Cosmeceutical Potential of Mitragyna speciosa (Kratom): Anti-Adipogenic and Antioxidant Properties of Extracts and Mitragynine

Kratom (Mitragyna speciosa (Korth.) Havil.) is a medicinal plant containing bioactive alkaloids, notably mitragynine and 7-hydroxymitragynine, which are psychoactive compounds with analgesic and stimulant properties. Due to safety concerns, the use of Kratom leaves and mitragynine in oral pharmaceutical products is restricted. Therefore, their potential as topical cosmeceutical agents merits further exploration. This study aimed to investigate the antioxidant and anti-adipogenic activities of Kratom ethanolic (Et-MS) and alkaloid-rich (Alk-MS) extracts, as well as purified mitragynine, to determine whether mitragynine is the major bioactive compound responsible for lipid reduction in 3T3-L1 adipocytes. The antioxidant properties were assessed using DPPH, ABTS, and FRAP assays, yielding EC50 values of 0.06 mg/mL, 0.29 mg/mL, and 55 g Fe2+/100 g for Et-MS, respectively. In comparison, ascorbic acid (positive control) showed a DPPH EC50 value of 0.002 mg/mL. Both Alk-MS and mitragynine significantly inhibited lipid accumulation in 3T3-L1 adipocytes by up to 50–70% at non-cytotoxic concentrations (≤25 µg/mL), as determined by Oil Red O staining. These findings provide preliminary in vitro evidence that phenolic constituents contribute to antioxidant capacity, while mitragynine is the principal anti-adipogenic constituent in Kratom extracts. Collectively, the results support the potential for further development of Kratom-derived extracts and mitragynine as plant-based candidates for topical or cosmeceutical applications targeting subcutaneous fat and oxidative skin damage.