Cytotoxic activity and mechanism of action of metabolites from the Goniothalamus genus

The World Health Organization estimates that 4 billion people or 80 % of the population use plants for curative purposes or for their natural health benefits. Accordingly, biodiversity is an important source of active natural products especially used in traditional medicine as healers transmitted knowledge of traditional usage of medicinal plants from generation to generation whereas pharmacologically active compounds within remained obscure. The present review documents cytotoxicity and anti-cancer potential of known compounds of the Goniothalamus species from the Annonaceae family existing in tropical and subtropical Asia and being intensively used for medicinal purposes.     

Growth and infectivity of callus cultures of tomato plants infected with a mycoplasma disease — Potato witches' broom

Callus tissues were derived from the stem of healthy tomato plants (Lycopersicum esculentum Mill. ev. Pr?honické) and of plants infected with potato witches' broom—a disease caused by mycoplasma. Callus cultures were established on modified fully synthetic media described byMorel (1948) and byMurashige andSkoog (1962). Callus cultures obtained from diseased plants were grown and subcultured on both media, growth in primary isolates from healthy plants took place on the Murashige and Skoog medium only. Growth of callus tissue derived from diseased plants was more vigorous even after several subcultivations in comparison with callus tissues isolated from healthy plants. Variations in the morphology in these callus cultures were not noted. Callus cells of diseased plants varied in size; they were about 50% larger than those from healthy ones. Implantation of primary and subcultivated callus tissues into tomato stems of healthy plants did not show any symptoms of infection on test plants.     

A survey of medicinal plants of Curaçao

Autopsy records (1936–66) show esophageal cancer to be the most common tumor for both men and women among the locally-born negroid population of Curaçao. Crude incidence rate of 20.9 per 100,000, virtually constant over 30 years, is exceeded only by that of certain parts of Russia and the Transkei region of South Africa. The island of Aruba (42 miles distant) has a very low incidence. Drought conditions and food and water supply are virtually identical in both islands, also reverse smoking by women only. But there are striking contrasts in the use of plants for remedies. In Curaçao, more than 100 species of local plants are employed for self-medication and for “tea.” Interrogation of living esophageal cancer victims and survivors of deceased has revealed consistent use of these plants. Species cited most frequently in interviews are being collected, lyophilized, and supplied to the Laboratory of Pathology, National Cancer Institute, for animal-testing.     

A mixed diet of toxic plants enables increased feeding and anti-predator defense by an insect herbivore

Some insect herbivores sequester plant secondary metabolites (PSMs) for their own defense, raising the interesting possibility that grazing herbivores are defended by combinations of PSMs from different plant species. In this study, we tested the hypothesis that the grazing caterpillar, Grammia incorrupta, deters the ant, Aphaenogaster cockerelli, by eating a mixture of plants containing iridoid glycosides (IGs) and those containing pyrrolizidine alkaloids (PAs), and that this deterrence is greater than that attained by eating either plant alone. This hypothesis was tested against the non-mutually exclusive hypothesis that mixing plants containing PAs with those containing IGs improves growth performance. Caterpillar survival and growth were measured on three experimental diets: a PA plant, an IG plant, and a mixture of the two. We measured the degree of deterrence associated with these, and an additional experimental diet devoid of PSMs at naturally occurring A. cockerelli nests. Caterpillars fed both plants gained more mass than those fed either plant alone, but took longer to develop. These differences were not caused by diet-based variation in growth efficiency, but by eating more food when offered the mixed-plant diet relative to single-plant diets. The mixed diet was shown to provide deterrence to ants, whereas caterpillars fed single-plant diets were not significantly more deterrent than caterpillars that had eaten the PSM-free diet. We hypothesize that enhanced defense results from increased food consumption in response to multiple plant species, perhaps leading to greater PSM sequestration. Through this mechanism, bottom-up and top-down effects may mutually reinforce the grazing dietary strategy.     

Effect of TiO2 nanoparticles on oxidative damage and antioxidant defense systems in chickpea seedlings during cold stress

The effects of TiO₂ nanoparticles (NPs) on physiologo-biochemical responses were studied in two chickpea (Cicer arietimun L.) genotypes differing in cold sensitivity (tolerant Sel11439 and sensitive ILC533) during cold stress (CS). The results showed that hydrogen peroxide and MDA contents and electrolyte leakage index (ELI) increased under CS conditions in both genotypes and that these damage indices were higher in ILC533 than in Sel11439 plants. In plants treated with TiO₂ NPs, a decreased H₂O₂ level was accompanied by a decrease in the MDA content and ELI compared to control plants, and these changes occurred more effectively in Sel11439 than in ILC533 plants. The antioxidant enzymes were more effective in cell protection against CS in Sel11439 plants compared to ILC533 plants, as well as in plants treated with TiO₂ NPs compared to control plants. The lipoxygenase activity was induced efficiently only in Sel11439 plants treated with TiO₂ NPs during CS, probably indicating its role in stress response (which was confirmed by measuring allen oxide synthase activity). TiO₂ NPs caused stability of chlorophyll and carotenoid contents during CS. Results suggest that TiO₂ NPs confer an increased tolerance of chickpea plants to CS, decreasing the level of injuries and increasing the capacity of defense systems.     

Preliminary studies of the effects of an induced phosphate deficiency on carbohydrate-nitrogen ratios inAlternanthera philoxeroides [Centrospermae: Amaranthacea] and on the feeding ofAgasicles hygrophila [Col.: Chrysomelidae]

In no-choice tests but not in choice tests, alligatorweed flea beetles,Agasicles hygrophila Selman & Vogt (Col.: Chrysomelidae) exposed to alligatorweed plants grown with two levels of mineral nutrition fed significantly more on those grown in full mineral nutrient than those grown with deficient phosphate. Chemical analysis showed that the full nutrient plants had more ethanol-soluble nitrogen compounds but less total carbohydrate than the phosphate-deficient plants. The response of beetles to phosphate-deficient alligatorweed may thus result from a change in the carbohydrate-nitrogen composition of host plants, though further investigation is needed for confirmation. Flea beetle response was identical to terminal and mature leaf tissue of full nutrient plants.     

Regulation of androgenesis inNicotiana tabacum L. cv. White Burley andDatura innoxia Mill. Effect of bivalent and trivalent iron and chelating substances

The effect of FeSO₄.7H₂O, Fe₂(SO₄)₃.9H₂O, disodium salt of ethylene-diaminotetraacetic acid, dihydrate (EDTA) and N-(2-acetamido) iminodiacetic acid (ADA) and their combinations on the androgenesis was studiedin vitro in tobacco (cv. White Burley) and datura (Datura innoxia Mill.). Simultaneously the reversibility and irreversibility of the morphogenic process leading to the conversion of the pollen embryoid into complete plant was followed. Complete plants developed in anthers on media with trivalent iron, chelated trivalent iron, chelated bivalent iron, bivalent iron in the presence of ADA and of media with EDTA. The number of androgenic plants in anthers increased in the following order: Fe₃₊ < Fe₃₊ EDTA ≦ ≦ EDTA < Fe²⁺ EDTA. The marked brown colour of cultured anthers was due to the presence of trivalent iron in the medium. The androgenic development was most rapid on the medium containing only trivalent iron, slower on media with chelated iron and slowest on medium with EDTA. The viability of cultures with complete plants decreased in the reverse order. No complete plants grew on media without trivalent iron and without EDTA and on media containing only bivalent iron whereas globular embryoids arose and developed continuously on these media. The anthers reacted in the same way on both complete and minimal media. Isolated embryoids formed complete plants in corresponding variants on complete media only. The development of pollen embryoids into complete plants was stopped by the transfer of globular and torpedo-shaped embryoids from medium with EDTA to the medium without EDTA. Isolated greenish cotyledonar embryoids continued to grow even on the medium without EDTA.     

In vitro study of the anti-inflammatory activity of some medicinal and edible plants growing in Russia

The effects of the ethanolic extracts of 105 plants used in Russian traditional medicine, 26 vegetables and fruits and 2 mushrooms on the release of tumor necrosis factor α (TNF-α) and prostaglandin E₂ (PGE₂) in lipopolysaccharide (LPS)-stimulated differentiated human acute monocytic leukemia THP-1 cells were studied using TNF-α and PGE₂ assays, respectively. We found that 16 plant extracts inhibited TNF-α production and 15 extracts decreased PGE₂ release in the cells in a concentration-dependent manner. Guilder rose, tansy, shrubby cinquefoil, wintergreen, and prince’s pine, the last two of which belong to the Pyrolaceae family, notably inhibited the levels of both of the inflammatory mediators.     

Land or plants: Agricultural tenure in agroforestry systems

The distinction between the rights to land and rights to plants is often overlooked when viewing agricultural tenure in developing countries. This distinction is crucial to understanding traditional agricultural systems, especially where agroforestry is practiced or its introduction has been proposed. Rights to land versus rights to plants are viewed in two Asia-Pacific agroforestry systems: one in Indonesian Borneo and the other in Papua New Guinea. Conflicts are discussed between the traditional dichotomy of land and plant rights and government policy. The success of an indigenous agroforestry system based on plant rights is contrasted to the failure of a proposed agroforestry system for similar reasons. It is concluded that the perceptual separation of land and plant rights needs to be explored if agroforestry practices are not only to be ecologically and economically feasible but also culturally acceptable.     

Geocarpa groundnut (Kerstingiella geocarpa) in Ghana

The geocarpa groundnut, Kerstingiella geocarpa Harms, is grown only in the northern and upper regions of Ghana. The seeds of this crop are produced in 1-or 2- or rarely 3-loculed pods which mature on or under the soil surface. The fresh mature or dry seeds are used for food, and they serve as a source of protein supplement in the local diet. The seeds are also said to have medicinal and emetic properties. Among the Sisalas in Ghana the boiled seeds are the only food served to surviving children during the final funeral rites of their mothers.     

Development of embryoids in carrot root callus culture (Daucus carota L.)

Embryogenesis occurred in carrot root callus (Daucus carota L.) cultivated on simple synthetic medium containing IAA and 2,4-D. Embryoid development continued also during successive years when the tissue was cultivated on the same nutrient medium without those substances. Sometimes production of plants with atypical leaves was also observed. In those plants development of adventive embryoids occurred repeatedly. Result of this work confirmed reports about the organogenic potentiality of this species and about its sensitivity to some chemical substances.     

Feeding behavior and diet of the Japanese monkey (Macaca fuscata yakui) on Yakushima Island,Japan

Feeding behavior in a troop of one subspecies of the Japanese monkey, the Yakuzaru (Macaca fuscata yakui), was observed for 407 hr on Yakushima Island between March and December 1976, after a three-month preliminary survey in 1975. The troop dwells in a mature warm temperate forest at a density of over 30 animals/km². The 5-min scanning technique was employed from August to December 1976, to detect the quantitative features of feeding behavior. The members of this troop fed on 76 plant species: on the leaves of 26, the fruits of 45, and other parts of 12 species. The Yakuzaru is essentially frugivorous. The pattern of food selection is discussed in relation to fruit production. The animals fed much more on the leaves of deciduous than of evergreen woody plants. “Selection ratio” the percentage of time spent feeding on each species to the percentage abundance of each species in the sample strip, was calculated in order to evaluate food selection from the plant community. In addition, the food habits of this subspecies were compared with that of six other populations in various habitats in Japan, by computing the similarity index for the woody plant community, all woody plant food species, and all major woody plant food species.     

Harvest Security and Intraspecific Diversity in Traditional Tropical Agriculture

The horticultural strategies of traditional tropical agriculturists center on the preservation of harvest security. In addition to cultivating simultaneously numerous species of crops, traditional tropical farmers also plant multiple varieties of each crop. These cultivars are frequently distinguished on the basis of color, ranging from white to yellow to red to purple. In addition to varying in appearance and taste and in resistance to environmental stresses, the color-based varieties often differ in length of growing season. By practicing multicolored, intraspecific polyculture, the traditional tropical farmer either provides himself several opportunities to secure a complete single harvest and/or staggers his harvest throughout the year and thus, in either case, preserves his lifestyle. Acceptance of Green Revolution technologies by traditional tropical farmers would accelerate if they were offered multiple, high-yielding varieties of staple food crops of varying color and maturation periods.     

Opposing effects of strychnine and brucine on the germination and growth of lettuce seeds

Strychnine and brucine, two related alkaloids that occur in plants belonging to theStrychnos species, were shown to have opposing effects on the elongation of the radicle of lettuce seeds. Strychnine was found to be inhibitory, whereas brucine was found to be stimulating to radicle elongation. Alkaloids, generally, are more commonly known for their inhibitory effects on plant growth rather than on their stimulating effects.