Attenuation of capsaicin-induced acute and visceral nociceptive pain by α- and β-amyrin, a triterpene mixture isolated from Protium heptaphyllum resin

Abstract The triterpene mixture, a-and h-amyrin, isolated from Protium heptaphyllum resin was evaluated on capsaicinevoked nociception in mice. Orally administered a-and h-amyrin (3 to 100 mg/kg) significantly suppressed the nociceptive behaviors-evoked by either subplantar (1.6 Ag) or intracolonic (149 Ag) application of capsaicin. The antinociception produced by a-and h-amyrin against subplantar capsaicin-induced paw-licking behavior was neither potentiated nor attenuated by ruthenium red (1.5 mg/kg, s.c.), a non-specific antagonist of vanilloid receptor (TRPV1), but was greatly abolished in animals pretreated with naloxone (2 mg/kg, s.c.), suggesting an opioid mechanism. However, participation of a 2 -adrenoceptor involvement was unlikely since yohimbine (2 mg/ kg, i.p.) pretreatment failed to block the antinociceptive effect of a-and h-amyrin in the experimental model of visceral nociception evoked by intracolonic capsaicin. The triterpene mixture (3 to 30 mg/kg, p.o.) neither altered significantly the pentobarbital sleeping time, nor impaired the ambulation or motor coordination in open-field and rota-rod tests, respectively, indicating the absence of sedative or motor abnormality that could account for its antinociception. Nevertheless, a-and h-amyrin could significantly block the capsaicin (10 mg/kg, s.c.)-induce

Nutritional status and fruit production of Carica papaya as a function of coated and conventional urea

ABSTRACT As a strategy to minimize N losses in the soil, mineral N sources, such as polymer-coated urea, have been studied as possibility to increase the synchronization of N release by the fertilizer and its absorption by plants. Thus, this study aimed to evaluate the contents of macronutrients and the production of Formosa papaya as a function of sources and doses of N fertilizer applied as top-dressing in the region of Bom Jesus-PI, Brazil. The treatments were arranged in a 2 x 4 factorial scheme corresponding to N sources (coated urea and conventional urea) and N doses (350, 440, 530 and 620 g plant-1 of N), with four replicates and four plants per plot. The contents of macronutrients in the leaf dry matter and fruit production were evaluated. The sources and doses of top-dressing N fertilization incremented the leaf contents of macronutrients and the production of Formosa papaya hybrid Caliman 01. Under the experimental conditions and based on the macronutrient contents considered as adequate for crop nutrition, associated with maximum fruit production (8.08 kg plant-1), the supply of 525 g of N plant-1 is recommended in the form of coated urea

Nutritional status and fruit production of Carica papaya as a function of coated and conventional urea

ABSTRACT As a strategy to minimize N losses in the soil, mineral N sources, such as polymer-coated urea, have been studied as possibility to increase the synchronization of N release by the fertilizer and its absorption by plants. Thus, this study aimed to evaluate the contents of macronutrients and the production of Formosa papaya as a function of sources and doses of N fertilizer applied as top-dressing in the region of Bom Jesus-PI, Brazil. The treatments were arranged in a 2 x 4 factorial scheme corresponding to N sources (coated urea and conventional urea) and N doses (350, 440, 530 and 620 g plant-1 of N), with four replicates and four plants per plot. The contents of macronutrients in the leaf dry matter and fruit production were evaluated. The sources and doses of top-dressing N fertilization incremented the leaf contents of macronutrients and the production of Formosa papaya hybrid Caliman 01. Under the experimental conditions and based on the macronutrient contents considered as adequate for crop nutrition, associated with maximum fruit production (8.08 kg plant-1), the supply of 525 g of N plant-1 is recommended in the form of coated urea

Germination and initial growth of guava plants irrigated with saline water Germinação de sementes e crescimento inicial da goiabeira irrigada com água salina

The present study was carried in order to evaluate the effect of saline water irrigation with electrical conductivity (ECw) of 0.5; 1.5; 3.0; 4.5 and 6.0 dS m-1, on germination and some growth variables during the seedling formation process of four guava cultivars (Psidium guajava L.): Pentecoste, Paluma, Surubim and IPA B-38. Water salinity inhibited the germination process, plant height, stem diameter, leaf area and dry matter production of roots, stems and leaves, independently of cultivar. After germination, the seedlings did not survive due to saline water effects of ECw 4.5 and 6.0 dS m-1. After 180 days of sowing, the seedlings irrigated with ECw more than 1.5 dS m-1 did not present agronomic quality for planting. Dry matter production sequence of different parts of plants was as follows: leaves > roots > stems, without significant differences among cultivars especially when irrigated with saline water of ECw > 3.0 dS m-1.Avaliou-se o efeito da salinidade da água de irrigação, através dos níveis de condutividade elétrica (CEa) de 0,5; 1,5; 3,0; 4,5 e 6,0 dS m-1, sobre a germinação de sementes e algumas variáveis de crescimento, durante a formação de mudas de quatro cultivares de goiabeira (Psidium guajava L.) Pentecoste, Paluma, Surubim e IPA B-38. A salinidade da água inibiu a germinação, o crescimento em altura, diâmetro do caule, área foliar e fitomassa das raízes, caules e folhas das plantas, independente da cultivar. Após a germinação, as plântulas não sobreviveram aos efeitos salinos das águas de condutividade elétrica CEa 4,5 e 6,0 dS m-1. Ao final do ensaio, 180 dias após a semeadura, não se obtiveram mudas com qualidade agronômica nos tratamentos irrigados com água de salinidade superior a 1,5 dS m-1. A ordem de produção de matéria seca pelos distintos órgãos das plantas, foi: folhas > raízes > caules, mas sem diferir entre cultivares, principalmente quando irrigadas com água de maior salinidade > 3,0 dS m-1