This compound was isolated over 100 years ago from the bark of an Indian tree with the name of Myrica. When it was extracted it was mostly utilized as a dye because of the yellowing nature.
Hence these naturally-occurring substances can have pro-oxidant effects under some reaction conditions and cannot be classified simplistically as “antioxidants”.
Anti-Inflammatory - Myrica rubra Sieb. et Zucc. leaves are commonly used in folk medicine to treat inflammatory disorders in China. Present studies on the anti-inflammatory effect of myricetin from Myrica rubra Sieb. et Zucc. leaves was evaluated with various in vivo models of both acute and chronic inflammations such as xylene-induced ear edema, acetic acid-induced vascular permeability, carrageenan-induced paw edema, leukocyte migration assay, and cotton pellet granuloma models.
Concurrently, myricetin also significantly decreased leukocyte count. During chronic inflammation, myricetin inhibited the formation of granuloma tissue. These results, collectively, demonstrate that myricetin possesses a potent anti-inflammatory function on acute and chronic inflammation.
Its anti-inflammatory mechanisms are probably associated with the inhibition of antioxidant activity. These results also support the claims of traditional Chinese medicine practitioners about the use of Myrica rubra Sieb. et Zucc. leaves in the treatment of inflammatory diseases.
Anti-Cancer - Drug combination therapies are common practice in the treatment of cancer. In this study, they evaluated the anticancer effects of myricetin (MYR), methyl eugenol (MEG) and cisplatin (CP) both separately as well as in combination against cervical cancer (HeLa) cells.
To demonstrate whether MYR and MEG enhance the anticancer activity of CP against cervical cancer cells, we treated HeLa cells with MYR and MEG alone or in combination with cisplatin and evaluated cell growth and apoptosis using MTT
The combination treatment also increased the number of cells in G0/G1 phase dramatically as compared to single drug treatment. Mitochondrial membrane potential loss (ΛΨm) as well as Caspase-3 activity was much higher in combination treatment as compared to single drug treatment.
Findings of this investigation suggest that MYR and MEG combined with cisplatin is a potential clinical chemotherapeutic approach in human cervical cancer.
Anti-Diabetes - They report here that after 2 days of treatment with myricetin (3 mg/12 h), hyperglycemia in diabetic rats was reduced by 50% and the hypertriglyceridemia that is often associated with diabetes was normalised. Treatment with myricetin increased hepatic glycogen and glucose-6-phosphate content.
The hypoglycemic effect of myricetin is likely to be due to its effect on glycogen metabolism. There was no indication of serious hepatotoxicity with myricetin treatment and therefore, myricetin could be of therapeutic potential in diabetes.
Increased levels of thiobarbituric acid reactive substances and decreased levels of superoxide dismutase, catalase and reduced glutathione in the heart tissue were observed in animals treated with DOCA, which were reversed by myricetin.
Thus, myricetin shows antihypertensive and antioxidant properties in the DOCA model of hypertension.
Skin Protection - Here, they show that myricetin suppresses UVB-induced cyclooxygenase-2 (COX-2) expression in mouse skin epidermal JB6 P+ cells. The activation of activator protein-1 and nuclear factor-kappaB induced by UVB was dose-dependently inhibited by myricetin treatment.
Western blot and kinase assay data revealed that myricetin inhibited Fyn kinase activity and subsequently attenuated UVB-induced phosphorylation of mitogen-activated protein kinases.
Overall, these results indicated that myricetin exerts potent chemopreventive activity mainly by targeting Fyn in skin carcinogenesis.
Bone Protection - Results indicate that myricetin stimulates osteoblast differentiation at various stages, from maturation to terminally differentiated osteoblasts. Induction of differentiation by myricetin is associated with increased bone morphogenetic protein-2 (BMP-2) production.
The BMP-2 antagonist noggin blocked myricetin-mediated ALP activity and osteocalcin secretion enhancement, indicating that BMP-2 production is required in myricetin-mediated osteoblast maturation and differentiation.
Myricetin increased BMP-2 synthesis, and subsequently activated SMAD1/5/8 and p38 MAPK, and this effect may contribute to its action on the induction of osteoblast maturation and differentiation, followed by an increase of bone mass.
Lifespan Extension (32%) - Myricetin is a naturally occurring flavonol found in many plant based food sources. It increases the lifespan of Caenorhabditis elegans, but the molecular mechanisms are not yet fully understood. We have investigated the impact of this flavonoid on the transcription factors DAF-16 (C. elegans FoxO homologue) and SKN-1 (Nrf2 homologue), which have crucial functions in the regulation of ageing.
Myricetin is rapidly assimilated by the nematode, causes a nuclear translocation of DAF-16 but not of SKN-1, and finally prolongs the mean adult lifespan of C. elegans by 32.9%. The lifespan prolongation was associated with a decrease in the accumulation of reactive oxygen species (ROS) detected by DCF. Myricetin also decreases the formation of lipofuscin, a pigment consisting of highly oxidized and cross-linked proteins that is considered as a biomarker of ageing in diverse species.