Skunkvine

Paederoside, paederosidic acid and paederosidic acid methyl ester at 40 mg/kg per day for seven days lowered serum urate, creatinine and blood urea nitrogen in rats made hyperuricaemic with potassium oxonate and adenine, while raising urinary urate excretion, creatinine clearance and fractional excretion of uric acid. Renal transporter expression shifted with URAT1 and GLUT9 down and ABCG2, OAT1 and OAT3 up, so the compounds act by promoting urate excretion rather than inhibiting its synthesis. This is the best mechanistic support for the traditional use of the herb in damp-heat and joint conditions, but it uses isolated compounds in a rat model and there is no human data.

The most complete safety study on the species. A whole-plant methanol extract, the most polyphenol-rich and most antioxidant of the three extracts tested, was given to male and female Wistar rats acutely at 500 to 2000 mg/kg and sub-acutely at 500 to 1500 mg/kg per day for 28 days. Acute dosing caused no mortality and no haematological, biochemical or histopathological change, giving an LD50 above 2000 mg/kg. Sub-acute dosing was uneventful at 500 and 1000 mg/kg per day, establishing a NOAEL of 1000 mg/kg per day, but at 1500 mg/kg per day there were significant haematological and serum biochemical changes with liver and kidney histopathology, and female rats showed more histological abnormality than males. The reported absolute polyphenol contents are implausibly large and should not be relied on for standardisation, but the toxicology is usable.

An ethanolic leaf extract dosed at 400, 2000 and 10000 mg/kg under an OECD 423-informed protocol. No deaths at 400 mg/kg; one animal died at each of 2000 and 10000 mg/kg. Leukocytes rose from 8.54 to 28.40 thousand per microlitre at 2000 mg/kg and alanine aminotransferase from 38.67 to 98.50 U/L at 10000 mg/kg, with minimal sinusoidal dilation at 400 mg/kg and mild to moderate hepatocellular degeneration with steatosis at the higher doses, hepatic architecture otherwise preserved. This is the clearest demonstration that the leaf drug has a dose-dependent hepatic signal rather than being unconditionally benign. A corrigendum to this paper was published in the same journal later that year; the conclusions summarised here are those of the original article.

The first controlled test of the northeast Indian Mising practice of using dried root for fertility regulation. Methanolic root extract at 250 and 500 mg/kg for 21 days in ovary-intact mice, against 17-beta-oestradiol as reference; at 500 mg/kg it produced degenerative ovarian histoarchitecture with significantly more atretic follicles, significantly fewer endometrial glands and disrupted reproductive hormones. GC-MS identified stigmasterol among the constituents, and sterols docked strongly to human oestrogen receptors alpha and beta. Single study, single species, root only.

Two previously undescribed acylated iridoid glycosides were isolated from a 90 percent ethanol extract of the air-dried aerial parts and tested in vivo. The caffeoylated derivative had an antinociceptive ID50 of 53.4 micromoles per kilogram, about half the dose required for aspirin or paracetamol in the same assay. A companion paper from the same group reported paefoetines A and B from the leaves with a comparable ED50 of 49.2 micromoles per kilogram. Together these give the traditional analgesic use a specific chemical basis in the acylated iridoids, though no human analgesic trial exists.

Localised the antidiarrhoeal activity of the herb to the n-butanol fraction, identified ten constituents in it by HPLC-ESI-MS, and confirmed the effect in a mouse diarrhoea model, with EGFR, AKT1 and PIK3CA proposed as targets by network pharmacology. Published under the name Paederia scandens, which is treated as a synonym of Paederia foetida, so the material is the same drug; much of the Chinese pharmacology on this species is indexed under that synonym.