The document discusses research on ricin, a toxin that has long been seen as dangerous. Recent studies debunk the idea that ricin is "good for nothing" and show it can induce hair follicle dystrophy when applied topically, inhibiting hair regrowth. Pilot studies on mice and human hair follicles in culture showed ricin delayed and spars hair regrowth. Toxicology studies found ricin safe in acute and subacute dermal toxicity tests, with no signs of intoxication or changes in bloodwork. The findings suggest ricin may be a promising topical treatment for unwanted hair by inducing follicle dystrophy without harming other skin.
1. Ugly Duckling or a Swan:
Ricin
Is it truly ugly?
or
a swan waiting to be discovered!
2. Preamble
• Ricin: Extensively researched since 1888, and first protein
responsible for the beginning of Immunology.
• For more than a century notoriously known as ‘Good for
Nothing’.
• Recently published (February 2017) research paper at
‘Matters’ debunks the ‘sheer nuisance’ theory around
Ricin.
• Though known to be dermally inactive, Ricin induced hair
follicle dystrophy, not just in lab animals but also in human
hair follicles in culture.
• The scientific findings of this study present a possibility of
creating a new treatment for unwanted hair, an unmet in
need in cosmetic industry.
3. Pilot studies
• The action of ricin and related
protein abrin was examined on
hair follicle (HF) and re-growth
of hair.
• Topical application of ricin
after hair is removed by
waxing, resulted in ‘sparse’
and ‘delayed re-growth’ of
hair.
• Histopathological examination
of untreated (C) HFs show
normal ladder-like pattern (as
indicated by arrowheads) and
ricin treated HFs show
dystrophy in H-E stained
mouse skin.
4. In vivo studies
• Ricin treated hair follicles
showed immediate dystrophic
catagen induction and were
found to be dystrophic.
• The characteristic features of
ricin treated hair follicles
resembled chemotherapy
induced hair follicle dystrophy
such as
• Presence of many ectopic
melanin granules,
• Follicular and hair shaft
distortion and
• Irregular diameter of hair
bulbs
5. Human HF organ culture
• In vitro human hair
follicle organ culture, of
ricin and abrin treated
hair follicles showed;
– inhibition of hair shaft
elongation,
– premature HF
regression,
– hair follicle dystrophy.
Untreated hair follicle
Ricin-treated hair follicles
6. Toxicological studies
• Acute oral toxicity test :
– Ricin (200 μgm/ml) solution was found to be safe at 2000 mg/kg.
– No clinical signs of intoxication were observed
– no mortality observed.
• Acute dermal toxicity test : The Sub acute (14 days) dermal toxicity with ricin (200
μgm/ml) showed
– No mortality at a dose of 2000 mg/kg body weight. All the
– Animals appeared normal and showed no clinical signs of intoxication.
– No change in the food consumption was observed.
• Sub acute dermal toxicity test : The Sub acute (90 days) dermal toxicity studies with
ricin (200 μgm/ml) found to have
– No mortality at a dose of 1000 mg/kg body weight. All the
– Animals appeared normal and showed no clinical signs of intoxication.
– No change in the food consumption was observed.
– No statistically significant difference in the haematology and blood chemistry parameters
• The histopathology of liver, kidney and heart did not show any toxicity
• Ricin was found to be safe for sub-acute dermal test for 90 days for a dose
equivalent to human dose of 160μg/kg dose each.
7. Where are we now?
Observations propose ricin to be a promising
topical candidate for inhibiting growth of hair
follicle by inducing dystrophy without
adversely affecting other skin structures.
• Paper: https://sciencematters.io/articles/201702000001