BACKGROUND: Hyperpigmentation disorders are commonly encountered in dermatology clinics. Botanical and natural ingredients have gained popularity as alternative depigmenting products. OBJECTIVE: We sought to review clinical studies evaluating the use of different natural products in treating hyperpigmentation so clinicians are better equipped to educate their patients. Specific ingredients reviewed include azelaic acid, aloesin, mulberry, licorice extracts, lignin peroxidase, kojic acid, niacinamide, ellagic acid, arbutin, green tea, turmeric, soy, and ascorbic acid. METHODS: Systematic searches of PubMed and SCOPUS databases were performed in March 2016 using the various ingredient names, “melasma”and “hyperpigmentation.” Two reviewers independently screened titles, leading to the selection of 30 clinical studies. RESULTS: Review of the literature revealed few clinical trials that evaluated the treatment of hyperpigmentation with natural ingredients. Despite the limited evidence-based research, several natural ingredients did show efficacy as depigmenting agents, including azelaic acid, soy, lignin peroxidase, ascorbic acid iontophoresis, arbutin, ellagic acid, licorice extracts, niacinamide, and mulberry. CONCLUSION: The aforementioned ingredients show promise as natural treatments for patients with hyperpigmentation disorders. These agents might also provide clinicians and researchers with a way to further characterize the pathogenesis of dyschromia. However, the paucity of clinical studies is certainly a limitation. Additionally, many of the in-vivo studies are limited by the short length of the trials, and questions remain about the long-term efficacy and safety of the ingredients used in these studies. Lastly, we suggest a standardized objective scoring system be implemented in any further comparative studies.
Month: June 2018
The main transporter for biotin is sodium dependent multivitamin transporter (SMVT), which is overexpressed in various aggressive cancer cell lines such as ovarian (OV 2008, ID8), leukemia (L1210FR), mastocytoma (P815), colon (Colo-26), breast (4T1, JC, MMT06056), renal (RENCA, RD0995), and lung (M109) cancer cell lines. Furthermore, its overexpression was found higher to that of folate receptor. Therefore, biotin demand in the rapidly growing tumors is higher than normal tissues. Several biotin conjugated organic molecules has been reported here for selective delivery of the drug in cancer cell. Biotin conjugated molecules are showing higher fold of cytotoxicity in biotin positive cancer cell lines than the normal cell. Nanoparticles and polymer surface modified drugs and biotin mediated cancer theranostic strategy was highlighted in this review. The cytotoxicity and selectivity of the drug in cancer cells has enhanced after biotin conjugation.(Eur J Med Chem. 2018 Feb 10;145:206-223. )
The rise of resistant bacteria has prompted the search for new antimicrobial agents. Antimicrobial membrane lytic peptides have potential as future microbial agents due to their novel mode of action. Recently conjugation of a fatty acid to antimicrobial peptides has been explored as a method to modulate the activity and selectivity of the peptide. Our work further explores these phenomena by testing two peptides, YGAAKKAAKAAKKAAKAA (AKK) and LKKLLKLLKLLKL (LKK), conjugated to fatty acids of varying length for their activity, structure, solution assembly properties and the ability to bind model membranes. We found that increasing the length of fatty acids conjugated to peptide AKK, up to a 16 carbons in length, increases the antimicrobial activity. Peptide AKK appears to lose activity when the minimal active concentration is higher than the critical miscelle concentration (CMC) of the molecule. Thus, if the CMC of the peptide conjugate is too low the activity is lost. Peptide LKK has no activity when conjugated to lauric acid and appears to aggregate at very low concentrations. Conjugation of AKK with a fatty acid increases its affinity to model supported lipid membranes. It appears that the increased hydrophobic interaction imparted by the fatty acid increases the affinity of the peptide to the surface thus increasing its activity. At concentrations above the CMC, solution self-assembly inhibits binding of the peptide to cell membranes.