Euphorbia resinifera, theresin spurge, is a species ofspurge native toMorocco, where it occurs on the slopes of theAtlas Mountains. The dried latex of the plant was used in ancient medicine. It containsresiniferatoxin, an extremely potentcapsaicin analog tested as ananalgesic since 1997.
It is ashrub growing to 61 centimetres (24 in) tall, forming multi-stemmed cushion-shaped clumps up to 2 metres (6 ft 7 in) wide. The stems are erect,succulent, superficially like acactus, four-angled, with short but sharp pairs of 6-millimetre (0.24 in) spines on the angles, spaced about 1-centimetre (0.39 in) apart up the stem.[2]
Euphorbia resinifera @ the US Botanic Garden (2024 Winter)
Euphorbia resinifera contains a milky fluid or latex, which in its dried form is calledEuphorbium. It has high concentration ofresiniferatoxin, an analog ofcapsaicin, the primary vanilloid compound found in hot peppers. It can interact with avanilloid receptor on primary sensory neurons mediating pain (nociception) and neurogenic inflammation. The pain sensing cation channel isTRPV1.[4] Resiniferatoxin has been used as a starting point in thedevelopment of a novel class ofanalgesics. Desensitization to topical resiniferatoxin has been tested in clinical trials to evaluate its potential to relieve neuropathic pain, as in diabetic polyneuropathy and postherpetic neuralgia.[4] Resiniferatoxin injected subcutaneously into a rat hind paw several minutes before a surgical incision reduced postsurgical pain for 10 days in a NIH study published March 2018.[5] It has been tested to treat pain with advanced cancer.[6]
Resiniferatoxin was isolated in 1975.[4] Euphorbium has been used since at least its first written record from the time of Roman Emperor Augustus.[4]
^abcdAppendino, Giovanni; Szallasi, Arpad (1997). "Euphorbium: Modern research on its active principle, resiniferatoxin, revives an ancient medicine".Life Sciences.60 (10):681–696.doi:10.1016/S0024-3205(96)00567-X.PMID9064473.
