Thursday, 11 April 2013

Black pepper shows promise in breast cancer, vitiligo treatment


Can extracts of black pepper provide the next novel drug for the treatment of breast cancer and the skin disease, vitiligo? CHUKWUMA MUANYA writes.

BRITISH and United States (U.S.) researchers have found that black pepper could provide a new treatment for breast cancer and the skin disease, vitiligo.
Botanically called Piper nigrum (uziza in Ibo), black pepper is of plant family Piperaceae.

Vitiligo is disfiguring in the darker racial ethnic group as a result of the sharp contrast between the normal skin and the de-pigmented skin.

U.S. researchers have confirmed that extracts of black pepper stops the proliferation of cancer in humans. They found that black pepper and its constituents like hot pepper, exhibit anti-inflammatory, antioxidant and anticancer activities.

The study published in Natural Product Communications is titled “Inhibitory effects of black pepper (Piper nigrum) extracts and compounds on human tumor cell proliferation, cyclooxygenase enzymes, lipid peroxidation and nuclear transcription factor-kappa-B.”

Cyclooxygenase (COX) is an enzyme that is responsible for the formation of prostanoids, which are each involved in the inflammatory response. COX is implicated in the production of fever, inflammation, and pain.
Lipid peroxidation or oxidation of lipids is a crucial step in the pathogenesis of several disease states in adult and infant patients.

Nuclear factor kappa B (NF-KB) is an ubiquitous rapid response transcription factor in cells involved in imune and inflammatory reactions.

The United States researchers at the Bioactive Natural Products and Phytoceuticals, Department of Horticulture and National Food Safety and Toxicology Center, Michigan State University, East Lansing, Michigan, concluded: “All compounds derived from black pepper suppressed TNF-induced NF-kappaB activation, but alkyl amides, compound 4 from black pepper and 5 from hot pepper, were most effective. The human cancer cell proliferation inhibitory activities of piperine and alklyl amides in Capsicum and black pepper were dose dependant.

“The inhibitory concentrations 50 per cent (IC50) of the alklylamides were in the range 13-200 microg/mL. The extracts of black pepper at 200 microg/mL and its compounds at 25 microg/mL inhibited lipid peroxidation (LPO) by 45 to 85 per cent, COX enzymes by 31 to 80 per cent and cancer cells proliferation by 3.5 to 86.8 per cent. Overall, these results suggest that black pepper and its constituents like hot pepper, exhibit anti-inflammatory, antioxidant and anticancer activities.”
The British researchers from the Department of Pharmacy, King’s College London, in a study published in Journal of Pharmacy and Pharmacology concluded: “Piper nigrum, therefore, contains several amides with the ability to stimulate melanocyte proliferation. This finding supports the traditional use of P. nigrum extracts in vitiligo and provides new lead compounds for drug development for this disease.”
Melanocytes are pigment-producing cells in the skin of humans and other vertebrates.

The study is titled “Amides from Piper nigrum L. with dissimilar effects on melanocyte proliferation in-vitro.”
Until now, melanocyte proliferation stimulants are of interest as potential treatments for the depigmentary skin disorder, vitiligo. The researchers discovered that black pepper’s water extract, and its main alkaloid, piperine, promote melanocyte proliferation in-vitro.

The study, by King’s College London, also appeared in the British Journal of Dermatology.
The British researchers found that a crude chloroform extract of black pepper containing piperine was more stimulatory than an equivalent concentration of the pure compound, suggesting the presence of other active components.

They wrote: “Piperine (one), guineensine (two), pipericide (three), N-feruloyltyramine (four) and N-isobutyl-2E, 4E-dodecadienamide (five) were isolated from the chloroform extract. Their activity was compared with piperine and with commercial piperlongumine (six) and safrole (seven), and synthetically prepared piperettine (eight), piperlonguminine (nine) and 1-(3, 4-methylenedioxyphenyl)-decane (10).
“Compounds six to 10 either occur in P. nigrum or are structurally related. Compounds 1, 2, 3, 8 and 9 stimulated melanocyte proliferation, whereas 4, 5, 6, 7 and 10 did not.

“Comparison of structures suggests that the methylenedioxyphenyl function is essential for melanocyte stimulatory activity. Only those compounds also possessing an amide group were active, although the amino component of the amide group and chain linking it to the methylenedioxyphenyl group can vary.”

The King’s team examined the effects of piperine, and its synthetic derivatives, when applied to the skin of mice, either alone or followed by Ultra Violet Ray (UVR). Used alone, piperine and two of its derivatives stimulated pigmentation to an even, light brown colour within six weeks.

Combining the treatment with UVR the skin became darker still. The effect was achieved much faster than using UVR treatment alone, and lasted longer. In addition, the combined therapy gave a much more even pigmentation than UVR alone, which can often result in a patchy appearance.

The researchers believe that piperine stimulates the production of the skin’s pigment cells, called melanocytes.
Previous studies showed that the fruits and seeds are used to cure dyspepsia (indigestion), diarrhoea, cholera, piles, urinary problems, boils, rheumatism, toothaches and headaches. Black pepper is also used to stabilise the womb in women after birth.

Indeed, ground black pepper is one of the most commonly consumed spices. Black pepper has been shown to have antioxidant, anti-inflammatory, antibacterial and antimutagenic (stops changes in genetic material) properties and helps improve digestion. Black pepper is a dietary source of vitamin C, vitamin K and manganese. The spiciness of black pepper is due to its piperine content.

Piperine has been shown to significantly increase the bioavailability of selenium and beta-carotene, among other nutrients. Black pepper and piperine have been shown to inhibit the development of carcinogen-induced colon and lung cancers in laboratory animals.
According to dermatologists, vitiligo occurs when melanocytes, the cells responsible for skin pigmentation, die or are unable to function. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmune, genetic, oxidative stress, neural, or viral causes. The incidence worldwide is less than one per cent. The most common form is non-segmental vitiligo, which tends to appear in symmetric patches, sometimes over large areas of the body.

It has been shown that the incidence of breast cancer in Nigeria is increasing just like in other developing countries and those advanced countries that used to have a low incidence.

Oncologists have shown that several factors are responsible for this increasing incidence, but the most important are increasing average life expectancy, increased access to diagnostic facilities, empowerment of women which is increasing women’s ability to make independent decisions about their own health care, increasing westernisation of dietary, physical activity and obstetric and gynecological factors among others.

Black pepper (Piper nigrum) and hot pepper (Capsicum spp) are widely used in traditional medicines. Although hot Capsicum species extracts and its active principles, capsaicinoids, have been linked with anticancer and anti-inflammatory activities, whether black pepper and its active principle exhibit similar activities is not known.

The American study evaluated the antioxidant, anti-inflammatory and anticancer activities of extracts and compounds from black pepper by using proinflammatory transcription factor NF-kappaB, COX-1 and -2 enzymes, human tumor cell proliferation and lipid peroxidation (LPO).

The capsaicinoids, the alkylamides, isolated from the hot pepper Scotch Bonnet were also used to compare the bioactivities of alkylamides and piperine from black pepper.

Results of a study published in the West African Journal of Medicine by researchers at the Dermatology Unit, Department of Medicine, College of Medicine, University of Lagos, showed that the diagnosis of vitiligo was made in 186 (2.8 per cent) patients, with a slight female preponderance.

The epidemiology and clinical profile of vitiligo patients at the dermatology clinic of Lagos University Teaching Hospital (LUTH) showed that vitiligo affected all age groups: the youngest presented at age one and the oldest at 86 years of age. The face and the limbs were the most affected parts of the body. Fifteen (0.81 per cent) patients presented with features suggestive of associated autoimmune disease like, Type 1 diabetes.

The researchers concluded: “The frequency of vitiligo in this study is similar to those obtained in previous studies from different parts of Nigeria. The patients will benefit from other modalities of management apart from the medical management offered hence a designated centre for management of vitiligo will be a respite to them.”

Current treatments include corticosteroids applied to the skin, and phototherapy using UV radiation (UVR) to re-pigment the skin.

However, less than a quarter of patients respond successfully to corticosteroids. And UVR causes a re-pigmentation that is spotted and patchy and in the long-term could lead to a higher risk of skin cancer.

culled from The Guardian ,Author:CHUKWUMA MUANYA

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