Lespedeza capitata

Lespedeza capitata is also known as round bush clover and belongs to the Fabaceae family. It is native to eastern North America, including eastern Canada and the eastern half of the United States. The plant has many medicinal properties and was used as a treatment for rheumatoid, as an anecdote for poison. The leaves and the stems were routinely used to make tea. Several species of Lespedeza were studied with reference to their significance in human health in general, skin health, and the circadian cycle.1

Circadian rhythm is the body’s natural sleep-wake cycle that plays an important role in health and well-being. A set of genes called circadian clock genes involved in this cycle are switched on and off, the implications of which have been known and proven to affect overall health including skin health. Each cell, the organ has its own circadian cycle and collectively forms a global rhythm. This global rhythm is regulated by the brain, but the skin, specifically each cell, possesses its own internal clock governing major biological responses following this 24-hour rhythm.2,Figure 1

Four genes are implicated in circadian rhythm: B-mal, Per, Cry, and Clock. But their expression can be altered by external factors. Stress including physical, mental, intense lifestyle, extended and unusual work hours, shift working hours, jet lag or even prolonged exposure to blue light via devices, etc cause disruption of circadian clock which leads to dysregulation of skin’s circadian rhythm.3,4 A dysregulated circadian rhythm affects the skin’s well-being, which shows signs of fatigue. Genes that should be expressed in the morning (Per/Cry) are no longer well expressed, and the same happens to evening genes (Bmal-1/Clock): the rhythm is dysregulated. Figure 2 This phenomenon weakens many biological functions of the skin resulting in tired and dull-looking skin. Factors affected by circadian variations are transepidermal water loss, keratinocyte proliferation, skin blood flow, and skin temperature, etc. Transepidermal water loss is higher in the nighttime, skin permeability and absorption are higher in the evening than in the morning. A good night skincare regimen with functional ingredients that can sync with the internal circadian clock will help in the repair and healing of the skin.5,6

Figure 1: Different physiological activities in a 24 our circadian cycle.

Figure 2: Circadian cycle showing the expression of circadian genes and the physiological response of the body.

Figure 3: Ageing and Circadian rhythm. Left side of teh picture depicts the changes happening in a normal sleep cycle pattern and the right side of the figure shows the changes that would happen when we do not sleep at right time, when exposed to blue lights etc. 9

While 25 percent of skin aging can be attributed to genetics, 75 percent is influenced by epigenetics, or environmental and lifestyle factors like sleep. These factors disrupt the sleep-wake cycle leading to dull and damaged skin. Lespedeza extract aids to mitigate this effect and brings back the balance in the sleep-wake cycle. 7

Lespedeza extract has demonstrated its efficacy to resynchronize the rhythm of Bmal-1, Per, and Cry circadian genes on a unique model of synchronized skin exposed to blue light as a stress factor to deregulate its circadian rhythm. As a consequence, it also demonstrated its efficiency in regulating key biological functions such as aquaporin 3 and Nrf2 pathway, known to follow a circadian rhythm. Invitro experiments using Lespedeza extract have proven that blue light damages the skin and that Lespedeza extract is effective in countering the damage caused due to the blue light and other stress inducers which dysregulates circadian rhythm. The skin looked radiant with an improved complexion and enhanced biorhythms and antioxidant activity. 6 With the ability to aid in balancing the dysregulated circadian rhythm resulting due to stress inducers such as lack of recommended hours of sleep, lespedeza extract might facilitate the healing, repair, and rejuvenation of the skin in a normal process which otherwise would have got dysregulated as well. 7,8

References

  1. Biological activities of the legume crops Melilotus officinalis and Lespedeza capitata for skincare and pharmaceutical applications. Giulia et al. Industrial crops and products, Volume 96, February 2017, Pages 158-16.
  2. Circadian Rhythm and the Skin: A Review of the Alexis B. Lyons etal. TJ Clin Aesthet Dermatol. 2019;12(9):42–45.
  3. Circadian rhythms in the skin and other elastic Michael J Sherrat etal. Matrix Biol, 2019 Nov;84:97-110.
  4. Blue light disrupts the circadian rhythm and creates damage in skin K Dong etal. Int J Cosmet Scin 2019 Dec;41(6):558-562.
  5. The circadian clock in skin: implications for adult stem cells, tissue regeneration, cancer, aging, and Maksim V. Plikus etal. J Biol Rhythms. 2015 June ; 30(3): 163–182.
  6. Skin, Reactive Oxygen Species, and Circadian Clocks. Mary A. Ndiaye Antioxidants and Redox Signaling, Volume 20, Number 18, 2014.
  7. Compositions comprising Lespedeza plant US 20200281845A1, Sep 10, 2020.
  8. PER, a Circadian Clock Component, Mediates the Suppression of MMP-1 Expression in HaCaT Keratinocytes by Miji Yeom et al, Molecules 2018, 23, 745; frontiersin.org.