Pain is a common symptom and is important because it gives both signals disease and aids diagnosis. The intensity of pain is poorly correlated with intensity of the nociceptive stimulus. [1]
Azadirachta indica (neem) is a divine tree mainly cultivated in the Indian subcontinent, belonging to the botanical family Meliaceae, commonly known as neem [2, 3] It is a tree 40–50 feet or higher, with a straight trunk and long spreading branches forming a broad round crown; it has rough dark brown bark with wide longitudinal fissures separated by flat ridges. The leaves are compound, imparipinnate, each comprising 5–15 leaflets Fruits are green, turning yellow on ripening, aromatic with garlic like odor. [4, 5]
Neem has been an inherent part of ayurveda since ages; its blood purification property made it a favorite natural ingredient, as a remedy for skin ailments and curing diabetes. [6, 7]
Different parts of neem (leaf, bark, and seeds) have been shown to exhibit wide pharmacological activities such as anti fungal, antibacterial [8], antiviral [9], anti-inflammatory activity [10], anti-carcinogenic activity [11], parasitic disease [12], and skin disease [11] cardioprotective effect [13] neuroprotective effect. [14]
Flowers also yield a waxy material consisting of several fatty acids like arachidic (0.7%), stearic (8.2%), palmitic (13.6%), oleic (6.5%) and linoleic (8.0%). The pollen of neem contains several amino acids like glumatic acid, tyrosine, arginine, methionine, phenylalanine, histidine, arminocaprylic acid and isoleucine. [15, 16]
Experimental Animals
Wister albino male rats (180–220 g) were obtained from the animal house of Department of pharmacy, MJP Rohilkhand University Bareilly, India. The animals were housed at room temperature (22–28 ºC) for 7 days 12 hrs dark and light cycle and given standard laboratory feed and water ad-libitum. There was maintained hygiene environment in our animal house. The study was approved and conducted as per the norms of the Institutional Animal Ethics Committee (CPCSEA).
Plant Material And Extraction
The leaves of azadirachta indica (neem) plant were collected during the april from department of pharmacy, MJP Rohilkhand University, Bareilly India. The plant was authenticated by DR. Alok Shrivastava, Department of Botany and voucher specimen of the plant were preserved at department herbarium library at MJPRU, Bareilly.
The plant leaves were separately washed to remove different impurities and dry in room without sunlight and subsequently reduced to a coarse powder with the help of mixer. Then about 250 gm of the azadirachta indica leaves powder was extracted for 6 hours with 75% ethanol in soxhlet apparatus at temperature 45-550C. The plant extract was filtered, concentrated with a rotary evaporator and dried over a water bath at 45°C. The extract from the plant leaves was used for next process of experiment.
Experimental Design
Healthy Wister albino male rats weighing 180–220 g were used. They were randomized into 6 groups in which each group consist 6 albino rats as follows:-
Group I
administered with normal saline by orally.
Group II
administered with morphine at dose 1mg/kg body weight by i.p. route
Group III
administered with neem leaf extract (NLE) at dose 62.5mg/kg body weight, i.p.
Group IV
administered with neem leaf extract (NLE) at dose 125mg/kg body weight, i.p.
Group V
administered with neem leaf extract (NLE) at dose 250mg/kg body weight, i.p.
Group VI
administered with neem leaf extract (NLE) at dose 500mg/kg body weight, i.p.