Effects of water-soluble mangosteen extract on cognitive function and neuropsychiatric symptoms in patients with mild to moderate Alzheimer's disease (WECAN-AD): A randomized controlled trial.

Introduction: The water-soluble mangosteen pericarp extract's (WME) effect was investigated in Alzheimer's disease (AD). Methods: The participants received 4 mg/kg/day of WME for 24 weeks (low dose, n = 33), 4 mg/kg/day for 12 weeks and then 8 mg/kg/day for 12 weeks (high dose, n = 33); or a placebo (n = 42). The outcomes were neuropsychiatric test scores, safety, tolerability, and the blood 4-hydroxynonenal level. Results: The proportion of participants who achieved the minimum clinically important difference for the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog; -2.6 points) at 24 weeks was significantly higher in the low-dose group (and a trend in the high-dose group) than in the placebo group. WME appeared safe and well tolerated. At 24 weeks, the 4-hydroxynonenal level declined in both intervention groups. The participants with a 5% reduction in this level showed greater ADAS-Cog improvements. Conclusion: WME is a safe and well-tolerated cognitive enhancer in AD with varying benefits across individuals based on antioxidative response.

Comparison of the biological activity of two different isolates from mangosteen.

OBJECTIVE: Mangosteen has been used in traditional medicine for treatment of many diseases. Recent studies have reported the active constituents isolated from this plant. In this study, purified α-mangostin, a major component and partially purified water-soluble fraction found in fruit pericarps, was carefully isolated, and their biological activity was compared, i.e. antioxidative activity and cytotoxic effect in breast cancer cells: SKBR3. METHODS: Antioxidative activity was determined using the 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) assay and reactive oxygen species (ROS) assay, whereas the cytotoxic effect was evaluated by the MTT assay and morphological changes by fluorescence staining. KEY FINDING: The DPPH scavenging capacities of α-mangostin and water-soluble extract were obtained, the IC50 at 183.95 and 54.57 µg/ml, respectively. Meanwhile, the intracellular ROS level was significantly decreased after treatment with α-mangostin and water-soluble extraction at 20 and 200 µg/ml, respectively. α-mangostin exhibited the cytotoxicity at ED50 8.21 µg/ml, while the water-soluble extract was non-toxic to cells at ED50 higher than 160 µg/ml. Both constituents showed antioxidative activity by chemical assay and in cells, but α-mangostin expressed strong cytotoxicity and showed apoptotic bodies. CONCLUSION: The different isolated constituents would be further studied for future possible use as chemotherapy in cancer and chemoprevention in Alzheimer's disease.

Immunomodulatory activities of alpha-mangostin on peripheral blood mononuclear cells.

Mangosteen (Garcinia mangostana L.) a tropical fruit, has been used in traditional medicine. A frequently used part of mangosteen is the pericarp, containing a high content of xanthones. alpha-Mangostin, one of the major xanthone derivatives, exhibits a variety of actions, including antimicrobial, antioxidant, cytotoxic and antitumor; however, its function on the immune system is still equivocal. This study aimed to examine the immunomodulatory activities of alpha-mangostin on lymphocyte lineage and cytokine production in human peripheral blood mononuclear cells (PBMCs). The cytotoxic activity of alpha-mangostin was measured by MTT assay. The concentration of alpha-mangostin at 5.55 microg/mL resulted in a 50% survival of PBMCs, which was as potent a cytotoxic activity as that of paclitaxel. After 24 h of PBMCs culture, the percentages of T cells (CD3+), B cells (CD19+) and NK cells (CD3-CD16+CD56+) were not significantly changed by treatment with 1, 2 and 4 microg/mL of alpha-mangostin compared with untreated-PBMCs; in addition, the percentages of these lymphocytes treated with the combination of alpha-mangostin (1, 2 and 4 microg/mL) and the mitogen concanavalin A (ConA) was not significantly different from that of ConA-treated PBMCs. For cytokine secretion, alpha-mangostin (1, 2 and 4 microg/mL) did not significantly induce either proinflammatory cytokines (i.e., TNF-alpha and IL-1beta) or cytokine of adaptive immunity (i.e., IL-2). The combination of alpha-mangostin (1, 2 and 4 microg/mL) and ConA did not significantly alter the relative difference of TNF-alpha and IL-1beta compared with ConA-treated PBMCs; however, these combinations could significantly decrease the relative difference of IL-2 compared with ConA-treated PBMCs. These data indicated that alpha-mangostin was able to inhibit IL-2 release without interfering with human immune cells; therefore, further studies are necessary to investigate its effect on IL-2 production.

Protective effects of mangosteen extract on H2O2-induced cytotoxicity in SK-N-SH cells and scopolamine-induced memory impairment in mice.

Mangosteen extracts (ME) contain high levels of polyphenolic compounds and antioxidant activity. Protective effects of ME against ß-amyloid peptide (Aß), induced cytotoxicity have been reported. Here, we further studied the protective effects of ME against oxidative stress induced by hydrogen peroxide (H2O2) and polychlorinated biphenyls (PCBs), and demonstrated the protection against memory impairment in mice. The cytoprotective effects of ME were measured as cell viability and the reduction in ROS activity. In SK-N-SH cell cultures, 200 µg/ml ME could partially antagonize the effects of 150 or 300 µM H2O2 on cell viability, ROS level and caspase-3 activity. At 200, 400 or 800 µg/ml, ME reduced AChE activity of SK-N-SH cells to about 60% of the control. In vivo study, Morris water maze and passive avoidance tests were used to assess the memory of the animals. ME, especially at 100 mg/kg body weight, could improve the animal's memory and also antagonize the effect of scopolamine on memory. The increase in ROS level and caspase-3 activity in the brain of scopolamine-treated mice were antagonized by the ME treatment. The study demonstrated cytoprotective effects of ME against H2O2 and PCB-52 toxicity and having AChE inhibitory effect in cell culture. ME treatment in mice could attenuate scopolamine-induced memory deficit and oxidative stress in brain.