Cláudia M. Furlan

Tropical fruit trees as bioindicators of industrial air pollution in southeast Brazil

Psidium guajava L., Psidium cattleyanum Sabine and Mangifera indica L. were tested under field conditions as possible tropical bioindicators of industrial air pollution. The study was performed around the industrial complex of Cubatão, SE Brazil, which comprises 23 industries, including fertilizer, cement, chemical, petrochemical, and steel plants, with 110 production units and 260 emission sources of pollutants. Saplings were exposed to environmental conditions during four periods of 16 weeks each (September 1994-September 1995), at four different sites in the coastal mountains near the industrial complex: the Valley of Pilões River (VP), the reference area; the Valley of Mogi River (VM), with high contamination of particulate matter, fluorides (F), sulfur (S) and nitrogen (N) compounds; Caminho do Mar (CM1, CM2), mainly affected by organic pollutants, S and N compounds, and secondary pollutants; and Paranapiacaba (PP), affected by secondary pollutants, such as ozone. M. indica did not adapt to the climatic conditions at the exposure sites. In the two Psidium species, the presence of visible symptoms, root/shoot ratio, foliar contents of F, S and N, amounts of ascorbate (AA) and water-soluble thiols (-SH), as well as peroxidase activity (POD) were determined. P. guajava showed higher foliar accumulation of F, S and N, more pronounced alterations of biochemical indicators, and less visible leaf injury than P. cattleyanum. P. guajava may be used as an accumulative indicator in tropical climates, while further studies will be needed before P. cattleyanum might be applied as a sensitive species in biomonitoring programs.

Influence of air pollution on leaf chemistry, herbivore feeding and gall frequency on Tibouchina pulchra leaves in Cubatão (Brazil)

Fully expanded leaves of trees of Tibouchina pulchra were collected at three sites around the industrial complex of Cubatao: the valley of Piloes river (VP), bearing virtually undamaged vegetation; Caminho do Mar (CM), affected mainly by petrochemical industries; and the valley of Mogi river (VM), severely affected by pollution. The amounts of leaf nitrogen, soluble phenols, tannins, lignins and dietary fibers were determined. Leaf area consumed by herbivores and numbers of leaf galls were used to evaluate the influence of fluctuations of those parameters on the leaf damage caused by herbivores. Comparing with the reference site, leaves from VM and CM were shown to have higher amounts of nitrogen and dietary fibers and lower amounts of soluble phenols and tannins. The highest, lowest and intermediate amounts of lignins corresponded, respectively, to CM, VM and reference site. The largest, lowest and intermediate leaf area consumed by herbivores corresponded, respectively, to VM, CM and reference site. The observed percentages of galled leaves were higher at VM and lower at CM in comparison with the reference site. In all sites, the amounts of nitrogen, fibers and lignins in 1997 were higher than in 1996, but the reverse occurred as to the total soluble phenols. Leaf areas consumed by herbivores were not different in 1996 in comparison with 1997, but galled leaf percentages were lower at VM in 1997. Although air pollution damage is evident at the selected sites and certain chemical parameters and leaf herbivory are significantly correlated, the coefficients of explanation in regression analysis are low.

Leaf contents of nitrogen and phenolic compounds and their bearing with the herbivore damage to Tibouchina pulchra Cogn. (Melastomataceae), under the influence of air pollutants from industries of Cubatão, São Paulo

The Atlantic Forest on the slopes of Serra do Mar around Cubatao (Sao Paulo, Brazil) has been affected by massive emissions of pollutants from the local growing industrial complex. The effects of air pollution on the amounts of leaf nitrogen, total soluble phenols and total tannins of Tibouchina pulchra Cogn., a common species in the area of Cubatao, were investigated, as well as the possible influence of the altered parameters on the leaf area damaged by herbivores. Fully expanded leaves were collected at two sites: the valley of Piloes river (VP), characterized by a vegetation virtually not affected by air pollution and taken as a reference; and valley of Mogi river (VM), close to the core region of the industrial complex, and severely affected by air pollution. No differences were observed for any parameters between samples collected in the summer and winter in both sites. On the other hand, compared to VP, individuals growing in VM presented higher amounts of nitrogen and lower amounts of total soluble phenols and total tannins, as well as higher percentages of galls per leaf and higher leaf area lost to herbivores. Regression analysis revealed that the increase in leaf area lost to herbivores can be explained by the increase of the content of nitrogen and decrease in the contents of total soluble phenols and total tannins. Although significant, the coefficients of explanation found were low for all analyses, suggesting that other biotic or abiotic factors are likely to influence leaf attack by herbivores.

Guava flavonoids and the effects of industrial air pollutants

Abstract Saplings of Psidium guajava (guava, Myrtaceae), a tropical tree species, were exposed to industrial air pollutants at Cubatâo, the largest industrial complex of Latin America, along two periods, each one comprising one-year: period I, July/2000 – June/2001; period II, December/2000 – November/2001. Saplings were exposed in two experimental sites: Piloes River Valley (PV), reference site, with low contamination by air pollutants; and Mogi River Valley (MV), a site severely affected by pollutants from chemical, fertilizer, ceramic, iron and steel industries. At both sites, the main flavonoids found were guaijaverin, quercitrin and two quercetin diglycosides. No interactions among factors were found as well as no significant differences were found among periods and among sites. However, total foliar flavonoid amounts showed the tendency of decrease after 12 months of experimentation. Cubatao industrial air pollution, with high concentrations of NO2, SO2 and particulate matter, plus climatic conditions of the initial months of exposure seem that does not influence flavonoid composition and quantities.

Photosynthetic Responses of Tropical Trees to Short-Term Exposure to Ozone

Saplings of the tropical trees Tibouchina pulchra (Cham.) Cogn., Caesalpinia echinata Lam., and Psidium guajava L. cv. Paluma were exposed in open-top chambers with charcoal filtered air and measurements of gas exchange and chlorophyll fluorescence were made before (t1) and after exposure to non-filtered air plus O3 (t2), simulating 6-h peaks of O3 similar to those observed in São Paulo city (SE Brazil, reaching an AOT40 of 641 nmol mol−1). After the fumigation, the net photosynthetic rate, stomatal conductance, transpiration rate, and Fv/Fm were reduced (p<0.05) for the three species. C. echinata was the most sensitive species and P. guajava cv. Paluma the most resistant.

Anthocyanins and tannins: is the urban air pollution an elicitor factor?

Abstract(Anthocyanins and tannins: is the urban air pollution an elicitor factor?) In order to survive in highly adverse conditions, plants have evolved a genetic capacity for compensating drastic environmental changes, by producing antioxidants that neutralize the effects of stress, such as those caused by oxidant pollutants. One example is Psidium guajava cv. Paluma (guava), which is described as an efficient bio-indicator of tropospheric ozone, by displaying typical foliar injury, characterized by reddening on the adaxial surface. The aim of this study was to investigate alterations in phenolic compounds content (anthocyanins and tannins) in P. guajava on a field condition of atmospheric pollutants at São Paulo city. Four field exposure assays were performed to investigate the alterations on phenolic contents under pollution stress and under seasonal variations. Principal components and regression analysis indicated that the concentrations of ozone and phenolic compounds accumulation can be highly correlated. Accumulated precipitation during the field exposures showed significant correlations with tannin contents. Contents of foliar proanthocyanidins were correlated to precipitation, global solar radiation, and leaf injury. On a field condition, many factors can elicit response on phenolic contents, e.g., presence of other pollutants, climatic conditions, and biotic factors. Urban air pollution seems to be an elicitor factor to the production of phenolic compounds on P. guajava, specially anthocyanins and tannins, but the weather conditions are crucial to determine this pollution influence.

Chemical composition and efficacy of dichloromethane extract of Croton sphaerogynus Baill. (Euphorbiaceae) against the cattle tick Rhipicephalus microplus (Acari: Ixodidae).

The cattle tick Rhipicephalus microplus is widely distributed in tropical and subtropical regions, causing high economic impact on cattle production. The control of tick infestations is regarded worldwide as critical and has been based on the use of organophosphates, synthetic pyretroids, amitraz and recently ivermectin and fipronil. The present study reports the analysis by gas chromatography/mass spectrometry of the constituents of leaf extracts of Croton sphaerogynus and results of acaricidal activity against the cattle tick R. microplus. The larval package test using the serial dilutions 0.625%, 1.25%, 2.5%, 5.0%, 10.0% and 20.0% (v/v) gave mortality rates 2.25%, 8.26%, 8.81%, 24.80%, 83.66% and 99.32%, respectively. Relevant constituents identified were abietanes, podocarpenes and clerodane type furano diterpenes. The present work may represent a possibility of attainment of natural substances useful for the control of R. microplus.

Levels of phenolic compounds in Tibouchina pulchra after fumigation with ozone

Tibouchina pulchra (Cham.) Cogn. (Melastomataceae) is a native tree species from the southeast region of Brazil. This early successional species significantly contributes to the characteristic physiognomy and structure of the Atlantic Rain Forest. Saplings were exposed to carbon filtered air (CF), ambient non–filtered air (NF), and ambient non–filtered air +40 ppb ozone (NF+O3), 8 h per day during two months, using open top chambers (OTC). The AOT40 values at the end of the experiment were 48, 910 and 12 895 ppb h –1 , respectively for each treatment. After 25 days of exposure, interveinal red stippling appeared in plants in the NF+O3 chamber (AOT40=3 871 ppb h –1 ). In the NF chamber, symptoms were observed only after 60 days of exposure (AOT40=910 ppb h –1 ). No changes were observed for total phenolic contents when comparing ozone treatments. However, amounts of tannins and flavonoids were different among treatments. NF+O3 and NF treatment showed enhanced contents of flavonoids, when tannins seem to be reduced after ozone fumigation (p<0.01). Results suggest alteration on phenolic metabolism when saplings are ozone fumigated; those responses, considered T. pulchra, seem to occur before leaf injury appeared, once contents of flavonoids and tannins are also altered by NF treatment (AOT40=910 ppb h –1 ). This study demonstrates that total phenolic and tannins contents of saplings of T. pulchra also decreased when exposed to ozone. The same alterations were observed for T. pulchra after industrial air pollution, suggesting the reduction on total phenolic and tannins probably is a characteristic response of T. pulchra to presence of any kind of pollutant.

Antiproliferative activity of methanol extracts of four species of Croton on different human cell lines

Several species of Croton have been described with biological activities, mainly due to diterpenes, alkaloids and/or other secondary metabolites. These activities account for the traditional use of Croton species to treat certain diseases in South America, Asia and Western Africa. The crude methanol extracts obtained from leaves and steam bark of Croton dichrous Mull. Arg., C. erythroxyloides Baill., C. myrianthus Mull. Arg. and C. splendidus Mart. ex Colla were tested for antiproliferative activity against ten human cancer cell lines. Chemical analyses of all extracts were carried out by GC/MS and HPLC/MS/MS. The leaf extract obtained from C. erythroxyloides showed potent activity against PC-3 (prostate) and OVCAR-3 (ovary) cell lines. Lupeol is suggested to be involved in such activity. Tiliroside, an acyl-glycosilated flavonoid ubiquitous in all tested extracts, seems to play an important role in the observed moderate activity of most extracts against the leukemia K562 cell lineage.

Avaliação da influência de substâncias fenólicas e carotenoides na anomalia do epicarpo da goiaba, "anelamento"

ABSTRACT - Guava epicarp injuries, popularly known as “girdling”, have been concerned technicians and producers due to misunderstand about their causes. The objective of this study was to analyze the amounts of phenolic compounds and carotenoids present on guava epicarp region affected by injury (“girdling”) in order to characterize chemically those regions. Concentrations of phenolic compounds (tannins, flavones/flavonols, anthocyanins and total phenolic compounds) and carotenoids were analyzed on tissue from un-ripe and ripe guava injured and non-injured epicarp fruits (Psidium guajava cv. Paluma). The experimental design was randomized, and were established six treatments: epicarp from ripe fruit without injury in the lower (FMSI) and upper region (FMSS) of the fruit, unriped fruit without injury (lower – FVSI - and upper region - FVSS), injured unriped fruit with injury (lower – FVCI - and upper region - FVCS). Higher concen-trations of phenolic compounds, carotenoids of tannins, were found on tissues of unripe fruit epicarp with “girdling” when compared with health epicarps. Results showed the participation of phenolics compounds (tannins) and carotenoids as possible substances that characterized the injury formation. Although phenolic compounds and carotenoids have antioxidant properties and are often related as antioxidant defenses, the causes of “girdling” of guava fruits are still unknown.Index terms: Psidium guajava, tannins, phenols, carotenoids, fruit, injuries.