Influence of seasons, different plant parts, and plant growth stages on saponin quantity and distribution in Bacopa monnieri

Brahmi or Bacopa monnieri (L.) Wettst. is becoming popular as a food supplement due to its enhancing effect on memory and intellect. Previous studies showed that a group of saponins are active compounds in this plant. However, until now little evidence has been obtained to indicate whether saponins are consistently present throughout the plant growth stages or the compounds are affected by the seasons. In order to answer those questions, we cultivated Brahmi under the net house in three seasons. Influence of plant growth stages on saponin quantity and distribution was also investigated. In each season, treatments were plant ages with different plant parts having a factorial completely randomized design with 3 replications. Five saponins, i.e. bacoside A₃, bacopaside II, bacopaside X, bacopasaponin C and bacopaside I, were analyzed using HPLC and reported as total saponins. The results showed that total saponin contents in Brahmi were the highest in rainy season while the weight yield of Brahmi was the highest in summer. Ages of Brahmi (1-4 months) slightly affected total saponin content. High level of total saponins (1.91±0.48% w/w) was detected at the shoot of Brahmi. These findings indicate that the saponin quantity is affected by seasons and the distribution of the saponins is different in each part of the plant. This information will be beneficial to the production of Brahmi for both household and industry.