Rapid micropropagation of <Emphasis Type="Italic">Curcuma longa</Emphasis> using bud explants pre-cultured in thidiazuron-supplemented liquid medium

Multiple shoots of Curcuma longa were induced by culture of bud explants for 1week in Murashige and Skoog (MS) liquid medium supplemented with 72.64M thidiazuron (TDZ) prior to culture on MS gelled medium without growth regulator for 8weeks. The regeneration rate was up to 11.4±1.7shoots/explant. Rooting was spontaneous and the regenerated plants were successfully transferred to soil. This protocol can be an alternative for rapid micropropagation of C. longa used for phytomedicine raw material production.     

Growth and isoflavonoid accumulation of Pueraria candollei var. candollei and P. candollei var. mirifica cell suspension cultures

We established cell suspension cultures derived from leaf, stem, and root calli of Pueraria candollei var. candollei and P. candollei var. mirifica using liquid Murashige and Skoog (MS) medium supplemented with 0.56 μM 6-benzyladenine (BA) and 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Growth of the cell suspension cultures progressed to the stationary phase within 15–24 days. Methanolic extracts of cell suspension cultures of both varieties of P. candollei were analyzed using a validated HPLC protocol. All cell lines derived from leaf, stem, and root explants produced four major isoflavonoids: daidzein, daidzin, genistein, and genistin; these isoflavonoids were detected only in the roots of intact plants. Furthermore, the isoflavonoid contents of the cell suspension cultures were higher than those of intact plants. Thus, cell suspension culture of both varieties of P. candollei may be an effective tool for isoflavonoid production.     

An improved protocol for micropropagation of Mallotus repandus (Willd.) Müll.Arg.

Node and internode explants of Mallotus repandus were precultured on basal medium (BM: Murashige and Skoog (MS) medium with 3% sucrose and 0.55% Agargel) for 0–18 d before culture on shoot induction Medium (SIM: BM added with 4.44 μM of benzylaminopurine) for 4 wk. The cultures were subsequently transferred to BM for 4 wk for shoot elongation. Node explants precultured on BM for 14 d before incubation on SIM were at an optimum for shoot regeneration with the response rate of 95%, compared to a 21% response for the control without preculture. Internode explants precultured on BM for 16 d responded with an optimal shoot formation response rate of 69%, whereas the control response rate was 6%. The maximum shoot regeneration rates were 3.1 ± 0.3 and 2.7 ± 0.4 shoots/responding explant in node and internode explants, respectively. This study demonstrates for the first time that shoot organogenesis can be induced from internode explants of M. repandus. Furthermore, the results suggest that the explants need to acquire competence before shoot organogenesis. Rooting was obtained by incubation of regenerated shoots on half-strength MS with 10.74 μM of 1-naphthylacetic acid for a week before culture on half-strength MS for 4 wk. Regenerated plants were successfully transferred to soil.     

In vitro induction of polyploidy in Centella asiatica (L.) Urban

Mutational breeding was conducted using in vitro-grown shoot-tips of Centella asiatica (L.) Urban treated with colchicine (0.025–0.400% for 12–36 h) to induce polyploidy. Treated shoot-tips were grown on Murashige and Skoog (MS) medium supplemented with 4.54 μM thidiazuron (TDZ), and regenerated plantlets were acclimatized and transferred to soil. Two months following transfer to ex vitro conditions, ploidy levels of regenerated plants were determined by flow cytometry and by determining chromosome counts. Treating shoot-tips with colchicine concentrations ranging from 0.050–0.200% for 12–24 h promoted induction of tetraploids. Morphological and growth characteristics and the triterpenoid contents of the polyploids were also measured. Tetraploid plants demonstrated significantly longer stomata and a higher stomatal index compared to those of the diploid control plants. Furthermore, a positive trend in both biomass and triterpenoid production was obtained with the tetraploid and mixoploid plants of C. asiatica.     

Combined Therapy of Iron Chelator and Antioxidant Completely Restores Brain Dysfunction Induced by Iron Toxicity

Background

Excessive iron accumulation leads to iron toxicity in the brain; however the underlying mechanism is unclear. We investigated the effects of iron overload induced by high iron-diet consumption on brain mitochondrial function, brain synaptic plasticity and learning and memory. Iron chelator (deferiprone) and antioxidant (n-acetyl cysteine) effects on iron-overload brains were also studied.

Methodology

Male Wistar rats were fed either normal diet or high iron-diet consumption for 12 weeks, after which rats in each diet group were treated with vehicle or deferiprone (50 mg/kg) or n-acetyl cysteine (100 mg/kg) or both for another 4 weeks. High iron-diet consumption caused brain iron accumulation, brain mitochondrial dysfunction, impaired brain synaptic plasticity and cognition, blood-brain-barrier breakdown, and brain apoptosis. Although both iron chelator and antioxidant attenuated these deleterious effects, combined therapy provided more robust results.

Conclusion

In conclusion, this is the first study demonstrating that combined iron chelator and anti-oxidant therapy completely restored brain function impaired by iron overload.     

Pharmacokinetics of isoflavones,daidzein and genistein,after ingestion of soy beverage compared with soy extract capsules in postmenopausal Thai women

Background  

Isoflavones from soybeans may provide some beneficial impacts on postmenopausal health. The purpose of this study was to compare the pharmacokinetics and bioavailability of plasma isoflavones (daidzein and genistein) after a single dose of orally administered soy beverage and soy extract capsules in postmenopausal Thai women.     

Swiddeners' Household Strategies for the Wild Harvest of Rauvolfia serpentina and Amorphophallus bulbifer in a Karen Swidden System in the Bago Mountains,Myanmar

Economic Botany - Swiddeners in the Bago Mountains, Myanmar collect two economically important non-timber forest products (NTFPs)—Rauvolfia serpentina (L.) Benth. ex Kurz (Apocynaceae) roots...     

Effects of abiotic and biotic elicitors on growth and isoflavonoid accumulation in Pueraria candollei var. candollei and P. candollei var. mirifica cell suspension cultures

This study demonstrates the effects of various concentrations of abiotic and biotic elicitors on the cell growth and isoflavonoid accumulation of P. candollei var. mirifica (PM) and P. candollei var. candollei (PC) cell suspension cultures. The two plant varieties exhibited different growth responses and varied isoflavonoid accumulation after the addition of elicitors. Copper sulfate, methyl jasmonate (MeJA), and yeast extract did not significantly affect the growth of either plant variety, whereas oligosaccharide and the biotic elicitors used in this study [i.e., 50 mg l⁻¹ chitosan and all concentrations of laminarin (LAM)] suppressed the growth of PM. The addition of MeJA to the medium principally induced an effect on the isoflavonoid content in both PM and PC, with 2.0 μM MeJA inducing the highest isoflavonoid content, as indicated by the induction index—4.41 in PM and 9.62 in PC cells on the 12th and ninth day of culture, respectively. A maximum total isoflavonoid content of 40.49 mg g⁻¹ dry weight was achieved in PM 21 days after elicitation with 2.0 μM MeJA. LAM elicited the PM cell suspension culture to produce puerarin, which was not found in the unelicited culture. The results of this study provide information that will be useful for enhancing the accumulation of isoflavonoids in P. candollei cell suspension cultures.     

High-frequency shoot multiplication in<Emphasis Type="Italic"> Curcuma longa</Emphasis> L. using thidiazuron

The effects of plant growth regulators, explant types, and culture regimens were investigated on in vitro shoot proliferation from terminal bud explants of Curcuma longa. Each bud was longitudinally divided into four equal pieces, each 1 cm in length, and used as explants. These were then cultured on MS medium supplemented with 18.17 microM thidiazuron for 4 weeks prior to transfer to MS medium without growth regulator for 8 weeks. Under these conditions, a shoot induction rate of 18.22+/-0.62 shoots/explant was obtained after 12 weeks of cultures. Spontaneous rooting was achieved. The regenerated plants were transferred to soil under greenhouse conditions and subsequently grown successfully in the field.