Evaluation of Manuka Honey Estrogen Activity Using the MCF-7 Cell ...

Mānuka honey dược liệu kháng MCF7

From Wikipedia, the free encyclopedia

A native bee visits a mānuka flower (Leptospermum scoparium)

A bowl of mānuka honey

Mānuka honey is a monofloral honey produced in Australia and New Zealand from the nectar of the mānuka tree. The honey is commonly sold as an alternative medicine. While a component found in mānuka honey has antibacterial properties in vitro, there is no conclusive evidence of medicinal or dietary value other than as a sweetener.

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Identification[edit]

Mānuka honey is produced by introduced European honey bees (Apis mellifera)^[1] foraging on the mānuka or tea tree (Leptospermum scoparium) which grows uncultivated throughout New Zealand and southeastern Australia.^[2]

Mānuka honey is markedly viscous, having the highest viscosity among a range of honeys.^{[citation needed]} This property is due to the presence of a protein or colloid and is its main visually defining character, along with its typical dark cream to dark brown colour.^[3]^[4] To be labelled New Zealand mānuka honey,^[5] at least 70% of its pollen content should come from Leptospermum scoparium.^[4]

The mānuka tree flowers at the same time as Kunzea ericoides, another Myrtaceae species also called kānuka, which often shares the same growing areas. Some apiarists cannot readily differentiate these species, as both flowers have similar morphology and pollen differentiation between the two species is difficult. Therefore, melissopalynology as identification for the type of honey is valid only in association with other identification tests. In particular, L. scoparium honey is dark, whereas K. ericoides honey is pale yellow and clear, with a "delicate, sweet, slightly aromatic" aroma and a "sweet, slightly aromatic" flavour, and is not viscous.^[4]

Heather (Calluna vulgaris) honey is also viscous, but the plant flowers in late summer and its mountain distribution in north temperate Europe and central Asia does not correspond with that of Leptospermum scoparium. Therefore, its harvest cannot be mistaken for that of manuka honey.^[4]^{[clarification needed]}

Food[edit]

Mānuka honey has a strong flavour,^[3] characterised as "earthy, oily, herbaceous",^[6] and "florid, rich and complex".^[7] It is described by the New Zealand honey industry as having a "damp earth, heather, aromatic" aroma and a "mineral, slightly bitter" flavour.^[4]

Research[edit]

There is insufficient evidence from existing studies to conclude that honey helps improve superficial burns or leg ulcers compared to a standard dressing.^[8] Mānuka honey also does not reduce the risk of infection following treatment for ingrown toenails.^[9]

Preliminary studies indicate that methylglyoxal is an antibacterial component of mānuka honey.^[10]

Adulteration[edit]

As a result of the high premium paid for mānuka honey, an increasing number of products now labelled as such worldwide are counterfeit or adulterated. According to research by UMFHA, the main trade association of New Zealand mānuka honey producers, whereas 1,700 tons of mānuka honey are made there annually representing almost all the world's production, some 10,000 tons of produce is being sold internationally as mānuka honey, including 1,800 tons in the UK.^[11]

In governmental agency tests in the UK between 2011 and 2013, a majority of mānuka-labelled honeys sampled lacked the non-peroxide anti-microbial activity of mānuka honey. Likewise, of 73 samples tested by UMFHA in Britain, China and Singapore in 2012-13, 43 tested negative. Separate UMFHA tests in Hong Kong found that 14 out of 56 mānuka honeys sampled had been adulterated with syrup. In 2013, the UK Food Standards Agency asked trading standards authorities to alert mānuka honey vendors to the need for legal compliance.^[11]

There is a confusing range of systems for rating the strength of mānuka honeys. In one UK chain in 2013, two products were labelled “12+ active” and “30+ total activity” respectively for “naturally occurring peroxide activity” and another “active 12+” in strength for “total phenol activity," yet none of the three was labelled for the strength of the non-peroxide antimicrobial activity specific to mānuka honey.^[11]

There have been increasing turf disputes between producers operating close to large mānuka tree clumps, and also cases reported of many hives being variously sabotaged or stolen.^[12]

One British supermarket has taken to stocking jars of the honey in tagged security cassettes, such were the losses from shoplifting.^[13]

Induction of apoptosis in human breast cancer cell line MCF-7 by ...

Phytochemicals (Gmelina Asiatica) hợp chất kháng MCF7

From Wikipedia, the free encyclopedia

The various colors of berries derive mainly from polyphenol phytochemicals called anthocyanins

Cucurbita fruits, including squash and pumpkin, typically have high content of the phytochemical pigments called carotenoids

Phytochemicals are chemical compounds produced by plants, generally to help them thrive or thwart competitors, predators, or pathogens. The name comes from the Greek word phyton, meaning plant. Some phytochemicals have been used as poisons and others as traditional medicine.

As a term, phytochemicals is generally used to describe plant compounds that are under research with unestablished effects on health and are not scientifically defined as essential nutrients. Regulatory agencies governing food labeling in Europe and the United States have provided guidance for industry limiting or preventing anti-disease claims concerning phytochemicals on food product labels.

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Definition[edit]

Plants are composed entirely of chemicals of various kinds.^[1] Phytochemicals (from Greek phyto, meaning "plant") are chemicals produced by plants through primary or secondary metabolism.^[2]^[3] They generally have biological activity in the plant host and play a role in plant growth or defense against competitors, pathogens, or predators.^[2]

Phytochemicals generally are regarded as research compounds rather than essential nutrients because proof of their possible health effects has not been established yet.^[4]^[5] Phytochemicals under research can be classified into major categories, such as carotenoids^[6] and polyphenols, which include phenolic acids, flavonoids, and stilbenes/lignans.^[5] Flavonoids can be further divided into groups based on their similar chemical structure, such as anthocyanins, flavones, flavanones, and isoflavones, and flavanols.^[5]^[7] Flavanols further are classified as catechins, epicatechins, and proanthocyanidins.^[5]^[7]

Phytochemists study phytochemicals by first extracting and isolating compounds from the origin plant, followed by defining their structure or testing in laboratory model systems, such as cell cultures, in vitro experiments, or in vivo studies using laboratory animals.^[2] Challenges in that field include isolating specific compounds and determining their structures, which are often complex, and identifying what specific phytochemical is primarily responsible for any given biological activity.^[2]

History of uses[edit]

Berries of Atropa belladonna, also called deadly nightshade

Without specific knowledge of their cellular actions or mechanisms, phytochemicals have been used as poison and in traditional medicine. For example, salicin, having anti-inflammatory and pain-relieving properties, was originally extracted from the bark of the white willow tree and later synthetically produced to become the common, over-the-counter drug, aspirin.^[8]^[9]The tropane alkaloids of A. belladonna were used as poisons, and early humans made poisonous arrows from the plant.^[10] In Ancient Rome, it was used as a poison by Agrippina the Younger, wife of Emperor Claudius on advice of Locusta, a lady specialized in poisons, and Livia, who is rumored to have used it to kill her husband Emperor Augustus.^[10]^[11]

The English yew tree was long known to be extremely and immediately toxic to animals that grazed on its leaves or children who ate its berries; however, in 1971, paclitaxel was isolated from it, subsequently becoming an important cancer drug.^[2]

As of 2017, the biological activities for most phytochemicals are unknown or poorly understood, in isolation or as part of foods.^[2]^[5] Phytochemicals with established roles in the body are classified as essential nutrients.^[4]^[12]

Functions[edit]

The phytochemical category includes compounds recognized as essential nutrients, which are naturally contained in plants and are required for normal physiological functions, so must be obtained from the diet in humans.^[12]^[13]

Some phytochemicals are known phytotoxins that are toxic to humans;^[14]^[15] for example aristolochic acid is carcinogenic at low doses.^[16] Some phytochemicals are antinutrients that interfere with the absorption of nutrients.^[17] Others, such as some polyphenols and flavonoids, may be pro-oxidants in high ingested amounts.^[18]

Nondigestible dietary fibers from plant foods, often considered as a phytochemical,^[19] are now generally regarded as a nutrient group having approved health claims for reducing the risk of some types of cancer^[20] and coronary heart disease.^[21]

Eating a diet high in fruits, vegetables, grains, legumes and plant-based beverages has long-term health benefits,^[12] but there is no evidence that taking dietary supplements of non-nutrient phytochemicals extracted from plants similarly benefits health.^[4] Phytochemical supplements are neither recommended by health authorities for improving health^[5]^[22] nor approved by regulatory agencies for health claims on product labels.^[23]^[24]

Consumer and industry guidance[edit]

While health authorities encourage consumers to eat diets rich in fruit, vegetables, whole grains, legumes, and nuts to improve and maintain health,^[12] evidence that such effects result from specific, non-nutrient phytochemicals is limited or absent.^[4] For example, systematic reviews and/or meta-analyses indicate weak or no evidence for phytochemicals from plant food consumption having an effect on breast, lung, or bladder cancers.^[25]^[26] Further, in the United States, regulations exist to limit the language on product labels for how plant food consumption may affect cancers, excluding mention of any phytochemical except for those with established health benefits against cancer, such as dietary fiber, vitamin A, and vitamin C.^[27]

Phytochemicals, such as polyphenols, have been specifically discouraged from food labeling in Europe and the United States because there is no evidence for a cause-and-effect relationship between dietary polyphenols and inhibition or prevention of any disease.^[23]^[28]

Among carotenoids such as the tomato phytochemical, lycopene, the US Food and Drug Administration found insufficient evidence for its effects on any of several cancer types, resulting in limited language for how products containing lycopene can be described on labels.^[29]

Effects of food processing[edit]

Phytochemicals in freshly harvested plant foods may be degraded by processing techniques, including cooking.^[30]^[31]^[32] The main cause of phytochemical loss from cooking is thermal decomposition.^[32]

A converse exists in the case of carotenoids, such as lycopene present in tomatoes, which may remain stable or increase in content from cooking due to liberation from cellular membranes in the cooked food.^[33] Food processing techniques like mechanical processing can also free carotenoids and other phytochemicals from the food matrix, increasing dietary intake.^[32]^[34]

In some cases, processing of food is necessary to remove phytotoxins or antinutrients; for example societies that use cassava as a staple have traditional practices that involve some processing (soaking, cooking, fermentation, etc.), which are necessary to avoid getting sick from cyanogenic glycosides present in unprocessed cassava.^[35]

Cây Tu Hú - Gmelina Asiatica

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Xem tất cả

Thứ sáu, 29/01/2016 3:08 PM

Bộ

Bộ Hoa Môi (Lamiales)

Họ

Họ Cỏ Roi Ngựa (Verbenaceae)

Chi

Chi Gmelina

Loài

Loài G. Asiatica

Tên khác

Lõi Thọ Lẻo, Tu Hú Đông

Tên khoa học

Gmelina Asiatica L

Cây Tử Hoa Cự Đài - Loxostigma Griffithii

Mô tả: Cây nhỡ leo, phân cành nhiều, với các nhánh nhỏ ở nách biến đổi thành gai. Lá xoan, xoan ngược hay bầu dục thành góc ở gốc, nhọn ở đầu, nguyên hay có 4-5 thuỳ, dạng màng nhẵn ở trên, có tuyến và dính ở dưới, dài 2-7cm, rộng 1,5-6cm, cuống lá mảnh, dài 2-2,5cm. Hoa vàng xếp thành chùm những xim nhỏ ở ngọn, có lông mềm màu hung. Quả hạch dạng trứng, màu vàng, nhẵn, dài 18-20mm.

Bộ phận dùng: Rễ, lá, cành nhánh - Radix, Folium et Ramulus Gmelinae Asiaticae.

Nơi sống và thu hái: Cây mọc phổ biến khắp nước ta và nhiều nước nhiệt đới châu Á, thường gặp mọc ven rừng, ven đường đi trong rừng; cũng có khi được trồng.

Thành phần hoá học: Cây chứa một glucosid nhưng không phải là saponin. Phần không xà phòng hoá của dầu hạt gồm có sitosterol.

Tính vị, tác dụng: Rễ nhầy, gây chuyển hoá. làm se. Lá và nhánh non tiết chất nhầy nhớt dính khi ngâm trong nước lạnh.

Công dụng, chỉ định và phối hợp: Ta thường dùng làm thuốc gây nôn, chữa lậu, thông tiểu, đau tai.

Ở Ấn Độ, rễ được dùng trị tê thấp, lậu và chứng chảy của bọng đái.

Ở Campuchia rễ cùng dùng trị đái dầm, thường phối hợp với Sao và Chùm bao lớn.

Người ta cũng dùng nước ngâm lá và cành nhánh làm thuốc điều trị bệnh lậu để làm gi?m cỏc cơn đau khi tiểu tiện.

Phap Lac Pagoda (Vietnamese: Chùa Pháp Lạc, Pháp Thuận Thiền Thạch Tự, Nam Dược Đường)

Wednesday, 7 June 2017