Andrographolide

It may not enter the human blood stream when andrographis is taken orally according to some herbalists.

The effectiveness of diterpenes can be affected by factors that limit their oral bioavailability, such as their poor water solubility, slow dissolution rates, low gastrointestinal absorption, high chemical and metabolic instability, and rapid excretion. In this context, the purpose of the present review is to compile and compare literature data on the bioavailability of diterpene lactones from A. paniculata after oral administration in medicinal plant extracts or in their free forms and to highlight strategies that have been used to improve their oral bioavailability. Considering that medicinal plant extracts are commonly used as dried powder that is reconstituted in water before oral administration, novel pharmaceutical formulation strategies that are used to overcome difficulties with diterpene solubility are also compiled in this review. The use of self-microemulsifying drug delivery systems is a good strategy to enhance the dissolution and consequently the bioavailability of andrographolide after oral administration of A. paniculata extract formulations. On the other hand, herbosome technology, pH-sensitive nanoparticles, nanosuspensions, nanoemulsions, nanocrystal suspensions, nanocrystal-based solid dispersions, and solid dispersion systems are useful to formulate andrographolide in its free form and increase its oral bioavailability. The use of a suitable andrographolide delivery system is essential to achieve its therapeutic potential. Read more...

Pharmacokinetics

Andrographolide is a specific diterpene lactone derived from the plant Andrographis paniculata, commonly known as the "King of Bitters." While specific pharmacokinetic data for andrographolide is limited, here is some general information based on available research:

Absorption: Andrographolide is orally bioavailable but has low water solubility. Its absorption from the gastrointestinal tract may be limited, and it undergoes extensive metabolism during the absorption process. Enhancing the solubility and bioavailability of andrographolide through appropriate formulation approaches may improve its absorption.

Distribution: Once absorbed, andrographolide is likely to distribute throughout the body. It may undergo distribution to various tissues, including the liver, kidney, and intestine. However, the specific details of its distribution in different organs and tissues are not extensively studied.

Metabolism: Andrographolide undergoes extensive metabolism in the body, primarily through phase I and phase II metabolic reactions. Phase I metabolism involves processes such as hydroxylation, demethylation, and glucuronidation, while phase II metabolism involves glucuronidation, sulfation, and methylation. The primary metabolites of andrographolide include dihydroandrographolide, neoandrographolide, and andrographiside.

Elimination: The elimination of andrographolide occurs primarily through the liver, where it is metabolized and subsequently excreted in the bile. It may also undergo enterohepatic circulation, which can prolong its presence in the body. The exact route and extent of elimination via urine or feces are not well characterized.

It is worth noting that andrographolide's pharmacokinetics can be influenced by factors such as dose, route of administration, formulation, and individual variations in metabolism and elimination processes. Additionally, further research is necessary to fully elucidate the pharmacokinetic properties of andrographolide in different populations and clinical settings.

Bioavailability of andrographolide and protection against carbon tetrachloride-induced oxidative damage.