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Betel

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Betel
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Magnoliids
Order: Piperales
Family: Piperaceae
Genus: Piper
Species:
P. betle
Binomial name
Piper betle

Betel (Piper betle) is a species of flowering plant in the pepper family Piperaceae, native to Southeast Asia. It is an evergreen, dioecious[1] vine, with glossy heart-shaped leaves and white catkins. Betel plants are cultivated for their leaves which are most commonly used as flavoring in chewing areca nut.

Etymology

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The term betel was derived from the Tamil/Malayalam word vettila via Portuguese.[2][3]

Distribution

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Piper betle is originally native to Southeast Asia, from India, Philippines, Timor-Leste and Indonesia and Peninsular Malaysia to Indochina, Vietnam, Cambodia, Laos, Thailand, and Myanmar. Its cultivation has spread along with the Austronesian migrations and trade to other parts of Island Southeast Asia, Papua New Guinea and Melanesia, Micronesia, South Asia, the Maldives, Mauritius, Réunion Island, and Madagascar. It was introduced during the Colonial Era to the Caribbean by Indian indentured immigrants.[4][5]

Cultivation

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Betel leaf and Areca nut consumption in the world.

The betel leaf is cultivated mostly in South and Southeast Asia, from India[6] to Papua New Guinea.[7] It needs a compatible tree or a long pole for support. Betel requires well-drained fertile soil. Waterlogged, saline and alkali soils are unsuitable for its cultivation.[8]

In Bangladesh, farmers called barui[9] prepare a garden called a barouj in which to grow betel. The barouj is fenced with bamboo sticks and coconut leaves. The soil is plowed into furrows of 10 to 15 m length, 75 cm in width and 75 cm depth. Oil cakes, manure, and leaves are thoroughly incorporated with the topsoil of the furrows and wood ash. The cuttings are planted at the beginning of the monsoon season.

Betel plant cultivation in Bangladesh
Betel leaves in Kolkata market, West Bengal, India

Proper shade and irrigation are essential for the successful cultivation of this crop. Betel needs constantly moist soil, but there should not be excessive moisture. Irrigation is frequent and light, and standing water should not remain for more than half an hour.

Dried leaves and wood ash are applied to the furrows at fortnightly intervals and cow dung slurry is sprinkled. Application of different kinds of leaves at monthly intervals is believed advantageous for the growth of the betel. In three to six months, the vines reach 150 to 180 cm in height, and they will branch. Harvest begins with the farmer plucking the leaf and its petiole with his right thumb. The harvest lasts 15 days to one month. The betel plant has made its way to research labs of many Bangladesh chemical and food nutrition companies.

The harvested leaves are consumed locally and exported to other parts of Asia, the Middle East, Europe, and the Americas. Betel is grown and cultivated as an important crop in rural Bangladesh.[citation needed]

Cultural significance

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The primary use of betel leaf is as a wrapper for the chewing of areca nut, or in modern times, tobacco, where it is mainly used to add flavour. The practice originated in the Philippines around 5,000 years ago, where the oldest remains of areca nuts and calcium from crushed sea shells have been found in the Duyong Cave archaeological site. It spread along with the Austronesian migrations to the rest of Southeast Asia, Taiwan, South China, and South Asia. It is unknown when or why betel leaves were first combined with areca nuts, since areca nuts can be chewed alone.[5]

While the practice of chewing Betel leaf existed even before the common era, with attested references from at least the 3rd century CE, the ingredient mix (paan/ betel quid) it was chewed with changed over time.[10] Areca nut, Calcium hydroxide and catechu were the historic ingredients, as referenced in texts from 9th century CE. Tobacco started to feature in the 20th century.[10][11] The practice of chewing betel leaf is on the decline, and now quid consisting of tobacco, areca nut, and limewater, known as gutka, is more popular.[11]

In India and Sri Lanka, a sheaf of betel leaves is traditionally offered as a mark of respect and auspicious beginnings. Occasions include greeting elders at wedding ceremonies, celebrating the New Year, and offering payment to physicians and astrologers, to whom money and/or areca nut, placed on top of the sheaf of leaves, are offered in thanks for blessings. In Bengali weddings, the bride is brought to the groom, seated on a platform and her face covered in betel leaves.

In Papua New Guinea and the Solomon Islands, the inflorescence stalk of the betel tree, known as daka or "mustard stick", is consumed together with the leaves.[12][13]

It may also be used in cooking, usually raw, for its peppery taste. Use of binlang, or betel, has over a 300-year history in areas of China, where it was once promoted for medicinal use.[14]

Health effects

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Epidemiological studies demonstrate a close association between the incidence of cancer in India and the chewing of betel quid containing tobacco, areca nut, limewater and betel leaf.[15] Chewing paan (betel quid) is strongly associated with a higher risk of developing head and neck cancer,[16] as well as oropharyngeal squamous cell carcinoma (OPSCC), a form of cancer that affects the mouth, tonsils, and throat.[17] Attempts have been made to confirm the carcinogenic/ mutagenic of betel quid or its ingredients. Betel leaf extract alone has not been shown to cause adverse effects. Smokeless tobacco products have been shown to exhibit mutagenic and carcinogenic behavior.[18][19]

A scientific study from Japan found that lab rats that ate a mixture of betel leaf and areca nuts had severe thickening of the upper digestive tract, whereas after a diet of betel leaves alone, only one laboratory rat developed a forestomach papilloma.[20] Multiple studies demonstrate that betel quid without added tobacco also causes esophageal cancer, and in some instances, liver cancer.[21]

In a cancer diagnosis patterns study with patients that chewed betel quid with different ingredient combinations, the risk was found to be the highest for those using any form of tobacco.[22] International Agency for Research on Cancer (IARC) and the World Health Organization (WHO) accept the scientific evidence that chewing tobacco and areca nut is carcinogenic to humans.[23][24][25][26] As with chewing tobacco, chewing betel quid with tobacco and areca nut is discouraged by preventive healthcare efforts.[17]

Reports suggest that betel leaf by itself has beneficial effects, in part because of its anti-mutagenic effects against mutagens (tobacco and areca nut) in betel quid.[15] While earlier studies hypothesized a potential mutagenic role for betel leaf in causing oral cancers, subsequent studies invalidated it by isolating compounds (eugenol and hydroxychavicol) in betel leaf that have anti-mutagenic roles.[27][15] These compounds were also found to reduce the carcinogenic burden imposed by tobacco and areca nut.[28][29][30] Hydroxychavicol is found to demonstrate anti-prostate cancer efficacy in an in vitro (human prostate cancer cells) and in vivo ( BALB/c nude mice) study.[31]

Assessment tools for betel-quid chewing have been developed to address its complex behavioral and cultural aspects. The Reasons for Betel-quid Chewing Scale (RBCS) identifies key motivational factors driving its use, offering insight into users' reasons for chewing.[32] Although various scales exist to measure betel quid dependency, more comprehensive and validated tools are still needed to assess this dependency effectively across different populations.[33] The Self-Rating Screening Test for Areca Abusers (SSTAA) is designed to detect betel quid abuse by evaluating psychosocial dysfunction and craving.[34] Betel Year is a metric introduced to quantify lifetime exposure to betel quid chewing.[35] This is an initial pilot effort with calls for further research to explore the carcinogenic potential of other additives and to refine the metric for broader application.[36]

Chemical composition

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Chemistry of betel leaf varies geographically and is mostly chavibetol dominant.[1][37] Safrole is a major component of Sri Lankan Piper betle.[38] Eugenol, isoeugenol, and germacrene D are other dominant compounds in other chemotypes.[39]

Leaves also contain eugenol, chavicol, hydroxychavicol,[40][41] and caryophyllene.[37]

Stems contain phytosterols (β-sitosterol, β-daucosterol, stigmasterol etc.), alkaloids (piperine, pellitorine, piperdardine, guineensine etc.), lignan (pinoresinol) and other components. Some of them are oleanolic acid, dehydropipernonaline, piperolein-B, bornyl cis-4-hydroxycinnamate and bornyl p-coumarate.[42][43][44][45]

Roots contain aristololactam A-II, a phenylpropene, 4-allyl resorcinol and a diketosteroid stigmast-4-en-3,6-dione.[46]

Its essential oil consists of 50 different compounds, of which major components are eugenol, caryophyllene, terpinolene, terpinene, cadinene, and 3-carene.[47]

Economics

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Betel leaves for selling in the market
Betel in Bangladesh
A Bengali woman selling betel leaves in Howrah

Betel vines are cultivated throughout southeast Asia, in plots typically 20 to 2,000 square metres (0.005 to 0.5 acre) in size.

Malaysian farmers cultivate four types of betel plants: sirih India, sirih Melayu, sirih Cina and sirih Udang. The harvest is then sold in bundles of leaves, each bundle costing in 2011 between MYR 0.30 and 0.50 ($0.07 and $0.12).

In Sri Lanka, betel is grown all over the country. Commercial production of betel, with bigger leaves with dark green colour combined with thickness, known as “kalu bulath”, is confined to a few districts, such as Kurunagala, Gampaha, Kegalle, Kalutara and Colombo.[8] These are sold at a wholesaler in lots of 1,000 leaves. According to a report published by the United Nations Food and Agriculture Organization (FAO),[48] a successful betel farm in Sri Lanka can provide a supplemental income to a farmer by providing six days of work every six months and net income when the leaf prices are attractive.[49]

The FAO study found the successful farm's yield to be 18,000 leaves per 150 square feet (14 m2). The additional salary and income to the Sri Lankan betel grower, assuming he or she provides all needed labor and keeps all net profit, is SL Rs. 1635 per 150 square feet (14 m2) of betel farm every 6 months ($90 per "decimal" per year, or $9000 per acre per year). If the farmer hires outside labor to tend the betel vines and harvest the crop, the net income to the betel farm owner was SL Rs. 735 per 150 square feet (14 m2) of betel farm every six months ($40 per decimal per year, or $4000 per acre per year). The market prices for betel leaves vary with the wet and dry seasons in Sri Lanka, and in 2010 averaged SL Rs. 200–400 per 1,000 leaves ($1.82 to $3.64 per 1000 leaves).[50] The FAO study assumes no losses from erratic weather and no losses during storage and transportation of perishable betel leaves. These losses are usually between 35% and 70%.[51]

In Bangladesh, betel leaf farming yields vary by region and vine variety. In one region where betel leaf cultivation is the main source of income for farmers, a total of 2,825 hectares of land is dedicated to betel vine farming.[52] The average production costs for these betel farms in Bangladesh are about Tk 300,000 per hectare ($4,000 per hectare, $16 per decimal). The farm owners can earn a profit of over Tk 100,000 per hectare ($1,334 per hectare, $5.34 per decimal).

In India, a 2006 research reported[51] betel vines being cultivated on about 55,000 hectares of farmland, with an annual production worth of about IN Rs. 9000 million ($200 million total, averaging $1,455 per acre). The betel farming industry, the report claims, supports about 400,000 – 500,000 agricultural families.

A March 2011 report claims that betel farming is on a decline in India.[53] While in ideal conditions some farms may gross annual incomes after expenses of over IN Rs. 26,000 per 10 decimal farm ($5,780 per acre), a betel farm's income is highly erratic from year to year, due to varying rainfall patterns, temperature, and spoilage rates of 35% to 70% during transport over poor infrastructure.[51] Simultaneously, the demand for betel leaves has been dropping in India due to acceptance of gutkha (chewing tobacco) by consumers over betel leaf-based ‘‘paan’’ preparation.[54] The report cites betel leaf trading has dropped by 65% from 2000 to 2010 and created an oversupply. As a result, the report claims Indian farmers do not find betel farming lucrative anymore.[53]

See also

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References

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  1. ^ a b Rimando, Agnes M.; Han, Byung Hoon; Park, Jeong Hill; Cantoria, Magdalena C. (1986). "Studies on the constituents of Philippine Piper betle leaves". Archives of Pharmacal Research. 9 (2): 93–97. doi:10.1007/BF02857217. ISSN 0253-6269. S2CID 98263258.
  2. ^ "betel". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  3. ^ Portuguese Vocables in Asiatic Languages: From the Portuguese Original of M S R Dalgado. New Delhi: Asian Educational Services. 1988. ISBN 812060413X.
  4. ^ "Piper betle L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 23 April 2022.
  5. ^ a b Zumbroich, Thomas J. (2007–2008). "The origin and diffusion of betel chewing: a synthesis of evidence from South Asia, Southeast Asia and beyond". eJournal of Indian Medicine. 1: 87–140.
  6. ^ "Betel-leaf farming in coastal area". Dawn. 13 May 2002. Retrieved 30 October 2014.
  7. ^ Cassey, Brian (9 November 2013). "Chewing over a betel ban". Sydney Morning Herald. Retrieved 30 October 2014.
  8. ^ a b Government of Sri Lanka. "Betel – Piper Betle L". Archived from the original on 2016-05-14. Retrieved 2011-07-31.
  9. ^ Karim, ASM Enayet (2012). "Pan1". In Islam, Sirajul; Jamal, Ahmed A (eds.). Banglapedia: National Encyclopedia of Bangladesh (Second ed.). Asiatic Society of Bangladesh.
  10. ^ a b Gutierrez, Andrea (2015). "Modes of betel leaf consumption in early India". Scripta Instituti Donneriani Aboensis. 26: 114–34. doi:10.30674/scripta.67450.
  11. ^ a b Toprani, Rajendra; Patel, Daxesh (2013). "Betel leaf: Revisiting the benefits of an ancient Indian herb". South Asian Journal of Cancer. 2 (3): 140–141. doi:10.4103/2278-330X.114120 (inactive 1 November 2024). PMC 3892533. PMID 24455591.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
  12. ^ "BICON - Import Conditions - Conditions". bicon.agriculture.gov.au. Retrieved 11 March 2023.
  13. ^ "Making Lime for Betelnut Chewing in M'Buke, Manus, PNG". WWF Coral Triangle Blog. 25 July 2010. Retrieved 11 March 2023.
  14. ^ Levin, Dan (19 August 2010). "Despite Risks, an Addictive Treat Fuels a Chinese City". The New York Times. Retrieved 16 November 2019.
  15. ^ a b c Amonkar, A.J.; Nagabhushan, M; D'Souza, A.V.; Bhide, S.V. (1986). "Hydroxychavicol: A new phenolic antimutagen from betel leaf". Food and Chemical Toxicology. 24 (12): 1321–1324. doi:10.1016/0278-6915(86)90065-7. PMID 3100406.
  16. ^ "Head and Neck Cancers". NCI. 29 March 2017. Retrieved 7 February 2021.
  17. ^ a b A, Fatima; Zohaib, J (4 December 2020). "Oropharyngeal Squamous Cell Carcinoma". Definitions (Updated ed.). Treasure Island (FL): StatPearls Publishing. doi:10.32388/G6TG1L. PMID 33085415. S2CID 229252540. Bookshelf ID: NBK563268. Retrieved 7 February 2021 – via NCBI. {{cite book}}: |work= ignored (help)
  18. ^ Guttenplan, Joseph B. (1987). "Mutagenic activity in smokeless tobacco products sold in the USA". Carcinogenesis. 8 (5): 741–743. doi:10.1093/carcin/8.5.741. PMID 3581433.
  19. ^ Friedell, H.L.; Rosenthal, L.M. (1941). "The etiologic role of chewing tobacco in cancer of the mouth: Report of eight cases treated with radiation". JAMA: The Journal of the American Medical Association. 116 (19): 2130–2135. doi:10.1001/jama.1941.02820190006002.
  20. ^ Mori, H.; Matsubara, N.; Ushimaru, Y.; Hirono, I. (1979). "Carcinogenicity examination of betel nuts and piper betel leaves". Experientia. 35 (3): 384–5. doi:10.1007/BF01964368. PMID 446629. S2CID 30379485.
  21. ^ Secretan, Béatrice; Straif, Kurt; Baan, Robert; Grosse, Yann; El Ghissassi, Fatiha; Bouvard, Véronique; Benbrahim-Tallaa, Lamia; Guha, Neela; Freeman, Crystal; Galichet, Laurent; Cogliano, Vincent (2009). "A review of human carcinogens—Part E: tobacco, areca nut, alcohol, coal smoke, and salted fish". The Lancet Oncology. 10 (11): 1033–1034. doi:10.1016/S1470-2045(09)70326-2. PMID 19891056.
  22. ^ Phukan, R. K.; Ali, M. S.; Chetia, C. K.; Mahanta, J. (2001). "Betel nut and tobacco chewing; potential risk factors of cancer of oesophagus in Assam, India". British Journal of Cancer. 85 (5): 661–667. doi:10.1054/bjoc.2001.1920. PMC 2364125. PMID 11531248.
  23. ^ IARC Working Group. Betel-quid and areca-nut chewing and some areca-nut-derived Nitrosamines (PDF). The World Health Organization. ISBN 9789283215851.
  24. ^ WHO Report on the Global Tobacco Epidemic, 2008: the MPOWER package (PDF). Geneva: World Health Organization. 2008. ISBN 978-92-4-159628-2. Archived from the original (PDF) on March 8, 2008.
  25. ^ Warnakulasuriya, S.; Trivedy, C; Peters, TJ (2002). "Areca nut use: An independent risk factor for oral cancer". BMJ. 324 (7341): 799–800. doi:10.1136/bmj.324.7341.799. PMC 1122751. PMID 11934759.
  26. ^ Dave, Bhavana J.; Trivedi, Amit H.; Adhvatyu, Siddharth G. (1992). "Role of areca nut consumption in the cause of oral cancers. A cytogenetic assessment". Cancer. 70 (5): 1017–23. doi:10.1002/1097-0142(19920901)70:5<1017::AID-CNCR2820700502>3.0.CO;2-#. PMID 1515978. S2CID 196365532.
  27. ^ Sadasivan, G.; Rani, Gulab; Kumari, C.Kusuma (1978). "Chromosome-damaging effect of betel leaf". Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis. 57 (2): 183–5. Bibcode:1978MRFMM..57..183S. doi:10.1016/0027-5107(78)90266-X. PMID 661839.
  28. ^ Padma, P.R; Lalitha, V.S.; Amonkar, A.J.; Bhide, S.V. (1989). "Anticarcinogenic effect of betel leaf extract against tobacco carcinogens". Cancer Letters. 45 (3): 195–202. doi:10.1016/0304-3835(89)90077-3. PMID 2731162.
  29. ^ Morton, J. F. (1992). Widespread tannin intake via stimulants and masticatories, especially guarana, kola nut, betel vine, and accessories (pp. 739–765). Springer USA
  30. ^ Chang, Mei-Chi; Pan, Yu-Hwa; Wu, Hsyueh-Liang; Lu, Yi-Jie; Liao, Wan-Chuen; Yeh, Chien-Yang; Lee, Jang-Jaer; Jeng, Jiiang-Huei (2019). "Stimulation of MMP-9 of oral epithelial cells by areca nut extract is related to TGF-β/Smad2-dependent and –independent pathways and prevented by betel leaf extract, hydroxychavicol and melatonin". Aging (Albany NY). 11 (23): 11624–11639. doi:10.18632/aging.102565. PMC 6932916. PMID 31831717.
  31. ^ Reddy Gundalaa, Sushma; Yang, Chunhua; Mukkavilli, Rao; Paranjpe, Rutugandha; Brahmbhatt, Meera; Pannu, Vaishali; Cheng, Alice; Reid, Michelle D.; Aneja, Ritu (2014). "Hydroxychavicol, a betel leaf component, inhibits prostate cancer through ROS-driven DNA damage and apoptosis". Toxicology and Applied Pharmacology. 280 (1): 86–96. Bibcode:2014ToxAP.280...86G. doi:10.1016/j.taap.2014.07.012. PMC 4363134. PMID 25064160.
  32. ^ Little, Melissa A; Pokhrel, Pallav; Murphy, Kelle L; Kawamoto, Crissy T; Suguitan, Gil S; Herzog, Thaddeus A (2014-06-03). "The reasons for betel-quid chewing scale: assessment of factor structure, reliability, and validity". BMC Oral Health. 14: 62. doi:10.1186/1472-6831-14-62. ISSN 1472-6831. PMC 4059468. PMID 24889863.
  33. ^ Deshpande, Ashwini; Nagi, Ravleen; Byatnal, Amit; Lingappa, Ashok; Ashok, Sujatha; Sahu, Pitambra (2023). "Instruments to Measure Betel Quid Dependency among Young and Adult Chewers – A Systematic Review with Meta-analysis". Contemporary Clinical Dentistry. 14 (3): 180–190. doi:10.4103/ccd.ccd_101_23. ISSN 0976-237X. PMC 10699192. PMID 38075534.
  34. ^ Chen, M-J; Yang, Y-H; Shieh, T-Y (2002-07-01). "Evaluation of a self-rating screening test for areca quid abusers in Taiwan". Public Health. 116 (4): 195–200. doi:10.1038/sj.ph.1900861. ISSN 0033-3506. PMID 12087477.
  35. ^ Rajakumar, Hamrish Kumar; Coimbatore Sathyabal, Varsha; Jabarulla, Kolsamma Nasrin; Balamurugesan, Pushpa (2024-08-01). "Development and validation of betel-year: a clinical tool for quantifying exposure to betel quid chewing, utilizing nuclear morphometric analysis and validated by cytomorphological analysis". BMC Cancer. 24 (1): 930. doi:10.1186/s12885-024-12685-w. ISSN 1471-2407. PMC 11293172. PMID 39090612.
  36. ^ Rajakumar, Hamrish Kumar; Coimbatore Sathyabal, Varsha (2024-02-20). "A call for the development of a clinical tool to quantify lifetime betel quid exposure, inspired by the pack-years concept in smoking— Betel-years". Journal of Oral Pathology & Medicine. 53 (3): 172–173. doi:10.1111/jop.13521. ISSN 0904-2512. PMID 38379255.
  37. ^ a b "Chemical Composition and Biological Activities of Nepalese Piper betle L." (PDF). Retrieved 11 March 2023. {{cite journal}}: Cite journal requires |journal= (help)
  38. ^ Arambewela LS, Arawwawala LD, Kumaratunga KG, Dissanayake DS, Ratnasooriya WD, Kumarasingha SP (July 2011). "Investigations on Piper betle grown in Sri Lanka". Pharmacognosy Reviews. 5 (10): 159–63. doi:10.4103/0973-7847.91111. PMC 3263050. PMID 22279373.
  39. ^ Dwivedi, Vandana; Tripathi, Shalini (2014). "Review study on potential activity of Piper betle" (PDF). Journal of Pharmacognosy and Phytochemistry. 3: 93–98. Retrieved 27 September 2021.
  40. ^ Murata K, Nakao K, Hirata N, Namba K, Nomi T, Kitamura Y, Moriyama K, Shintani T, Iinuma M, Matsuda H (July 2009). "Hydroxychavicol: a potent xanthine oxidase inhibitor obtained from the leaves of betel, Piper betle". Journal of Natural Medicines. 63 (3): 355–9. doi:10.1007/s11418-009-0331-y. PMID 19387769. S2CID 19647900.
  41. ^ Atiya A, Sinha BN, Lal UR (March 2020). "The new ether derivative of phenylpropanoid and bioactivity was investigated from the leaves of Piper betle L". Natural Product Research. 34 (5): 638–645. doi:10.1080/14786419.2018.1495634. PMID 30169967. S2CID 52139286.
  42. ^ Yin Y, Huang XZ, Wang J, Dai JH, Liang H, Dai Y (June 2009). "[Studies on the chemical constituents of the stems of Piper betle]". Zhong Yao Cai = Zhongyaocai = Journal of Chinese Medicinal Materials (in Chinese). 32 (6): 887–90. PMID 19764326.
  43. ^ Huang X, Yin Y, Huang W, Sun K, Cheng C, Bai L, Dai Y (September 2010). "[Alkaloids and lignans from stems of Piper betle]". Zhongguo Zhong Yao Za Zhi = Zhongguo Zhongyao Zazhi = China Journal of Chinese Materia Medica (in Chinese). 35 (17): 2285–8. PMID 21137339.
  44. ^ Wu YJ, Su TR, Chang CI, Chen CR, Hung KF, Liu C (May 2020). "(+)-Bornyl p-Coumarate Extracted from Stem of Piper betle Induced Apoptosis and Autophagy in Melanoma Cells". International Journal of Molecular Sciences. 21 (10): 3737. doi:10.3390/ijms21103737. PMC 7279146. PMID 32466337.
  45. ^ Yang TY, Wu YJ, Chang CI, Chiu CC, Wu ML (May 2018). "The Effect of Bornyl cis-4-Hydroxycinnamate on Melanoma Cell Apoptosis Is Associated with Mitochondrial Dysfunction and Endoplasmic Reticulum Stress". International Journal of Molecular Sciences. 19 (5): 1370. doi:10.3390/ijms19051370. PMC 5983650. PMID 29734677.
  46. ^ Ghosh K, Bhattacharya TK (August 2005). "Chemical constituents of Piper betle Linn. (Piperaceae) roots". Molecules (Basel, Switzerland). 10 (7): 798–802. doi:10.3390/10070798. PMC 6147577. PMID 18007349.
  47. ^ Das, Suryasnata; Parida, Reena; Sandeep, I. Sriram; Kar, Basudev; Nayak, Sanghamitra; Mohanty, Sujata (2016). "Chemical composition and antioxidant activity of some important betel vine landraces". Biologia. 71 (2): 128–132. Bibcode:2016Biolg..71..128D. doi:10.1515/biolog-2016-0030. ISSN 1336-9563. S2CID 88132584.
  48. ^ Jan B. Orsini. "Success Case Replication – A Manual for Increasing Farmer Household Income, see case study 12 in the report".
  49. ^ "Life in the hill country of Sri Lanka". The Food and Agriculture Organization of United Nations.
  50. ^ "Life in the hill country of Sri Lanka". The Food and Agriculture Organization of United Nations.
  51. ^ a b c P. Guha (2006). "Betel Leaf – The neglected green gold of India" (PDF). 19 (2): 87–93. {{cite journal}}: Cite journal requires |journal= (help)
  52. ^ "Betel-leaf farming benefiting farmers". The Independent. Dhaka. 6 May 2011. Archived from the original on 15 March 2012.
  53. ^ a b "Too costly to grow". CSE.
  54. ^ "Paan loses flavour". CSE.

Further reading

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