---

Background & Objective: Addiction to opiates such as morphine is one of major public health problems. It has been shown that in addicted animals, administration of antioxidant agents such as vitamin C can reduce the withdrawal symptoms (WDS). The aim of this study was to evaluate the preventional effect of grapefruit juice (Citrus Paradisi Macf.) on withdrawal symptoms in rats. Materials & Methods: In this experimental study, Sixteen male Wistar rats (250-300g) randomly divided into two groups (n=8). All animals were addicted by intraperitoneal (i.p) injection of morphine (the 1-3 days: 10 mg/kg, the 4-6 days: 20 mg/kg and the 7-9 days 40 mg/kg daily) for 9 days. The first group received 2 ml Citrus Paradisi Macf. orally 1 hour before morphine administration. The sham group received 2 ml of normal saline. Naloxone (10mg/kg, s.c) was administrated 45 minutes after of an additional dose of morphine (40 mg/kg) in the tenth day for withdrawal symptoms inducing. Then withdrawal symptoms such as frequency of wet-dog shaking, teeth chattering, defecation and penis licking were evaluated for 30 minutes. Results: All withdrawal symptoms including frequency of wet-dog shaking, teeth chattering, defecation and penis licking were reduced in the Citrus Paradisi Macf. group in comparison with the sham group significantly (p<0.05). Conclusion: Our results showed that presumably antioxidant activity of Citrus Paradisi Macf. can reduce withdrawal symptoms. Although the exact mechanisms of its effect in brain need to be elucidate.

---

Background and Objective: Alzheimer's disease is an age-related disease that is characterized by dementia and loss of neurons in the brain. It has been shown that brain oxidative stress plays an important role in aging and neurodegenerative disorders. This study was done to evaluate the effect of grape seed extract (GSE) on memory impairment induced by intracerebroventricular (ICV) injection of streptozotocin (STZ) in animal model of Alzheimer's disease.

Methods: In this experimental study, Eighty adult male Wistar rats were randomly allocated into control, sham, grape seed extract (100 mg/kg/bw, 30 days, orally) plus STZ and STZ plus grape seed extract. Animals memory were evaluated using Morris water maze, shuttle box and T maze tests.

Results: Intracerebroventricular injection of STZ caused memory corruption in all tests. Administration of GSE before and after of administration of intracerebroventricular STZ in the Morris water maze test, significantly reduced latency to get to the hidden platform compared to Alzheimer's group (P<0.05). The latency to enter the dark compartment in passive avoidance memory test significantly increased in compare to animal model of Alzheimer's disease (P<0.05). The selection of the right arm of the T-maze test in animals that received grape seed extract before and after of STZ injection significantly increased compared to animal model of Alzheimer's disease(P<0.05).

Conclusion: Grape seed extract has important effect in prevention and improving memory impairment induced by intracerebventricular injection of STZ.