Composição química e atividades biológicas de extratos e frações de Guadua chacoensis (Rojas) Londoño & P.M. Peterson / Chemical composition and biological activities of extracts and fractions of Guadua chacoensis (Rojas) Londoño & P.M. Peterson

O Brasil é o país que possui a maior diversidade de bambus em todo o continente americano, com mais de 200 espécies catalogadas. Devido à alta resistência e durabilidade, essas espécies são muito utilizadas na construção civil e confecção de móveis e utensílios. No entanto, faltam estudos que investiguem a composição química e as atividades biológicas. Neste projeto foram avaliados extratos etanólicos de folhas e colmos de Guadua chacoensis (Rojas) Londoño & P.M. Peterson e frações em hexano, clorofórmio, acetato de etila e n-butanol. Também se obteve o óleo volátil, mas com um rendimento extremamente baixo (0,00079%). As frações dos extratos apresentaram teores de compostos fenólicos variando entre 1,92 e 15,80 µg EAG/mg. Esses compostos mostraram-se mais abundantes nas amostras de colmos. Em relação ao teor de flavonoides, as folhas apresentaram maior quantidade, variando entre 0,39 e 1,18 µg EQ/mg contra 0,17 a 0,34 µg EQ/mg nos colmos. Investigou-se a atividade antimicrobiana dos extratos, frações e óleo volátil frente cinco microrganismos: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans e Aspergillus brasiliensis. As amostras demonstraram potencial inibitório moderado a bom contra S. aureus e C. albicans, porém fraca para as demais espécies. Testou-se a capacidade antioxidante frente o radical DPPH e os resultados indicaram atividade antioxidante significativa, especialmente as frações acetato e butanol de colmos. As folhas apresentaram EC50 variando entre 67,5 e 124,0 µg/mL e os colmos entre 40,2 e 124 µg/mL. A inibição da enzima tirosinase, que está associada à produção de melanina, também se mostrou boa a uma concentração de 1 mg/mL, com o extrato bruto de colmos apresentando 43% de inibição, seguido pelas frações acetato (36%) e n-butanol (38%) de folhas. As análises por CG-MS detectaram pelo menos 44 compostos diferentes no óleo volátil, com vários terpenos e sesquiterpenos, e com ß-ionona sendo o componente majoritário (8,75%). As amostras de colmos e folhas apontaram grande diversidade de compostos, cerca de 20 para cada fração, onde os ácidos graxos como ácido palmítico e linoleico e seus ésteres derivados foram os mais abundantes. A análise dos perfis cromatográficos por CCD e CLAE revelaram a presença de ácido p-cumárico nos colmos de G. chacoensis. Esse composto tem relevante atividade antioxidante e de inibição da tirosinase. Também foi possível identificar a quercetagetina-7-O-glicosídeo, uma flavona glicosilada, com propriedades anti-inflamatorias e antidiabéticas. Desta forma, constatou-se que G. chacoensis apresenta grande diversidade de metabólitos secundários com atividades biológicas relevantes, como atividade antioxidante e clareadora, abrindo caminho para investigações mais profundas de suas aplicações, especialmente no segmento de cosméticos e produtos naturais

Brazil is the country with the greatest diversity of bamboo in the entire American continent, with more than 200 species catalogued. Due to their high resistance and durability, they are widely used in home construction and manufacture of furniture and utensils. However, studies investigating chemical composition and biological activities are absent. In this project, ethanol extracts from leaves and stems of Guadua chacoensis (Rojas) Londoño & P.M. Peterson and fractions in hexane, chloroform, ethyl acetate and n-butanol were evaluated. Volatile oil was also obtained, but with an extremely low yield (0.00079%). The fractions of the extracts presented contents of phenolic compounds varying between 1.92 and 15.80 µg GAE/mg. These compounds were more abundant in culm samples. In relation to the flavonoid content, leaves showed a greater amount, varying between 0.39 and 1.18 µg QE/mg against 0.17 to 0.34 µg QE/mg in culms. The antimicrobial activity of extracts, fractions and volatile oil were investigated against five microorganisms: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus brasiliensis. The samples showed moderate to good inhibitory potential against S. aureus and C. albicans, but weak for the other species. The antioxidant capacity was tested against the DPPH radical and the results indicated significant antioxidant activity, especially acetate and butanol culm fractions. The leaves presented EC50 varying between 67.5 and 124.0 µg/mL and culms between 40.2 and 124 µg/mL. The inhibition of the enzyme tyrosinase, which is associated with the production of melanin, was also shown to be good at a concentration of 1 mg/mL, with the raw culm extract showing 43% inhibition, followed by acetate (36%) and n-butanol (38%) fractions of leaves. CG-MS analysis detected at least 44 different compounds in volatile oil, with several terpenes and sesquiterpenes, and with ß-ionone being the major component (8.75%). Culm and leaf samples showed great diversity of compounds, about 20 for each fraction, where fatty acids such as palmitic and linoleic acid and their derivative esters were the most abundant. The analysis of the chromatographic profiles by TLC and HPLC revealed the presence of p-coumaric acid in culms of G. chacoensis. This compound has relevant antioxidant and tyrosinase inhibiting activity. It was also possible to identify quercetagetine-7-O-glucoside, a glycosylated flavone, with anti-inflammatory and anti-diabetic properties. Thus, it was found that G. chacoensis presents a great diversity of secondary metabolites with relevant biological activities, such as antioxidant and whitening activity, opening ways for deeper investigations of its applications, especially in the segment of cosmetics and natural products

Thiocyanate in excess develops goiter followed by auto immune thyroid diseases even after effective salt iodization in a rural community of north east India.

PURPOSE: Salt iodization in Manipur of north-east India failed to prevent endemic goiter, therefore an in depth study carried out to evaluate thyroid functions of goitrous subjects in a randomly selected region. METHODS: Goiter survey conducted in children and women of reproductive ages by palpation followed by measurement of urinary iodine, thiocyanate and house-hold salt iodine to evaluate iodine nutritional status and consumption pattern of bamboo-shoots (BS). In all grade-2 goitrous subjects, free thyroxine, triiodothyronine, TSH, TPO and Tg antibodies, thyroid volume and echogenecity by ultrasonography and cytomorphology of thyroid by FNAC studied. RESULTS: Study population was 2486 children and 1506 women, goiter prevalence was 12.59% and 16.27% respectively; median urinary iodine and mean thiocyanate were 166 µg/l and 0.729 ± 0.408 mg/dl while salt iodine was ≥30 ppm. Serum thyroid hormones and TSH profiles of all grade-2 goitrous subjects showed 16.21% were subclinically hypothyroid, 2.16% overt hypothyroid, 4.86% subclinically hyperthyroid and 6.48% overt hyperthyroid, serum TPO- and Tg-antibodies found positive in 41.62%. Ultrasonographic results showed 24% had enlarged thyroid and 86.4% hypoechoic. Cytomorphological studies showed prevalence of colloid goiter (41.08%), lymphocytic thyroiditis (37.83%), Hashimoto's thyroiditis (8.10%), autoimmune thyroiditis (4.32%), sub-acute thyroiditis (2.16%) and 1.62% each papillary, medullary carcinoma, simple diffused hyperplasia and adenomoid nodular goiter. CONCLUSIONS: Grade-2 goitrous individuals in this mild goiter endemic region were affected by hypo- and hyperthyroidism with hypoechoic thyroid and thyroiditis. Thiocyanate that originates from BS even in presence of adequate iodine developed goiter and led goitrous population towards such diseases.

Role of bamboo-shoot in the pathogenesis of endemic goiter in manipur, north East India.

OBJECTIVE: Endemic goiter is prevalent in the iodine-sufficient region of Manipur, India. Bamboo shoot (BS), a goitrogenic plant food, are consumed regularly in the area. The objective of this study was to examine the role of BS in the pathogenesis of endemic goiter. METHODS: Goiter prevalence, urinary iodine, and thiocyanate (SCN) excretion in school children, iodine content in drinking water, and the household consumption of salt fortified with iodine were measured. To confirm the goitrogenic potential of BS, its progoitrogenic constituents were fed to rats as part of an iodine-sufficient diet, after which the animals' thyroid gland morphology and functional status were assessed. RESULTS: Goiter prevalence was 31% in 4852 children, and the median urinary I and SCN levels were 176.3 µg/L and 0.962 ± 0.190 mg/dL, respectively. Of the households assessed, 90% consumed salt fortified with adequate iodine. Progoitrogenic constituents were high in BS from Manipur. Increased thyroid weight, hypertrophy and hyperplasia of follicular cells, decreased thyroid peroxidase activity, and low serum thyroxine (T4) and triiodothyronine (T3) levels were observed in BS-fed rats. CONCLUSION: Nearly one third of the studied participants had palpable goiter, despite a successful salt iodine fortification program. SCN from BS causes goiter in iodine-sufficient experimental animals. Similar ingestion in study participants was confirmed and is the likely cause for the persistence of endemic goiter in the Manipur region.

Bamboo shoot preservation for enhancing its business potential and local economy: a review.

Bamboo shoot as food has been used in traditional ways by the tribal community the world over. For enhancing its business potential, research on various aspects of bamboo shoot as food is being carried out in Japan, Taiwan, Thailand, and Asian countries and several products are available in the market. Bamboo shoots are used as a delicacy in human food, are a good source of dietary fiber, low in fat and calories. The research studies included in this review paper focus on post-harvest preservation of bamboo shoot. In view of the seasonal availability of bamboo shoot, the post-harvest preservation system for handling cynogenic toxicity in raw shoot while keeping nutrients intact and enhancement of shelf life of the value added products assume great significance for the business potential of this natural product. A yardstick of assessing the "Shelf life-Quality Matrix" developed in this review paper would give a new perspective of quality control in case of preservation of bamboo shoot. Also, knowledge gaps identified in this paper would give impetus to new academic and R&D activities, in turn generating an innovative job profile in the food industry as well as rural entrepreneurship.