Diallyl trisulfide regulates rat colonic smooth muscle contractions by inhibiting L-type calcium channel currents

Effects of Thai Local Ingredient Odorants, Litsea cubeba and Garlic Essential Oils, on Brainwaves and Moods

The functional food market is growing with a compound annual growth rate of 7.9%. Thai food recipes use several kinds of herbs. Lemongrass, garlic, and turmeric are ingredients used in Thai curry paste. Essential oils released in the preparation step create the flavor and fragrance of the famous tom yum and massaman dishes. While the biological activities of these ingredients have been investigated, including the antioxidant, anti-inflammatory, and antimicrobial activities, there is still a lack of understanding regarding the responses to the essential oils of these plants. To investigate the effects of essential oil inhalation on the brain and mood responses, electroencephalography was carried out during the non-task resting state, and self-assessment of the mood state was performed. The essential oils were prepared in several dilutions in the range of the supra-threshold level. The results show that Litsea cubeba oil inhalation showed a sedative effect, observed from alpha and beta wave power reductions. The frontal and temporal regions of the brain were involved in the wave alterations. Garlic oil increased the alpha wave power at lower concentrations; however, a sedative effect was also observed at higher concentrations. Lower dilution oil induced changes in the fast alpha activity in the frontal region. The alpha and beta wave powers were decreased with higher dilution oils, particularly in the temporal, parietal, and occipital regions. Both Litsea cubeba and turmeric oils resulted in better positive moods than garlic oil. Garlic oil caused more negative moods than the others. The psychophysiological activities and the related brain functions require further investigation. The knowledge obtained from this study may be used to design functional food products.

Relaxant effect of diallyl sulfide on nonpregnant rat uterus: Involvement of voltage-dependent calcium channels

AIM

We aimed to determine the effect and mechanism of action of diallyl sulfide (DAS), an active component of sulfur-containing foods such as garlic on rat uterine activity.

METHODS

Isometric tension changes in longitudinal uterine strips obtained from 20 female Sprague-Dawley rats (250-300 g) in estrus stage of estrous cycle were studied in isolated organ baths containing Krebs-Henseleit solution.

RESULTS

Diallyl sulfide (10^-8 -10^-6  M) caused a concentration-dependent relaxation on KCl (60 mM)-induced contractions and inhibited spontaneous peristaltic activity of uterine strips (P < 0.05). None of the following antagonists significantly changed the inhibitory effect of DAS on both KCl-precontracted uterine strips and spontaneous peristaltic activity of the uterus (P > 0.05): nitric oxide synthase inhibitor L-NAME (10^-4  M), hydrogen sulfide-producing enzymes cystation β synthase and cystation γ-lyase inhibitors, aminooxyacetic acid (10^-4  M) and propargylglycine (10^-3  M) and nonselective cyclooxygenase inhibitor indomethacin (10^-4  M). However, in calcium-free Krebs solution containing high KCl (30 mM), DAS significantly inhibited CaCl₂ (10^-5 -10^-2  M)-induced uterine contractions in a concentration-dependent manner (P < 0.05).

CONCLUSION

Diallyl sulfide has a relaxing effect on KCl-contracted rat uterus strips and an inhibitory effect on spontaneous uterine activity, possibly by decreasing the calcium influx into the cytoplasm of uterine smooth muscle cells.

Neuroprotective Potential of Allium sativum against Monosodium Glutamate-Induced Excitotoxicity: Impact on Short-Term Memory, Gliosis, and Oxidative Stress

This study evaluated the neuroprotective potential of Allium sativum against monosodium glutamate (MSG)-induced neurotoxicity with respect to its impact on short-term memory in rats. Forty male Wistar albino rats were assigned into four groups. The control group received distilled water. The second group was administered Allium sativum powder (200 mg/kg of body weight) orally for 7 successive days, then was left without treatment until the 30th day. The third group was injected intraperitoneally with MSG (4 g/kg of body weight) for 7 successive days, then left without treatment until the 30th day. The fourth group was injected with MSG in the same manner as the third group and was treated with Allium sativum powder in the same manner as the second group, simultaneously. Phytochemical analysis of Allium sativum powder identified the presence of diallyl disulphide, carvone, diallyl trisulfide, and allyl tetrasulfide. MSG-induced excitotoxicity and cognitive deficit were represented by decreased distance moved and taking a long time to start moving from the center in the open field, as well as lack of curiosity in investigating the novel object and novel arm. Moreover, MSG altered hippocampus structure and increased MDA concentration and protein expression of glial fibrillary acidic protein (GFAP), calretinin, and caspase-3, whereas it decreased superoxide dismutase (SOD) activity and protein expression of Ki-67 in brain tissue. However, Allium sativum powder prevented MSG-induced neurotoxicity and improved short-term memory through enhancing antioxidant activity and reducing lipid peroxidation. In addition, it decreased protein expression of GFAP, calretinin, and caspase-3 and increased protein expression of Ki-67 in brain tissues and retained brain tissue architecture. This study indicated that Allium sativum powder ameliorated MSG-induced neurotoxicity through preventing oxidative stress-induced gliosis and apoptosis of brain tissue in rats.