Callistemon Species Research Articles

A Review on Phytochemical and Pharmacological Activities of Callistemon viminalis

Callistemon viminalis belongs to the family Myrtaceae and also known as bottlebrush which is or found throughout in India. It has a remarkable place in Ayurvedic medicine of India, due to presence of phytoconstituents and pharmacological activities. Callistemon species as a farm tree are planted for forestry or ornamental purposes and for weed as well. In traditional Chinese medicines, C. viminalis is used for treating hemorrhoids. Hot drink locally ‘tea’ in Jamaica from C. viminalis has been used for the treatment of gastroenteritis, diarrhea and skin infections. The phytochemical research carried out on C. viminalis extracts and showed that the plant is rich in phenolics, triterpenoids, flavonoids, saponins, steroids, alkaloids, tannin, carbohydrates, amino acids and proteins compounds. The investigated pharmacological studies reported the presence of anti-inflammatory, Alzheimer, hemolytic activity, anthelmintic, anti-oxidant property, anti-bacterial, antifungal and hepatoprotective activities in C. viminalis.

A Minireview on Medicinal Benefits of Melaleuca viminalis and Tabebuia rosea

From plants, novel chemotherapy medicines can be derived. Ancient medicinal herbs were used to heal illness, and prevent epidemics. Tropical and subtropical Central and South American tree Tabebuia rosea is grown globally. For centuries, the tree's anti-inflammatory, analgesic, antibacterial, immune-boosting, and antioxidant qualities have treated numerous maladies. Little, bushy Callistemon (Melaleuca viminalis) has lanceolate leaves and hairy blooms. It features crimson "bottlebrush" inflorescences, thicker, leatherier leaves, and darker, fissured bark. This Callistemon species sheds seeds annually, unlike others. Spring and summer bottlebrushes develop multi-flower spikes. Flower pollen grows on a fine, multi-coloured thread. Filaments and pollen can tint flower spikes golden, although yellow is more typical. Each flower produces a woody fruit with many small seeds that lasts for years. Callistemon leaves are antioxidant, antibacterial, antifungal, and anti-platelet aggregation. Hence, this article briefly addresses the two medicinal plants (Melaleuca viminalis and Tabebuia rosea) in Bengaluru's Agara lake.

Callistemon genus- a review on phytochemistry and biological activities

Callistemon is an important genus in the family Myrtaceae which contains about 34 species. The members of this genus are known for their ornamental potentials, in addition to their outstanding value in conventional medicine in many parts of the world. Updated chemical analysis of the Callistemon genus has provided a variety of essential phytocompounds belonging to different chemical classes including terpenes, phenolic derivatives, flavonoids, anthocyanins, neolignans, phloroglucinol derivatives and other miscellaneous compounds. Hence, this dissertation reflects a systematic evaluation of the Callistemon genus phytochemical and biological studies, in addition to a summary of the previous studies’ results as well as an overview of the possible directions of Callistemon species study.

Comparative metabolite profiling of Callistemon macropunctatus and Callistemon subulatus volatiles from different geographical origins

Since ancient times, essential oils from medicinal plants have supplied a huge repository of secondary metabolites. Genus Callistemon, Myrtaceae, was described to have nematicidal, antithrombotic, antistaphylococcal, antioxidant, and insecticidal activities. In this study we investigate the chemical composition of essential oils from the leaves and the flowers of C. macropunctatus (Dum.Cours.) Court and Callistemon subulatus (Cheel) from two geographical locations: Australia and Egypt. GCMS analysis identified a total of sixty-one volatile components and showed that the major constituents were 1,8-cineole, α-pinene, α-terpineol, limonene and α-phellandrene in the leaves and α-pinene, 1,8-cineole, α-phellandrene, limonene and α-terpineol in the flowers of Callistemon species. To discriminate the oil complexity within factors as location, plant parts and species, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed. Furthermore, the cytotoxic effect of the oil samples was assayed against the human liver cancer cell line HepG2 to reveal a potent anticancer potential with half-maximal inhibitory concentration (IC50) values ranging from 1.76 μg/mL to 13.41 μg/mL. To gain insight into the cellular mechanism of the cytotoxic activity, Callistemon volatile oils’ activities on topoisomerases I-β and II-β were explored, which demonstrated significant enzyme inhibition with IC50 values as low as 819.6 ng/mL. Molecular in-silico docking study of the major oil components within the active binding site of the human topoisomerases I-β and II-β was conducted. α-terpineol showed promising alkyl interactions in the binding pockets of topoisomerase IB and IIB, with a docking Gibb’s free energy values of -27.0913 and -26.6478 kcal/mol, respectively. Whereas it bounded to Arg503 and four nucleotide regions deoxyadenosine DA12, deoxythymidine DT9, deoxyguanosine DG13, deoxycytidine DC8 in the topoisomerase II-β enzyme pocket, it interacted with Topo I-β enzyme through hydrophobic alkyl and Pi-alkyl binding interactions with DA12, DG13 and Arg503. Furthermore, the oxygen in the hydroxyl group showed two additional non-covalent bonds: a conventional hydrogen bond with Asp533 and water hydrogen bond with a water molecule in the vicinity of the binding surface. This research highlights the future possibility of having Callistemon subulatus as a potential natural drug for treatment of liver cancer.

Phytochemical profiling and seasonal variation of essential oils of three Callistemon species cultivated in Egypt

The genus Callistemon comprises evergreen shrubs or small trees, widely cultivated as ornamentals and for essential oil production. Callistemon is well-recognized in folk medicine for its anti-cough, anti-bronchitis, and insecticidal activities. In the current study, we profiled the essential oil composition of the leaves of C. citrinus, C. rigidus and C. viminalis (Myrtaceae) collected during different seasons by GLC-MS coupled to multivariate data analysis. Antioxidant, anti-inflammatory and anti-proliferative activities of Callistemon essential oils were evaluated. A total of 29 compounds were tentatively identified. Oxygenated monoterpenes dominated in essential oils, where eucalyptol represented the major constituent in the three Callistemon species in all seasons. Multivariate data analysis including Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were applied to discriminate between different Callistemon species in each season and to investigate any correlation between the metabolic profile of each species within different seasons. As expected, PCA plot could discriminate the three Callistemon species in the four seasons. The dendrogram from HCA confirmed the results of PCA as it showed the same segregation pattern regarding the discrimination of different Callistemon species. C. viminalis showed more pronounced antioxidant activity than C. citrinus, exhibiting IC50 values of 1.40 mg/mL and 1.77 mg/mL, respectively. Meanwhile, C. rigidus showed very weak antioxidant activity. All oils showed membrane stabilization activity in hypotonic solution induced haemolysis assay, where C. viminalis showed potent membrane stabilizing activity exhibiting IC50 value of 25.6 μg/mL comparable to that of the standard drug, indomethacin (17.02 μg/mL). Nevertheless, Callistemon essential oils were not cytotoxic in HCT-116 and Hela human cancer cell lines.

A Review, Outlook, and Insight, of the Properties and Characteristics of Callistemon Citrinus

Callistemon citrinus, an invasive plant species that's native to Australia, is known for its uses by traditional healers in herbal medicinal formulations. Although the use of this plant species in alternative medicine strategies is varied, and well reported in the literature, there isn't enough information in a succinct format that can be accessed by the public, in general. Furthermore, very little information is accessible on the epidermal appendages found in this species of Callistemon. Therefore, in this paper, what's known and isn't about this plant species is being provided. Also, few observations on the epidermal appendages of C. citrinus is given as a means to compare it's morphology with its function.

Volatile organic compounds emitted by bottlebrush species affect the behaviour of the sweet potato whitefly

The behavioural response of the sweet potato whitefly, Bemisia tabaci biotype B, to the volatiles emitted by three different species of Callistemon (C. laevis, C. pallidus and C. phoeniceus) was assayed in still-air, and Y-tube olfactometers. B. tabaci adults showed a preference for C. pallidus, while C. laevis and C. phoeniceus were less attractive to the insects when compared to a blank control or to C. pallidus. Volatile organic compounds emitted by the leaves of the three Callistemon species were analysed by solid phase microextraction coupled with GC–MS. 1,8-Cineole was detected in high percentages in C. phoeniceus and C. laevis headspaces, while linalool was abundant in the headspace of C. pallidus. Because of this difference, behavioural tests in the Y-tube olfactometer were carried out also with 1,8-cineole and linalool. Adults of B. tabaci were attracted by linalool, while they were repelled by 1,8-cineole compared with pure air or linalool. These results support the role of these volatiles in the host plant selection process by a herbivorous insect and lay the foundations for the development of sustainable control strategies based on the manipulation of insect pest behaviour.

Glossary ofCallistemon lanceolatusD.C.-An ornamental plant with Marvellous Properties

Most of the drugs used in primitive medicine were obtained from plants and are the earliest and principal natural source of medicines. Plants are a reservoir of potentially useful chemical compounds which serve as drugs and provide newer leads and clues for modern design by synthesis. Callistemon lanceolatus DC belongs to the family Myrtaceae commonly known as bottle brush, is frequently cultivated throughout India in gardens as ornamental plant. Humming birds love the flowers, and the plant. Callistemon species had a role as traditional bush medicine. The genus is known in folk medicine for its anti-cough, anti-bronchitis, and insecticidal effects and its volatile oils have been used as anti-microbial and anti-fungal agents, anti-phylococcal, nematicidal, larvicidal, pupicidal agent. The phytoconstituents present in this plant are flavonoids, tannins, saponins, steroids, monoterpenoids, triterpenoids, phloroglucinol derivatives, carbohydrates, proteins and essential oils. So this review article is a collective source of the various information regarding Callistemon lanceolatus published in various journals and books.

Assessment of the terpenic profile of Callistemon citrinus (Curtis) Skeels from Mexico

Callistemon species are well known due to its medicinal properties and due to, among others, the relevant health benefits of their terpenic components. This paper aims to in-depth study the terpenic profile of the leaf and flower extracts of Callistemon citrinus with two ages. To fulfill this objective, initially, a screening of the terpenic composition of ethanolic extracts of C. citrinus was performed using GC–MS, and a total of 17 terpenic components were identified in leaf and flower ethanolic extracts. In order to obtain a deeper knowledge, comprehensive two dimensional gas chromatography with time of flight mass spectrometry detection (GC×GC–ToFMS) was also applied, allowing to identify a total of 100 terpenic components in the analyzed ethanolic extracts, from which 77 were identified for the first time in C. citrinus species. A total of 74 and 64 terpenic components were identified in the 4 years old leaf and flower ethanolic extracts, respectively, and 68 and 70 in 20 year old ethanolic extracts, respectively. Moreover, the most abundant terpenic components detected in leaf extracts were 1,8-cineole, α-terpineol, linalool, 4-terpineol, spathulenol, β-gurjunene and viridiflorol, and in flowers were p-cymene, myrtanol, 1,8-cineole, linalool, spathulenol and rosifoliol. Flowers and leaves extracts present a different terpenic profile, with significant differences concerning the type and level of their components, also differences may be noticed related to the extract from 4 and 20 years old. This work allowed achieving a deep characterization of the terpenic composition of leaf and flower C. citrinus, a crucial step in the bioprospection of this plant raw-material as a source of terpenic compounds.

Antimicrobial activity of Callistemon citrinus and Callistemon salignus methanolic extracts

Introduction: Australian Callistemon species had roles as traditional bush medicines for Australian Aborigines, including uses as antiseptic agents. Despite this ethnobotanical usage, the antimicrobial properties of Callistemon spp. have not been rigorously studied. Methods: The antimicrobial activity of methanolic extracts of Callistemon citrinus and Callistemon salignus were investigated by disc diffusion and growth time course assays against a panel of bacteria and fungi. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: C. citrinus leaf extracts inhibited the growth of 43% and flower extracts inhibited the growth of 64% of the bacteria tested respectively. Gram-positive bacteria (100% inhibited) were more susceptible to C. citrinus extracts than were Gram-negative bacteria (27% inhibited by leaf extracts; 55% inhibited by flower extracts). In comparison, C. salignus leaf extract inhibited the growth of 29% of the bacteria tested compared with 43% inhibited for the flower extract. Gram-positive bacteria (100% inhibited) were more susceptible to C. salignus leaf extract than were Gram-negative bacteria (9% inhibited). Similar results (27% Gram-negative bacteria inhibited and 100% Gram-positive bacterial inhibition) were also seen for C. salignus flower extract. Very little antifungal activity was seen for any extract with only C. albicans being inhibited by C. salignus leaf extract. The antibacterial activity of the C. citrinus and C. salignus flower extracts were further investigated by growth time course assays. These extracts showed significant growth inhibition activity in cultures of Bacillus cereus, Aeromonas hydrophilia, Pseudomonas fluorescens and Bacillus subtilis within 1 hour. All extracts displayed low toxicity in the Artemia franciscana nauplii bioassay. Conclusions: The low toxicity of these Callistemon extracts and their inhibitory bioactivity against a panel of bacteria validate Australian Aboriginal usage of Callistemon citrinus and Callistemon salignus as antiseptic agents and confirms their medicinal potential.

Pollen morphology of the Myrtaceae. Part 2: tribes Backhousieae, Melaleuceae, Metrosidereae, Osbornieae and Syzygieae

Pollen morphology of 16 genera and 101 species from the Myrtaceae tribes Backhousieae, Melaleuceae, Metrosidereae, Osbornieae and Syzygieae was surveyed using scanning electron microscopy (SEM) and light microscopy (LM). The most common pollen type observed in these tribes was parasyncolpate with arcuate or angular colpi, and a rugulate exine pattern. There was little size variation in observed pollen, except for larger pollen in tribe Melaleuceae. All Metrosideros pollen grains had apocolpial islands, as well as all Callistemon species viewed by LM. Choricarpia of tribe Backhousieae had pollen with a distinctive exine pattern. Dicolporate pollen were observed in two tribes, Metrosidereae (Tepualia) and Syzygieae (Acmena), and may be of systematic value. The dicolporate grains of these two genera were also easily distinguishable from each other by using size and pollen side shape as diagnostic characters. Two pollen types were observed within the genus Melaleuca, and a number of pollen types were observed within the species-rich genus Syzygium.

Total Phenolic Content and Antioxidant Activity of Standardized Extracts from Leaves and Cell Cultures of Three Callistemon Species

A comparative study was carried out with ethanolic (80%) extracts from leaves and cell cultures of three Callistemon species, namely C. lanceolatus (CL), C. viridiflorous (CV), and C. comboynensis (CC). Cell suspensions of the three species were grown in liquid Murashige and Skoog (MS) medium (100 ml) supplemented with 0.9 mg·g-1 kinetin in combination with 1.1 mg·g-1 NAA. The CL leaf extract was standardized to contain the highest amount of phenolics (104 ± 2.0 mg·g-1), followed by CC (95.8 ± 1.2 mg·g-1) and CV (79.8 ± 4.6 mg·g-1). On the other hand, cell cultures of CV contained more phenolics (14.9 ± 0.6 mg·g-1) than those of the other two species, CL and CC, which contained 12.2 ± 0.16 and 9.12 ± 0.16 mg·g-1, respectively. Nevertheless, CV leaf extract exhibited the highest antioxidant activity (91.4% ± 0.4%) at a concentration of 1000 µg·ml-1, comparable to 100 µg·ml-1 gallic acid (90.8% ± 1.5%).

Melaleuca revisited: cpDNA and morphological data confirm that Melaleuca L. (Myrtaceae) is not monophyletic

AbstractWith about 335 species, the tribe Melaleuceae comprises a major lineage within the Australian Myrtaceae. Here we investigate relationships within Melaleuceae using cpDNA sequences (ndh)F and 27 morphological characters. We find strong evidence for the non–monophyly of Melaleuca, with all other currently recognized genera of Melaleuceae (Beaufortia, Calothamnus, Conothamnus, Eremaea, Lamarchea, Petraeomyrtus, Phymatocarpus, Regelia) falling within that genus. Our findings are broadly consistent with previous studies using nuclear ITS DNA sequence data; however, the cpDNA phylogeny estimate is more resolved and has higher support for major nodes. Melaleuceae is found to comprise three major clades, each containing species of Melaleuca and each with good support. The M. leucadendra (broad–leaf paper–barks), M. uncinata, M. pungens and M. acacioides groups, New Caledonian callistemons, and all other currently recognized genera of Melaleuceae form one clade. Australian Callistemon species, which have been synonymised recently with Melaleuca, cluster within a second clade of Melaleuca that includes the M. fulgens, M. laxiflora and M. ordinifolia groups, and some members of the M. lanceolata and M. cuticularis groups. A third clade includes other members of the M. lanceolata and M. cuticularis groups, M. foliolosa and the M. huegelii group. No morphological support or diagnostic synapomorphies are identified for any of these clades. Together with previous studies, our findings indicate that the circumscription of Melaleuca, and the generic status of other genera within Melaleuceae, is poorly supported, and we propose that all genera within the Melaleuceae are synonymised with Melaleuca.

New Combinations in Melaleuca for Australian Species of Callistemon (Myrtaceae)

The Australian species of the bottlebrush genus Callistemon R. Brown are not sufficiently distinct from Melaleuca L. for Callistemon to be maintained as a separate genus. The primary character states used to justify maintenance of Callistemon are that its staminal filaments are free and not grouped. This breaks down as fused filaments in five groups, the defining features of Melaleuca, occur in some Callistemon species. Therefore, it is concluded that the two genera should be combined. The following new names are proposed for species being treated in a forthcoming account of Melaleuca for Flora of Australia: M. faucicola Craven, M. flammea Craven, M. orophila Craven, M. paludicola Craven, M. salicina Craven, M. virens Craven, and M. williamsii Craven. The following new combinations are established as transferred from Callistemon M. brachyandra (Lindley) Craven, M. chisholmii (Cheel) Craven, M. comboynensis (Cheel) Craven, M. flavovirens (Cheel) Craven, M. formosa (S. T. Blake) Craven, M. montana (S. T. Blake) Craven, M. pachyphylla (Cheel) Craven, M. pearsonii (R. D. Spencer & Lumley) Craven, M. phoenicea (Lindley) Craven, M. pityoides (F. Mueller) Craven, M. polandii (F. M. Bailey) Craven, M. recurva (R. D. Spencer & Lumley) Craven, M. shiressii (Blakely) Craven, and M. subulata (Cheel) Craven. The following new combinations are also established from Metrosideros Melaleuca linearifolia (Link) Craven, M. linearis var. pinifolia (Wendland) Craven, M. pallida (Bonpland) Craven, and M. rugulosa (Schlechtendal ex Link) Craven. Issues concerning a name in Melaleuca for the accepted species presently known as Callistemon glaucus (Bonpland) Sweet are mentioned.

Comparing fractal analysis, electrical impedance and electrolyte leakage for the assessment of cold tolerance in Callistemon and Grevillea spp.

SummaryLethal low temperatures were examined in two species of Grevillea and four species of Callistemon, two taxa originating from Australia. The demand in Europe and America for Australian plants is increasing both as cut flowers and as potted or landscape plants, but there is little information available on the cold hardiness of these species. LT50 (lethal temperature at which 50% of damage occurs) was determined by measuring electrical conductivity (electrolyte leakage), impedance spectroscopy and fractal spectrum of leaf colour. All the experiments were conducted on non-acclimated and cold-acclimated plants. LT50 calculated on non-acclimated plants were about 2–3°C higher than in acclimated plants, except for G. olivacea. In every case, the LT50 estimated by the three methods were very similar and ranged from –4.6°C for G. olivacea, the species most sensitive to freezing, to about –9.5°C for C. salignus, the most resistant to freezing among the species tested.

Molecular phylogeny and biogeography of Melaleuca, Callistemon and related genera (Myrtaceae)

To resolve the relationships of taxa within the Beaufortia suballiance (Myrtaceae), 72 ingroup taxa were analysed by parsimony methods and nrDNA sequence data from the 5S and ITS-1 ribosomal DNA spacer regions. Although basal nodes in the consensus tree (combined data set) are not supported by bootstrap or jackknife values, a number of clades are well supported, showing that Melaleuca is polyphyletic. Monophyletic groups include: endemic species of Melaleuca from New Caledonia (including species of Callistemon recently transferred to Melaleuca); the tropical Melaleuca leucadendra group; Australian species of Callistemon, which relate to species of Melaleuca predominantly from the South-East; and a group of south-western and eastern Australian melaleucas that relate to a clade of three south-western genera, Eremaea, Conothamnus and Phymatocarpus. Calothamnus, Regeliaand Beaufortiamay also relate to this latter group. Lamarchea is possibly related to northern melaleucas. The results have implications for generic revisions of the large genus Melaleuca. Biogeographic subtree analysis, based only on supported nodes of the taxon cladogram, showed New Caledonia, New Guinea, Eastern Queensland and the Northern Desert unresolved at the base of the area cladogram. The position of some of these areas is likely to be artifactual, but New Caledonia is interpreted as in the correct position. At a higher node, the monsoonal northern areas of Australia (Kimberley, Arnhem and Cape York), Atherton, the Pilbara and Western Desert relate to the southern regions, which form a group. The South-West of Australia is related to Eyre and Adelaide (designated area ‘South’) and Tasmania is related to the South-East and MacPherson–Macleay. The vicariance between northern and southern regions in Australia possibly relates to an early major climatic change (from the Early Tertiary). The biogeographic analysis helped illuminate taxon relationships.

C-Methyl-flavonoids from the leaf waxes of some Myrtaceae

The thin waxy coatings on leaves of nine species of Callistemon, two of Melaleuca and one species of Metrosideros, have been studied for the occurrence of leaf surface flavonoids. The Callistemon species and Metrosideros robusta exhibit only C-methylated flavonoids, while O-methyl flavonoids were detected in Melaleuca huegelii. The new natural C-methyl flavonol, 5,7-dihydroxy-3,8,4′-trimethoxy-6-C-methylflavone, was isolated from Metrosideros robusta. The leaf wax of Callistemon coccineus contains the novel C-methylflavonoid, 5,4′-dihydroxy-8-C-methyl-7-methoxy flavanone.

Floral development in Melaleuca and Callistemon (Myrtaceae)

Floral development of seven species of Melaleuca and four species of Callistemon is compared. The multistaminate fascicles of Melaleuca develop from stamen primordia initiated on antepetalous pre-staminal bulges (PSBs); the resultant bundles of stamens become separated by hypanthial expansion as the flower bud enlarges. In most species of Callistemon examined the stamen primordia are initiated directly on the floral apex, and the stamens are distributed evenly around the hypanthium at anthesis. The possession of large and prominent PSBs, and thus stamen fascicles, is a feature of most species of Melaleuca and their total absence is a feature of most species of Callistemon; however, there is a continuum between these two extremes. Several taxa of both genera exhibit intermediate morphology. In C. glaucus (Bonpl.) Sweet, small but distinct PSBs develop, which influence antepetalous stamen groups that remain contiguous at anthesis. This also occurred in M. leucadendra (L.) L. This variable expression of PSBs is the result of differences in the timing of stamen initiation. Other variable features are determined by the space available for primordium initiation and the patterns of growth and expansion of the developing flower.

The genus Phyllachora from Australia: observations on taxa from Callistemon species

Collections of Phyllachora on species of Callistemon from north Queensland, Australia are reported and compared with previously described species. Phyllachora callistemonis is retained, while P. langdonii is transferred to subspecies level and P. callistemonis subsp. similis is described as new. The fungi are illustrated with differential interference contrast micrographs.

Proline Analogues in Melaleuca Species: Response of Melaleuca lanceolata and M. uncinata to Water Stress and Salinity

Fifteen species of Melaleuca and two species of Callistemon from the field were examined to determine whether they accumulated nitrogen-containing compatible solutes and, if so, which. In addition to L-proline, N-methyl-L-proline (MP) (isolated for the first time from plants), trans-4-hydroxy-N-methyl- L-proline (MHP), and N, N'-dimethyl-trans-4-hydroxy-L-proline (DHP) were found in various combinations in the 15 Melaleuca species. M. lanceolata seedlings were subjected to water or salinity stress and M. uncinata to water stress under laboratory conditions. In both species significant reductions in leaf water potential (Ψw), osmotic potential (Ψs), turgor potential (Ψp), and relative water content (RWC) were observed in response to water stress. Salinised M. lanceolata plants showed considerable osmotic adjustment and maintained Ψp comparable to that of control plants; salinity, however, decreased RWC. In response to the imposed stresses under laboratory conditions, proline and MHP levels in M. lanceolata, and MHP and DHP levels in M. uncinata, increased. In addition to possible protective or osmotic roles in vivo, these proline analogues may be useful in chemotaxonomic investigations of Melaleuca species.