Question: Can regular intake of food replete with extracts of garlic (Allium sativum), mango (Mangifera indica) and bush candle (Cassia alata/Senna alata) provide the elusive cure for lung cancer and diabetes? 

 

CASSIA alata also known as Senna alata is a shrub from the leguminosae family. It is called Asunrun Oyinbo in Yoruba and Ogalu in Ibo.

 

  Mango is botanically called Mangifera indica and belongs to the plant family Anacardiaceae. Garlic (Allium sativum) is of plant family Liliaceae.  It is called Ayuu Ibo and Ayu in Yoruba.

 

Mango and lung cancer

 

  The active ingredient in mango, mangiferin, has been found to reduce the risk of developing lung cancer, and also in treating already established cases.

 

  The study published in June 15, 2013 edition of International Journal of Biomedical Science concluded: “In conclusions, mangiferin showed a potential as one of the immunomodulatory agents. These results suggest that mangiferin exerted a strong immuno stimulant effect.”

 

  The study is titled “Immunomodulatory Effect of Mangiferin in Experimental Animals with Benzo(a)Pyrene-induced Lung Carcinogenesis.”

 

  “Our present findings can thus possibly explain the immunomodulatory effect of mangiferin, as they revealed an antioxidant effect of mangiferin that ameliorated Benzo(a)Pyrene (abbreviated as B(a)P) -induced immunological damage,” the researchers wrote.

 

  Mangerin is a naturally occurring xanthone glucoside. It is found widely distributed in plants such as Anacardiaceae and Gentianaceae families (example Mangifera indica, mango), especially in the fruit, leaves, bark and bark root. The pharmacology of mangiferin has gained increased attention in recent years owing to its modulatory actions on oxidative mechanisms in various disorders, and on antitumor, antiviral, immunomodulatory, and radioprotective activities under different experimental conditions.

 

  B(a)P, a proven carcinogen, is the most prevalent member of the Polycyclic aromatic hydrocarbons (PAH) family. PAHs such as B(a)P constitute a major class of widely distributed and persistent environmental contaminants. PAHs are among the most common classes of chemical contaminants found at hazardous waste sites.

 

  Previous study by the researchers found that mangiferin significantly reduced the malonaldehyde (MDA) level, a marker of lipid peroxidation, in different tissues, example, lung and liver, under oxidative stress, thus offering protection against B(a)P-induced carcinomas in mice. 

 

  The current study was aimed at determining the link between the effects of mangiferin on oxidative stress caused by reactive intermediates specific to the immune system and its protective role against immune dysfunction. B(a)P was used in vivo to produce reactive intermediates toxic to the immune system.

 

  The ability of mangiferin to reverse the reactive intermediate-induced immunological deficits in antibody production and cellular responses was investigated. The mechanism by which B(a)P induced immunosuppression through oxidative stress on the immune system and the protective role of mangiferin against such stress were demonstrated.

 

  The team of Indian and Japanese researchers studied the immunomodulatory activity of mangiferin in various groups of animals. For this study, adult Swiss albino male mice were treated with B(a)P at 50 mg/kg body weight orally twice a week for four weeks; and mangiferin was also given orally (pre- and post-initiation of carcinoma) at 100 mg/kg body weight. 

 

  Immunocompetence and immune complexes as measured by phagocyte index, avidity index, and soluble immune complex (SIC) levels (p<0.001), as well as NBT reduction, were decreased in the B(a)P-treated animals; whereas increased levels of immunocompetence were noted in the mangiferin-treated animals given B(a)P. 

 

  The researchers wrote: “This study confirms the immunomodulatory effect of mangiferin and shows an immunoprotective role arbitrated through a reduction in the reactive intermediate-induced oxidative stress in lymphocytes, neutrophils, and macrophages.”

 

  Another study published recently in Journal of Agriculture and Food Chemistry has established that polyphenolics from several mango varieties exerted anticancer effects.

 

  The researchers from the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas, United States, found that nany polyphenolics contained in mango have shown anticancer activity. 

 

  The objective of the study was to compare the anticancer properties of polyphenolic extracts from several mango varieties (Francis, Kent, Ataulfo, Tommy Atkins, and Haden) in cancer cell lines, including Molt-4 leukemia, A-549 lung, MDA-MB-231 breast, LnCap prostate, and SW-480 colon cancer cells and the non-cancer colon cell line CCD-18Co. 

 

  Cell lines were incubated with Ataulfo and Haden extracts, selected on the basis of their superior antioxidant capacity compared to the other varieties, where SW-480 and MOLT-4 were statistically equally most sensitive to both cultivars followed by MDA-MB-231, A-549, and LnCap in order of decreasing efficacy as determined by cell counting. 

 

  The efficacy of extracts from all mango varieties in the inhibition of cell growth was tested in SW-480 colon carcinoma cells, where Ataulfo and Haden demonstrated superior efficacy, followed by Kent, Francis, and Tommy Atkins. 

 

  The results of the study showed that At 5 mg of GAE/L, Ataulfo inhibited the growth of colon SW-480 cancer cells by approximately 72 per cent while the growth of noncancer colonic myofibroblast CCD-18Co cells was not inhibited. 

 

  The researchers said the growth inhibition exerted by Ataulfo and Haden polyphenolics in SW-480 was associated with an increased mRNA expression of pro-apoptotic biomarkers and cell cycle regulators, cell cycle arrest, and a decrease in the generation of reactive oxygen species. 

 

  “Overall, polyphenolics from several mango varieties exerted anticancer effects, where compounds from Haden and Ataulfo mango varieties possessed superior chemopreventive activity,” they concluded.

 

Mango and diabetes

 

  The results of another study published in Phytotherapy Resident indicated that the aqueous extract of the leaves of mango possess blood glucose lowering (hypoglycaemic) activity.

 

  The researchers from the Department of Pharmacology and Therapeutics, Faculty of Health Sciences, University of Ilorin, assessed the leaves of mango were for antidiabetic properties using normoglycaemic, glucose-induced hyperglycaemia and streptozotocin (STZ) induced diabetic mice. 

 

  They wrote: “The aqueous extract produced a reduction of blood glucose level in normoglycaemic and glucose-induced hyperglycaemia, but did not have any effect on streptozotocin-induced diabetic mice. The hypoglycaemic effect of the aqueous extract was compared with that of an oral dose of chlorpropamide under the same conditions.”

 

  A more recent study published in Journal of Chemical and Pharmaceutical Research found mango to be beneficial in the treatment of diabetes.

 

  The Indian researchers from the Department of Biochemistry, Sengamala Thayaar Educational Trust Women’s College, Sundarakkottai, Mannargudi, Tamilnadu, India, wrote: “Present investigation was undertaken to evaluate antihyperglycemic, activity of ethanolic extract of Mangifera indica leaves in alloxan induced diabetic rats. Alloxan produced a significant increase in serum glucose, creatinine, urea, uric acid, ALT, AST levels. 

 

  “Treatment with Mangifera indica extract produced decrease in alloxan induced glucose, urea, uric acid, and creatinine levels. There was a significant decrease in total protein, haemoglobin, body weight, albumin and globulin. Administration of Mangifera indica to diabetic rats reduced the effect of alloxan and increased the levels of above parameters. The results suggest Mangifera indica to be beneficial for the treatment of diabetes mellitus.”

 

Garlic and lung cancer

 

  Also, a new study claims that eating raw garlic twice a week can nearly halve the risk of developing lung cancer, even lowering the danger for smokers. According to the study published in the journal Cancer Prevention Research, Chinese researchers found that those who consumed raw garlic as part of their diet were 44 per cent less likely to suffer the disease.

 

  Even when they allowed for whether people smoked - the biggest single cause of lung cancer, the scientists found garlic still seemed to reduce the dangers by around 30 per cent, the ‘Telegraph’ reported.

 

  Previous research has suggested that the popular herb can ward off stomach cancer and colon cancer, and a study at the University of South Australia suggested that it could reduce the risk of bowel tumours by nearly a third.

 

  Scientists at Jiangsu Provincial Centre for Disease Control and Prevention compared 1,424 lung cancer patients with 4,500 healthy adults.

 

  They found that those who ate raw garlic at least twice a week were significantly less likely to get lung cancer, even if they smoked or were exposed to high-temperature cooking oil fumes, which is thought to be another trigger for the disease.

 

  The key ingredient behind this effect seems to be a chemical called allicin, released when the clove is crushed or chopped, according to previous studies. It is thought to dampen down inflammation in the body and act as an anti-oxidant, reducing damage from so-called free radicals to the body’s cells. However, it is not clear whether cooked garlic would have the same effect. “Garlic may potentially serve as a preventive agent for lung cancer,” researchers said.

 

Garlic and diabetes

 

  Researchers have also shown that intake of garlic could prevent diabetes.

 

  The researchers from Bingham University, Karu Nasarawa State found that pre-administration of garlic extract before alloxan induction prevents the elevation of blood glucose in alloxan induced rats.

 

  The study was published last year in ARPN Journal of Agricultural and Biological Science.

 

  The researchers wrote: “This study was carried out to evaluate the possible protective effects of garlic extract on alloxan-induced diabetic rats. The rats were divided into four groups: group 1 serves as diabetic control; group 2 served as normal control; group 3 received garlic extract seven days before alloxan induction and 14 days after the induction while the last group received normal saline before induction and garlic extract after induction. 

 

  “The blood glucose levels of the rats were determined before the treatment and at regular interval till the end of the study. The result obtained showed that pre-administration of garlic extract before alloxan induction prevents the elevation of blood glucose in alloxan induced rats.”

 

  Another study published in Pakistan Journal of Pharmacological Science showed that garlic supplementation with standard anti-diabetic agent provides better diabetic control in type 2 diabetes patients.

 

  The researchers from the Department of Pharmacology, University of Karachi, Pakistan noted that garlic has been used safely since ancient times as both food and medicine in human populations, but studies of its efficacy in the management of diabetes have yielded conflicting results. 

 

  The study evaluated the potential hypoglycemic effects of garlic in type 2 diabetic patients. 

 

  The researchers wrote: “The study was conducted in diagnosed type 2 diabetic patients (n=60) with fasting blood sugar level above 126 mg/dl to evaluate the effects of adding garlic tablets with standard anti-diabetic therapy on blood sugar. Patients were divided randomly into 2 groups. Group 1 (n=30) was given tablet Garlic (KWAI) 300 mg thrice daily + Metformin 500 mg twice daily and Group 2 (n=30) was given Placebo+Metformin 500 mg twice daily respectively for 24 weeks. Serum lipids and fasting blood glucose were measured at week 0, 12 and week 24. Group1 showed significant reduction in fasting blood sugar at week 24 with a percentage decrease of as compared to group 2. 

 

  “At the end of week 24, GR1 group also showed considerable decrease in mean total cholesterol, Low Density Lipo-protein (LDL-C)/bad cholesterol, triglycerides while High Density Lipo-protein (HDL)/good cholesterol was significantly increased as compared to GR2 group. 

 

  “Combination of garlic with typical antidiabetic remedy has shown to improve glycemic (blood glucose) control in addition to antihyperlipidemic (reduces blood cholesterol) activity. Garlic may be a good addition in the management of patients with diabetes and hyperlipidemia (high levels of fats).

 

Cassia alata and lung cancer

 

  Cassia alata (Bush candle) is employed in traditional medicine for the treatment of various ailments. It grows in tropical region of Nigeria and can also be found in other countries.

 

  Its common name is bush candle because of the orientation of the flowers like the shape of a candle flame but it is more popularly called Ringworm plant because it is known to be very effective in the treatment of ringworm infection. 

 

  Researchers have also established the anticancer properties of the leaves of Cassia alata.

 

  The study published in Asian Pacific Journal of Cancer Preview is titled “In Vitro Antitumor Properties of an Isolate from Leaves of Cassia alata L.”

 

  The researchers evaluated the leaf extracts of Cassia alata, traditionally used for treatment of a variety of diseases, for their potential antitumor properties in vitro.    

 

  MTT assays were used to examine the cytotoxic effects of crude extracts on five human cancer cell lines, namely MCF-7, derived from a breast carcinoma, SK-BR-3, another breast carcinoma, T24 a bladder carcinoma, Col 2, a colorectal carcinoma, and A549, a non- small cell lung adenocarcinoma. 

 

  Hexane extracts showed remarkable cytotoxicity against MCF-7, T24, and Col 2 in a dose-dependent manner. This observation was confirmed by morphological investigation using light microscopy. 

 

  Further bioassay-directed fractionation of the cytotoxic extract led to the isolation of a TLC-pure isolate labeled as f6l. Isolate f6l was further evaluated using MTT assay and morphological and biochemical investigations, which likewise showed selectivity to MCF-7, T24, and Col 2 cells with IC50 values of 16, 17, and 17 ?g/ml, respectively. 

 

 According to the study, isolate f6l, however, showed no cytotoxicity towards the non-cancer Chinese hamster ovarian cell line (CHO-AA8). Cytochemical investigation using DAPI staining and biochemical investigation using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-a method used to detect DNA fragmentation-together with caspase assay, demonstrated apoptotic cell death. 

 

  Spectral characterisation of isolate f6l revealed that it contained polyunsaturated fatty acid esters. 

 

  The researchers concluded: “Considering the cytotoxicity profile and its mode of action, f6l might represent a new promising compound with potential for development as an anticancer drug with low or no toxicity to non-cancer cells used in this study.”

 

  Another study published in West Indian Medical Journal found that Cassia alata leaf extract destroys lung cancer cells in a dose dependent manner.

 

The study is titled “Cassia alata leaf extract induces cytotoxicity in A549 lung cancer cells via a mechanism that is caspase 8 dependent.”

 

     The researchers from the Department of Basic Medical Sciences, Pharmacology section, The University of the West Indies, Kingston, Jamaica, evaluated the cytotoxic effect of a hexane extract of Cassia alata leaves in A549 lung cancer cells.

 

  Parental A549 lung cancer cells were exposed to various concentrations (100-180 microg/ml) of Cassia alata leaf extract for 24 hours. Following treatment, the cells were evaluated using the 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay to determine the cytotoxic effect of the extract. 

 

  Caspase 8, 3 and 9 negative A549 cells were also prepared using lentiviral based shRNA knockdown of the caspase 8, 3 and 9 genes, respectively. The cytotoxic effect of Cassia alata leaf extract was then evaluated in these knockdown cells using the MTT assay. Chemical analysis was performed on the extract using high performance liquid chromatography (HPLC).

 

  The results showed that Cassia alata extract was cytotoxic in parental and caspase-9 negative, but not caspase 3 and 8 negative A549 cells. The IC50 values were 143 microg/ml and 145 microg/ml in parental and caspase 9 negative A549 cells respectively. The flavanoid kaempferol was identified as a constituent of Cassia alata leaf extract.

 

  The researchers concluded: “Cassia alata produces cytotoxicity in A549 cancer cells that is mediated by caspase 8 activation. This effect may be attributable to kaempferol.”

 

Cassia alata and diabetes

 

  In an ethno-botanical survey which identified and documented twenty-two (22) plants from south- western Nigeria used by traditional healers in the region, Cassia alata, closely followed by Vernonia amygdalina (bitter leaf) remains the most frequently used plant in the management of diabetes. 

 

  Researchers have also shown that Cassia alata and other Cassia species have anti-diabetic properties and could help tackle obesity as well. 

 

  A team of researchers at the University of Greenwich, United Kingdom (UK) plans to investigate Cassia auriculata and Cassia alata whose extracts could yield active ingredients for a remedy to diabetes, which exists in two forms - Type 1 and Type 2.

 

  The former normally affects children, while type 2, which is most common in adults, (often diagnosed later in life) can be managed by diet, exercise and weight loss to some extent.

 

  The group had previously hit upon a constituent called kaempferol 3-O-rutinosidehe from the extracts of one of the plants, which was proven to be eight times more potent than the standard anti-diabetic drug acarbose.

 

  The researchers have also identified anti-oxidant properties of the plants, which aids in diabetes treatment.

 

  Leader of the research team, Dr. Solomon Habtemariam, said: “Our other most interesting finding is that many of the active ingredients from the Cassia auriculata plant work through a process called ‘synergism’ – in other words, they work together to produce an effect greater than the sum of their individual effects.” 

 

  A Nigerian study by researchers from the Department of Human Anatomy, University of Calabar, Cross River State, concluded: “Leaf extracts of Cassia alata has dose-dependent hypoglycemic effects and increases the glycogen content of the liver though the mechanism of action is yet to be determined.” The study was published in The Pacific Journal of Science and Technology. 

 

  The study was performed to investigate the hypoglycemic effects of ethanol leaf extracts of Cassia alata (candle bush) and its effect on the histology and glycogen content of the liver of streptozocin-induced diabetic albino rats. 

 

  Twenty four albino rats were used and were divided equally into six groups; A, B, C, D, E, and F. Diabetes was induced in B, C, and D while A, E, and F were non diabetic. A, served as normal control while B served as diabetic control.

 

  The two control groups received normal diet and was administered 0.3ml normal saline. C and E received 300mg/kg body weight of plant extract while D and F received 500mg/kg body weight of plant extract, given in two divided doses daily, 12 hours duration for twenty-one days. 

 

  Blood glucose was measured every seven days. At the end of the 21st day, the animals were anaesthetized and dissected. The livers were isolated, processed and stained with hematoxylin and eosin (H&E) and Periodic Acid Schiff’s (PAS) staining techniques. 

 

  The result of this study indicates that ethanol leaf extracts of Cassia alata was able to reduce blood sugar significantly in D compared with B. And also in F compared with A using t- test. Increase in the density of liver glycogen was obvious in the groups that received 500mg/kg body weight of extracts.

 

  The researchers wrote: “Having noted the various effects of leaf-extract of Cassia alata on blood glucose, histology and glycogen content of the liver as shown with a light microscope, it is obvious that it is anti- hyperglycaemic and non-toxic to the liver. Based on the result obtained from this work, significant changes were not observed at a low dose of 300mg/kg but a very remarkable improvement was observed at the dose of 500mg/kg. This shows that the effects of hydro-ethanol leaf extract of Cassia alata is dose dependent.

 

  “It can therefore be concluded that hydro-ethanol leaf extract of Cassia alata has hypoglycemic effects, increases the glycogen content of the liver and generally improves liver cytoarchitecture.”

 

By CHUKWUMA MUANYA

Guardian