Medicinal plants are a globally important resource for the treatment of disease and improvement of human health, and the only form of healthcare used by millions of people. Currently, the status of many medicinal species is threatened by overharvesting caused by increasing demand. While many species have been cultivated in soil, the resulting material often contains lower levels of medicinal compounds than that of wild-harvested plants. Hydroponic cultivation of medicinal plants may provide sustainable access, with research demonstrating increased secondary metabolite content in some species compared to both wild and soil-grown plants. There are a variety of hydroponic systems and techniques available, each with its own advantages and disadvantages. As medicinal compounds are often localised within specific plant organs, selecting hydroponic systems that maximise the yield of the desired organs and metabolites is necessary. However, as of yet there has been no attempt to examine the literature with regards to the cultivation of specific plant organs of medicinal plants in hydroponics. This article explores the use of different hydroponic systems to cultivate medicinal plants and how the choice of system differs depending on the desired plant organ, as well as highlighting studies with novel outcomes that may provide value to the field.

Antrodia cinnamomea is a fungus endemic to Taiwan that exhibits various medicinal properties, many of which stem from its unique triterpenoids. Studies on A. cinnamomea generally focus on the red phenotype while only a handful of studies on its naturally-occurring mutant white phenotype exist. This study investigated the effect of two different culture types (solid-state dish culture and submerged flask culture) and three carbon sources (glucose, maltose and sucrose) on the mycelial dry weight and triterpenoid content of red (AC) and white (W) strains of A. cinnamomea. The concentrations of eight key triterpenoid compounds were also determined to compare triterpenoid profiles. Biomass accumulation in solid-state culture was significantly larger for the W strain than for the AC strain. In submerged culture mycelial biomass was not significantly different between strains. The AC strain had significantly higher triterpenoid content in both culture systems. Although both strains responded similarly to each carbon source with regards to mycelial dry weight, their triterpenoid content differed in solid state culture. None of the eight key compounds were found in the W strain. This study indicates that the triterpenoid profile of in vitro cultured white A. cinnamomea differs from red strains, and that further investigation of their metabolomic profiles is required.

Antrodia cinnamomea is a fungus endemic to Taiwan that exhibits various medicinal properties, including anti-cancer and anti-inflammatory effects, many of which stem from its unique triterpenoids. Studies on A. cinnamomea generally focus on the red phenotype, while only a handful of studies on its naturally-occurring mutant white phenotype exist. This study investigated the effect of two different culture types (solid-state dish culture and submerged flask culture) and three carbon sources (glucose, maltose, and sucrose) on the mycelial dry weight and triterpenoid content of red (AC) and white (W) strains of A. cinnamomea. The concentrations of eight key triterpenoid compounds were also determined to compare triterpenoid profiles. Biomass accumulation under solid-state culture was more than two-fold for the W strain than for the AC strain. In submerged culture mycelial biomass was not significantly different between strains. Total triterpenoid content was 29%, 88%, and 134% greater in the AC strain than the W strain under submerged culture with glucose, maltose, and sucrose, respectively. Similarly, triterpenoid content of solid-state-cultured fungus increased by 10% with glucose and 53% with maltose. Although both strains responded similarly to each carbon source with regards to mycelial dry weight, their triterpenoid profiles differed in solid-state culture. Five of the eight key compounds were detected in the solid-state culture of the AC strain (antcin A, antcin B, antcin C, antcin K, and DMMB) and four were detected in the submerged culture (antcin A, antcin B, antcin K, and DMMB). The concentration of individual triterpenoid compounds was up to 100 times greater in the solid-state culture than in the submerged culture. None of the eight key compounds were found in the W strain. This study indicates that the triterpenoid profile of in vitro cultured white A. cinnamomea differs from red strains, and that further investigation of their metabolomic profiles is required.