The evaluation of topical administration of Bellis perennis fraction on circular excision wound healing in Wistar albino rats.

CONTEXT: Bellis perennis L. (Asteraceae) has been used traditionally in the treatment of bruises, broken bones, and wounds by European people. OBJECTIVE: To investigate the wound healing activity of B. perennis flowers in Wistar albino rats. MATERIALS AND METHODS: Dried B. perennis flowers were extracted with ethanol, then fractioned with n-butanol and an oinment was prepared. Twelve male adult Wistar rats were used. Six wounds were created for each animal by using circular excision wound model. The first two wounds were treated topically with HOTBp (hydrophilic ointment treatment containing n-butanol fraction). The second two wounds were control group and not treated with anything. The third two wounds were treated only with HOT (hydrophilic ointment treatment without n-butanol fraction). Treatments were applied once a day and lasted for 30 days. Wound samples were excised on days 5(th), 10(th) and 30(th). The percentage of wound healing was calculated by Walker's formula after measurement of the wound area and the tissue samples were examined histopathologically. RESULTS: The percentages of wound closure (HOTBp: 100%; HOT: 85% and control: 87%) and histopathological observations showed that there were statistically significant differences between HOTBp, HOT and control groups (p < 0.05) at 30(th) day. DISCUSSION AND CONCLUSION: Topically administered ointment prepared from the n-butanol fraction of B. perennis flowers has a wound healing potential without scar formation in circular excision wound model in rats. Thus, traditional usage of wound healing activity of B. perennis was scientifically verified for the first time.

The effects of the intraamygdalar melatonin injections on the anxiety like behavior and the spatial memory performance in male Wistar rats.

In the present study, the effects of intraamygdalar administrations of melatonin (1 and 100µg/kg), saline and diazepam on the anxiety-like behavior and spatial memory performance in pinealectomized and sham-pinealectomized Wistar rats were investigated. The animals were tested by open field and elevated plus maze tests for anxiety-like behavior, and Morris water maze test for spatial memory. In open field, (a) diazepam was more effective in reducing the anxiety, (b) control subjects were more mobile than pinealectomized subjects and (c) 100µg/kg melatonin administrations reduced the velocity of the animals. In elevated plus maze, (a) 100µg/kg melatonin administrations increased the distance totally travelled and (b) enhanced the time spent in open arms, however, after the pinealectomy, 1µg/kg melatonin administrations decreased it and (c) control animals were less mobile than pinealectomized ones. In Morris water maze, (a) diazepam group travelled more distance than the others in control condition whereas, in pinealectomy condition high dose of melatonin and saline groups travelled more distance than the others, (b) in pinealectomy condition subjects who received 100µg/kg melatonin also travelled more distance than those who received 1µg/kg melatonin and diazepam, (c) the subjects who received 1µg/kg spent less time than those who received other treatments, and (d) in control condition subjects who received 100µg/kg melatonin were slower than those who received the other treatments. In conclusion, melatonin administration to amygdala decreased the anxiety; however, spatial memory performance of the rats was impaired by the pinealectomy and melatonin administrations.

Serum leptin levels following acute experimental spinal cord injury.

BACKGROUND/OBJECTIVE: Spinal cord injury influences many hormones that are known to be involved in the modulation of neurotrophic, neurogenic, and neuroprotective events. Recent studies showed that leptin could be neuroprotective, enhancing neuronal survival in vitro and in vivo. The objective of this study was to evaluate the pattern of the serum leptin levels in rats during acute traumatic SCI. METHODS: Forty male Sprague-Dawley rats were divided randomly into 4 groups. In the control group, neither laminectomy nor SCI was performed; only laminectomy was performed without SCI in the sham group. In the cervical and thoracic spinal trauma groups, laminectomies were performed following the same trauma procedure. Blood samples were drawn 2, 6, 12, and 24 hours after the procedures and assayed immediately. RESULTS: In the first 2 hours, levels of leptin were similar in control and sham-operated groups and higher in neurotrauma groups (P < 0.05). At the sixth hour, leptin levels increased in the sham-operated group, decreased in the neurotrauma groups (P < 0.05), and did not change in the control group (P > 0.05). At the 12th hour, the levels of leptin increased in all groups (P > 0.05). At the 24th hour, they decreased in the control, sham-operated, and cervical groups (P < 0.05); levels did not change in the thoracic group (P > 0.05). The decrease was higher in the control group than in the other groups (P < 0.05). CONCLUSIONS: Activation of endogenous leptin secretion started immediately after the SCI. The level of neurologic lesion (either cervical or thoracic regions) affected the levels of serum leptin differently, but with the exception of the first 12-hour period, this difference did not reach a statistically significant level.

Serum cortisol levels following acute experimental spinal cord injury.

BACKGROUND AND PURPOSE: Cortisol has neuroprotective effects. We monitored the serum cortisol levels after cervical and thoracic spinal cord injury (SCI) in four groups of rats. MATERIAL AND METHODS: Forty male Sprague-Dawley rats were randomized to four groups. The control group received neither laminectomy nor SCI. The sham group received laminectomy without SCI. The cervical spinal trauma group received a C5-C6 laminectomy and spinal trauma at this level. The thoracic spinal trauma group received a T6-T7 laminectomy and spinal trauma. Blood samples were drawn 2, 6, 12 and 24 hours after surgeries and assayed immediately. RESULTS: The level of cortisol in the cervical spinal trauma group was highest at the second hour of the experiment and the lowest in control and sham-operated groups at the same time. At the sixth hour, cortisol levels increased in control and sham-operated groups, decreased in the cervical group and did not change in the thoracic group. At the 12th hour, cortisol levels in control and sham-operated groups decreased, but increased in thoracic and cervical groups. At the 24th hour, serum cortisol levels in thoracic and cervical groups decreased but did not change significantly in control and shamoperated animals. CONCLUSIONS: Activation of endogen cortisol secretion of the organism starts immediately after the SCI injury and throughout the experiment the serum cortisol levels in neurotrauma groups remained high compared with the control and sham-operated groups. At the beginning, the level of neurological lesion (cervical or thoracic) affected differently the level of serum cortisol at a statistically significant level but this difference disappeared at the 6th hour.

The effect of pinealectomy and leptin hormone on the proliferation and apoptosis activation in Syrian hamster testis in different photoperiods.

The effects of pinealectomy and leptin hormone on proliferative and apoptotic processes in the epithelia of testicular seminiferous tubules of Syrian hamsters have been investigated. Proliferative and apoptotic processes were assessed semi-quantitatively by proliferating cell nuclear antigen (PCNA) and caspase-3 immune stainings. Animals used in the study were divided into four groups; control, pinealectomy (PinX), leptin-treated (10 microg/mL/day/kg body weight, intraperitoneally) and pinealectomy + leptin groups. Half of the hamsters in each group were exposed to short and the other half to long photoperiods for 8 weeks. In short photoperiod, PCNA activity especially in spermatogonia was significantly higher in the pinealectomy and leptin-treated groups compared with the control group. Histological score (HSCORE) value of PCNA in the PinX + leptin group was lower than those of PinX and leptin-treated groups. HSCORE value of caspase-3 in PinX and PinX + leptin groups was increased. In the long photoperiod, PCNA activation in the PinX group was significantly lower than the control group while the differences between the controls and other groups were not significant. The difference between the increases in caspase-3 activity in the PinX and control groups was significant. Thus, it was observed that photoperiods had no effect on the proliferation activity in the control groups. The inhibiting effect of short photoperiod on testis was not observed throughout 8 weeks. PinX eliminated the inhibiting effect of short photoperiod but did not alter the stimulating effect of long photoperiod. Leptin did not show any effect in long photoperiod but decreased proliferation by stimulating melatonin in short photoperiod.

Effects of European mistletoe (Viscum album L. subsp. album) extracts on activity rhythms of the Syrian hamsters (Mesocricetus auratus).

Antitumor drugs may have some significant nervous system side-effects such as disrupted sleep, eating and drinking patterns. European Mistletoe has been investigated for many decades for its potential use against cancer. To test the hypothesis that the non-antineoplastic effects of mistletoe might be mediated by the actions on the circadian timing system, we have applied mistletoe extracts and vehicle and have measured locomotor activity, feeding and drinking rhythms under constant darkness. Four groups (vehicle, 20 mg kg(-1) ip injection, 40 mg kg(-1) ip injection and 6 g kg(-1) oral administration) were performed for both heat-treated and freeze-dried extracts. None of the administrations changed the locomotor activity, feeding and drinking rhythms in the groups except for 40 mg kg(-1) freeze-dried injected group. The locomotor activity levels decreased in 40 mg kg(-1) freeze-dried extract injected group. These results suggest that, side-effects of mistletoe on circadian timing system of the Syrian hamster depend on the dose and the preparation method of the extract.

Suprachiasmatic nuclei may regulate the rhythm of leptin hormone release in Syrian hamsters (Mesocricetus auratus).

The suprachiasmatic nuclei (SCN) generate the circadian rhythm of many hormones. The hormone leptin is a metabolic signal that informs the brain about fat and energy stores of the body. We investigated whether the rhythm of leptin hormone release in Syrian hamsters is directly controlled by the SCN. Three experiments were performed: in the first, hamsters were SCN-lesioned; in the second, hamsters were exposed to different feeding regimes; and in the third, hamsters were adrenalectomized and implanted with cortisol capsules to maintain constant glucocorticoid release. Blood samples were collected before and after the experiments at different clock times and examined for leptin levels by enzyme-linked immunosorbant assay (ELISA). Different feeding regimes and constant glucocorticoid release did not alter the rhythm of leptin release; whereas, SCN lesions abolished the rhythm. The results of the present study suggest the rhythm in leptin release in Syrian hamsters may be controlled by the SCN.

Effects of photoperiod and food availability on growth, leptin, sexual maturation and maintenance in the Mongolian gerbils (Meriones unguiculatus).

Reproductive activity of Mongolian gerbils is regulated by photoperiod nevertheless body weight regulation is controlled without ambient photoperiod. Food intake is a major factor affecting rodent reproductive efficiency. Leptin is a hormone secreted by adipose tissue and modulates food intake, energy expenditure and body fat stores. In this study we studied the interaction of photoperiod and food availability on growth, sexual maturation and leptin concentration in the male and female gerbils. Gerbils were gestated and reared in either 14L:10D or 2L:22D. At weaning, gerbils were housed individually and divided into three groups: fed ad libitum, fed 80% of ad libitum or fed 60% of ad libitum. Body weights were recorded at weaning and every week thereafter. After twelve weeks of treatment, animals were sacrificed and testes and uterine weights were determined and blood was collected for leptin measurement. Food restriction reduced body weight and inhibited reproductive development. Absolute paired testis weights were similar in ad lib and 80% of ad lib groups but significantly different compared with the 60% of ad lib group in both photoperiods. Body weights were also directly dependent upon the level of food restriction. Uterine mass was only affected in the 60% of ad lib group in 14L but both food restriction levels significantly affected the uterine weights in 2L. Significant variations were found in leptin profiles. Leptin concentration was highest in ad lib and 80% of ad lib groups and lowest in 60% of ad lib groups. These results suggest that the reproductive activity of Mongolian gerbils is sensitive to food intake and multiple potential environmental cues (e.g., food availability, temperature) can be utilized.

Effect of different photoperiods on gonadal maintenance and development in Mongolian gerbils (Meriones unguiculatus).

The role of photoperiod in adult testicular maintenance and body weight and juvenile development was assessed in male Mongolian gerbils (Meriones unguiculatus). Gerbils were raised on a 14L (14 hr of light) photoperiod. In the first study, adult gerbils with functional testes were transferred to thirteen different photoperiods (0L, 2L, 4L, 6L, 8L, 10L, 12L, 14L, 16L, 18L, 20L, 22L, or 24L) and body weights and testicular size were measured every week for 10 weeks. Body weights were similar in all groups. Testicular regression had occurred in animals housed on 0L, 2L, 4L, 6L, 8L, and 24L by week 10. In the second study, 14L-born prepubertal gerbils were transferred to thirteen different photoperiods as in the first study. Body weights and testicular development were examined for 10 weeks. At the end of 10 weeks the body weights of animals in all groups except 24L were similar to those of adults. Animals in 24L had a lower body weight gain. Exposure to 0L, 2L, and 24L inhibited testicular development and testes weights were significantly different from those of the other groups. These results demonstrate that maintenance of body weight in adult gerbils appears to be independent of photoperiodic signal. Exposure to very long (24L) and short photoperiods (< 10 hr) causes testicular regression in adult gerbils. Moreover, different photoperiods experienced in early life can influence prepubertal testis growth and body weight gain.