.93	159.13	152.92

References:

[1] European Pharmacopoeia 7.3. Hawthorn – Crataegi folim cum flore, Yarrow – Millefolii herba. Council of Europe 2012: 01/2012:1382, 3879 – 3880.

[2] Singleton VL, Rossi JA Colorimetry of total phenolics with phosphomolibdicphosphotungistic acid reagents. Am J Enol Vitic 1965; 161: 144 – 158.