Effects of Lactuca sativa extract on exploratory behavior pattern, locomotor activity and anxiety in mice

Lactuca sativa belonging to Asteraceae family is an important leafy vegetable known for its medicinal properties. As per traditional knowledge, it is used in the treatment of insomnia, anxiety, neurosis, dry coughs, rheumatic pain, etc. [1]. The whole plant has also been used for the treatment of stomach problems, to stimulate digestion and to enhance appetite and relieve inflammation [2].The latex from Lactuca sativa contains 15 oxalyl and 8 sulfate conjugates of the guaianolide sesquiterpenelactones, lactucin, deoxylactucin and lactucopicrin [3]. Lettucenin-A is highly antimicrobial [4]. Antioxidant activity of lettuce has been reported to prevent chronic diseases related to oxidative stress such as cancer [5]. Analgesic potency of Lactuca sativa opium extracts has been reported[6].Lactuca sativa gives protection against D-galactose induced oxidative stress and reduces accumulation of lipofuscin granules [7]. However, the leaves of Lactuca sativa has not been thoroughly studied with respect to its anxiolytic properties. Anxiety may be regarded as a particular form of behavioural inhibition that occurs in response to environmental events that are novel. It has been established that there are lot of plant secondary metabolites being employed in the treatment of psychotic disorders especially for anxiety in traditional medicine practice, most of which directly or indirectly affect the central nervous system [8, 9]. Considering the varied important activities reported in traditional system of medicine about Lactuca sativa, it was planned to study the effects of the extract of Lactuca sativa L. leaves on exploratory behaviour pattern, locomotor activity and anxiolytic properties in mice.