Effects of Nigella sativa seeds (black cumin) on insulin secretion and lipid profile: A pilot study in healthy volunteers.

It has been claimed that Nigella sativa seeds (NSS), also known as black cumin, have antidiabetic and lipid-lowering properties. Our pilot study investigated the effects of powdered NSS on insulin secretion and lipid profile in healthy male volunteers. We conducted a double-blind, randomized, placebo-controlled 4-week trial in 30 subjects, receiving NSS powder (1 g/day) or placebo orally (15 subjects/group). Insulin secretion as determined by the hyperglycaemic clamp technique, insulin sensitivity as well as cholesterol and triglycerides serum concentrations, were measured before and after treatment. NSS powder administration was clinically well tolerated. It did not modify fasting glycaemia and insulinaemia, and was ineffective on glucose-induced insulin secretion and insulin sensitivity. No significant changes on serum lipids were observed after treatment in any treatment groups, nor between the two treatment groups. However, in the treated group only, there was a significant correlation between total cholesterol change after treatment and its baseline level (r = -0.71, P = 0.006, n = 13), and between low-density lipoprotein (LDL) cholesterol change after treatment and its baseline level (r = -0.74, P = 0.004, n = 13). No such correlations were found for high-density lipoprotein (HDL) cholesterol, and for triglycerides. These results do not confirm any NSS effect on glucose regulation; however, they suggest that NSS powder may be of interest in lowering lipid concentrations in hyperlipidaemic subjects.

Premature pubarche in Mediterranean girls: high prevalence of heterozygous CYP21 mutation carriers.

AIM: This study investigated the prevalence and consequences of heterozygous CYP21A2 mutations in premature pubarche (PP) girls. MAIN FINDING: We investigated 36 French Mediterranean girls with isolated PP. We performed synacthen testing with 17OHP and 21-deoxycortisol evaluation, along with molecular analysis of the CYP21A2 gene in girls with abnormal elevation of one of these two adrenal steroids. Three girls (8.3%) had nonclassical adrenal hyperplasia, secondary to compound heterozygosity that associated at least one severe mutation for the three girls. A heterozygous mutation of the CYP21A2 gene was confirmed by molecular biology in eight girls (22%); a deletion of the CYP21A2 gene was found in one of them. Biological hyperandrogenism was found in the prepubertal CYP21A2 mutation carriers, whereas the four heterozygous girls who were followed long enough to have reached pubertal age presented biological and clinical hyperandrogenism. CONCLUSIONS: We underline the high prevalence of heterozygous CYP21A2 mutations in girls with PP and demonstrate the usefulness of systematic screening by synacthen testing, both to improve their future clinical management and to prevent the transmission of classical adrenal hyperplasia to future offspring. Because of the severe metabolic and cardiovascular consequences of hyperandrogenism, long-term follow-up of these heterozygous patients is mandatory.