Reviews 653 Plectranthus barbatus: A Review of Phytochemistry, Ethnobotanical Uses and Pharmacology – Part 1 Authors Rawiya H. Alasbahi 1, Matthias F. Melzig 2 Affiliations 1 Faculty of Pharmacy, Department of Pharmacognosy, University of Aden, Crater-Aden, Yemen 2 Institute of Pharmacy, Free University Berlin, Berlin, Germany Key words Abstract liver fatigue, respiratory disorders, heart diseases l" Plectranthus barbatus ! and certain nervous system disorders. Forskolin l" Lamiaceae Plectranthus barbatus Andr. is one of the most im- as one of the major constituents with its unique l" forskolin portant species of the genus Plectranthus L′ Herit. adenylyl cyclase activation that underlies the l" phytochemistry (Lamiaceae), with a wide variety of traditional wide range of pharmacological properties could l" ethnobotanical uses l" pharmacology medicinal uses in Hindu and Ayurvedic tradition- explain the different traditional uses of Plectran- l" 6‑(3‑dimethylaminopropio- al medicine as well as in the folk medicine of Bra- thus barbatus. Forskolin is involved in a number nyl)forskolin hydrochloride zil, tropical Africa and China. The plant has there- of patented pharmaceutical preparations used as (NKH477) fore been an attractive target for intensive chem- over-the-counter drugs for the treatment of sev- ical and pharmacological studies up to now. This eral ailments. However, the water-insoluble na- review presents data about the phytochemistry, ture of forskolin limits its clinical usefulness. For- ethnobotanical uses and pharmacology of Plec- skolin thus served as a prototype for the develop- tranthus barbatus as well as the pharmacology of ment of 6-(3-dimethylaminopropionyl)forskolin its constituents. In addition to essential oil, abie- hydrochloride (NKH477) as a potent water-solu- tane diterpenoids and 8,13-epoxy-labd-14-en- ble forskolin derivative that finds use in the ther- 11-one diterpenoids are the main constituents apy for a number of diseases especially of the car- found in Plectranthus barbatus. The major ethno- diovascular system. botanical uses are for intestinal disturbance and Introduction East Africa, Asia (South of Arabian Peninsula, Chi- ! na) and Brazil [3–5]. Plectranthus L′ Herit., is a complex genus of the P. barbatus is one of the most commonly used me- received May 19, 2009 family Lamiaceae (Labiatae) that contains about dicinal species of the genus Plectranthus.Adiver- revised Dec. 7, 2009 300 species distributed in tropical Africa, Asia sity of traditional medicinal uses of P. barbatus in accepted January 25, 2010 and Australia [1]. Taxonomically the genera Co- India (Hindu and Ayurvedic medicine), East and This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. Bibliography leus and Plectranthus are recombined by the Japa- Central Africa, China, and Brazil have been re- DOI http://dx.doi.org/ nese authors to the genus Plectranthus [2]. One of ported. The majority of uses are for intestinal dis- 10.1055/s-0029-1240898 the most important species of this genus is Plec- turbance and liver fatigue, respiratory disorders, Published online February 22, tranthus barbatus Andr., which is commonly re- heart diseases and certain central nervous system 2010 ferred to by a number of synonyms such as Plec- disorders [1,3,4, 6,7]. P. barbatus root extracts, Planta Med 2010; 76: 653–661 © Georg Thieme Verlag KG tranthus forskohlii Briq, Plectranthus forskalaei such as the 50% ethanolic and methanolic ex- Stuttgart · New York · Willd., Plectranthus kilimandschari (Gürke) H.L. tracts were therefore, in the middle of the 1970s, ISSN 0032‑0943 Maass., Plectranthus grandis (Cramer) R.H. Wil- independently involved in screening programs Correspondence lemse, Coleus forskohlii Briq., Coleus kilimand- for biological activities such as cardiovascular Prof. Dr. Matthias F. Melzig schari Gürke ex Engl., Coleus coerulescens Gürke, properties in the Central Drug Research Institute Institute of Pharmacy Coleus comosus A. Rich., and Coleus barbatus (CDRI), Lucknow, India, and by the group at Free University Berlin Königin-Luise-Str. 2 + 4 (Andr.) Benth [1]. Plectranthus barbatus grows Hoechst India Limited in Bombay, India. Reports 14195 Berlin perennially over the tropical and subtropical re- from both research groups revealed the hypoten- Germany gions of the Indian subcontinent and is cultivated sive and antispasmodic effects of the root extracts Phone: + 493083851451 Fax:+493083851461 commercially for its use in pickles. It is also dis- as well as the isolation of the major active princi- [email protected] tributed over parts of Pakistan, Sri Lanka, tropical ple which was named coleonol by CDRI [6,8,9], Alasbahi RH, Melzig MF. Plectranthus barbatus: A Review… Planta Med 2010; 76: 653–661 654 Reviews Table 1 Diterpenoids isolated from Plectranthus barbatus. No. of the Name of the compound Parta used P. barbatus location References compound Abietane diterpenoids 1 (+)-Allylroyleanone (plectranthone J) L East Africa – Kenya [15] 2 Coleon S L China [16, 17] 3 Coleon O L East Africa – Kenya [18] 4 ColeonT L China [16, 17] 5 Plectrin L East Africa – Kenya [15, 18] 6 Barbatusin L Brazil [7,19,20] 7 3β-Hydroxy-3-deoxybarbatusin L Brazil [7] 8 Cyclobutatusin L Brazil [7,19,21] 9 7β-Acetyl-12-deacetoxycyclobutatusin L Brazil [19] 10 (16R)-Coleon E L East Africa – Kenya [15, 22] 11 Coleon F L East Africa – Kenya [15, 23] 12 (16R)-Plectrinon A L Brazil, East Africa – Kenya [3,15] 13 Plectrinon B L East Africa – Kenya [15] 14 14-Deoxycoleon U R China [24] 15 Coleon C WP China [25] 16 6,7-Secoabietane diterpene I S Brazil [26] 17 6,7-Secoabietane diterpene II S Brazil [26] 18 Cariocal S Brazil [27] 19 Abietatriene (dehydroabietane) R India [28] 20 Demethylcryptojaponol (11-hydroxysugiol) R China [24] 21 Ferruginol S Brazil [29] 22 Sugiol WP China [30] 23 20-Deoxocarnosol S Brazil [31, 32] 24 6β-Hydroxycarnosol S Brazil [33] 25 Barbatusol S Brazil [29] 8,13-Epoxylabd-14-en-11-one-diterpenoids 26 Forskolin (7β-acetoxy-1α,6β,9α-trihydroxy-8,13-epoxy-labd-14-en-11-one; R, R India, China [5,10,34–37] coleonol; colforsin; 1-deacetylforskolin B, 6-deacetylforskolin J) 27 9-Deoxyforskolin (7β-acetoxy-1α,6β-dihydroxy-8,13-epoxy-labd- 14-en-11- R India [5,35,38] one) 28 1,9-Dideoxyforskolin (7β-acetoxy-6β-hydroxy-8,13-epoxy-labd-14-en-11- R India [5,10,35] one) 29 1,9 Dideoxy-7-deacetylforskolin (6β,7β-dihydroxy-8,13-epoxy-labd-14-en- R India [5,10,35] 11-one) 30 Deacetyl-1-deoxyforskolin (6β,7β,9α- trihydroxy-8,13-epoxy-labd-14-en-l l- R India [35] one) 31 6-Acetyl-1-deoxyforskolin WP China [39] 32 6-Acetyl-1,9-dideoxyforskolin WP China [39] 33 1,6-Di-O-acetylforskolin (1α,6β,7β triacetoxy-9α-hydroxy-8,13-epoxy-labd- R, WP China [4,40,41] 14-en-11-one; forskolin A; 1,7-diaceylisoforskolin) 34 1-Acetylforskolin (1α,7β-diacetoxy-6β,9α-dihydroxy-8,13-epoxy-labd-14-en- R, WP China [4,40,41] 11-one; forskolin B) 35 Isoforskolin (6β-acetoxy-1α,7β,9α-trihydroxy-8,13-epoxy-labd-14-en-11- R, R, L, WP India, China [4,10,16, 37, one; coleonol B; forskolin C; 1-deacetylforskolin I) 40–45] 36 1,9-Dideoxycoleonol B (7β-hydroxy-6β-acetoxy-8,13-epoxy-labd-14-en-11- R India, [46] one) This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. 37 7-Deacetylforskolin (1α,6β,7β,9α-tetrahydroxy-8,13-epoxy-labd-14-en-11- R, R, WP India, China [4,5,10, 35,40, one; deacetylforskolin; 6-deacetylisoforskolin; forskolin D) 41] 38 Forskolin E (lα,7β-diacetoxy-6β-hydroxy-8,13-epoxy-labd-14-en-l1-one; 9-de- R, WP China [4,47] hydroxyforskolin B) 39 Forskolin F (7β-acetoxy-6β,9α-dihydroxy-8,13-epoxy-labd-14-en-11-one; R, R, WP India, China [4,35,43, 47,48] 1-deoxyforskolin; 1-deacetoxyforskolin B; coleonol D) 40 Forskolin G (1α-hydroxy-6β,7β-diacetoxy-8,13-epoxy-labd-14-en-11-one; R, WP China [44, 45,47, 49, l-deacetyl-9-dehydroxyforskolin A; l-deacetyl-6-acetylforskolin E) 50] 41 Forskolin H (1α,6β-diacetoxy-8,13-epoxy-labd-14-en-11-one; 7-deacetoxy-9- R, WP China [44, 45,47, 49] dehydroxyforskolin A; plectromatin C) 42 Forskolin I (1α,6β-diacetoxy-7β,9α-dihydroxy-8,13-epoxy-labd-14-en-11- R, WP China [44, 45,51, 52] one; 7-deacetylforskolin A; 1-acetylforskolin C) 43 Forskolin J (1α,9α-dihydroxy-6β,7β-diacetoxy-8,13-epoxy-labd-14-en-11- R China [44, 51,52] one; 6-O-acetylforskolin;1-deacetylforskolin A; 7-acetylforskolin C) 44 1,6-Diacetoxy-9-deoxyforskolin (1α,6β,7β-triacetoxy-8,13-epoxy-labd-14- R, WP China [30, 44,52] en-11-one; forskolin K; 9-dehydoxyfoskolin A) 45 6β-Hydroxy-8,13-epoxy-labd-14-en-11-one (forskolin L) R, R China, India [35, 44,52] (continued) Alasbahi RH, Melzig MF. Plectranthus barbatus: A Review… Planta Med 2010; 76: 653–661 Reviews 655 Table 1 Continued No. of the Name of the compound Parta used P. barbatus location References compound 46 Coleosol (6β,9β-dihydroxy-8,13-epoxy-labd-14-en-11-one; 6β,9β-dihydroxy- R India [43, 53] 11-oxomanoyloxide) 47 1-Acetoxy coleosol (1α-acetoxy-6β,9α-dihydroxy-8,13-epoxy-labd-14-en-11- R India [46] one) 48 Coleol (9α-hydroxy-8,13-epoxy-labd-14-en-11-one) R India [35, 43,54, 55] 49 11-Oxomanoyloxide (8,13-epoxy-labd-14-en-11-one) R India [35] 50 Coleonol E (7α-acetoxy-6β-hydroxy-8,13-epoxy-labd-14-en-11-one) R India [56] 51 Coleonol F (6β-acetoxy-7α,9α-dihydroxy-8,13-epoxy-labd-14-en-11-one) R India [56] 52 Deoxycoleonol (7α-acetoxy-1α,6β-dihydroxy-8,13-epoxy-labd-14-en-11- R India [57] one) 8,13-Epoxy-labd-diterpenoids with some deviations 53 3-Hydroxyforskolin WP China [58] 54 3-Hydroxyisoforskolin WP China [58] 55