Researchers in Japan have been exploring the benefits of dozens of botanicals for potential effects on the health of human skin, focussing particularly on an extract of lotus germ — the embryo within the seed — which they hope may be used in cosmetics and skincare products.
Commonly found in east Asia, the lotus is an aquatic plant, easily recognized by its large white or pink flowers and floating leaves. It has featured in art and traditional medicine for thousands of years, and different parts of the plant have been explored by modern scientists for their potential medical uses ranging from improving liver health1 to treating Alzheimer’s disease2.
A recent in vitro study exploring how lotus germ extract affects skin cells was led by Takushi Namba, a pharmaceutical researcher at Kochi University, working with researchers at Maruzen Pharmaceuticals, in Hiroshima, Japan.
Maruzen Pharmaceuticals began extracting licorice roots in the 1930s and has developed its own extraction techniques. Since then, the company has been working to identify and create ingredients derived from a wide range of botanicals for use in foods and cosmetics.
Skin and ageing
Namba has been interested in making scientific discoveries related to health since he was a child. From an early age, he struggled with asthma, which caused him to be hospitalized while his friends were attending classes and playing sport. While in hospital, Namba was inspired by the kindness and care of his doctors, and decided he wanted to understand what made people healthy.
Several decades later, as a young researcher, he studied the treatment of cancer, liver fibrosis and inflammatory bowel disease, and he realized how many diseases share a common factor — ageing.
“Ageing is the common base, and the onset for many diseases,” he explains.
Ageing is highly complex and not fully understood, but there are known impacts on intra-cellular processes. Autophagy, for example, is the process by which cells break down parts that are no longer useful — such as spent proteins — and recycles or disposes of them.
This clearing-out process keeps a cell healthy and ‘young’. But as cells age, autophagy becomes less efficient, detritus accumulates within the cell, and its function is affected. In human skin, one of the consequences of this is a loss of firmness and youthful-looking appearance.
Understanding skin health and how it is impacted by ageing, has become a key research focus for Namba.
The health of our skin is important because it affects how we think about ourselves, he says: “When see our faces, we feel good if our skin looks good. How we feel about ourselves also affects our overall health”.
This is why collaborating with researchers at Maruzen Pharmaceuticals — a relationship which began in 2019 — was a natural fit for Namba. Together the scientists set out on a quest to look for plant extracts that might have applications related to improving the health of skin, and slowing the ageing process.
Botanicals and skincare
Together the researchers have now explored the effects of extracts from 75 different plants on ageing skin cells in the laboratory. These plants include gingko and Centella asiatica which is often called ‘Cica’ in skincare products. Extracts derived from these botanicals have previously been studied for effects related to skin health, but one material in particular stood out.
“Lotus germ extract was superior compared to all the other botanicals in our tests3,” says Hiroyasu Iwahashi, a researcher with Maruzen Pharmaceuticals.
In order to explore whether the plant extracts slowed cellular ageing in vitro, the researchers aged human skin fibroblasts by proliferation and replication repeatedly over a 60–70 day period.
Fibroblast cells are found in skin, tendons and other connective tissue, and among their many roles in the body, they secrete collagen. As the test cells aged, their proteins and organelles, such as the mitochondria, became progressively disordered and the secretion of collagen slowed down, says Namba, following the trajectory of the normal ageing process within the body.
But, in their experiments in the lab, the researchers found that lotus germ extract increased autophagy in cells, restimulating their ability to clear out unnecessary proteins, via the so-called DAPK1-Beclin1 signalling pathway, which is involved in regulating autophagy.
The extract also appeared to help the cell restore mitochondrial function and restimulate collagen production. As a result, the extract reduced the expression of the senescence marker ‘senescence-associated β-galactosidase’3.
Protecting nature
In addition to their focus on skin care, Maruzen Pharmaceuticals and Namba are committed to creating sustainable processes and products.
Maruzen Pharmaceuticals is pursuing ways to maximize the potential of botanicals, from the time of harvest to the processing conditions and extraction methods.
“We take a lot from nature,” says Iwahashi. “We want to give back to nature as well.” This means also minimizing waste all the way through the manufacturing process. “We use the waste generated by extracting ingredients from botanicals, and we send it back to our own farms to use as compost to grow new plants,” he adds.
The researchers are now continuing their journey to explore plants for extracts that may affect the health of human skin.
