February 18, 2014

Anticancer Drug From Aromatic Herb of Wormwood

Artemisia absinthium Artemisia annua
Artemisia absinthiumArtemisia annua

Wormwood, perennial aromatic herb, is native to North America, Europe, Asia, and North Africa. Wormwood (Artemisia absinthium) has grooved, and angled stems bear silky, fernlike leaves, and small, drooping, yellow flowers.

Wormwood leaves yield a bluish green volatile oil, which is used to make absinthe, a green alcoholic drink, which has strong and bitter flavor. Absinthe has antihelminthic properties, and may be used medicinally to treat intestinal worms. But, the excessively use of absinthe may have a fatally toxic effect, such as, convulsion and kidney failure.

There are many varieties of wormwood from Artemisia family. Artemisia annua, which is known as sweet wormwood, or Qing Hao (Chinese), has been used for centuries as herb, in Traditional Chinese Medicine (TCM), to treat malaria, dysentery, and many diseases.

Since the discovery of artemisinin, an active compound isolated from sweet wormwood, in early 1970s, several scientific studies have focused on its anti-parasitic effects. Scientists also studied artemisinin semi-synthetic derivatives, in which include, dihydroartemisinin (DHA), artemether, arteether, and artesunate. The effects of artemisinin has being investigated in diseases, such as, infections, cancers and inflammation.

Some studies have been reported, both in vitro, and in vivo, the anticancer activity of artemisinin, and demonstrated its cytotoxic effects against a variety of cancer cells. Artemisinin had shown its inhibitory effects on cancer cell growth, and anti-angiogenetic activity. A study found that artemisinin, might be used as a potential chemotherapeutic agent, in melanoma (skin cancer) treatment. (Buommino E, et al. 2009)

Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, isolated from Artemisia annua, has been shown to possess promising anticancer activities, and induced cancer cell death. A study had shown that, DHA can inhibit proliferation, and induce apoptosis. The result provided evidence for further studies of DHA, as a possible anticancer drug, in the clinical treatment of lung adenocarcinoma. (Lu YY, et al. 2009)

Artemisinin had been shown to kill cancer cells in vitro selectively, and slowed the growth of tumors in rats. A study resulted that artemisinin, and its semi-synthetic analogs, could be inexpensive, and effective cancer agents. (Singh NP, et al. 2004)

While another study found that, artemisinin was a relatively safe compound, and caused no known side effects, even at high oral doses. The study indicated that, artemisinin might be a potent cancer chemoprevention agent. (Lai H, et al. 2006)









All images from Wikimedia

February 06, 2014

Zinc vs. Cancer

Zinc Gluconate 50 mg by Now Foods
Zinc Gluconate 50 mg by Now Foods

Zinc For Human Body

Zinc, an essential mineral in human nutrition, which plays as antioxidants to protect DNA from damage, and assists in its repair. Zinc is also required for producing energy, healing wound, regulating body immune system, and cell metabolism.

Zinc deficiency, due to low dietary intake, may lead to immune dysfunction, impaired growth, diarrhea, infection, neuropathy, loss of appetite, dermatitis, hair loss, bleeding, cold, hypotension, hypothermia, and cancer. Zinc as a dietary intake, could be found in seafoods, meats, nuts, eggs, cheese, grains, cereal, beans, peas, and seeds.

Dietary Intake of Zinc

Below is the tolerable upper intake level for zinc, according to the Food and Nutrition Board, Institute of Medicine:

  • Infants:
    0 to 6 months = 4 mg/d
    6 to 12 months = 4 mg/d
  • Children:
    1 to 3 years = 7 mg/d
    4 to 8 years = 12 mg/d
  • Both Males/Females, and Pregnancy/Lactation:
    9 to 13 years = 23 mg/d
    14 to 18 years = 34 mg/d
    19 to 70 years and above = 40 mg/d

Dietary intake of zinc, whether from foods or zinc supplements, more than the upper level per day, may increase the risk of nausea, fatigue, kidney failure, urinary tract problems, vomiting, headache, infections, anemia, low HDL cholesterol, low immune function, copper deficiency, and the development of prostate cancer in men. Also, pregnant and lactation women should consult to the doctor, or pharmacist, before taking any zinc supplements.

Zinc in Cancer Prevention Studies

Prostate Cancer

High concentration of zinc, in the prostate suggests that, zinc may play a role in prostate health. A 14 years follow up study among 46,974 U.S. men, from 1986 to 2000, was found 2,901 new cases of prostate cancer, of which 434 cases were diagnosed in advanced stage.

The study found that, dietary intake of zinc supplements up to 100 mg/d, was not associated with prostate cancer risk, but an overdose of zinc may play a role in prostate carcinogenesis. (Leitzmann MF, et al. 2003)

Head and Neck Cancer

Head, and neck cancer is a form of cancers of the mouth, nose, sinuses, salivary glands, throat, and lymph nodes, in the neck. A randomized double blind, placebo controlled trial among 144 head, and neck cancer patients, was conducted to determine the efficacy of zinc sulfate supplementation, in reducing radiation induced oral mucositis, and pharyngitis.

The study concluded that, zinc sulfate administered during head, and neck radiation therapy, produced no significant benefit, in relieving radiation induced oral mucositis and pharyngitis with acceptable side effects. (Sangthawan D, et al. 2013)

Colorectal Cancer

In 1988, a double blind randomized trial, in Italy, was started to demonstrate the efficacy of a combination of antioxidant supplement (200 μg selenium, 30 mg zinc, 2 mg vitamin A, 180 mg vitamin C, and 30 mg vitamin E), in reducing the incidence of recurrent adenomas (benign tumor) of the large bowel, among 411 patients, on post polypectomy (surgical removal of a polyp) endoscopic.

All patients were assigned to receive either a supplement, or a placebo, daily for five years. After follow up of four years, in range of 1 to 15 years, the study showed significant effect of antioxidant supplementation, on adenoma recurrence. Since the study used a combination of antioxidant supplement all together, it is difficult to determine the role of zinc, in reducing the risk for colorectal cancer. (Bonelli L, et al. 2013)

Leukemia

Recent study managed to develop zinc sulfide nanoparticles (ZnS NPs), to study their cytotoxicity against the KG-1A (human acute myeloid leukemia) cell line. Cell viability study, and flow cytometric analysis, confirmed the potent cytotoxic effects of ZnS NPs, on cancer cells.

The study found that, ZnS NPs had no toxic effects on normal lymphocytes, at doses up to 50 µg ml, and clarified the mechanism of ZnS NPs, in inducing anticancer activities in vitro. More studies were needed to investigate ZnS NPs application to cancer treatment in vivo. (Dash SK, et al. 2014)