OBJECTIVE: This study aimed to investigate the effect of turmeric (20mg/kg) on learning and memory and cholinergic system in a mouse model of stress along with cholinergic blockade.
METHODS: Restrained stress was induced and cholinergic receptors were blocked using scopolamine in mice. Animals were treated with turmeric (turmeric rhizome powder which was also subjected to NMR analyses) and learning and social behavior was examined. Effect of turmeric on cholinergic muscarinic receptors (mAChR; M1, M3 and M5) gene expression was assessed by RT-PCR in both pre-frontal cortex and hippocampus.
RESULTS: Ar-turmerone, curcuminoids and α-linolenic acid were the lead compounds present in turmeric extract. Increased serum corticosterone levels were observed in stressed mice when compared to the control group, while turmeric treatment significantly reduced serum corticosterone level. Turmeric treatment caused an improved learning and memory in Morris water maze test in stressed animals. Social novelty preference was also restored in turmeric treated animals. Following turmeric treatment, M5 expression was improved in the cortex and M3 expression was improved in the hippocampus of stress + scopolamine + turmeric treated group.
CONCLUSIONS: These findings highlight the therapeutic role of turmeric by increasing the expression of M3, M5 and improving learning and memory. Turmeric can be an effective candidate for the treatment of amnesia caused by the stress.
METHODS: Essential oils obtained by steam distillation were analyzed by gas chromatography-mass spectrometry (GC-MS). The antimicrobial activity of the essential oils was evaluated against four bacteria: Bacillus cereus (B. cereus), Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa); and two fungi: Candida albicans (C. albicans) and Cyptococcus neoformans (C. neoformans), using disc-diffusion and broth microdilution methods.
RESULTS: Cycloisolongifolene, 8,9-dehydro formyl (35.29%) and dihydrocostunolide (22.51%) were the major compounds in C. aeruginosa oil; whereas caryophyllene oxide (18.71%) and caryophyllene (12.69%) were the major compounds in C. mangga oil; and 2,6,9,9-tetramethyl-2,6,10-cycloundecatrien-1-one (60.77%) and α-caryophyllene (23.92%) were abundant in Z. cassumunar oil. The essential oils displayed varying degrees of antimicrobial activity against all tested microorganisms. C. mangga oil had the highest and most broad-spectrum activity by inhibiting all microorganisms tested, with C. neoformans being the most sensitive microorganism by having the lowest minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of 0.1 μL/mL. C. aeruginosa oil showed mild antimicrobial activity, whereas Z. cassumunar had very low or weak activity against the tested microorganisms.
CONCLUSIONS: The preliminary results suggest promising antimicrobial properties of C. mangga and C. aeruginosa, which may be useful for food preservation, pharmaceutical treatment and natural therapies.