Caralluma fimbriata

1.1. Sources and Origin

Caralluma is a widely growing plant in India and is associated with appetite suppression.^[1] The main supplemented herb for appetite suppression is Caralluma adscendens var. fimbriata and commonly referred to as Caralluma Fimbriata, containing both a high amount of and some unique molecules.^[2] The genus Caralluma belongs to the family Apocynaceae and the subfamily of Asclepiadaceae (divided into three subgenera of Boucerosia, Desmidorchis, and Urmalcala;^[3] the family used to be referred to as Asclepiadaceae prior to being merged into Apocynaceae), with over 260 species bearing the name of Caralluma being distributed across Asia and the Mediterranean^[4] and in general the genus is associated with a variety of traditional cure-alls such as the treatment of rheumatism, diabetes, leprosy, paralysis, and inflammation while also possessing antimalarial, antitrypanosomal, anti-ulcer, antioxidant, antinociceptive, and antiproliferative activities.^[4] Visually, Caralluma plants are quadrangular, perennial succulents with small caducous leaves, and are sometimes used for food.^[4]

1.2. Composition

As a herbal compound, Caralluma (the genus in general) contains a variety of bioactives including:

• Pregnane Glycosides^[5][6][2][7] including russeliosides B and C, stalagmoside V, and the caraumbellogenin class; glycosides being based on the skeletal backbones of calogerin, 5alpha-dihydrocalogerin, and boucerin^[7] thought to contribute to appetite suppression^[1] The sum of caraumbelloside I-III and boucerin reaches up to 4% in the whole plant extract without being detected in aerial parts^[8]

• Megastigmane Glycosides^[9]

• Flavonoid Glycosides

• Luteolin and its Glycosides^[9]

• The hydrocarbon pentatriacontane^[4]

• Chromium^[4]

• Beta-sitosterol

The suspected bioactive ingredients are the Pregnane Glycosides (due to the appetite suppressing plant Hoodia having pregnane glycosides as the main ingredient), but the exact glycoside causative of most of the effects is not know; most pregane glycosides from Caralluma share similar structures, however.

2.1. Appetite

One human intervention (n=62 at baseline, 50 completions) on Caralluma ingestion in overweight persons noted that 1g (made from aerial parts of the plant, 40/60 aqueous/ethanolic extract; 12:1 concentrated extract equivalent to 12g dried plant) was able to induce 2.5% weight loss in 60 days whereas placebo induced 1.2% weight loss when both groups were subject to 'standard weight loss through caloric restriction'.^[1] Only waist circumference decreased in a statistically significant manner, while weight and body fat trended towards signifiance with P values of 0.15 and 0.07; respectively.^[1] Final fat loss was 1.2kg in the Caralluma group and 0.2kg in the placebo, and the effects were hypothesized to be through reducing hunger (significant) and the urge to eat (non-significant) with no effect on satiety (feeling of fullness), and Caralluma resulted in a 200kcal deficit while placebo did not, indicating that these effects on fat loss were secondary to compliance to the diet.^[1] This study noted 20% decrease in subjective hunger that was causative for an 8% reduction in food.^[1]

These effects were mimicked in a rat study where Caralluma fimbriata was administrated at 25, 50, and 100mg/kg bodyweight for 90 days in conjunction with an ad libitum (no dietary controls) diet caused dose-dependent reductions in food intake and body weight, with the group fed both Caralluma and an obesogenic diet undereating the control balanced diet (and obesogenic diet without Caralluma eating more than control).^[10] The effects in this study appeared to manifest after 45 days, suggesting that the benefits are not acute (human study was not designed to answer the question as to what the time-related response was).^[10]

Mechanistically, it is not known exactly how Caralluma suppresses appetite. The aforementioned intervention hypothesized it may be through pregnane glycosides acting in a similar manner to steroidal glycosides from Hoodia, and act to increase ATP in the hypothalamus to decrease appetite.^[11]

Preliminary evidence suggests that Caralluma Fimbriata can suppress appetite, in mechanisms similar to Hoodia. The effects may require continued supplementation (and thus acute effects of supplementation may be placebo) if the rat study applies to humans, but not enough evidence exists to be sure

An intervention measuring fasting and postprandial (after meal) blood sugar failed to note any significant differences between placebo and 1g Caralluma over a period of 60 days.^[1]

4.1. Triglycerides and Lipoproteins

One human intervention with 1g Caralluma failed to note any changes with total cholesterol, LDL, HDL, or triglycerides over a period of 60 days.^[1] Previously, a rat study using 25,50, and 100mg/kg over 90 days found that ingestion of Caralluma alongside an obesogenic diet normalized abnormal lipid profiles and leptin levels induced by the abnormal diet, with the best normalization at the 100mg/kg group when measured at 90 days and, vicariously through a reduction in food intake, less artherogenic plaque was formed.^[10]

An unpublished animal study assessing the LD₅₀ of Caralluma (noted in discussion here^[1], Kurpad et al.) failed to note any significant toxicity associated with 5g/kg Caralluma daily.

The one human study on the subject matter using 1g Caralluma daily did not note any side-effects significantly different than placebo.^[1]