BLACK TEA: AN IMMUNOMODULATOR HELPS TO FIGHT AGAINST CANCER

BLACK TEA: AN IMMUNOMODULATOR HELPS TO FIGHT AGAINST CANCER

By Habiba Majeed

Image: https://freshtea.com/black-tea/

Cancer that is said to be the worst scourge of civilized mankind is the leading cause of deaths all across the globe. Looking at deaths, 9.6 million people have died due to cancer alone, in 2018 according to GLOBOCAN report. Not many know that one of the major cancer-causing agents or carcinogens is Arsenic, the metalloid that is widely distributed in the earth’s crust. When mixed with water inorganic arsenic, at the levels above the WHO provisional guideline value of 10 ug/L can be extremely malignant. In the list of hazardous substances, the United States’ Agency for Toxic Substances and Disease Registry (ATSDR) ranked arsenic as number ONE. 

Ingestion of arsenic is a global catastrophe and millions of people are affected through it, particularly in the under-developed world. Inorganic arsenic, one of the two forms of arsenic and a metalloid is found in abundance in groundwater in many parts of the world, including Argentina, Bangladesh, Pakistan, Chile, China, India, Mexico, and the United States of America can lead to a plethora of health hazards. 

In 2017, Joel Podgorski, an environmental scientist at the Swiss Federal Institute of Aquatic Science and Technology led a study for the estimation of arsenic levels in groundwater samples, collected from 1200 wells throughout Pakistan. Almost 66% of the samples were reported to exceed the WHO provisional guideline value of 10 ug/L. Further, high concentrations of arsenic were reported along the Indus River valley, practically over 200 ug/L. It was then estimated that roughly 50 million to 60 million individuals will be influenced by groundwater within the area at risk, with problem areas around Lahore and Hyderabad.

According to a review article, Punjab and Sindh remained worst hit by arsenic contamination. Results showed that over 3% of the population in Punjab was drinking water with over 50 ug/L arsenic in water and 20% of the population is exposed to over 10 ug/L, as per the gauges set by the World Health Organization. The situation in the Sindh province was more awful than in Punjab, the outcomes demonstrated that 16% of the population was consuming arsenic-contaminated water with over 50 ug/L arsenic in it and about 36% of the Sindh populace was exposed to over 10 ug/L arsenic in their drinking water, which is very alarming.

Why exactly arsenic is such a global threat?

It is so because arsenic is the number one potential causative agent of cancer. International Agency of Research on Cancer (IARC) has classified arsenic and inorganic arsenic compounds as “carcinogenic to humans.” This is based on sufficient evidence in humans that these compounds can cause lung cancer, bladder cancer, and skin cancer. IARC also notes links in some studies to kidney cancer, liver cancer, and prostate cancer. 

Inorganic arsenic is a known inducer of reactive oxygen species (ROS), which in turn triggers several events promoting carcinogenesis. Most of the arsenic compounds are readily absorbed from the gastrointestinal tract. These inorganic forms are capable of the generation of ROS, leading to DNA, protein, and lipid damage. Oxidative stress of arsenic is due to the production of free radicals like superoxide and hydrogen peroxide. Skin shows the first signs of long term exposure to the arsenic, indicating arsenic toxicity via a change in skin pigmentation, appearance of skin lesions, and hard patches on the palms and soles of the feet.

 

Image: https://www.atsdr.cdc.gov/csem/csem.asp?csem=1&po=11

Since there is no specific treatment for chronic arsenicosis yet; therefore stopping the further intake of arsenic-contaminated water and drinking arsenic-free water can help combat arsenic issues.

For short and long term solutions for prevention of arsenicosis, WHO suggests a few solutions. 

• High-arsenic sources should be substituted with low-arsenic sources, such as the substitution of groundwater with microbiologically safe sources such as rainwater and treated surface water.
• Low-arsenic water can be blended with higher-arsenic water to achieve an acceptable arsenic concentration level.
• Arsenic removal systems should be installed domestically to ensure the appropriate disposal of the removed arsenic.

But there is still room for a better course of action. So, it has become an absolute necessity to find a safe, effective, and affordable treatment of arsenic toxicity.

Black tea- as an immunomodulator

In recent research conducted by Ravi Kiran and his colleagues from India, the effect of Black Tea- Camellia sinensis on the mitigation of cancer via Model Analysis was seen. This study included the effects of black tea on tumor growth as well as how the variable influx of immune cells facilitated the immunomodulatory role of black tea. The study also revolved around how black tea and tumor cells interacted, how black tea and immune cells facilitated each other evidently, and beneficial effects of black tea were also seen through suppression of tumor cells and strengthening of immune cells. 

 

Image: https://freshtea.com/black-tea/

Black tea, the most popular beverage around the globe is already known for its excellent antioxidant activity. One active compound present in tea, particularly tea polyphenols, can directly or indirectly scavenge ROS to reduce oncogenesis.

But black tea has more to it. Black tea also acts as an immunomodulator- that has the potential to modulate the immune system either boost it or brings the ratio of different immune cells back to balance and enables the immune system to function correctly. Thus, employing black tea as an immunomodulator in immunotherapy can help reinforce the patients' immune response to work against the growth of cancer cells. 

 This study also included the effects of black tea on tumor growth as well as how the variable influx of immune cells facilitated the immunomodulatory role of black tea. The study also revolved around how black tea and tumor cells interacted, how black tea and immune cells facilitated each other evidently, and beneficial effects of black tea was also seen through suppression of tumor cells and strengthening of immune cells. 

Black tea keeps the tumor population below a certain threshold

While the perfect cure for cancer is still not possible, it is achievable to provide a good and prolonged life. One way to achieve that is by keeping the tumor cells always under control and lower than the normal cell population. This can be achieved by extensive chemotherapy, but the price is paid in the form of painful side-effects. Starting with a small tumor population, and supplementing the system with the immunomodulatory effects of black tea, it was observed that the tumor population can be kept below a certain threshold for a longer amount of time.

Black tea as a side accomplice to chemotherapeutic drugs

It was also shown that black tea can also be a side accomplice to chemotherapeutic drugs in chemotherapy- because chemotherapeutic drugs not only destroy the cancer cells but they also lower the body’s immune response, therefore, a combination of chemotherapy with an immune stimulatory agent such as black tea might be a promising regimen to treat cancer. It may be able to dispense with the chemotherapy. 

Delay in the differentiation of tumor cells

In another result, it showed that when black tea was employed in the system consisting of tumor cells and normal cells, the delay was observed in the differentiation of tumor cells. Due to this, the competition of normal cells and tumor cells also experienced some lag. 

Effect of arsenic and black tea on the variable influx model

The variable influx model constructed by researchers in this study depicted that when a system with tumor cells are added with immunity alone, the pronounced effects of the variable influx of immune cells are immediately observed and the tumor population comes down while increasing the normal cell population. Cancer-causing arsenic is added to the system, and the tumor population raised and decreasing the normal population. This is because arsenic converts a fraction of normal cells into tumorous. When black tea is introduced into the system in the form of drugs; it boosts the immune cells and decreases the growth of tumor cells.

Conclusion

Researchers have written down a model for the growth of cancer cells under the exposure of an environmental carcinogen and a mitigating agent. The immunomodulators regulate the immune function of the normal physiological process and also tries to maintain a healthy immune response in altered physiological conditions. Black tea, which has been studied extensively in the literature, is used as an immunomodulator to curb the side effects of traditional chemotherapeutic treatments. Black tea has mitigating effects on cancer growth via ROS reduction. The beneficial effect of black tea is seen through the suppression of tumor cells and strengthening of the immune cells, and it has no known adverse effects on the normal cells, unlike chemotherapy.

Author and Editor

Habiba Majeed, BS biotechnology (final semester), is very enthusiastic about writing and has written this article. This article was reviewed and edited by Muhammad Numan.

References: Some are given as internal links within the article and remaining references are enlisted here. 

World Health Organization. (2018). Latest global cancer data: Cancer burden rises to 18.1 million new cases and 9.6 million cancer deaths in 2018. International Agency for Research on Cancer. Geneva: World Health Organization.

Kiran, R., Tyagi, S., Abbas, S., Roy, M., & Taraphder, A. (2020). Immunomodulatory role of black tea in the mitigation of cancer induced by inorganic arsenic. arXiv preprint arXiv:2005.13489.

Fatmi, N., Fatima, N., Shahzada, M., Sharma, S., & Kumar, R. (2017). Effect of Aqueous Extracts of Green Tea in Arsenic induced Toxicity in Mice. Open Journal of Plant Science, 2(1), 001–014.

Sinha, D., Dey, S., Bhattacharya, R. K., & Roy, M. (2007). In vitro mitigation of arsenic toxicity by tea polyphenols in human lymphocytes. Journal of Environmental Pathology, Toxicology and Oncology, 26(3). 

Arsenic. (2018, February 15). Retrieved May 29, 2020, from https://www.who.int/news-room/fact-sheets/detail/arsenic