Following is a brief review of just some of the herbs that may be beneficial for the treatment of particular organ/system cancers. It is intended as a starting point rather than a comprehensive review. In vivo studies are discussed; herbs that are supported by in vitro studies are only listed.
Respiratory system: small cell lung carcinoma
Chaste Tree (Vitex agnus-castus): Metastasis.
Grape Seed (Vitis Vinifera): Oral administration of grapeseed extract reduced the number of metastatic nodules induced in mice by 26.07% compared with a control group treated with ethanol.
Green Tea and Black Tea (Camellia sinensis): Consumption of tea (Camellia sinensis) has been suggested to prevent cancer, heart disease and other diseases. Animal studies have shown that tea and tea constituents inhibit carcinogenesis of the skin, lung, oral cavity, esophagus, stomach, liver, prostate and other organs. For example, mice were given decaffeinated green or decaffeinated black tea in their drinking water before, during, and after treatment with a carcinogen. Mice that received 0.63% or 1.25% green tea, or 1.25% black tea, exhibited a reduction in liver tumor numbers of 54%, 50%, and 63%, and a decrease in the mean number of lung tumors of 40%, 46%, and 34%, respectively, compared with controls. In some experiments, reduction in tumor number and size has been observed in the tea-treated groups; in other experiments, decreased tumor incidence has also been observed (Yang 2005). Black tea preparations have been shown to reduce the incidence and number of spontaneously generated lung adenocarcinomas and rhabdomyosarcomas in mice; they also were noted to inhibit the progression of lung adenoma to adenocarcinoma. In many of these experiments, tea consumption resulted in reduced body fat and body weight; these factors may also contribute to the inhibition of tumorigenesis.
Cruciferous Vegetables: Feeding mice diets enriched in dried cruciferous vegetables (cabbage and collards) resulted in a significant decrease in the number of pulmonary metastases after the animals had been injected intravenously with mammary tumor cells. Cruciferous vegetables may be beneficial in cancer prevention.
Flaxseed (Linum Usitatissimum): Mice were fed a basal diet, or the basal diet supplemented with 2.5%, 5%, or 10% flaxseed, for 2 weeks before and after an intravenous injection of 0.75 x 105 melanoma cells. The median number of tumors in mice fed the 2.5%, 5%, and 10% flaxseed-supplemented diets was 32%, 54%, and 63% lower, respectively, than that in controls. The addition of flaxseed to the diet also caused a dose-dependent decrease in tumor cross-sectional area and tumor volume. Flaxseed reduces metastasis and inhibits the growth of metastatic secondary tumors in animals.
Reproductive system: mammary carcinoma
Calendula (Calendula officinalis): in a study of mice fed for 3 weeks a diet containing a calendula extract (high in the carotenoid lutein), mammary tumor cells were infused into the mammary glands. Tumor latency increased and tumor growth was inhibited in a dose-dependent manner by dietary lutein. In addition, dietary lutein was reported to enhance lymphocyte proliferation.
Chaste Tree (Vitex agnus-castus)
Garlic (Allium Sativum): Organosulphur compounds markedly inhibited growth of canine mammary cells in culture.
Grapeseed: Procyanidins in grapeseed could be used as chemopreventive agents against breast cancer through suppression of in situ estrogen biosynthesis.
Milk Thistle (Silybum marianum)
Flaxseed (Linum Usitatissimum): This herb is the richest source of lignans and α-linolenic acid; it was investigated regarding its effects on the growth and metastasis of established human breast cancer in a mice model. Compared with controls, those supplemented with 10% flaxseed showed a significant reduction in tumor growth rate and a 45% reduction in total incidence of metastasis. Lung metastasis incidence was 55.6% in the control group and 22.2% in the flaxseed group; the incidence of lymph node metastasis was 88.9% in controls and 33.3% in the flaxseed group. Metastatic lung tumor number was reduced by 82% in the flaxseed group. It was concluded that flaxseed inhibits human breast cancer growth and metastasis in a mouse model, and that this effect is due in part to the downregulation of insulin-like growth factor I and epidermal growth factor receptor expression.
Boswellia (Boswellia Serrata): Two observational reports of patients undergoing treatment for brain tumor suggest that boswellia extract may assist in reducing cerebral edema. Experimental and in vitro studies showed that boswellia extract may slow growth and increase apoptosis of tumor cells implanted in the brains of experimental animals.
Cannabis (Cannabis Sativa): Gliomas are brain tumors that are common in humans. Several studies have shown that cannabinoids — active components of the plant Cannabis sativa and their derivatives — slow the growth of different types of tumors, including gliomas, in laboratory animals. Cannabinoids induce apoptosis of glioma cells in culture and inhibit angiogenesis in vivo. It is remarkable that cannabinoids kill glioma cells selectively and can protect nontransformed glial cells from death.
Aloe Vera and Melatonin: a clinical study evaluated whether the concomitant administration of aloe may enhance the therapeutic results of melatonin in patients with advanced solid tumor for whom no effective standard anticancer therapies are available. This study included 50 patients with lung cancer, gastrointestinal tract tumor, breast cancer, or brain glioblastoma, who were treated with melatonin alone (20mg/d orally in the dark period) or melatonin plus Aloe vera tincture (1mL twice/d). The percentage of nonprogressing patients was significantly higher in the group treated with melatonin plus aloe than in the melatonin group (14/24 vs 7/26). The 1-year survival percentage was significantly higher in patients treated with melatonin plus aloe (9/24 vs 4/26). Both treatments were well tolerated. The combination may produce some therapeutic benefits, at least in terms of stabilization of disease and survival, in patients with advanced solid tumor, for whom no other standard effective therapy is available.
Mistletoe (Viscum Album): Patients with malignant glioma were prospectively enrolled in a clinical trial. The treatment group received a galactoside-specific lectin from mistletoe, called ML-1. Analyses of all patients revealed prolongation of relapse-free intervals/overall survival time for the treatment group as compared with the control group.