TOKYO, Aug. 24, 2021 /PRNewswire/ — In a study recently published in the International Journal of Molecular Sciences, researchers at Juntendo University show that essential oils extracted from the lemon verbena plant can inhibit the growth of skin cancer

Figure 1. Left- A graphical representation of the signaling pathways blocked by ALOC-EO in melanoma cells.  Right- The growth of melanoma cells was suppressed by ALOC-EO treatment when compared to no treatment (ctrl).

Figure 1. Left- A graphical representation of the signaling pathways blocked by ALOC-EO in melanoma cells. Right- The growth of melanoma cells was suppressed by ALOC-EO treatment when compared to no treatment (ctrl).

Melanoma is an aggressive form of skin cancer with a low survival rate. What’s more, patients often become resistant to the currently available forms of chemotherapy and stop responding to treatment. New forms of therapy for melanoma are thus under great scrutiny. In a partnership between Juntendo University and An-Najah National University, a group of researchers have recently shown that oils derived from the lemon verbena (Aloysia citrodora) plant have proved useful in this regard.

Aloysia citrodora essential oils (ALOC-EO) have been shown to possess anticancer properties in breast cancer models. To investigate similar effects in skin cancer the team first employed melanoma cells. When the cells were incubated with ALOC-EO, a suppression in their growth was indeed observed. Now, the growth of melanoma cells depends on an intracellular protein known as ERK1/2. When ERK1/2 was closely inspected it was found to be blocked after ALOC-EO treatment. Similar observations were seen in mouse models of melanoma.

Another critical but fatal feature of melanoma is its ability to move to distant organs within the body. Therefore, the effects of ALOC-EO on the migration of tumors was inspected next. Indeed, cells treated with ALOC-EO showed reduced migratory potential. Molecules that prevent cells from adhering to a surface (thereby enabling them to migrate) were also reduced after ALOC-EO treatment.

A cellular pathway that regulates certain types of melanomas is known as epidermal growth factor receptor (EGFR) signaling. When heparin-binding-epidermal growth factor (HB-EGF), a signaling protein, binds its partner (EGFR) a chain of events is set into motion which ultimately leads to uncontrolled cell growth, the classical cancer feature. However, ALOC-EO was found to obstruct the binding of these partners. The EGFR pathway is also responsible for the resistance that cancer cells develop when treated with chemotherapeutic drugs. Upon exposure to these drugs, melanoma cells stealthily start producing more EGFR and HB-EGF. However, when mice were treated with chemotherapeutic drugs in conjunction with ALOC-EO, this mechanism was negated. ALOC-EO thus not only prevented the growth and spread of skin cancer but also kept drug-resistance developed by melanoma cells in check.

“In summary, our study demonstrates that ALOC-EO blocks EGFR and ERK1/2 signaling, with preclinical efficacy as a monotherapy or in combination with myelosuppressive drugs in melanoma,” conclude the researchers. While these effects still need to be explored further, the use of ALOC-EO might just make the treatment of skin cancer easier. More time for us in the sun, perhaps.”


Melanoma and EGFR signaling: Heparin-binding-epidermal growth factor (HB-EGF) is a protein essential for physiological functions such as wound healing and development of organs. Recent evidence has found the increased presence of HB-EGF and its binding partner, epidermal growth factor receptor (EGFR), in various forms of cancer. The signals initiated by the interlocking of these two molecules are responsible for the uncontrolled growth and movement of cancer cells. HB-EGF and EGFR are present in skin cells, making them an important player in the progression of melanoma.

Given the importance of EGFR signaling in tumor growth, therapeutic agents that specifically target players of this pathway are under investigation for various forms of cancer.


Yousef Salama, Nidal Jaradat, Koichi Hattori, Beate Heissig. Aloysia Citrodora Essential Oil Inhibits Melanoma Cell Growth and Migration by Targeting HB-EGF-EGFR Signaling. International Journal of Molecular Sciences, 22(15), 8151, July 2021.

Mission Statement

The mission of Juntendo University is to strive for advances in society through education, research, and healthcare, guided by the motto “Jin – I exist as you exist” and the principle of “Fudan Zenshin – Continuously Moving Forward”. The spirit of “Jin”, which is the ideal of all those who gather at Juntendo University, entails being kind and considerate of others. The principle of “Fudan Zenshin” conveys the belief of the founders that education and research activities will only flourish in an environment of free competition. Our academic environment enables us to educate outstanding students to become healthcare professionals patients can believe in, scientists capable of innovative discoveries and inventions, and global citizens ready to serve society.

History of Juntendo University

Juntendo was originally founded in 1838 as a Dutch School of Medicine at a time when Western medical education was not yet embedded as a normal part of Japanese society. With the creation of Juntendo, the founders hoped to create a place where people could come together with the shared goal of helping society through the powers of medical education and practices. Their aspirations led to the establishment of Juntendo Hospital, the first private hospital in Japan. Through the years the institution’s experience and perspective as an institution of higher education and a place of clinical practice has enabled Juntendo University to play an integral role in the shaping of Japanese medical education and practices. Along the way the focus of the institution has also expanded, now consisting of six undergraduate programs and three graduate programs, the university specializes in the fields of health science, health and sports science, nursing health care and sciences, and international liberal arts, as well as medicine. Today, Juntendo University continues to pursue innovative approaches to international level education and research with the goal of applying the results to society.

Further information
Juntendo University
2-1-1, Hongo, Bunkyo-ku, Tokyo 113-8421 JAPAN
E-mail: [email protected]



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