Caralluma fimbriata is a succulent plant with a long history of consumption as a vegetable in rural India. It is renowned as a ‘famine food’, and has been used by hunters and other travellers as a portable food and thirst quencher.
The new study, published in Food and Nutrition Sciences, tested the effects of the extract on a pre-fat cells, called pre-adipocytes, and the results suggested that the apparent benefits were related to the doses used: The greater the dose, the better the effect.
The Caralluma fimbriata extract was Slimaluma, provided by Indian company GreenChem. The extract was produced from the aerial plants of the plant using ethanol to obtain a 25 per cent solution of pregnane glycosides.
“The initial phase of our study showed that Caralluma fimbriata extract standardized to pregnane glycosides inhibits proliferation and at high concentrations impairs the viability of 3T3-L1 pre-adipocytes,” wrote the researchers.
“These effects are generally dose- and duration-dependent and the optimal dose is at, or near, 100 micrograms per millitlitre.”
Using pre-adipocytes from mice, the researchers tested different concentrations of a Caralluma fimbriata extract ranging from 20 to 500 micrograms per millilitre.
Results showed that, as the dose and duration of cellular exposure increased, the efficacy of the extract to inhibit growth of the pre-adipocytes increased, but a minimum dose of 100 micrograms per millilitre was required to see an initial effect.
“This is the first report of the antiadipogenic mechanism of action of C. fimbriata,” wrote the researchers.
Health claim wrangle
Caralluma fimbriata has recently been the subject of debate into its efficacy, as in 2010 the European Food Safety Authority (EFSA) gave a negative health claim opinion. The opinions became EU law in May 2011.
However Hong Kong-based Gencor, which made the submission and was involved in the new study, challenged the conclusions of EFSA’s panel as in its initial opinion it said a clinical trial showed no statistical reduction in waistline circumference.
When Gencor pointed out that the trial showed there was, the NDA acknowledged its error and published an amended version of its opinion without changing its verdict that Slimaluma did not demonstrate weight loss.
In September 2010 Gencor managing director RV Venkatesh sent a letter to European Commission’s head of Food Law, Nutrition and Labelling, Basil Mathioudakis, in which he accused the panel of misrepresenting the studies reviewed on Slimaluma.
Despite a ‘thumbs down’ from EFSA’s NDA panel, GreenChem and Gencor continue to invest in research to support the reported benefits of their Caralluma fimbriata extract.
The researchers noted that the extract’s activity may be related to an effect on enzymes in the cell called cyclin-dependent kinases (CDKs), which are involved in cell growth signalling.
“We are investigating this, and are extending this work by studying the impact of CFE on primary mouse pre-adipocytes differentiating in culture, using pure pregnane and metastigmane glycosides,” they concluded.
Source: Food and Nutrition Sciences
2011, Volume 2, Pages 329-336, doi:10.4236/fns.2011.24047
“Effect of Caralluma Fimbriata Extract on 3T3-L1 Pre-Adipocyte Cell Division”
Authors: S. Kamalakkannan, R. Rajendran, R.V. Venkatesh, P. Clayton, M.A. Akbarsha