Muscadine Grape Skin Extract

Muscadine Grape Skin Extract (MPX) is a nutritional supplement derived from the skin of muscadine grapes (Vitis rotundifolia), which are indigenous to the southeastern United States and have been cultivated since the 16th century[2][9]. This extract contains several bioactive compounds including ellagic acid, quercetin, and resveratrol, which have demonstrated antioxidant, anti-inflammatory, and potential anticancer properties[1][2]. ## Composition and Formulation MPX is produced by pulverizing muscadine grape skin, typically from the Noble cultivar of Vitis rotundifolia[3]. Each 500 mg capsule of MPX contains approximately 1.2 mg of ellagic acid, 9.2 μg of quercetin, and 4.4 μg of trans-resveratrol[3]. The extract is manufactured through a process where muscadine grapes are pressed and processed according to good manufacturing practices, then dissolved in water, dried, and converted to powder before being encapsulated in vegetable capsules[6]. ## Mechanisms of Action Several mechanisms have been proposed for MPX's potential anticancer effects: 1. **Antioxidant Activity**: The polyphenols in MPX neutralize free radicals, potentially reducing oxidative stress that contributes to cancer development[9]. 2. **Anti-inflammatory Effects**: MPX has demonstrated anti-inflammatory properties that may help reduce cancer-promoting inflammation[6]. 3. **Cell Cycle Regulation**: Studies show MPX can induce cell-cycle arrest in prostate cancer cells, inhibiting their growth[4]. 4. **Apoptosis Induction**: MPX has been shown to downregulate the PI3K-Akt pathway in prostate cancer cell lines, leading to programmed cell death[9]. 5. **Migration Inhibition**: In metastatic prostate cancer cell lines, MPX inhibited cell migration and invasion, potentially reducing metastatic potential[4][9]. ## Clinical Studies MPX has been investigated in several clinical trials: 1. **Phase I Study in Biochemically Recurrent Prostate Cancer**: This study found that MPX at doses up to 4000 mg daily was safe and well-tolerated with no dose-limiting toxicities. An exploratory review suggested a median 5.3-month lengthening in PSA doubling time (PSADT)[2]. 2. **Phase I Study in Advanced Solid Tumors**: Another phase I study in patients with metastatic and unresectable cancers found that muscadine grape extract was safe and well-tolerated, even among patients with poor performance status[9]. 3. **Phase II Study**: A randomized, multicenter, placebo-controlled phase II trial investigated both low dose (500 mg) and high dose (4,000 mg) MPX in patients with biochemically recurrent prostate cancer[2][3]. ## Commercial Availability MPX is commercially available as a dietary supplement under brand names such as MuscadinePlus and Mighty Muscadine[3][8]. It's important to note that as a dietary supplement, MPX is not regulated as a pharmaceutical drug by the FDA. ## Safety Profile Clinical studies have shown that MPX is generally safe and well-tolerated, even at high doses (up to 1600 mg total phenolics/day)[6]. No dose-limiting toxicities were observed in phase I trials[9]. The extract continues to be investigated for its potential therapeutic applications, particularly in prostate cancer and other advanced solid tumors.

Brand names

MuscadinePlusMighty Muscadine

Other names

muscadine grape extract