Artificial polyploidy in medicinal plants: Advancement in the last two decades and impending prospects

Medicinal plants are in huge demand since the consumption is widespread and ever-increasing globally. The conventional breeding programs are generally environmental dependent; prone to different biotic and abiotic stresses as well as the secondary metabolite content is too low to harvest. In this context, developing polyploid individuals artificially would be a remarkable approach to increase vigor and attain this objective. Polyploids often exhibit some morphological features that are different or greater in forms than their diploid progenies. Polyploidization can be induced by quite a few antimitotic agents. The most frequently used antimitotic chemicals are colchicine, trifluralin, and oryzalin. The whole method of induced chromosome doubling consists of a series of steps, including an induction phase, regrowth phase, and a confirmation technique to evaluate the rate of achievement. The induction phase depends on different factors, such as explant types, antimitotic agents, its different concentrations, and exposure durations. To evaluate the accomplishment of polyploidization, morphological or anatomical observations are recorded as a rapid method. However, chromosome count and flow cytometry are the most eminent method for absolute confirmation. Despite significant prospects of polyploidization, there has been very little research on medicinal plants. The current review gives an overview of the different parameters of in vitro chromosome doubling, the history of the technique, and progress made over the last two decades.     

Chemical composition, iron bioavailability, and antioxidant activity of Kappaphycus alvarezzi (Doty)

Kappaphycus alvarezzi, an edible seaweed from the west coast of India, was analyzed for its chemical composition. It was found that K. alvarezzi is rich in protein (16.24% w/w) and contains a high amount of fiber (29.40% w/w) and carbohydrates (27.4% w/w). K. alvarezzi showed vitamin A activity of 865 mug retinal equivalents/100 g of sample. It contained a higher quantity of unsaturated fatty acids (44.50% of the total), in which relative percentage of oleic acid was 11%, cis-heptadecanoic acid 13.50%, and linoleic acid 2.3% and 37.0% of saturated fatty acids (mainly heptadecanoic acid). K. alvarezziwas also found to be good source of minerals, viz 0.16% of calcium, 0.033% of iron, and 0.016% of zinc, which are essential for various vital biological activities. Bioavailability of iron by in vitro methods showed a higher efficiency in intestinal conditions than in stomach conditions. Ascorbic acid influenced higher bioavailability of iron. Successive extracts of n-hexane, acetone, ethyl acetate, ethanol, and direct extractables of chloroform/methanol (1:1 and 2:1) were screened for antioxidant activity using a beta-carotene linoleic acid model system (B-CLAMS), DPPH (alpha,alpha-diphenyl-beta-picrylhydrazyl) model system and hydroxyl radical scavenging activity. The chloroform/methanol (2:1) extract has shown 82.5% scavenging activity at 1000 ppm. Acetone fraction extracts at the 1000 ppm level showed 63.31% antioxidant activity in beta-carotene linoleic acid system. The acetone extract showed 46.04% scavenging activity at 1000 ppm concentration. In the case of hydroxyl radical scavenging activity, all the extracts showed better activity at the concentrations of 25 and 50 ppm, where at the 50 ppm level ethyl acetate extract showed 76.0%, acetone 75.12%, and hexane 71.15% activity, respectively. Results of this study suggest the utility of K. alvarezzi (Eucheuma) for various nutritional products, including antioxidant for use as health food or nutraceutical supplement.     

马来西亚未尽利用热带水果概况

未尽利用热带水果,即在当地消费和医用的非贸易热带水果,未普及化,生长于野外,季节性强,但富含多酚类化合物、类胡萝卜素、花青素、脂肪酸、矿物质和氨基酸,因而具有一定的开发潜力。在马来西亚,热带水果丰富多样,主要有普通水果、观赏水果、特有水果、野生水果和高地水果,但大部分水果都未能充分利用,其中,典型的有罗望子、巴杖果、砂拉越芒果、钮扣山竹、榴莲、莲雾、挂尼芒果、野红毛丹和蛇皮果。这些水果可以分为3个类型：具有贸易开发潜力的主要包括无花果（Ficus sp.）、罗望子（Garcinia atroviridis）、尖必达（Artocarpus integer）、鲜花木果（Lepisan-thes alata）、野榴莲（Durio sp.）、橄榄木（Spondias cytherea）、菠萝蜜（Artocarpus heterophullus）、槟榔（Areca catechu）、野红毛丹（Nephelium ramboutan-ake）、蛇皮果（Salacca zalacca）和面包果（Artocarpus altilis）;具有适于当地人们利用潜力的水果种类包括木胡瓜（Averrhoe bilimbi）、榔拜果（Baccaurea motteyana）、单贝果Baccaurea macrocarpa）、喃喃果属（Cynometra cauliflora）、西柚（Dialum indum）、黄肉榴莲（Durio kutejensis）、野生山竹（Garcinia hombroiniana）、野檬果（Garcinia parvifolia）、巴杖果（Mangifera feotida）、醋栗（Phyllanthus emblica）、蒲桃（Syzygium jambos）;不具有经济利用开发潜力的水果种类包括哥露比（Salacca conferta）、青枣（Zizyphus mauritiana）、木奶果属（Baccaurea polyneura）、野檬果（Garcinia parvifolia）、番龙眼（Pometia sp.）、赤才果（Leppisanthes rubiginosa）、波漆果（Bouea microphylla）、蛋黄果（Pouteria campechiana）和仙都果（Sandoricum koetjape）。目前,有关未尽利用水果研究仍处于初期阶段,有必要使这些水果更为普及并得到有效利用,因此,政府和私人组织须采取一些措施以促进这些水果的消费。今后需对这些水果的营养成分、抗氧化作用以及疗效进行深入研究。     

Alleviation of Salt Stress in Durum Wheat (Triticum durum L.) Seedlings Through the Application of Liquid Seaweed Extracts of Fucus spiralis

Many research studies have shown the importance of seaweed extract (SWE) in alleviating stress damage to plants. In this study, we examined the effect of liquid SWEs made from brown seaweed, Fucus spiralis, on germination, growth, antioxidant enzymes and some biochemical attributes of durum wheat under different levels of NaCl concentrations. Application of SWE at different concentrations (5, 10, 25, and 50%) significantly enhanced seed germination and growth parameters under salt stress, especially with 25% of seaweed liquid extract. Results show that the activity of antioxidant enzymes increased with increasing the algal extract concentration to 50%. Therefore, algal treatment is proved to be an effective technique to improve the growth of wheat seedlings under salt stress conditions. This study provides important information on the identification and utilization of seaweed resources for agriculture and it is the first study to report on the uses of this macroalgae as biostimulants in agriculture.

Abbreviations TG: total germination (%); SL: shoot length (cm); SFW: seedling fresh weight (g); SDW: seedling dry weight (g); TC: total carotenoids (mg/g.FW); TSP: total soluble proteins (mg/g.FW); SSC: soluble sugars content (mg/g.FW); TPC: (µg equivalent AG/mg DW); CAT: catalase (U mg^?1 protein); SOD: superoxide dismutase (U mg^?1 protein); APX: ascorbate peroxydase (U mg^?1 protein).     

Management of type 2 diabetes mellitus by lifestyle, diet and medicinal plants

Globally, the prevalence of chronic, noncommunicable diseases is increasing at an alarming rate and diabetes is one of them. If diabetes is not controlled then a lot of complication like coronary artery disease, cerebrovascular disease, peripheral vascular disease, retinopathy, nephropathy and neuropathy arise in diabetic patients and causes morbidity and/or mortality. Diabetes is increasing at an epidemic form and in near future the largest increases will take place in the regions dominated by developing economies. So, it will be a great social and economical burden to developing countries as well as the developed. But if we be aware about our diet and lifestyle and take proper medication we may prevent and reduce the prevalence of diabetes. Oral medicine plays an important role in management of diabetes. But most of the oral drugs are costly and have a lot of side effects. For this it is also necessary to take medicines with fewer or no side effects. And antidiabetic medicinal plants may play an important role in this case. In this article we have tried to describe how diet and lifestyle with using medicinal plants may help to prevent or maintain diabetes and help to reduce the mortality and morbidity due to diabetes or complication related to it.     

Lifestyle related causes of cancer and chemoprevention through phytonutrients

Cancer is a leading cause of death worldwide. There are a lot of cancer causing agents which are divided as physical carcinogens, chemical carcinogens and biological carcinogens. But most of the carcinogens or causes of cancer are related to our lifestyle like diet, habit, occupation, radiation and some infection, etc. Chemoprevention is highly necessary to prevent cancer related preterm death. For this besides avoiding the causes of cancer we should concentrate ourselves on our diet. Because, numerous phytochemicals derived from edible plants have been reported to interfere with a specific stage of the carcinogenic process. Many mechanisms have been shown to account for the anticarcinogenic actions of dietary constituents and recently attention has been focused on intracellular-signalling cascades as common molecular targets for various chemopreventive phytochemicals. In this study, we tried to describe lifestyle related causes of cancer and the molecular basis of cancer prevention through the phytochemicals.     

A major genome region underlying artemisinin resistance in malaria

Evolving resistance to artemisinin-based compounds threatens to derail attempts to control malaria. Resistance has been confirmed in western Cambodia and has recently emerged in western Thailand, but is absent from neighboring Laos. Artemisinin resistance results in reduced parasite clearance rates (CRs) after treatment. We used a two-phase strategy to identify genome region(s) underlying this ongoing selective event. Geographical differentiation and haplotype structure at 6969 polymorphic single-nucleotide polymorphisms (SNPs) in 91 parasites from Cambodia, Thailand, and Laos identified 33 genome regions under strong selection. We screened SNPs and microsatellites within these regions in 715 parasites from Thailand, identifying a selective sweep on chromosome 13 that shows strong association (P = 10(-6) to 10(-12)) with slow CRs, illustrating the efficacy of targeted association for identifying the genetic basis of adaptive traits.     

Insecticidal properties of essential plant oils against the mosquito Culex pipiens molestus (Diptera: Culicidae)

The insecticidal activities of essential oil extracts from leaves and flowers of aromatic plants against fourth-instar larvae of the mosquito Culex pipiens molestus Forskal were determined. Extracts of Myrtus communis L were found to be the most toxic, followed by those of Origanum syriacum L, Mentha microcorphylla Koch, Pistacia lentiscus L and Lavandula stoechas L with LC50 values of 16, 36, 39, 70 and 89 mg litre-1, respectively. Over 20 major components were identified in extracts from each plant species. Eight pure components (1,8-cineole, menthone, linalool, terpineol, carvacrol, thymol, (1S)-(-)-alpha-pinene and (1R)-(+)-alpha-pinene) were tested against the larvae. Thymol, carvacrol, (1R)-(+)-alpha-pinene and (1S)-(-)-alpha-pinene were the most toxic (LC50 = 36-49 mg litre-1), while menthone, 1,8-cineole, linalool and terpineol (LC50 = 156-194 mg litre-1) were less toxic.