Toxicity assessment of Lavandula officinalis extracts in Brine Shrimp (Artemia salina).

The toxicity of extracts of lavender (Lavandula officinalis) leaves and flowers was evaluated. Aqueous ethanolic and acetone extracts had higher tannin content than that in the aqueous solution. Polyphenol and flavonoid contents were measured in aqueous extracts of leaves and flowers. Polyphenol concentration in aqueous leaf and flower extracts was 61.31 and 84.43 mg tannic acid/g, respectively, whereas flavonoid concentration was 194.1 and 109.9 mg quercetin/g, respectively. Saponin content was 7.85% and 6.22% in leaves and flowers extract, respectively, and alkaloids content was 0.2651% and 0.2132% for leaves and flowers extract, respectively. The EC50 (36 h) of hatching success of Artemia salina cysts was 0.301 and 0.915 mg/mL for aqueous extracts of leaves and flowers, respectively, whereas that for aqueous ethanolic extracts of leaves and flowers, it was 0.111 and 0.586 mg/mL, respectively. The EC50 (36 h) was 0.011 mg/mL for tannic acid. Additionally, the LC50 (24 h) for aqueous extracts of leaves and flowers was 0.467 and 0.724 mg/mL, respectively, whereas that of the aqueous ethanolic extracts of leaves and flowers was 0.074 and 0.126 mg/mL, respectively. The LC50 was 0.015 mg/mL for tannic acid. Although aromatherapy using lavender oils or extracts is beneficial to human health, particularly owing to its anxiolytic, analgesic, and antihyperlipidemic effects, we demonstrated that these extracts might exhibit toxicity. Hence, lavender should be used carefully by health practitioners, and lavender therapies should be closely monitored by medical staff to avoid its toxic effects.

Chemical composition, antischistosomal and cytotoxic effects of the essential oil of Lavandula angustifolia grown in Southeastern Brazil

This paper reports on the chemical composition, the in vitro antischistosomal effects, and the cytotoxicity of the essential oil from the leaves of Lavandula angustifolia Mill., Lamiaceae, grown in the Southeastern Brazil. Borneol (22.4%), epi-α-muurolol (13.4%), α-bisabolol (13.1%), precocene I (13.0%), and eucalyptol (7.9%) were the major essential oil constituents. Incubation with essential oil at 200 μg/ml killed all the adult S. mansoni worms after 24 h (LC50 117.7 and 103.9 μg/ml at 24 and 120 h of incubation, respectively). At a concentration of 50 μg/ ml, the essential oil significantly decreased the motor activity and reduced the percentage of egg development after 120 h. In addition, the essential oil separated all the coupled S. mansoni worm pairs into individual male and female at 25 and 50 μg/ml within 120 and 24 h, respectively. This oil was cytotoxic to GM07492-A cells at only concentrations higher than 200 µg/ml (IC50 243.7 µg/ml). These data indicate that LA-EO exhibits moderate in vitro activity against adult S. mansoni and exerts remarkable effects on eggs development.