Botanical name :Humulus lupulus
Species: H. lupulus
Synonyms: Humulus americanus. Humulus volubilis. Humulus vulgaris. Lupulus amarus.
Common names:Hop, Common hop, European Hop,
Habitat :Humulus lupulus is native to Europe, western Asia and North America.
It is a dioecious, perennial, herbaceous climbing plant which sends up new shoots in early spring and dies back to a cold-hardy rhizome in autumn. Strictly speaking it is a bine rather than a vine, using its own shoots to act as supports for new growth.
The plant grows to 6 m (19ft 8in) at a medium rate. It is not frost tender. It is in flower from Jul to August, and the seeds ripen from Sep to October. The flowers are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required) and are pollinated by Wind.The plant is not self-fertile.Bloom Color: Green, Yellow. Main Bloom Time: Early fall, Late summer, Mid summer. Form: Spreading or horizontal, Variable spread.It is noted for attracting wildlife.
The female plants produce strobiles, which are cone-like reproductive structures (Anon 1999a). The common and most well-known use of H. lupulus is in the flavoring of beer. Lupulin, a resinous substance found in the strobiles, is added to beer to give the distinct bitter taste (Anon 1999b).
Landscape Uses:Ground cover, Screen. Easily grown in a good garden soil in sun or semi-shade. Prefers a deep rich loam and a warm sheltered position. Plants can succeed in dry shade if plenty of humus is incorporated into the soil, once established they are also somewhat drought tolerant. Hops are reported to tolerate an annual precipitation of between 31 and 137cm, an annual temperature in the range of 5.6 to 21.3°C and a pH of 4.5 to 8.2. Plants are very hardy tolerating temperatures down to about -20°c when dormant. The young shoots in spring, however, can be damaged by any more than a mild frost. A climbing plant, supporting itself by twining around the branches of other plants. Hops are frequently cultivated, both commercially and on a domestic scale, in temperate zones for their seed heads which have many medicinal qualities and are also used as a flavouring and preservative in beer. There are many named varieties. They grow best between the latitudes of 35 – 51°N and 34 – 43°S, with mean summer temperatures of 16 – 18°C. Generally, for beer making, the unfertilized seed heads are preferred and so most male plants are weeded out. Hops are fairly deep rooted, but with a network of shallow feeding roots. These horizontal feeding roots spread out at depth of 20 – 30 cm in the soil and give rise to fibrous roots in upper layers of soil. The vertical roots develop downwards to a depth of about 150 cm with a spread of 183 – 244 cm and have no fibrous roots. The bruised leaves are refreshingly aromatic whilst the flowers cast a pleasing scent. A food plant for many caterpillars. Dioecious. Male and female plants must be grown if seed is required. Special Features: Edible, Invasive, Naturalizing, Attracts butterflies, Suitable for dried flowers, Inconspicuous flowers or blooms.
Seed – sow spring in a cold frame. Germination is fairly quick. Prick out the seedlings into individual pots as soon as they are large enough to handle and plant out in the summer or following spring. Division in spring as new growth begins. Very easy, you can plant the divisions straight out into their permanent positions if required[K]. Basal cuttings in March. Harvest the shoots when they are about 10 – 15cm long with plenty of underground stem. Pot them up into individual pots and keep them in light shade in a cold frame or greenhouse until they are rooting well. Plant them out in the summer.
Edible Parts: Leaves; Root.
Edible Uses: Drink; Rutin; Tea.
Young leaves and young shoots – cooked. The flavour is unique and, to many tastes, delicious. Young leaves can be eaten in salads. Use before the end of May. The leaves contain rutin. The fleshy rhizomes are sometimes eaten. A tea is made from the leaves and cones. It has a gentle calming effect. The dried flowering heads of female plants are used as a flavouring and preservative in beer. They are also medicinal. The flowering heads are sprinkled with bitter-tasting yellow translucent glands, which appear as a granular substance. This substance prevents gram-negative bacteria from growing in the beer or wort. Much of the hop’s use as a flavouring and medicinal plant depends on the abundance of this powdery substance. The seeds contain gamma-linolenic acid, an essential fatty acid that is said to have many important functions in the human body and is rarely found in plant sources. The essential oil in the flowering heads is used as a flavouring in cereal beverages and mineral waters. Extracts from the plant, and the oil, are used as flavouring in non-alcoholic beverages, frozen dairy desserts, candy, baked goods and puddings, with the highest average maximum use level of 0.072% reported for an extract used in baked goods
Humulus lupulus has also been used for medicinal purposes. Traditionally, it has been used to aid digestion and as a mild sedative to treat insomnia (Anon. 1999a).
From about 1950 to 1970, claims had been made that hops contained high quantities of estrogens (Fenselau 1973). Fenselau, et. al. (1973), assessed the degree of estrogenic activity in hops. They tested purified essential-oil fractions, alpha and beta bitter acids, and organic solvent extracts for estrogenic activity (Fenselau 1973). They also examined several dilutions by uterine-weight assay in immature female mice (Fenselau 1973). All tests indicated that hops lacked estrogenic activity (Fenselau 1973).
Another study by Fenselau (1976), tested samples of hops to detect for the presence of tetrahydrocannabinol, THC. This psychotropic compound is the active chemical component of Cannabis sativa (marijuana). They used the selected ion mode on a combined gas chromatograph – mass spectrometer to assay for the compound in 17 samples (Fenselau 1976). No THC was found in any of the samples (Fenselau 1976).
In 1989, H. lupulus was one of twelve plants studies for the treatment of diabetes mellitus (Swanston-Flatt 1989). The studies were done in vivo in normal and streptozotocin-induced diabetic mice (Swanston-Flatt 1989). Streptozotocin is an older intravenous chemotherapeutic (Anon. 1999c). It is used in the treatment of symptomatic or progressive metastatic islet and non-islet cell carcinoma of the pancreas (USP 1995). It also has diabetogenic and hyperglycemic effects (USP 1995). It has been shown to induce diabetes and lower pancreatic insulin content in insulin promoter-mB7-l transgenic mice when given in low doses (Harlen 1995). The mice were given preparations of the herb for 28 days (Swanston-Flatt 1989). In normal diabetic mice, the hops showed no effect on their basal plasma glucose and insulin, glucose tolerance, insulin-induced hypoglycemia, and glycated hemoglobin (Swanston-Flatt 1989). In the streptozotocin diabetic mice, the hops did not significantly affect the parameters of glucose homeostasis listed above or in pancreatic insulin concentration (Swanston-Flatt 1989).
Other modern day experimentation has led to the observance of a variety of possible medicinal uses of H. lupulus, including antibacterial activity (Langezaal 1992; Simpson 1992), treatment for gastritis (Krivenko 1989; Torosyan 1974), and even cancer prevention (Anon. 1998, Buhler 1999, Yasukawa 1995).
Two studies were done on the antibacterial and antimicrobial activity of H. lupulus. Simpson (1992) performed experiments on H. lupulus to determine what factors determine its antibacterial activity. It was determined that a decrease in pH caused the greatest stimulation of antibacterial activity in the weak acids (trans-isohumulone, humulone, colupulone and trans-humulinic acid) of the hops plant (Simpson 1992). The trans-isohumulone was found to have the greatest activity (Simpson 1992). Other monovalent cations stimulated activity, but not to the extent observed by protons (Simpson 1992). Divalent cations produced mixed reactions (from little effect to reduced effect) (Simpson 1992.) The activity of the trans-isohumulone was also found to be antagonized by lipids and beta-cyclodextrin (Simpson 1992). Langezaal (1992) did a study on the antimicrobial effects of essential oils and extracts of H. lupulus. He isolated the essential oils by hydrodistillation and the extracts by soaking the strobiles in chloroform (Langezaal 1992). The compounds had anntimicrobial effects against Bacillus subtilis, Staphlococcus aureus and Trichophylon mentagrophytes var. interdigitale but none against Escherichia coli and Candida albicans (Langezaal 1992).
In 1974, Totosyan conducted a study of H. lupulus in 46 chronic hyposecretory gastritis patients. A decoction of H. lupulus was given to the patients and in 36, a positive therapeutic effect was observed (Totosyan 1974). This was due to the high secretory-motor stimulating effect of the hops (Totosyan 1974). Later, another stuliy of this type was done by Krivenko (1989). He gave an herbal complex of H. lupulus, Achillea millefolium, Urtica dioica, Cichorium, Polygonum, Matricaria chamomilla, Helichrysum arenarium, Calendula, and corn stigmas to patients suffering from chronic hyposecretory gastritis, chronic hepatocholecystitis and/or angiocholitis (Krivenko 1989). No results were reported in this document.
Recent research has examined the role of H. lupulus on cancer prevention. Songsan (1990) used spectral methods to establish the structures of isoxanthohumol, xanthohumaol, and two new chalcone derivatives 3-(isoprenyl)-2,4-dihydroxy-4, 6- dimethyoxychalcone and 2,6 dimethyoxy-4,4-dihydroxychalcone. In 1998, xanthohumol was shown to inhibit the activity of the enzyme cytochrome P450, a component in the activation of the uncontrolled division of cancer cells (Anon. 1998). This research, conducted by Buh!er (1999) looked at the effects of the flavonoids and chalcones of hops on cancer chemoprevention and cancer chemotherapy. A study by Yasukawa (1995) looked at the effects of another compound in hops: humulon, on tumor promotion. It was shown that humulon inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA) induced inflammation (Yasukawa 1995). Humulon also had a pronounced inhibition of the tumor promoting factor of TPA on the growth of mouse skin tumors that had been activated by 7, 12-dimethylbenz[a]anthracene (Yasukawa 1995).
It is evident that more research needs to be conducted before proven medicinal significance of H. lupulus can be claimed. Clearly, the emphasis of the research will be on cancer prevention. And in this era, with the discovery of compounds such as Vincristine and Vinblastine in Vinca roseus, the possibility may not be so unrealistic.
Dye; Essential; Fibre; Paper.
A fine brown dye is obtained from the leaves and flower heads. An essential oil from the female fruiting heads is used in perfumery. Average yields are 0.4 – 0.5%. Extracts of the plant are used in Europe in skin creams and lotions for their alleged skin-softening properties. A fibre is obtained from the stems. Similar to hemp (Cannabis sativa) but not as strong, it is used to make a coarse kind of cloth. It is sometimes used for filler material in corrugated paper or board products, but is unsuited for corrugated paper because of low pulp yield and high chemical requirement, or for production of high-grade pulp for speciality paper. The fibre is very durable but it is difficult to separate, the stems need to be soaked beforehand for a whole winter. A paper can also be made from the fibre, the stems are harvested in the autumn, the leaves removed and the stems steamed until the fibres can be removed. The fibre is cooked for 2 hours with lye and then hand pounded with mallets or ball milled for 2½ hours. The paper is brown in colour
The species is a main ingredient of many beers, and as such is widely cultivated for use by the brewing industry . The fragrant flower cones (hops) impart bitterness and flavor, and also have preservative qualities. The extract is antimicrobial, which makes it useful for making natural deodorant. Hops also contain the potent phytoestrogen, 8-prenylnaringenin, that may have a relative binding affinity to estrogen receptors. Hop also contains myrcene, humulene, xanthohumol, myrcenol, linalool, tannins, and resin.
Known Hazards: Skin contact with the plant causes dermatitis in sensitive people. Hops dermatitis has long been recognized. Not only hands and face, but legs have suffered purpuric eruptions due to hop picking. Although only 1 in 3,000 workers is estimated to be treated, one in 30 are believed to suffer dermatitis. Dislodged hairs from the plant can irritate the eyes. Sedative effect may worsen depression. Avoid during pregnancy (due to antispasmodic action on uterus). Avoid with breast, uterine and cervical cancers
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider