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.

Antiplasmodial activity and cytotoxicity of plants used in West African traditional medicine for the treatment of malaria.

Eighteen plants originating from Ivory Coast were selected by ethnobotanical survey as plants commonly used by traditional healers for the treatment of malaria. Extracts of these plants were tested on two strains of Plasmodium falciparum: FcM29-Cameroon (chloroquine-resistant strain) and a Nigerian chloroquine-sensitive strain. The powdered plants were used to prepare three kinds of extracts: by decoction in water, in ethanol (95%) and in pentane. A radioactive micromethod allowed the evaluation of the antiplasmodial in vitro activity of the extracts on P. falciparum. Concentrations inhibiting 50% of the parasite growth (IC50) ranged from 18 microg/ml to more than 500 microg/ml for aqueous and ethanol extracts and from 4.3 microg/ml to more than 500 microg/ml for pentane extracts. Cytotoxicity was estimated on A375 melanoma cells and a cytotoxicity/antiplasmodial index (CAR) was calculated for each extract, ranging from 1 to 10. The pentane extracts of Cola caricaefolia and Uvaria afzelii, which revealed the strongest antiplasmodial activity had CAR values of about 10.

Influence of geography, seasons and pedology on chemical composition and anti-inflammatory activities of essential oils from Lippia multiflora Mold leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Lippia multiflora is a plant with nutritional and pharmaco-therapeutic properties that is native to central and occidental Africa. The potential effects of plants on health are associated with their chemical composition. Therefore, the present study aimed to identify chemical variations in essential oils of Lippia multiflora as a function of geographic origin and time of annual harvest to determine optimal chemical profiles for ethno-pharmacotherapeutic applications. MATERIALS AND METHODS: Experimental plants were cultivated at Abidjan (LPA), Toumodi (LPT) and Bondoukou (LPB). Natural Lippia multiflora seeds were sourced to produce standardized plants over a period of six months. Standard plants (n=40) were re-introduced into natural plots, cultivated for 12 months and leaves were sampled monthly in a standardized fashion. Essentials oils (n=36) were then extracted from these samples by hydro-distillation according to the European Pharmacopoeia and qualitatively and quantitatively analyzed using GC/FID and GC/MS. These data were then analyzed using Principal Component Analysis (PCA). Anti-inflammatory properties were also assessed against activated macrophages in vitro. RESULTS: The results indicated that chemical profiles and essential oil yields vary according to the location where the plants were cultivated. One essential oil chemotype corresponded to the LPA and LPT sites and one corresponded to the LPB site. Statistical analysis of the chemical profiles and monthly evolution of the three sites over a period of one year allowed assessment of variations in composition and the subsequent choice of the optimal harvest time for ethnopharmacological applications. Anti-inflammatory activity apparently correlated with chemical profiles of essential oils and the geographic origins of the plants. CONCLUSION: The optimal harvest time was associated with the maximum yield of pharmacological compounds with the most potential interest for health.

The anise-like odor of Clitocybe odora, Lentinellus cochleatus and Agaricus essettei.

The fruiting bodies of fresh and wild Clitocybe odora, Lentinellus cochleatus and Agaricus essettei were investigated for volatile compounds by gas chromatography-mass spectrometry analysis using hydro-distillation and solvent extraction techniques. The three mushroom species are well known to possess anise odors. The main volatile compounds of the three species were aromatic derivatives. Anise fragrance was due either to a single impact aroma compound, or to mixtures of volatile constituents. p-Anisaldehyde was identified as the key odorous component responsible for the pure anise fragrance of C. odora. p-Anisaldehyde, methyl p-anisate, methyl (Z)-p-methoxycinnamate and methyl (E)-p-methoxycinnamate were responsible for the aniseed smell of L. cochleatus. Benzaldehyde and benzyl alcohol may contribute to the anise-like odor of A. essettei.