Comparison of organic and conventional production methods in accumulation of biomass and bioactive compounds in Centella asiatica (L.) urban

Centella asiatica is a herb commonly grown across south and southeast Asia for nutritional and traditional medicinal value. Recent studies have shown that triterpenoids and their glycosides produced by C. asiatica may have applications in modern medicines. It is therefore important to determine how best to culture the herb to maximise the production of bioactive compounds while minimising any negative impact upon the environment or the health of the farmers. We have compared Vietnam Good Agricultural Practice (VIETGAP) with an organic (ORGANIC) production technique in Thua Thien-Hue province, Vietnam. This paper reports the results of the collection and analysis of the fresh mass, the dry mass, the raw ethanol/water extracts, and the levels of the main bioactive triterpenoids: madecassic, asiatic and terminolic acids over the course of two years. We found that the ratios of the dry mass to fresh mass, and extracts to dry mass were similar in both cases, with maximum raw extracts/dry mass ratios of 37% (VIETGAP) and 33% (organic). We have monitored these changes with respect to the seasons and found that the best time to harvest for bioactive compounds in this location is June-September, when the weather is warmer and drier. These results show that switching to an organic production method is not detrimental to the accumulation of valuable bioactive compounds, and we anticipate that application of these results will contribute to increasing the economic and social value of Centella asiatica while reducing the use of agrochemicals which can be deleterious to the environment and the health of farmers.