AIM OF STUDY: To investigate the effect of mitragynine after chronic morphine treatment on cyclic AMP (cAMP) level and mRNA expression of mu-opioid receptor (MOR) in human neuroblastoma SK-N-SH cell.
METHOD AND MATERIALS: Mitragynine was isolated from the Mitragyna speciosa plant using the acid-base extraction method. The cAMP level upon forskolin stimulation in the cells was determined using the Calbiochem(®) Direct Immunoassay Kit. The mRNA expression of the MOR was carried out using quantitative RT-PCR.
RESULT: Cotreatment and pretreatment of morphine and mitragynine significantly reduced the production of cAMP level at a lower concentration of mitragynine while the higher concentration of this compound could lead to the development of tolerance and dependence as shown by the increase of the cAMP level production in foskolin stimulation. In MOR mRNA expression study, cotreatment of morphine with mitragynine significantly reduced the down-regulation of MOR mRNA expression as compared to morphine treatment only.
CONCLUSION: These finding suggest that mitragynine could possibly avoid the tolerance and dependence on chronic morphine treatment by reducing the up-regulation of cAMP level as well as reducing the down-regulation of MOR at a lower concentration of mitragynine.
METHODS: The rats were divided into seven groups according to their pretreatment: an untreated control group, an ulcer control group, a reference control group (20 mg/kg omeprazole), and four experimental groups (50, 100, 200, or 400 mg/kg of extract). Carboxymethyl cellulose was the vehicle for the agents. Prior to the induction of gastric ulcers with absolute ethanol, the rats in each group were pretreated orally. An hour later, the rats were sacrificed, and gastric tissues were collected to evaluate the ulcers and to measure enzymatic activity. The tissues were subjected to histological and immunohistochemical evaluations.
RESULTS: Compared with the extensive mucosal damage in the ulcer control group, gross evaluation revealed a marked protection of the gastric mucosa in the experimental groups, with significantly preserved gastric wall mucus. In these groups, superoxide dismutase and malondialdehyde levels were significantly increased (P < 0.05) and reduced (P < 0.05), respectively. In addition to the histologic analyses (HE and periodic acid-Schiff staining), immunohistochemistry confirmed the protection through the upregulation of Hsp70 and the downregulation of Bax proteins. The gastroprotection of the experimental groups was comparable to that of the reference control medicine omeprazole.
CONCLUSIONS: Our study reports the gastroprotective property of an ethanolic extract of C. olitorius against ethanol-induced gastric mucosal hemorrhagic lesions in rats.
METHODOLOGY: This research was conducted on 1210 noninstitutionalized elderly Malaysian individuals with dementia. The effects of age, ethnicity, educational level, marital status, sex differences, social support, and having a partner on sleep quality were evaluated in the respondents. The multiple logistic regression analysis was used to predict the risk of sleep disturbances among the participants.
RESULTS: Approximately, 41% of the participants experienced sleep disruption. Further findings showed that ethnicity (odds ratio [OR] = 0.62), social support (OR = 1.35), marital status (OR = 2.21), educational level (OR = 0.65), and having a partner (OR = 0.45) significantly affected sleep quality (P < .05). Sex differences and age were unrelated predictors of sleep disturbances (P > .05).
CONCLUSION: It was concluded that social isolation and being single increased sleep disruption among respondents, but having a partner and ethnic non-Malay decreased the rate of sleep problems.