Antidepressant Effect of Tetragonia tetragonoides (Pall.) Kuntze Extract on Serotonin Turnover.

Tetragonia tetragonoides (Pall.) Kuntze (TTK) is a groundcover found along coastal areas of the Korean peninsula. TTK is traditionally used to improve women's health and treat gastrointestinal diseases. Use of herbal medicines in the treatment of mood disorders has recently been suggested as an alternative therapeutic strategy. In the present study, we determined that consumption of TTK extract ameliorated progression of depressive-like symptoms in ovariectomized (OVX) rats and further examined the mechanisms involved, i.e., synthesis, release, and reuptake(s) of serotonin (also known as 5-HT). We assessed the mRNA expression levels of tryptophan hydroxylases (TPH-1 and TPH-2) and serotonin transporter (SERT) as well as the reuptake activity of serotonin in RBL-2H3 cells. We also determined whether or not TTK extract regulates the serum level of serotonin and improves depressive-like symptoms in 0.5, 1, and 2% TTK-fed OVX female rats in a forced swimming test. Our results show that the mRNA levels of TPH-1 and SERT were significantly reduced, whereas the mRNA level of TPH-2 was dose-dependently elevated by TTK (50 and 100 µg/mL) in RBL-2H3 cells. TTK significantly inhibited LPS- (lipopolysaccharide-) induced serotonin uptake in RBL-2H3 cells in a dose-dependent manner. The serum level(s) of serotonin was elevated by 1% and 2% TTK treatment in OVX female rats. Moreover, immobility time in the forced swimming test was reduced by 1% and 2% TTK treatment but not altered by 0.5% TTK treatment in OVX female rats. Taken together, these results indicate that TTK may significantly inhibit depressive-like symptoms due to upregulation of serotonin level(s) and regulation of serotonin reuptake activity. Thus, TTK may exert beneficial effects on depression during pre- or/and postmenopausal periods via modulation of serotonin synthesis and metabolism.

Dangguijihwang-tang and Dangguijakyak-san Prevent Menopausal Symptoms and Dangguijihwang-tang Prevents Articular Cartilage Deterioration in Ovariectomized Obese Rats with Monoiodoacetate-Induced Osteoarthritis.

We investigated whether dangguijakyak-san (DJY) and dangguijihwang-tang (DJH), oriental medicines traditionally used for inflammatory diseases, could prevent and/or delay the progression of postmenopausal symptoms and osteoarthritis in osteoarthritis-induced estrogen-deficient rats. Treated ovariectomized (OVX) rats consumed either 1% DJY or 1% DJH in the diets. Positive-control rats were given 30 µg/kg bw 17ß-estradiol and control rats were given 1% fat as were the normal-control rats. All rats received high-fat diets for 8 weeks. At the 9th week, OVX rats received articular injections of monoiodoacetate (MIA) or saline (normal control) into the right knee. At 3 weeks after MIA injection, DJY reduced visceral-fat mass and improved glucose metabolism by reducing insulin resistance, whereas DJH increased BMD and decreased insulin resistance. DJH improved weight distribution in the right knee and maximum running velocity on a treadmill at days 14 and 21 as much as those of the positive control. TNF-α, IL-1ß, and IL-6 levels in articular cartilage were much higher in the control than the positive control, whereas both DJY and DJH reduced the levels to those of the positive control. The histological analysis assessed articular cartilage damage near the tidemark and proteoglycan loss in the control versus the positive control; DJY and DJH prevented this damage and proteoglycan loss. In conclusion, DJY may provide an effective treatment for improving glucose tolerance, and DJH may be appropriate for preventing osteoarthritis.

Asian Elm tree inner bark prevents articular cartilage deterioration in ovariectomized obese rats with monoiodoacetate-induced osteoarthritis.

OBJECTIVE: We investigated whether long-term consumption of Korean mistletoe or Asian Ulmi cortex would prevent or delay menopausal symptoms and progression of osteoarthritis in estrogen-deficient obese rats. METHODS: Ovariectomized (OVX) rats were provided a 45% fat diet containing either (1) 0.6% lyophilized water extract of Korean mistletoe (KME) + 1.4% dextrose (KME; n = 10), (2) 2% lyophilized water extract of Ulmi cortex (UCE; n = 10), (3) 30 µg/kg bw 17ß-estradiol + 2% dextrose (positive control; n = 10), (4) 2% dextrose (placebo; OVX-control; n = 10), or (5) 2% dextrose (normal-control; n = 10) for 4 weeks. At the beginning of the 5th week, OVX rats, except in the normal-control group, were given articular injections of monoiodoacetate into the right knee and the assigned diets were provided for an additional 3 weeks. The rats in the normal-control had injections of saline into the right knee. RESULTS: KME, but not UCE, partially prevented the insulin resistance and the loss of bone mineral density and lean mass. The limping scores were lower in the descending order of the OVX-control > KME and 17ß-estradiol > UCE > normal-control at day 14 and 21 (P < 0.05). The scores for pain behaviors measured by weight distribution on the right leg, maximum running velocity on a treadmill and locomotive activity, were markedly decreased in the same order as limping scores. Monoiodoacetate increased the expression of matrix metalloprotinase-3 and metalloprotinase-13 in the articular cartilage and elevated the production of inflammatory markers such as tumor necrosis factor-α, interleukin-1ß, and interleukin-6, but they were lower in the UCE than in the other groups (P < 0.05). Histology of the right knee revealed cartilage damage near the tidemark of the knee and proteoglycan loss was markedly less in UCE. CONCLUSIONS: UCE was an effective therapeutic agent for preventing osteoarthritis and KME prevented decreases in lean body mass, bone mineral density, and insulin sensitivity in estrogen-deficient rats.