The vitality secret of the Inca, maca (Lepidium meyenii) is a treasure from the Peruvian Andes that promotes energy and endurance. New research shows that maca also has efficiency on the skin. Maca contains, among other molecules, macaene and macamides, which are compounds identified by Naturex.
The activity of purified extracts of maca was evaluated, and showed a significant increase of the synthesis of components of the ECM and cell surface receptors that mediate various intracellular signals. Maca helps to reduce the effects of ageing, and gives new strength to the skin.
The vitality secret of the Inca, maca (Lepidium meyenii) is a treasure from the Peruvian Andes that promotes energy and endurance. Featured in worldwide media, this herbaceous plant is gaining popularity for its superior benefits to skin. Maca contains, among other molecules, macaene and macamides, which are compounds identified by NMR by Naturex. New research shows that maca has efficiency on skin. Naturex maca root extract (Macaderm) has been tested in vitro on normal human epidermal keratinocytes (NHEK), the main cells of the epidermis responsible for the synthesis of all the extracellular constituents. In the epidermis, all the cells are linked together and to the constituents of the extracellular matrix (ECM). Adhesion is an important mechanism of cell viability, and it is known that abnormal loss of adhesion leads quickly to apoptosis, cellular death. Cells reside in a protein network, the extracellular matrix (ECM), which they secrete and mold into the intercellular space. The ECM exerts profound control over cells and the effects of the matrix are primarily mediated by integrins, a family of cell surface receptors that attach cells to the matrix and mediate mechanical and chemical signals from it. These signals mediate dynamic linkages between intracellular actin cytoskeleton and the extracellular adhesive matrix. Many integrin signals converge on cell cycle regulation, to proliferate, or to exit the cell cycle and differentiate. Integrins are cell surface transmembrane adhesion receptors that interact with the extracellular matrix (ECM) and mediate various intracellular signals. They define cellular shape, mobility, and regulate the cell cycle. Collagens are proteins found in the ECM in most tissues. Their most notable function is to link all molecules and cellular constituents of the dermis, and store the tension strength. Type IV collagen is an essential component of the ECM, constituent of basement membranes used to promote cell attachment and proliferation. Collagen IV is the most important structural element in the basement membrane. It is a non-fibrous protein, made with 3 ??polypeptidic chains, two ?1 chains and one ?2 chain, which form a bi-dimensional lattice network. This network gives form, rigidity and stability to the membrane. During ageing phenomena, cohesion between the dermis and epidermis and basement membrane decreases, so communication and nutrition of the tissue become more difficult. It is also known that repeated sun exposure breaks down collagen and impairs the synthesis of new collagen. Similarly, the natural ageing process within the skin leads to collagen production slow-down. One of the consequences of these ageing phenomena is the appearance of fine wrinkles.
The aim of these tests was to assess the ability of the maca extract to boost the synthesis of elements of the extracellular matrix (ECM) by keratinocytes and to activate the mechanisms of linkage and stimulation of the cell proliferation. The maca root extract has been tested in vitro on NHEK, on their third culture. The cells were grown on SFM with epidermal growth factor (EGF), and antimicrobial agent. A preliminary cytotoxicity with MTT observation was made to ensure that the dosage of active principles is compatible with living cells. Reference components CaCl2 and retinoic acid were used to control the experimental conditions. An effect related to dosage is tested with maca root extract at 0.008 mg/mL, 0.04 mg/mL and 0.2 mg/mL. All the conditions were made in triplicate, except references were n=6. Using the technique of immunolabelling, the synthesis stimulation of the biomarkers of interest was highlighted. After treatment and incubation, the cell culture medium was removed and the cells washed, fixed, and marked with a primary antibody directed against collagen IV and integrin ?1, the proteins of interest. These antibodies were then linked to a secondary antibody, fluorochrome, which carries a fluorescent probe that can locate and display the desired effect. In parallel, nuclei were coloured by Hoechst reactant (bis-benzimide). Data acquisition was made by image analysis controlled by the InCell Analyzer 100 (GE Healthcare), and results were calculated and expressed against the untreated control, as base 100. Statistical analyses were made possible thanks to large numbers of automatic measurements made by the computer, classifying the results statistically. In this test, CaCl2 increases significantly +23 % the synthesis of collagen IV by NHEK, and retinoic acid has no effect. These two results validate the experimentation. Maca root extract has a significant dose dependant effect: +31% and 32% for concentration at 0.008 mg/mL and 0.04 mg/mL, and an extremely significant increase of collagen IV synthesis at 0.2 mg/mL. Collagen IV is the major macromolecule of the basement membrane between the epidermis and dermis, and this membrane has a major role in the adhesion between epidermis and dermis. The maca root extract applied on keratinocytes at doses between 0.008 mg/mL and 0.2 mg/mL causes a strong increase of the synthesis of collagen IV by the cells. This increased synthesis was quantified at 46%, and the statistical analysis of all measurements shows that the factor p of the student is 0.001 <p<0.01, representing a highly statistically significant result. In the same way, observations were made on the synthesis of adhesion markers, such as integrin ?1, by human keratinocytes. The cell cultures were treated by immunolabelling with a first antibody, then with a second marked by a fluorochrome. In this experiment, reference CaCl2 increases synthesis of integrin ?1, whereas retinoic acid decreases the production of integrin ?1. These results were expected and validate the trial. Measurements made automatically by computer show an increase of 54% of the synthesis of ?1 integrin by keratinocytes. This response is dose effect, with a factor p of the student <0.001, again representing a highly statistically significant result.
All these results demonstrate that the maca root extract significantly stimulates keratinocytes for the synthesis of major components of the extracellular matrix and the basal lamina, collagen IV, and for the synthesis of integrin ?1, essential structure for cells to complete adherence with the ECM. This active is used to place the skin cells under very favourable conditions for a healthy tissue. The maca root extract can be used in preventing the onset of ageing phenomena and it stimulates skin cells to be placed in better communication and nutrition. This extract can also be used for applications that fight the signs of ageing, in awakening mechanisms that have been slowed and boosting protein synthesis and tissular adhesion.