Summary

  • Chlorophyll a and chlorophyll b are natural, fat-soluble chlorophylls found in plants. (More information)
  • Chlorophyllin is a semi-synthetic mixture of water-soluble sodium copper salts derived from chlorophyll. (More information)
  • Chlorophyllin has been used orally as an internal deodorant and topically in the treatment of slow-healing wounds for more than 50 years without any serious side effects. (More information)
  • Chlorophylls and chlorophyllin form molecular complexes with some chemicals known or suspected to cause cancer, and in doing so, may block carcinogenic effects. Carefully controlled studies have not been undertaken to determine whether a similar mechanism might limit uptake of required nutrients. (More information)
  • Supplementation with chlorophyllin before meals substantially decreased a urinary biomarker of aflatoxin-induced DNA damage in a Chinese population at high risk of liver cancer due to unavoidable, dietary aflatoxin exposure from moldy grains and legumes. (More information)
  • Scientists are hopeful that chlorophyllin supplementation will be helpful in decreasing the risk of liver cancer in high-risk populations with unavoidable, dietary aflatoxin exposure. However, it is not yet known whether chlorophyllin or natural chlorophylls will be useful in the prevention of cancers in people who are not exposed to significant levels of dietary aflatoxin. (More information)

Introduction

Chlorophyll is the pigment that gives plants and algae their green color. Plants use chlorophyll to trap light needed for photosynthesis (1). The basic structure of chlorophyll is a porphyrin ring similar to that of heme in hemoglobin, although the central atom in chlorophyll is magnesium instead of iron. The long hydrocarbon (phytol) tail attached to the porphyrin ring makes chlorophyll fat-soluble and insoluble in water. Two different types of chlorophyll (chlorophyll a and chlorophyll b) are found in plants (Figure 1). The small difference in one of the side chains allows each type of chlorophyll to absorb light at slightly different wavelengths. Chlorophyllin is a semi-synthetic mixture of sodium copper salts derived from chlorophyll (2, 3). During the synthesis of chlorophyllin, the magnesium atom at the center of the ring is replaced with copper and the phytol tail is lost. Unlike natural chlorophyll, chlorophyllin is water-soluble. Although the content of different chlorophyllin mixtures may vary, two compounds commonly found in commercial chlorophyllin mixtures are trisodium copper chlorin e6 and disodium copper chlorin e4 (Figure 2).

Figure 1. Chemical structures of natural chlorophylls: chlorophyll a and chlorophyll b.

Figure 2. Chemcical structures of two compounds found in commercial sodium copper chlorophyllin: trisodium copper chlorin e6 and disodium copper chlorin e4.

Metabolism and Bioavailability

Little is known about the bioavailability and metabolism of chlorophyll or chlorophyllin. The lack of toxicity attributed to chlorophyllin led to the belief that it was poorly absorbed (4). However, significant amounts of copper chlorin e4 were measured in the plasma of humans taking chlorophyllin tablets in a controlled clinical trial, indicating that it is absorbed. More research is needed to understand the bioavailability and metabolism of natural chlorophylls and chlorin compounds in synthetic chlorophyllin.

Biological Activities

Complex formation with other molecules

Chlorophyll and chlorophyllin are able to form tight molecular complexes with certain chemicals known or suspected to cause cancer, including polycyclic aromatic hydrocarbons found in tobacco smoke (5), some heterocyclic amines found in cooked meat (6), and aflatoxin-B1 (7). The binding of chlorophyll or chlorophyllin to these potential carcinogens may interfere with gastrointestinal absorption of potential carcinogens, reducing the amount that reaches susceptible tissues (8). A recently completed study by Linus Pauling Institute investigator Professor George S. Bailey showed that chlorophyllin and chlorophyll were equally effective at blocking uptake of aflatoxin-B1 in humans, using accelerator mass spectrometry to track an ultra-low dose of the carcinogen (C Jubert et al., manuscript submitted).

Antioxidant effects

Chlorophyllin can neutralize several physically relevant oxidants in vitro (9, 10), and limited data from animal studies suggest that chlorophyllin supplementation may decrease oxidative damage induced by chemical carcinogens and radiation (11, 12).

Modification of the metabolism and detoxification of carcinogens

To initiate the development of cancer, some chemicals (procarcinogens) must first be metabolized to active carcinogens that are capable of damaging DNA or other critical molecules in susceptible tissues. Since enzymes in the cytochrome P450 family are required for the activation of some procarcinogens, inhibition of cytochrome P450 enzymes may decrease the risk of some types of chemically induced cancers. In vitro studies indicate that chlorophyllin may decrease the activity of cytochrome P450 enzymes (5, 13). Phase II biotransformation enzymes promote the elimination of potentially harmful toxins and carcinogens from the body. Limited data from animal studies indicate that chlorophyllin may increase the activity of the phase II enzyme, quinone reductase (14).

Therapeutic effects

A recent study showed that human colon cancer cells undergo cell cycle arrest after treatment with chlorophyllin (15). The mechanism involved inhibition of ribonucleotide reductase activity. Ribonucleotide reductase plays a pivotal role in DNA synthesis and repair, and is a target of currently used cancer therapeutic agents, such as hydroxyurea (15). This provides a potential new avenue for chlorophyllin in the clinical setting, sensitizing cancer cells to DNA damaging agents.

Disease Prevention

Aflatoxin-associated liver cancer

Aflatoxin-B1 (AFB1) a liver carcinogen produced by certain species of fungus, is found in moldy grains and legumes, such as corn, peanuts, and soybeans (2, 8). In hot, humid regions of Africa and Asia with improper grain storage facilities, high levels of dietary AFB1 are associated with increased risk of hepatocellular carcinoma. Moreover, the combination of hepatitis B infection and high dietary AFB1 exposure increases the risk of hepatocellular carcinoma still further. In the liver, AFB1 is metabolized to a carcinogen capable of binding DNA and causing mutations. In animal models of AFB1-induced liver cancer, administration of chlorophyllin at the same time as dietary AFB1 exposure significantly reduces AFB1-induced DNA damage in the livers of rainbow trout and rats (16-18), and dose-dependently inhibits the development of liver cancer in trout (19). One rat study found that chlorophyllin did not protect against aflatoxin-induced liver damage when given after tumor initiation (20). In addition, a recent study reported that natural chlorophyll inhibited AFB1-induced liver cancer in the rat (18).

Because of the long time period between AFB1 exposure and the development of cancer in humans, an intervention trial might require as long as 20 years to determine whether chlorophyllin supplementation can reduce the incidence of hepatocellular carcinoma in people exposed to high levels of dietary AFB1. However, a biomarker of AFB1-induced DNA damage (AFB1-N7-guanine) can be measured in the urine, and high urinary levels of AFB1-N7-guanine have been associated with significantly increased risk of developing hepatocellular carcinoma (21). In order to determine whether chlorophyllin could decrease AFB1-induced DNA damage in humans, a randomized, placebo-controlled intervention trial was conducted in 180 adults residing in a region in China where the risk of hepatocellular carcinoma is very high due to unavoidable dietary AFB1 exposure and a high prevalence of chronic hepatitis B infection (22). Participants took either 100 mg of chlorophyllin or a placebo before meals three times daily. After 16 weeks of treatment, urinary levels of AFB1-N7-guanine were 55% lower in those taking chlorophyllin than in those taking the placebo, suggesting that chlorophyllin supplementation before meals can substantially decrease AFB1-induced DNA damage. Although a reduction in hepatocellular carcinoma has not yet been demonstrated in humans taking chlorophyllin, scientists are hopeful that chlorophyllin supplementation will provide some protection to high-risk populations with unavoidable, dietary AFB1 exposure (8).

It is not known whether chlorophyllin will be useful in the prevention of cancers in people who are not exposed to significant levels of dietary AFB1, as is the case for most people living in the US. Many questions remain to be answered regarding the exact mechanisms of cancer prevention by chlorophyllin, the implications for the prevention of other types of cancer, and the potential for natural chlorophylls in the diet to provide cancer protection. Scientists from the Linus Pauling Institute’s Cancer Chemoprotection Program (CCP) are actively pursuing these research questions. 

Therapeutic Uses of Chlorophyllin

Internal deodorant

Observations in the 1940s and 1950s that topical chlorophyllin had deodorizing effects on foul-smelling wounds led clinicians to administer chlorophyllin orally to patients with colostomies and ileostomies in order to control fecal odor (23). While early case reports indicated that chlorophyllin doses of 100-200 mg/day were effective in reducing fecal odor in ostomy patients (24, 25), at least one placebo-controlled trial found that 75 mg of oral chlorophyllin three times daily was no more effective than placebo in decreasing fecal odor assessed by colostomy patients (26). Several case reports have been published indicating that oral chlorophyllin (100-300 mg/day) decreased subjective assessments of urinary and fecal odor in incontinent patients (23, 27). Trimethylaminuria is a hereditary disorder characterized by the excretion of trimethylamine, a compound with a “fishy” or foul odor. A recent study in a small number of Japanese patients with trimethylaminuria found that oral chlorophyllin (60 mg three times daily) for three weeks significantly decreased urinary trimethylamine concentrations (28).

Wound healing

Research in the 1940s indicating that chlorophyllin slowed the growth of certain anaerobic bacteria in the test tube and accelerated the healing of experimental wounds in animals led to the use of topical chlorophyllin solutions and ointments in the treatment of persistent open wounds in humans (29). During the late 1940s and 1950s, a series of largely uncontrolled studies in patients with slow-healing wounds, such as vascular ulcers and pressure (decubitus) ulcers, reported that the application of topical chlorophyllin promoted healing more effectively than other commonly used treatments (30, 31). In the late 1950s, chlorophyllin was added to papain and urea-containing ointments used for the chemical debridement of wounds in order to reduce local inflammation, promote healing, and control odor (23). Chlorophyllin-containing papain/urea ointments are still available in the US by prescription (32). Several studies have reported that such ointments are effective in wound healing (33). Recently, a spray formulation of the papain/urea/chlorophyllin therapy has become available (34).

Sources

Chlorophylls

Chlorophylls are the most abundant pigments in plants. Dark green, leafy vegetables like spinach are rich sources of natural chlorophylls. The chlorophyll contents of selected vegetables are presented in Table 1 (35).

Table 1. Chlorophyll Content of Selected Raw Vegetables
Food Serving Chlorophyll (mg)
Spinach 1 cup 23.7
Parsley ½ cup 19.0
Cress, garden 1 cup 15.6
Green beans 1 cup 8.3
Arugula 1 cup 8.2
Leeks 1 cup 7.7
Endive 1 cup 5.2
Sugar peas 1 cup 4.8
Chinese cabbage 1 cup 4.1

Supplements

Chlorophyll

Green algae like chlorella are often marketed as supplemental sources of chlorophyll. Because natural chlorophyll is not as stable as chlorophyllin and is much more expensive, most over-the-counter chlorophyll supplements actually contain chlorophyllin.

Chlorophyllin

Oral preparations of sodium copper chlorophyllin (also called chlorophyllin copper complex) are available in supplements and as an over-the-counter drug (Derifil) used to reduce odor from colostomies or ileostomies or to reduce fecal odor due to incontinence (36). Sodium copper chlorophyllin may also be used as a color additive in foods, drugs, and cosmetics (37). Oral doses of 100-300 mg/day in three divided doses have been used to control fecal and urinary odor (see Therapeutic Uses of Chlorophyllin).

Safety

Natural chlorophylls are not known to be toxic, and no toxic effects have been attributed to chlorophyllin despite more than 50 years of clinical use in humans (8, 23, 29). When taken orally, chlorophyllin may cause green discoloration of urine or feces, or yellow or black discoloration of the tongue (38). There have also been occasional reports of diarrhea related to oral chlorophyllin use. When applied topically to wounds, chlorophyllin has been reported to cause mild burning or itching in some cases (39). Oral chlorophyllin may result in false positive results on guaiac card tests for occult blood (40). Since the safety of chlorophyll or chlorophyllin supplements has not been tested in pregnant or lactating women, they should be avoided during pregnancy and lactation.


Authors and Reviewers

Originally written in 2004 by:
Jane Higdon, Ph.D.
Linus Pauling Institute
Oregon State University

Updated in December 2005 by:
Jane Higdon, Ph.D.
Linus Pauling Institute
Oregon State University

Updated in June 2009 by:
Victoria J. Drake, Ph.D.
Linus Pauling Institute
Oregon State University

Reviewed in June 2009 by:
Roderick H. Dashwood, Ph.D.
Director, Cancer Chemoprotection Program, Linus Pauling Institute
Professor of Environmental & Molecular Toxicology
Leader, Environmental Mutagenesis & Carcinogenesis Core, Environmental Health Sciences Center
Oregon State University

Copyright 2004-2015  Linus Pauling Institute


References

1.  Matthews CK, van Holde KE. Biochemistry. 2nd ed. Menlo Park: The Benjamin/Cummings Publishing Company; 1996.

2.  Sudakin DL. Dietary aflatoxin exposure and chemoprevention of cancer: a clinical review. J Toxicol Clin Toxicol. 2003;41(2):195-204.  (PubMed)

3.  Dashwood RH. The importance of using pure chemicals in (anti) mutagenicity studies: chlorophyllin as a case in point. Mutat Res. 1997;381(2):283-286.  (PubMed)

4.  Egner PA, Stansbury KH, Snyder EP, Rogers ME, Hintz PA, Kensler TW. Identification and characterization of chlorin e(4) ethyl ester in sera of individuals participating in the chlorophyllin chemoprevention trial. Chem Res Toxicol. 2000;13(9):900-906.  (PubMed)

5.  Tachino N, Guo D, Dashwood WM, Yamane S, Larsen R, Dashwood R. Mechanisms of the in vitro antimutagenic action of chlorophyllin against benzo[a]pyrene: studies of enzyme inhibition, molecular complex formation and degradation of the ultimate carcinogen. Mutat Res. 1994;308(2):191-203.  (PubMed)

6.  Dashwood R, Yamane S, Larsen R. Study of the forces of stabilizing complexes between chlorophylls and heterocyclic amine mutagens. Environ Mol Mutagen. 1996;27(3):211-218.  (PubMed)

7.  Breinholt V, Schimerlik M, Dashwood R, Bailey G. Mechanisms of chlorophyllin anticarcinogenesis against aflatoxin B1: complex formation with the carcinogen. Chem Res Toxicol. 1995;8(4):506-514.  (PubMed)

8.  Egner PA, Munoz A, Kensler TW. Chemoprevention with chlorophyllin in individuals exposed to dietary aflatoxin. Mutat Res. 2003;523-524:209-216.  (PubMed)

9.  Kumar SS, Devasagayam TP, Bhushan B, Verma NC. Scavenging of reactive oxygen species by chlorophyllin: an ESR study. Free Radic Res. 2001;35(5):563-574.  (PubMed)

10.  Kamat JP, Boloor KK, Devasagayam TP. Chlorophyllin as an effective antioxidant against membrane damage in vitro and ex vivo. Biochim Biophys Acta. 2000;1487(2-3):113-127.  (PubMed)

11.  Park KK, Park JH, Jung YJ, Chung WY. Inhibitory effects of chlorophyllin, hemin and tetrakis(4-benzoic acid)porphyrin on oxidative DNA damage and mouse skin inflammation induced by 12-O-tetradecanoylphorbol-13-acetate as a possible anti-tumor promoting mechanism. Mutat Res. 2003;542(1-2):89-97.  (PubMed)

12.  Kumar SS, Shankar B, Sainis KB. Effect of chlorophyllin against oxidative stress in splenic lymphocytes in vitro and in vivo. Biochim Biophys Acta. 2004;1672(2):100-111.  (PubMed)

13.  Yun CH, Jeong HG, Jhoun JW, Guengerich FP. Non-specific inhibition of cytochrome P450 activities by chlorophyllin in human and rat liver microsomes. Carcinogenesis. 1995;16(6):1437-1440.  (PubMed)

14.  Dingley KH, Ubick EA, Chiarappa-Zucca ML, et al. Effect of dietary constituents with chemopreventive potential on adduct formation of a low dose of the heterocyclic amines PhIP and IQ and phase II hepatic enzymes. Nutr Cancer. 2003;46(2):212-221.  (PubMed)

15.  Chimploy K, Diaz GD, Li Q, et al. E2F4 and ribonucleotide reductase mediate S-phase arrest in colon cancer cells treated with chlorophyllin. Int J Cancer. 2009;125(9):2086-94.  (PubMed)

16.  Dashwood RH, Breinholt V, Bailey GS. Chemopreventive properties of chlorophyllin: inhibition of aflatoxin B1 (AFB1)-DNA binding in vivo and anti-mutagenic activity against AFB1 and two heterocyclic amines in the Salmonella mutagenicity assay. Carcinogenesis. 1991;12(5):939-942.  (PubMed)

17.  Kensler TW, Groopman JD, Roebuck BD. Use of aflatoxin adducts as intermediate endpoints to assess the efficacy of chemopreventive interventions in animals and man. Mutat Res. 1998;402(1-2):165-172.  (PubMed)

18.  Simonich MT, Egner PA, Roebuck BD, et al. Natural chlorophyll inhibits aflatoxin B1-induced multi-organ carcinogenesis in the rat. Carcinogenesis. 2007;28(6):1294-1302.  (PubMed)

19.  Breinholt V, Hendricks J, Pereira C, Arbogast D, Bailey G. Dietary chlorophyllin is a potent inhibitor of aflatoxin B1 hepatocarcinogenesis in rainbow trout. Cancer Res. 1995;55(1):57-62.  (PubMed)

20.  Orner GA, Roebuck BD, Dashwood RH, Bailey GS. Post-initiation chlorophyllin exposure does not modulate aflatoxin-induced foci in the liver and colon of rats. J Carcinog. 2006;5:6.  (PubMed)

21.  Qian GS, Ross RK, Yu MC, et al. A follow-up study of urinary markers of aflatoxin exposure and liver cancer risk in Shanghai, People's Republic of China. Cancer Epidemiol Biomarkers Prev. 1994;3(1):3-10.  (PubMed)

22.  Egner PA, Wang JB, Zhu YR, et al. Chlorophyllin intervention reduces aflatoxin-DNA adducts in individuals at high risk for liver cancer. Proc Natl Acad Sci U S A. 2001;98(25):14601-14606.  (PubMed)

23.  Chernomorsky SA, Segelman AB. Biological activities of chlorophyll derivatives. N J Med. 1988;85(8):669-673.  (PubMed)

24.  Siegel LH. The control of ileostomy and colostomy odors. Gastroenterology. 1960;38:634-636.  (PubMed)

25.  Weingarten M, Payson B. Deodorization of colostomies with chlorophyll. Rev Gastroenterol. 1951;18(8):602-604.

26.  Christiansen SB, Byel SR, Stromsted H, Stenderup JK, Eickhoff JH. [Can chlorophyll reduce fecal odor in colostomy patients?]. Ugeskr Laeger. 1989;151(27):1753-1754.  27.  Young RW, Beregi JS, Jr. Use of chlorophyllin in the care of geriatric patients. J Am Geriatr Soc. 1980;28(1):46-47.  (PubMed)

28.  Yamazaki H, Fujieda M, Togashi M, et al. Effects of the dietary supplements, activated charcoal and copper chlorophyllin, on urinary excretion of trimethylamine in Japanese trimethylaminuria patients. Life Sci. 2004;74(22):2739-2747.  (PubMed)

29.  Kephart JC. Chlorophyll derivatives - their chemistry, commercial preparation and uses. Econ Bot. 1955;9:3-38.

30.  Bowers WF. Chlorophyll in wound healing and suppurative disease. Am J Surg. 1947;73:37-50.

31.  Carpenter EB. Clinical experiences with chlorophyll preparations. Am J Surg. 1949;77:167-171.

32.  2004 Physicians' Desk Reference. 58th ed. Stamford: Thomson Health Care, Inc.; 2003.

33.  Smith RG. Enzymatic debriding agents: an evaluation of the medical literature. Ostomy Wound Manage. 2008;54(8):16-34.  (PubMed)

34.  Weir D, Farley KL. Relative delivery efficiency and convenience of spray and ointment formulations of papain/urea/chlorophyllin enzymatic wound therapies. J Wound Ostomy Continence Nurs. 2006;33(5):482-490.  (PubMed)

35.  Bohn T, Walczyk S, Leisibach S, Hurrell RF. Chlorophyll-bound magnesium in commonly consumed vegetables and fruits: relevance to magnesium nutrition. J Food Sci. 2004;69(9):S347-S350.

36.  GPO Access. Electronic Code of Federal Regulations: Miscellaneous Internal Drug Products for Over the Counter Use. [Web page]. Available at http://www.ecfr.gov/cgi-bin/text-idx?SID=fca8520c1cf723314cd462d3596b8682&node=pt21.5.357&rgn=div5. Accessed 2/26/15.

37.  GPO Access. Electronic Code of Federal Regulations: Listing of Color Additives Exempt from Certification [Web page]. http://www.ecfr.gov/cgi-bin/retrieveECFR?gp=&SID=3463c48f55ae08efd099682901bb9500&r=PART&n=pt21.1.73. Accessed 2/26/15.

38.  Hendler SS, Rorvik DR, eds. PDR for Nutritional Supplements. 2nd ed. Montvale: Physicians' Desk Reference, Inc; 2008.

39.  Smith LW. The present status of topical chlorophyll therapy. N Y State J Med. 1955;55(14):2041-2050.  (PubMed)

40.  Gogel HK, Tandberg D, Strickland RG. Substances that interfere with guaiac card tests: implications for gastric aspirate testing. Am J Emerg Med. 1989;7(5):474-480.  (PubMed)