Poisonbulb

Forty-two Amaryllidaceae alkaloids were isolated from the leaf of Crinum asiaticum var. asiaticum, including eleven previously undescribed alkaloids named crinasiaticines C to M. Several inhibited nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophages with IC50 values of 2.5 to 2.6 micromolar, comparable to dexamethasone, but the same compounds were cytotoxic to the cells; only one compound showed a useful selectivity index of 22.5. The practical message for a practitioner is that this plant's anti-inflammatory chemistry is inseparable from its cytotoxic chemistry.

Bulb alkaloids of the same variety were isolated and screened against human carbonic anhydrase II. The work is useful chiefly as a reference for what the bulb, the most toxic organ, actually contains; the enzyme activity reported is a laboratory finding with no established clinical correlate.

ICR mice received a chloroform bulb extract orally at 2000 and 5000 mg/kg acutely, and 500 and 1500 mg/kg daily for fourteen days. The authors found no significant effect on liver, kidney, body weight, neurological function, haematology or biochemistry and put the LD50 above 5000 mg/kg. This result should be read narrowly and not as a clean bill of health for the plant: it tested one solvent fraction of the bulb in one rodent species, and a chloroform extract is not the aqueous or fresh material a person actually ingests. The documented human poisoning syndrome stands, and absence of toxicity in this assay is not evidence that the crude drug is safe to swallow.

Animal and isolated-tissue study of the plant's anti-inflammatory action, including antagonism of bradykinin-induced uterine contraction. It gives a pharmacological basis for the traditional topical anti-swelling use, but it is a preclinical study and says nothing about safety or efficacy in people.

Compares how different pre-extraction treatments of the leaf, as used in Thai traditional practice, change the chemistry and the in vitro anti-inflammatory activity of the resulting extract. Relevant to the point that processing changes this drug substantially, so a monograph should specify which preparation it describes.

Screen of Amaryllidaceae alkaloids showing selective inhibition of CYP3A4. This is the basis for treating the alkaloids of this plant family, including those of Crinum asiaticum, as potential pharmacokinetic perpetrators in the absence of species-specific data.

Establishes acetylcholinesterase inhibition across the lycorine series of Amaryllidaceae alkaloids and maps the structural features that drive it. Lycorine is the principal alkaloid of Crinum asiaticum, which is why anticholinesterase drugs are flagged as a caution for this species.

Fractionates the leaf and compares antioxidant and antimicrobial activity across solvent fractions. A laboratory characterisation study; it supports the topical antiseptic tradition only weakly and provides no clinical evidence.