Cholinesterase-inhibiting withanolides from Ajuga bracteosa

Three new withanolides, bracteosin A (= (22R)-5beta,6beta : 22,26-diepoxy-4beta,28-dihydroxy-3beta-methoxyergost-24-ene-1,26-dione; 1), bracteosin B (= (22R)-5beta,6beta : 22,26-diepoxy-4beta,28-dihydroxy-3beta-methoxy-1,26-dioxoergost-24-en-19-oic acid; 2), and bracteosin C (= (22R)-22,26-epoxy-4beta,6beta,27-trihydroxy-3beta-methoxyergost-24-ene-1,26-dione; 3), have been isolated from the whole plants of Ajuga bracteosa. Their structures were deduced by spectral analysis, including 1D- and 2D-NMR techniques. In addition, dihydroclerodin-1, clerodinin A, lupulin A, and dihydroajugapitin have also been isolated for the first time from this species. Compounds 1-3 exhibited evident inhibitory potential against cholinesterase enzymes in a concentration-dependent fashion.     

Micropropagation of Centella asiatica (L.), a valuable medicinal herb

A protocol is described for rapid and large-scale in vitro clonal propagation of the valuable medicinal herb Centella asiatica (L.) by enhanced axillary bud proliferation in nodal segments isolated from mature plants. Although bud break was dependent on BA supply, the synergistic combination of 22.2 μM BA and 2.68 μM NAA induced the optimum frequency (91%) of shoot formation as well as shoot number (4 to 5 shoots per node). Subculturing of nodal segments harvested from the in vitro derived axenic shoots on the multiplication medium enabled continuous production of healthy shoots with similar frequency. MS medium supplemented with 6.7 μM BA and 2.88 μM IAA was found most suitable for shoot elongation. Rooting was highest (90%) on full-strength MS medium containing 2.46 μM IBA. Micropropagated plants established in garden soil were uniform and identical to the donor plant with respect to growth characteristics. This micropropagation procedure could be useful for raising a stock of genetically homogenous plant material for field cultivation. This revised version was published online in August 2006 with corrections to the Cover Date.     

Micropropagation of Heracleum candicans wall: A rare medicinal herb

Summary A protocol was developed for micropropagation of Heracleum candicans Wall. by axillary shoot proliferation. Maximum shoot proliferation was obtained on Murashige and Skoog medium supplemented with 0.5 mg (2.2 μM) 6-benzyladenine per 1 and 0.1 mg (0.4 μM) 1-naphthaleneacetic acid per 1. Regenerated shoots were rooted on MS medium fortified with 1 mg (4.9 μM) indole-3-butyric acid per 1. Complete plants were transferred to soil and all of these plants were morphologically and cytologically identical to the mother plant.     

Micropropagation of safed musli (Chlorophytum borivilianum), a rare Indian medicinal herb

In vitro clonal multiplication of safed musli (Chlorophytum borivilianum Sant. et. Fernand.), a rare Indian medicinal herb, has been achieved on Murashige and Skoog's (MS) medium supplemented with 22.2 M benzyladenine using young shoot bases as explants. Shoots multiplied at a rate of four-fold every 3 weeks. All shoots rooted when transferred to MS medium with 3/4-strength inorganic and organic constituents and 9.8 M indolebutyric acid and 67% of the micropropagated plants were successfully established in pots. Such plants produced normal fasciculated storage roots as in wild plants.Abbreviations BA 6-benzyladenine - 2,4-d 2,4-dichlorophenoxyacetic acid - IAA indoleacetic acid - IBA indolebutyric acid - MS Murashige and Skoog (1962) - NAA -naphthaleneacetic acid     

Micropropagation of Ajuga species: a mini review

The genus Ajuga L., belonging to Lamiaceae family, is widespread. The demand for Ajuga species has risen sharply because of their medicinal, ornamental, and pharmacological properties. These wide-ranging plants are being rapidly depleted due to over-collection for ornamental and medicinal purposes, as well as by habitat destruction and deforestation. Ajuga boninsimae, A. bracteosa, A. ciliate, A. genevensis, A. incisa, A. makinoi, A. multiflora, A. pyramidalis, A. shikotanensis, A. reptans, and A. vestita are categorized and protected as endangered plants. In vitro plant culture has therefore emerged for the conservation and mass clonal propagation of rare plants. This mini-review covers the current in vitro scenario in the propagation of Ajuga species. Adventitious or axillary shoots are initiated on the leaf, petiole and internodes, as well as roots, nodes, and shoot tip explants. Shoot induction is predominantly dependent on plant growth regulators added to the culture medium. Full- or half-strength Murashige and Skoog medium with or without auxin is used for in vitro rooting. Rooted shoots need to be acclimatized in the greenhouse with an estimated 82–100% survival rate.     

Isolation and enzyme-inhibition studies of the chemical constituents from Ajuga bracteosa

Bractin A (=(2S,3S,4R,5E)-2-{[(2R)-2-hydroxydodecanoyl]amino}triacont-5-ene-1,3,4-triol; 1) and bractin B (=(2S,3S,4R,5E,8E)-2-{[(2R)-2-hydroxyhexacosanoyl]amino}pentadeca-5,8-diene-3,4,15-triol 1-O-beta-D-glucopyranoside; 2), new sphingolipids, and bractic acid (=(5Z,10Z,15Z)-2-decyl-4,7,8,12,13,17,18-heptahydroxy-20,23-dioxopentacosa-5,10,15-trienoic acid; 3), a long-chain polyhydroxy acid, were isolated from the whole plant Ajuga bracteosa along with four known diterpenoids 4-7. Their structures were deduced by spectral studies including 1D- and 2D-NMR spectroscopy. Compounds 1-3 displayed inhibitory potential against enzyme lipoxygenase, while compounds 4-7 inhibited cholinesterase enzymes in a concentration-dependent manner with IC(50) values in the range 10.0-33.0, 14.0-35.2, and 10.0-19.0 microM for lipoxygenase, acetylcholinesterase, and butyrylcholinesterase, respectively. Lineweaver-Burk, and Dixon plots, and their secondary replots indicated that all compounds exhibit non-competitive type of inhibition with K(i) values in the range of 9.5-35.2, 15.2-36.0, and 11.6-20.5 microM, for lipoxygenase, acetylcholinesterase, and butyrylcholinesterase, respectively.     

Micropropagation of a medicinal plant, Plantago major L.

An efficient micropropagation protocol was developed for an important medicinal plant, Plantago major L. For this purpose, it is recommended to culture shoot-tips on modified MS medium [412.5 mg dm-3 NH4NO3 and 340 mg dm-3 KH2PO4] supplemented with 50 g dm-3 glucose and 0.5 μM 6-benzylaminopurine. Maximum rooting frequency was obtained at 1 μM naphthaleneacetic acid. This revised version was published online in August 2006 with corrections to the Cover Date.     

Functional and phylogenetic diversity of root-associated bacteria of Ajuga bracteosa in Kangra valley

Present study investigates the cultivable diversity of root-associated bacteria from a medicinal plant Ajuga bracteosa in the Kangra valley, in order to determine their plant growth promoting (PGP) and biotechnological potential. The plant was found to exhibit a positive rhizosphere effect of 1.3-1.5. A total of 123 morphologically different bacteria were isolated from the rhizospheric soil and roots of the plant. Medium composition was found to have significant effect on the composition of isolated bacterial populations. Majority of the rhizospheric soil isolates belonged to α- and γ-Proteobacteria, with Pseudomonas constituting the most dominant species. Endophytic bacterial community, on other hand, consisted almost exclusively of Firmicutes. Majority of the isolates showed PGP activity by producing siderophores and indole acetic acid. Several isolates were found to exhibit very high antioxidant activity in the culture medium. A significant proportion of isolates also demonstrated other ecologically important activities like phosphate solubilization, nitrogen fixation, and production of hydrolytic enzymes including amylase, protease, lipase, chitinase, cellulase, pectinase and phosphatase. Firmicutes were found to be metabolically the most versatile group and performed multiple enzyme activities. This is the first systematic study of culturable bacterial community from the rhizosphere of A. bracteosa, particularly in the Kangra valley region.     

In vitro examination of anti-parasitic,anti-Alzheimer,insecticidal and cytotoxic potential of Ajuga bracteosa Wallich leaves extracts

This research study is mainly focused to evaluate the anti-parasitic, insecticidal, cytotoxic and anti-alzheimer potential of various leaf extracts of Ajuga bracteosa Wallich ex Bentham. 04 different extracts were prepared using solvent of different polarity to determine the best candidate for potent bioactivity i.e. n-hexane (NH), Ethyl acetate (EA), Ethanol (EL) and Chloroform (CH). Concentrations of each extracts were made specified for all activities. All extracts were exploited for broad range of biomedical applications including leishmaniasis, in vitro anti-Alzheimer, insecticidal and cytotoxic studies. Our results showed that A. bracteosa n-hexane extract was highly active against Leishmania Tropica with significant inhibition of 58 ± 1.61 for promastigote and 63 ± 2.29 for amastigote at 1000 μg/mL. Furthermore, promising anti-alzheimer activity acetylcholinesterase (AChE) 46 ± 0.83 and butrylcholineterase (BChE) 49 ± 1.17 was noted for n-hexane. The insecticidal potential of these extracts were test against five different insects (Rhyzopertha dominica, Trogoderma granarium, Tribolium castaneum, Sitophilus oryze, and Callosobruchus analis). The higest mortality rate of insecticidal activity was recorded by n-hexane followed by Ethyl acetate whereas ethanol extract was found to be less effective against all the test species. Significant cytotoxic potential of each plant sample against Artemia salina thus aware us for further detailed research to find out novel drugs. Based on our results we believe that Ajuga bracteosa could be used to develop as a potential botanical insecticide against different insect and pests, such as aphids as well as an excellent source for the compound isolation as anti-tumor agent.     

Micropropagation of Cunila galioides,a popular medicinal plant of south Brazil

Axillary buds of field plants of Cunila galioides Benth. were used to evaluate the effect of growth regulators and culture media on the in vitro shoot proliferation and growing. The highest multiplication rate was obtained using Murashige and Skoog (MS) medium supplemented with 8.8 M of benzyladenine. Repeated subcultures of shoot tips and single nodes at 4-week intervals for eight months on the above medium enabled mass multiplication of shoots without any evidence of decline. The best conditions for rooting were MS medium plus 0.5 to 2.5 M of indolebutyric acid. The rooted plants were successfully transferred to soil, exhibiting a normal development.     

Micropropagation of Allium wallichii kunth, a threatened medicinal plant of Nepal

Summary Bulbs and aerial parts of the Nepalese plant Allium wallichii are widely used for medicinal purposes and as a spice. Due to overharvesting the natural populations of the species have been increasingly reduced and the domestication of the species should be considered. For the purpose of the production of plantlets suitable for field culture, a micropropagation procedure based on multiple shoot culture has been established. Multiplication factors of 4.6 on average were possible on MS medium supplemented with 20 μM zeatin. After rooting on MS medium with 10 μM indolebutyric acid, plantlets were acclimatized to greenhouse conditions and transferred to the field with good success. Part of the PhD thesis of P. R. Malla.     

Micropropagation of the medicinal plant, Scilla natalensis Planch.

Primary bulb explants of Scilla natalensis were cultured in vitro on modified MS medium. Some of these explants initiated shoots, which provided a sterile source of secondary leaf and bulb explants. The secondary explants responded similarly to various combinations of plant growth regulators. Shoots were initiated spontaneously on medium containing no plant growth regulators. The number of shoots initiated was increased by the addition of kinetin or thidiazuron (TDZ) alone, but was reduced by the addition of indole-3-acetic acid (IAA) or naphthalene acetic acid (NAA) alone. Optimal shoot initiation occurred on medium containing 1 to 2 mg l^–1 kinetin and 1 to 2 mg l^–1 IAA. These shoots were rooted on medium containing 1 mg l^–1 IAA. The plantlets were successfully acclimatised in the misthouse/shadehouse.     

Micropropagation ofUraria picta, a medicinal plant, through axillary bud culture and callus regeneration

Summary Micropropagation ofUraria picta, a leguminous herb, was achieved through axillary bud culture and nodal callus culture. Bud break was best when nodes were cultured on Murashige and Skoog (1962) (MS) medium supplemented with 2.6 μM α-naphthalene acetic acid and 4.4 μM N⁶-benzyladenine. Optimum shoot multiplication was observed in adenine sulphate at 2.47 μM concentration. Competent callus was initiated around the nodal ring of the explant on the basal medium supplemented with cytokinins and auxin (α-naphthalene acetic acid and N⁶-benzyladenine), which regenerated into new profusely growing shoots on transferring to 0.13 μM N⁶-benzyladenine. Shoots elongated to 5 node length with 1.11 μM N⁶-benzyladenine were rooted on half-strength MS basal medium. The rooted plants were successfully established with 80% survival. About 400 such plants were transferred to the field.     

Micropropagation of Croton sublyratus Kurz – a tropical tree of medicinal importance

A shoot tip culture procedure has been developed for the rapid multiplication ofCroton sublyratus Kurz, a tropical plant species cultivated in Thailand for the production of an anti-ulcer medicine, plaunotol. Optimum conditions were established : (1) for the regeneration of shoots from shoot tips: (2) for axillary shoot formation and rooting and (3) for adaptation of regenerated plants to the open ground. The results demonstrate the feasibility of applying the shoot tip culture technique for enhancing production of plaunotol by cultivating uniform populations ofC. sublyratus with higher plaunotol levels.     

Micropropagation,encapsulation, and conservation of Decalepis salicifolia,a vanillin isomer containing medicinal and aromatic plant

In Vitro Cellular & Developmental Biology - Plant - An efficient in vitro propagation and synthetic seed production protocol was established for the conservation of Decalepis salicifolia (Bedd....     

In vitro plantlet production system for Kaempferia galanga,a rare Indian medicinal herb

A rapid clonal propagation system for Kaempferia galanga (Zingiberaceae), a rare folk medicinal herb has been developed. Various concentrations of 6-benzyladenine (BA) and a range of auxins have been investigated for in vitro plantlet production, using rhizomes as explants. In vitro plantlet production has been achieved on 0.75 × Murashige and Skoog (MS) medium supplemented with 12 μM BA, 3 μM ∝-naphthaleneacetic acid (NAA) and 3% sucrose. The procedure ensures 13-fold rate of plantlet production every 4 weeks. Hardened plantlets produced normal storage roots as the parent plants. Around 1,000 plantlets have been produced successfully for field transfer. This revised version was published online in August 2006 with corrections to the Cover Date.     

Micropropagation ofTribulus terrestris L., an important medicinal plant

Direct regeneration of shoots and roots through juvenile expiants has been achieved inTribulus terrestris. Cotyledonary leaves along with epicotyl segment from young seedlings were cultured on MS medium containing various concentrations of auxin with cytokinin and glutamine. A combination of 0.2 mgL⁻¹ NAA, 0.5 mgL⁻¹ BAP and 50 mgL⁻¹ glutamine induced high frequency of shoot and root differentiation in 10 weeks. The callus also could be induced on the above medium from the cut end of radical segments. Morphogenic response such as per cent shoot and root differentiation was recorded at regular intervals.