The blossoming flower of Plumbago zeylanica Linn.
Plumbago zeylanica Linn., or known as daun encok, in Bahasa Indonesia, is an African wild bush that can grow near a river, and highlands up to 800 m asl. Plumbago zeylanica has been used as folk medicine, in Ayurveda, and Traditional Chinese Medicine (TCM). Plumbago zeylanica is believed to be originated from Sri Lanka. (Sentra Informasi IPTEK)
Plumbago zeylanica is also known by many common names, such as, Ceylon leadwort, doctorbush, white flowered leadwort (English), chitrakmool, citrak, agni, chitra, chitraka (India, Pakistan), bama (Balinese), ki encok (Sundanese), godong encok (Javanese), kareka (Maduranese), ceraka (Sumatera), and oporie (Timor Leste).
Several studies have indicated that plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone), compounds isolated from the roots of Plumbago zeylanica, possess antifertility, anticancer, antidiabetic, anti-bacterial, and anti-inflammatory activities. Moreover, plumbagin have been proven to possess anti-tumor activity both, in vitro, and in vivo.
The roots of Plumbago zeylanica have been used in Ayurveda for more than 2500 years ago, as an anti-atherogenic (helps manage healthy cholesterol, and triglyceride levels), cardiotonic (a cardiac stimulant, which acts as a stimulant of the heart), hepatoprotective (an antihepatotoxicity, the ability to prevent damage to the liver), and neuroprotective (the ability to exert a destructive, or poisonous effect upon nerve tissue) agent.
Plumbagin and Leukemia
An in vivo study by Institute of Hematology, Beijing, China, was aimed to investigate the anticancer effect of plumbagin, using human promyelocytic leukemia (a cancer of the blood forming tissue) cells, NB4, in NOD/SCID (Non Obese Diabetic/ Severe Combined Immunodeficiency) mice. The study was observed the incidence of formation, growth characteristics, body weight, and volume of tumors.
The results showed that intraperitoneal injection (IP injection, the injection of a substance into the peritoneum, or body cavity)of plumbagin (2mg/kg body weight) daily, for three weeks, resulted to a 64.49% reduction of tumor volume.
Moreover, there was no side effects, such as, weight loss, tissue damage, and behavior change, which appeared in doxorubicin (adriamycin, a chemotherapy drug given to treat many different types of cancer) treated mice. The results indicated that plumbagin has potential as a novel therapeutic agent for myeloid leukemia. (Xu KH, et al. 2010)
Plumbagin and Gastric Cancer
A study which aimed to investigate the effects of plumbagin, on human gastric cancer cells (SGC-7901, MKN-28, and AGS), had resulted that 10 μmol/L of plumbagin managed to controll the expression of NF-κB gene products, including IAP1 (Inhibitor of Apoptosis Protein 1), XIAP (X-linked Inhibitor of Apoptosis Protein), Bcl-2 (B-cell lymphoma 2), Bcl-xL (B cell lymphoma extra long), TF (Tumor Factor), and VEGF (Vascular Endothelial Growth Factor).
The study concluded that plumbagin managed to inhibit cell growth, and have potentially apoptosis, in human gastric cancer cells, through the NF-κB pathway. (Li J, et al. 2012)
Plumbagin and Skin Cancer
Two types of skin cancer are basal cell carcinoma, and squamous cell carcinoma. Squamous cell carcinoma may occur in normal skin, or in skin that has been injured, or inflamed. A study at University of Wisconsin, Madison, WI, USA, presented the application of non toxic doses (100-500 nmol) of plumbagin, which managed to inhibit the development of squamous cell carcinomas, in ultraviolet radiation induced mice.
During the period of the experiment, mice were gained weight and did not exhibit any signs of toxicity. The study suggested that plumbagin may be used as a novel agent for the prevention of skin cancer. (Sand JM, et al. 2012)
Plumbagin and Pancreatic Cancer
Pancreatic cancer is the most aggressive malignant disease, in which became the fourth most leading cause of cancer related death among men, and women, in the United States. Another study at University of Wisconsin, demonstrated the effect of plumbagin against pancreatic cancer cells (PANC1, BxPC3 and ASPC1) in mouse model.
The IP injection of plumbagin (2 mg/kg body weight), for 5 days, in SCID mice, which began three days after the implantation of PANC1 cells, had resulted in a significant inhibition of both tumor weight, and volume. The study suggested that plumbagin, which had shown to inhibit the growth of pancreatic cancer cells, both in vitro, and in vivo model systems, may be used as a novel therapeutic agent against human pancreatic cancer. (Hafeez BB, et al. 2012)
Plumbagin and Prostate Cancer
Recent study by Bilal Bin Hafeez, which was indexed in PubMed, seven months later, after the previous study, presented that plumbagin inhibits growth, and metastasis of human prostate cancer (PC-3M-luciferase cells) in mouse model. The study suggested that plumbagin could be used as a therapeutic agent for the prevention, and treatment of human prostate cancer, because managed to inhibits tumor growth, and metastasis of human prostate cancer, PC3-M-luciferase cells. (Hafeez BB, et al. 2013)
Plumbagin and Lung Cancer
Recent study at Nanjing Medical University, Nanjing, China, had demonstrated the effects of plumbagin on proliferation (rapid reproduction of a cell, part, or organism), and apoptosis (the process of programmed cell death, or death of a cell in any form), in human non small cell lung cancer cell lines (A549, H292 and H460). All cancer cell lines were treated with various concentrations of plumbagin.
The study concluded that plumbagin managed to inhibit cell growth, and induce apoptosis, in human lung cancer cells, through inactivation of NF-κB (nuclear factor-kappaB, a protein complex that controls the transcription of DNA, in which regulates several genes associated with inflammation, proliferation, carcinogenesis, and apoptosis). (Xu TP, et al. 2013)
Plumbagin and Human Tongue Carcinoma
Recent study at Wuhan University, Wuhan, China, reported the inhibitory effect, and the underlying mechanism of plumbagin, on the growth of human tongue squamous cell carcinoma (Tca8113). The study resulted that plumbagin inhibited the growth, proliferation, and induced the apoptosis of Tca8113 cells, in vitro, in a concentration, and time dependent manner. (Qiu JX, et al. 2013)
Even though from several studies above, had shown that plumbagin inhibit the growth of human cancer cells, both in vitro, and in vivo model systems, but all studies were only using human cancer lines, in mouse model, and not in real cancer patients. Further studies are still needed to be demonstrated in real cancer patients.