Variation of chemical composition of essential oils in wild populations of Thymus algeriensis Boiss. et Reut., a North African endemic Species

<p>Abstract</p> <p>Background</p> <p><it>Thymus algeriensis </it>is an endemic aromatic plant to Tunisia largely used in folk medicine and as a culinary herb. The bulks aromatic plants come from wild populations whose essential oils compositions as well as their biological properties are severely affected by the geographical location and the phase of the plant development. Therefore, the aim of the present work is to provide more information on the variation of essential oil composition of <it>T. algeriensis </it>collected during the vegetative and the flowering phases and from eight different geographical regions. Besides, influence of population location and phenological stage on yield and metal chelating activity of essential oils is also assessed.</p> <p>Methods</p> <p>The essential oil composition of <it>Thymus algeriensis </it>was determined mainly by GC/FID and GC/MS. The chemical differentiation among populations performed on all compounds was assessed by linear discriminate analysis and cluster analysis based on Euclidean distance.</p> <p>Results</p> <p>A total of 71 compounds, representing 88.99 to 99.76% of the total oil, were identified. A significant effect of the population location on the chemical composition variability of <it>T. algeriensis </it>oil was observed. Only 18 out of 71 compounds showed a statistically significant variation among population locations and phenological stages. Chemical differentiation among populations was high. Minor compounds play an important role to distinguish between chemical groups. Five chemotypes according to the major compounds have been distinguished. Chemotypes distribution is linked to the population location and not to bioclimate, indicating that local selective environmental factors acted on the chemotype diversity.</p> <p>Conclusions</p> <p>The major compounds at the species level were α-pinene (7.41-13.94%), 1,8-cineole (7.55-22.07%), <it>cis</it>-sabinene hydrate (0.10-12.95%), camphor (6.8-19.93%), 4-terpineol (1.55-11.86%), terpenyl acetate (0-14.92%) and viridiflorol (0-11.49%). Based on major compounds, the populations were represented by (α-pinene/1,8-cineole/<it>cis</it>-sabinene hydrate/camphor/viridiflorol), (1,8-cineole/camphor/terpenyl acetate), (α-pinene/1,8-cineole/camphor), (1,8-cineole/camphor/4-terpineol) and (α-pinene/1,8-cineole/<it>cis</it>-sabinene hydrate/camphor/4-terpineol) chemotypes. Variation of phenological stage did not have a statistically significant effect on the yield and metal chelating activity of the essential oil. These results can be used to investigate the geographical location and the harvesting time of this plant for relevant industries.</p

The cruciferous Diplotaxis simplex: Phytochemistry analysis and its protective effect on liver and kidney toxicities, and lipid profile disorders in alloxan-induced diabetic rats

Abstract Background Type 2 diabetes mellitus is a prevalent systemic disease affecting an important proportion of the population worldwide. It has been suggested that excessive reactive oxygen species generation and therefore development of an oxidative stress status is a key factor leading to diabetic complications. Accordingly, it seems that medicinal plants can offer a wide range of new antidiabetic drugs. Diplotaxis simplex (Viv.) Spreng. (Brassicaceae) is an edible plant largely distributed in the Mediterranean region. D. simplex flowers display important in vitro antioxidant potential and inhibitory activity of the α-glucosidase, a key enzyme linked to type 2 diabetes mellitus. In this paper, the antihyperglycemic potential of D. simplex flowers on diabetic rats were investigated. Methods Bioactive substances were determined by liquid chromatography-high resolution electrospray ionization mass spectrometry (LC-HRESIMS) analysis. Animals were divided into four groups of six rats each: a normal control group, a diabetic control group, a diabetic group receiving flowers extract (200 mg/kg body mass) and a diabetic group receiving acarbose (10 mg/kg body mass) as standard drug. Results Many glycosides of rhamnetin, isorhamnetin, quercetin and kaempferol compounds were identified in the ethanolic flowers extract. Alloxan induced hyperglycemia, manifested by a significant (p < 0.05) increase in the blood glucose level as well as in serum α-amylase activity. Furthermore, diabetic rats exhibited oxidative stress, as evidenced by a decrease in antioxidant enzymes activities and an increase in lipid peroxidation level of the pancreas, liver and kidneys. Interestingly, the oral administration of D. simplex flowers extract during 30 days restored the glycemia, α-amylase activity, serum lipid profile and antioxidant enzymes. Moreover, the flowers extract exhibited a renal protective role by decreasing the urea and creatinine levels in diabetic rats serum. Conclusions D. simplex flowers contained bioactive compounds that possess important antioxidant and hypoglycemic properties and protected pancreas, liver and kidneys against hyperglycemia damage

Microstructure and characteristic properties of dogfish skin gelatin gels prepared by freeze/spray-drying methods

International audienceThe effects of two pretreatments (microwaves or oven-drying) on the dogfish (Squalus acanthias) skin as well as two drying processes (freeze-drying or spray-drying) on the extracted gelatins were studied. Thus six types of gelatins were obtained, three of which were freeze-dried (FG) and the others were spray-dried (SG), from the untreated skin (US), microwaves-pretreated skin (MS) and oven-pretreated skin (OS). The highest yield (8.67%) was obtained for the OSFG, while the lowest one (3.06%) was measured for the OSSG. Interestingly, all gelatins exhibited relatively high protein (84.02-89.53%), and low lipid (0.50-1.71%) and ash (3.05-7.17%) contents. In addition, gelatins were analyzed by the Fourier transform infrared and the spectra displayed important differences in some specific peaks, particularly in the amide I, amide II and amide III. The gelatins extracted from the untreated skin, regardless the drying method, presented the highest foaming capacity. The textural profile analysis showed that USSG was the hardest (213.6 g) and the chewier (23.8 N × mm) gelatin. Moreover, analysis of thermal properties showed that USSG also has the highest glass-transition temperature. The interesting properties of gelatin extracted from dogfish skin encourage their future use as a functional ingredient in industrial food formulations

The effects of agar addition and ultrasound treatment on thermomechanical and physical properties of smooth hound (Mustellus mustellus) skin gelatin film

International audienc