المیرا قاسمی

Scrophularia Striata has been used to treat inflammation, ear and eye infection, skin burn and infectious wounds. This study investigated the effects of hydro-alcoholic extract of Scrophularia striata on second-degree burn. In this experimental study, 21 male Wistar rats (250-300 g) were selected. Then animals randomly divided into control and 3 treatment groups which received olive oil as vehicle or Scrophularia extract with the doses of 2.5 and 5 percent for 21 days. The perimeter and area of the wounds were measured exactly every three days. Finally, tissues samples were collected from burned area for further histological study. Comparison of wound area showed in 5% dose on 6th day (1447.77±41.73), 15th day (885.74±159.35), 18th day (556.52±122.44) (p<0.05) and 21st day (293.12±58.06) (p<0.001) and in 2.5% on 18th day (664.66±123.35), 21st day (398.94±56.00) (p<0.05) significantly different from the control group on 18th (891.98±73.52), on 21st (538.13±55.70) and olive oil group on18th (756.93±96.31) and 21st day (480.69±43.34). Comparison of wound environments showed in 5% dose on 18th day (105.24±13.14) (p<0.01), 21st day (75.06±8.61) (p<0.05) significantly different from the control group on18th day (136.65±4.62), 21st day (104.47±4.86) and olive oil group on 18th day(122.07±12.73), on 21st day (100.76±11.04). Histological study showed ulcer granulation tissue, blood vessels, exudate and collagen significantly increased in both 2.5% and 5% groups. Muscle involvement was significantly decreased in 5% group. The results showed that hydro-alcoholic extract of Scrophularia Striata are effective for burn healing and dose of 5% more effective than 2.5%.

The present study examined the possible role of endogenous opioidergic system in effect of food deprivation on formalin-induced nociceptive behaviors in male and female rats. Also، we investigated the effect of food deprivation on the plasma level of beta-endorphin and sex hormones. Food was withdrawn 48 h prior to performing the formalin test، but water continued to be available ad libitum. The formalin was injected into hind plantar paw. There is significant difference between male and female control rats during phase 2B. Following 48-h food deprivation، both male and female rats exhibited enhanced nociceptive behavior in response to formalin. Food deprivation for 12 and 24 h increased and for 48 h decreased beta-endorphin level in male and female rats. Food deprivation for 24 h decreased testosterone level in male، while it had no significant effect on female rats and food deprivation for 48 h decreased testosterone level in both sexes. Food deprivation for 24 h increased estradiol level in female and that for 48 h had no significant effect on male and female rats. The present study demonstrates the existence of food deprivation for 48 h causes enhancement of nociception in the formalin test in male and female rats that has correlation with decrease in plasma beta-endorphin and testosterone levels.

Electromagnetic waves of cell -phone as an integral part of life make different biological effects.

The purpose of this study was to investigate the effect of cell- phonelike waves on a mouse epilepsy model induced by pentylenetetrazole.

This experimental study was conducted on 75 male mice (weighing 25-30 g) that were divided to 5 groups (n=15). Except for control group، they were exposed to 950 MHz magnetic waves with an antenna power density of 3 or 6 mW/cm2 and modulation of 100 or 217 KHz for a week. Then، 75mg/Kg of pentylenetetrazole was injected intraperitoneally to all mice. Seizure onset، duration of tonic and tonic-clonic seizures and total seizure duration (from start to finish of the seizure) were measured. Data were analyzed by ANOVA and Tukey test.

The seizure onset in treatment groups was not significantly different from control group. The duration of tonic seizures was significantly increased in the group which was exposed to 6 mW/cm2–100 KHz waves (P<0. 01). The duration of tonic-clonic seizures was significantly increased in the group which was exposed to 6 mW/cm2-217 KHz waves (P<0. 05). The total seizures duration was also significantly increased in the groups which were exposed to 6 mW/cm2 and 217 KHz waves (P<0. 01).

Electromagnetic waves of cell phone may increase duration of seizures. In this process، the effect of wave''s power is more than wave''s modulation. It is recommended for those prone to seizure to minimize their exposure to electromagnetic waves.

Stress have bidirectional effects on pain threshold and behaviours. Whereas acute stress often results in analgesia، chronic stress can trigger hyperalgesia/allodynia. The formalin test as an inflammation model، consist of three phases and the effects of repeated forced swim stress with different session numbers on these phases have not been investigated. Therefore، in this study the effects of chronic forced swim stress with different intensities evaluated in formalin test were performed in adult male Wistar rats. In this study، the formalin test (50 μL، 2%) was used to evaluate the effects of repeated swim stress with different duration and sessions on nociceptive responses. Animals were initially submitted to 6 minutes in day with different sessions (3، 5 and 10 days) of forced swim stress and after 24 hours of the last session، animals were submitted to formalin injection in hind paw to evaluate nociceptive behaviours. Exposing animals to 3 days for 6 minutes had an increasing effect on formalin-induced pain behavior only in the final stage of phase 2. This data showed that increase session number of stress have same effect on nociceptive behaviours in termination of phase 2. Moreover increasing exposure to forced swim stress for 5 and 10 sessions effected nociceptive behaviours in interphase. These findings suggest that increase sessions of chronic forced swim stress (3،5 and 10 days) effect on the nociceptive behaviours and significantly increase interphase of the Formalin Test. which could be related to modulating mechanism during this phase

Orexin-A and orexin-B are novel hypothalamic peptides which have a role in the regulation of feeding behaviour and pain modulation. The purpose of this study was to investigate the role of Orexin-A receptor antagonist (SB334867) on the analgesia produced by 12-14 h of food deprivation in rats. This experimental study was performed on 32 Male rats weighing 2 20 -300gr in Qazvin University of Medical Science in 2010. Animals underwent stereotaxic surgery and a guide cannula was inserted into the lateral ventricle of their brai n. One week after surgery، food was withdrawn 12-14 h prior to performing the formalin test، but water continued to be available ad labium. Formalin was injected subcutaneously into the dorsal surface of the right hindpaw and their pain behaviors observed and recorded for 90 minutes. SB334867 or vehicle (5 μ l، icv) were injected 5 min before formalin injection. Data were analyzed by T-test and one way ANOVA. Formalin injection into the right foot caused pain responses in two phases; first phase and second phase were separated with an interphase in which pain behavior was decreased to single and transient responses. 12-14 h starvation reduced pain behavior (analgesia) but Orexin antagonist injection prevent from the reduction of pain behaviors caused by acute food deprivation. The results of this study suggest that the orexinergic system has a role in the modulation of the pain following food deprivation.

Acute and chronic stress induces hormonal and neuronal changes which affect both pain threshold and nociceptive behaviors. But the effect of acute and chronic immobilization stress on formalin induced nociceptive behaviors are unknown. Therefore، this study evaluated the effects of acute and chronic immobilization stress formalin test on the male rat.

In this study، the formalin test (50 μL، 2%) was used to evaluate the effects of acute restraint stress on nociceptive responses. Animals (42) were initially submitted to one session of acute restraint stress (15، 30، 60 min) or chronic restraint stress (10 and 20 days، each day 30 min) and immediately submitted to the formalin injection in hind paw to evaluate nociceptive behaviors.

Acute 60 minutes exposure to restraint stress did not reduce the nociceptive behaviors by chemical stimulation (formalin 2%) of the rats، while 15 minutes exposure to restraint stress reduced formalin induced nociceptive behaviors in phase 2، and 30 minutes exposure to restraint stress reduced formalin induced nociceptive behaviors in phase 1، interphase and phase 2. Chronic restraint stress for 10 and 20 days (each day 30 min) did not increase the stress induced analgesia. These findings suggest that acute exposure to restraint for 30 minutes produce greater decrease in nociceptive behaviors than 15 and 60 minutes.

Acute restraint stress can produce short-term and long-term SIA (Stress Induced Analgesia) for tonic pain. The short-term SIA is reflected as a decreasing in nociceptive behaviors during phase 1، whereas the long-term SIA is reflected as a decrease in nociceptive behaviors during phase 2.

It is known that acute and chronic stress induce hormonal and neuronal changes which affecting both pain threshold and nociceptive behaviours. Orexin plays an important role in modulation of pain and stress. Considering pain modulation during stress and the role of orexin in pain and stress, orexin might be involved in pain modulation during stress.We evaluated the involvement of orexin receptor-1in acute immobilization stress on the tonic pain model. Adult male, Wistar rats (200–300 g), placed in a stereotaxic apparatus and canulla were inserted into their left cerebral ventricle. After 1 week of recovery, animals were initially submitted to one session of acute restraint stress (30 min) and immediately submitted to formalin injection in the hind paw to evaluate nociceptive behaviours. Orexin receptor 1 antagonist (SB 334867) was injected intracerebroventricularly, 5 minute before formalin injection, while the solvent was injected in the control group. two percent formalin produced typical biphasic pain responses in rats that was observed for more than 1 hour. Acute exposure to restraint stress reduced the nociceptive behaviour by chemical stimulation in phase 1, interphase and phase 2. The short-term stress induced analgesia was reflected in a decrease in the nociceptive behaviour during phase 1, whereas the long-term stress induced analgesia was reflected in a decrease in the nociceptive behaviours during phase 2. Pretreatment with orexin receptor 1 antagonist (SB 334867) attenuated the antinociceptive behavioral effect of restraint stress. Our results indicate that orexin receptor 1 antagonist attenuated antinociceptive effect of restraint stress assessed by formalin. These findings show that orexin receptor 1 might mediate an opioid-independent stress-induced analgesia.