Extending life has always been a fascinating topic in scientific studies. The idea of our being able to go beyond the expected human life’s years of existence truly interests many researchers. Hence, there are many substances emerged claiming to reverse the natural aging process, and one of them is senolytics. 

Imagine taking a pill that could enable you to live for more years than your expected years of existence – this is the ultimate dream, right? Brace yourselves, as scientists may have found the key to achieving healthy longevity through senolytics. Senolytics are found to be helpful in pushing back the aging process. They can also aid in acquiring age-related health issues, such as osteoarthritis, memory loss, macular degeneration and cancers – you name it, senolytics can probably help! 

Prolonging healthspan

The science of senolytics can tell you all about this area of antiaging medicine. Many gerontologists have studied and suggested the positive results of senolytics when clinically tested on animals, and now, they are embarking on human clinical trials [1]. If human studies on senolytics continue to be successful, we can see a brighter future for longevity. 

Having a longer life can be a good thing, but scientists are not only concerned with this. They are more after healthspan, as well as lifespan, meaning having more quality years of life without having to experience fatal chronic diseases rather than just existing. Healthspan refers to the percentage of your life having good health conditions. This is because it is scientifically believed that healthspan is good for old people and, most especially, for the population and economy [2].

The studies on senolytics purposely try to answer many questions about the possibility of longevity through these substances. Some angles of research include its capability to delay age-related disorders on a cellular level by non-invasive treatments, reduce the signs of aging for people suffering from Alzheimer’s disease and prevent or treat age-related diseases. Well, we still need to look forward to its deep research on human studies before scientists can answer these questions. But the good news is that senolytics show promising results. 

What are senolytics?

Now, let’s dive into the basics – what are senolytics? Basically, senolytics is the term referring to substances found in drugs, plant extracts or peptides. A senolytic compound is a cell-clearing therapies that eradicates senescent cells from the body. Some good sources of senolytics are theaflavins in black tea, dasatinib and quercetin, which is a flavonol found in many plants, like onions, apples or parsley. 

Furthermore, senolytics are considered a class of drugs that help in eliminating senescent cells, and the primary reason why it is a viable way to reverse aging, but more on that later. Senescent cells accumulate with aging and contribute to multiple chronic disorders [3]. 

Senolytics and senescent cells

Senescent cells are your body’s enemy. Senescent cells are irreversible arrests of the proliferation of cells that were first discovered and described in 1960 by Hayflick and his colleagues. They are found to adopt senescence which is associated secretory phenotype (SASP) that continuously secrete proinflammatory factors, such as cytokines and chemokines.

When you age, your body gets more numbers of cells going into senescence; senescent cells are bad for you as they neither divide nor support the tissues of which they are part. Instead, senescent cells just emit a range of possible harmful chemical signals that promote senescence to the nearby healthy cells. 

Senolytic cells send signals through the secretion of pro-inflammatory cytokines, chemokines and extracellular matrix proteases. With all these signals together, they form the senescence-associated secretory phenotype, or called the SASP. Acquiring senescent cells can happen when the immune system fails to diminish or clear these zombie cells or consistent exposure to senescence, inducing stimuli that make more cells than can be cleared in time. 

Having senescent cells can lead you to a chronic inflammatory state in the surrounding tissue microenvironment. This is also referred to as inflammaging, which further promotes senescence in neighbouring healthy cells. Because of the negative effects of cellular senescence, its cells have been the target of active research studies concerning age-related pathologies, either using senolytics or the approach of seno-rejuvenation [4]. 

Normally, senescent cells must destroy themselves through the naturally programmed process called apoptosis. Plus, they are removed by the immune system. However, when both processes fail to function due to the weakening of the immune system through age and increasing numbers of senescent cells escaping – they eventually build up in your body. 

Senescent cells’ presence in your body can cause health problems. Top of the list is they degrade tissue function. Next, they increase the levels of chronic inflammation and raise the risk of you developing cancer. 

How do senolytics work?

You know now that senescent cells cause health problems in your body. So, where do senolytics step in? 

Basically, proper cell regeneration and healthy function of every organ, bone and system within the body are needed to achieve longevity. In a healthy body, cells are constantly in action to undergo the process of dividing, regeneration and replacing new cells and stem cells. Skin cells regenerate every 27 days, which is enough to allow your skin to heal itself from wounds. 

Additionally, blood cell regeneration provides your body the ability to produce blood that lets you donate without having to feel ill afterward. Now, when your body ages, all these healthy functions may be disrupted, and one major reason is because of cellular senescence. 

Senescent cells or zombie cells are not capable of supporting your body’s healthy function because, in the first place, they should not be in your body anymore. Senolytics, when consumed inside the body, are found to target each senescent cell and prevent them from recruiting more healthy cells. They also aid in slowing down the aging process on the cellular level within your body. Thus, senolytics can promote the proper function of tissues and organs within your body [5]. 

Senolytics and age-related diseases

Recent studies confirmed senolytics as a potential substance to treat age-related diseases. It was found that senolytics have benefits to certain aspects of vascular aging, such as improving the aging process and chronic hypercholesterolemia. Hence, senolytics is a possible viable method for reducing morbidity and mortality from heart diseases.

Moreover, senolytics are also found to be helpful in treating atherosclerosis, as they address the foam cells that are a major factor in the disease. In type 2 diabetes, senolytics can aid by removing senescent cells inside the body. If you want to have more youthful skin, senolytics are the answer, as they also slow down skin aging. Osteoporosis patients can also benefit from taking senolytics as they can help in treating the disease. 

The key to effectively use senolytics in fighting off diseases is creating accurate biomarkers to measure the body’s senescent cell numbers in tissue. It should also be combined with cohesive delivery methods for the selective removal of senescent cells. 

Studies on senolytics

To make it more obvious, senolytics and senescent cells are counterparts – senescent cells cause you to age, while senolytics kill or remove them in your body. There are many studies conducted to fully understand the role of senolytics in prolonging healthspan. 

In one animal study in 2021 by Novais et al., it was discovered that long-term administration of senolytic drugs could mitigate mice’s age-dependent intervertebral disc degeneration. The senolytic drugs include dasatinib which is a tyrosine kinase inhibitor, and a naturally occurring flavonoid, quercetin. The mice were given these senolytic drug combinations for two years, and they experienced a decreased incidence of disc degeneration while exhibiting fewer senescent-related biomarkers [6]. 

One of the key researchers in senolytics is the Mayo Clinic in the United States. They first started studying its antiaging potential in 2011 [7], and since then, through their work, senolytics have been in the limelight in antiaging studies. In their 2016 trial, the experiment showed an increase in the lifespan of laboratory mice that were administered senolytics by 17 to 35 percent. 

From there, many scientists turned their attention to targeting senescent cells by any means in treating age-related diseases and reversing aging in general. One of the studies is from the Erasmus University Medical Center in the Netherlands, where the researchers have discovered a peptide that destroys senescent cells without damaging their nearby healthy cells. 

Moreover, one human trial of senolytics was conducted by researchers at the University of Texas San Antonio in collaboration with the Mayo Clinic and Wake Forest School of Medicine. In this big research project, senolytics showed promising results in treating Idiopathic Pulmonary Fibrosis (IPF), which is a type of lung disease as a result of scarring lung tissue. Patients who participated in the trial enhanced their six-minute timed walking distance by an average of 21.5 metres – no current other drug or therapy has shown the same results as senolytics [8]. 

[1] https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(21)00300-7/fulltext 
[2] https://publichealth.wustl.edu/heatlhspan-is-more-important-than-lifespan-so-why-dont-more-people-know-about-it/ 
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7405395/ 
[4] https://www.genengnews.com/insights/senolytics-to-tackle-age-related-pathologies/ 
[5] https://aspireregenerativehealth.com/what-are-senolytics-and-how-they-could-help-you/ 
[6] https://www.nature.com/articles/s41467-021-25453-2 
[7] https://www.nature.com/articles/nature10600 
[8] https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(18)30629-7/fulltext 

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