Wu Jia Pi

The most complete systematic review of this species, published under its currently accepted name Eleutherococcus nodiflorus, which is synonymous with Eleutherococcus gracilistylus and Acanthopanax gracilistylus and corresponds to the drug Wu Jia Pi or Nan Wu Jia Pi. It covers botany, traditional use for dispelling wind-damp, nourishing liver and kidney, diuresis and strengthening sinews and bones, phytochemistry, analytical methods and pharmacology. It is a narrative synthesis of largely preclinical literature; no controlled human trial of the single herb is identified.

Review of the natural products of Acanthopanacis cortex, concentrating on triterpenoid glycosides. It identifies acankoreagenin as the central anti-inflammatory sapogenin, with the acankoreosides as its abundant glycosides, and impressic acid as a closely related analogue, both acting largely through NF-kappaB inhibition. It also records explicitly that Wu Jia Pi is confused in commerce with Periploca root bark (Xiang Jia Pi) and with Hedyotis hedyotidea and Acanthopanax giraldii, and that adulteration of this drug is not rare. Plant extract cytotoxicity toward HL-60 leukaemia cells was negligible (IC50 above 800 µg/mL).

Sixteen lignans, four of them previously undescribed, were isolated from the root bark and screened against neutrophil elastase, cyclooxygenase-1 and cyclooxygenase-2. All were weak against neutrophil elastase and cyclooxygenase-1, but eight inhibited cyclooxygenase-2 with IC50 values of 0.75 to 8.17 µM, indicating selectivity. Enzyme-level in vitro work in a single laboratory.

Twenty-nine acyl-quinic acids were isolated from the root bark, eleven of them new, and six were characterised as previously unreported oxyneolignan-quinic acid heterodimers. This is the first report of acyl-quinic acids from Acanthopanacis Cortex. Their inhibition of neutrophil elastase and cyclooxygenase-2 was assessed in vitro.

An enantiomeric pair of cyperane-type sesquiterpenoids and a bicyclic-lactone norsesquiterpenoid were isolated from the root bark and shown to inhibit nitric oxide production significantly, supporting a sesquiterpenoid contribution to the anti-inflammatory activity of the drug alongside the triterpenoids.

Two kaurenoic acid-type diterpenoid positional isomers were separated to high purity and a validated HPLC-ELSD method was used to determine both simultaneously in nine batches of Acanthopanacis Cortex. Relevant to practice because it is one of the few quality-control methods published for authenticating and standardising this drug, in a species where positional isomerism had previously blocked quantitative analysis.

A single reported case of striking dark purple discolouration of the intestine following consumption of Acanthopanax gracilistylus medicinal wine. It is an endoscopic observation in one patient and establishes no causal toxicity, but it is one of very few published human observations on this drug and is the reason the medicinal-wine preparation is flagged separately from the decoction.