Antioxidant potential and α-glucosidase inhibitory activity of onion (Allium cepa L.) peel and bulb extracts

Allium cepa L. is a commonly consumed vegetable that belongs to the Amaryllidaceae family and contains nutrients and antioxidants in ample amounts. In spite of the valuable food applications of onion bulb, its peel and outer fleshy layers are generally regarded as waste and exploration of their nutritional and therapeutic potential is still in progress with a very slow progression rate. The present study was designed with the purpose of doing a comparative analysis of the antioxidant potential of two parts of Allium cepa, i.g., bulb (edible part) and outer fleshy layers and dry peels (inedible part). Moreover, the inhibitory effect of the onion bulb and peel extracts on rat intestinal α-glucosidase and pancreatic α-amylase of porcine was also evaluated. The antioxidant potential of onion peel and bulb extracts were evaluated using 2,2-diphenyl- 1-picryl hydrazyl (DPPH), ferric-reducing antioxidant power assay (FRAP), 2,2’-azino-bis- 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assay, H2O2 radical scavenging activity and Fe2+ chelating activity. Total flavonoids and phenolic content of ethanolic extract of onion peel were significantly greater as compared to that of onion bulb. Ethanolic extract of onion peel also presented better antioxidant and free-radical scavenging activity as compared to the ethanolic extract of bulb, while the aqueous extract of bulb presented weakest antioxidative potential. Onion peel extract’s α-glucosidase inhibition potential was also correlated with their phenolic and flavonoid contents. The current findings presented onion peel as a possible source of antioxidative agents and phenolic compounds that might be beneficial against development of various common chronic diseases that might have an association with oxidative stress. Besides, outer dry layers and fleshy peels of onion exhibited higher phenolic content and antioxidant activities, compared to the inner bulb. The information obtained by the present study can be useful in promoting the use of vegetable parts other than the edible mesocarp for several future food applications, rather than these being wasted.

Integrative analysis in toxicological assessment of the insecticide Malathion in Allium cepa L. system

For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-1 and 1.0 mg mL-1 MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-1). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-1, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.

PERTUMBUHAN DAN PRODUKSI BAWANG MERAH (ALLIUM CEPA L) DENGAN PEMBERIAN MIKROORGANIME LOKAL (MOL) FESES WALET PADA MEDIA GAMBUT

Penelitian pengaruh konsentrasi mikroorganisme lokal (MOL) feses walet terhadap pertumbuhan bawang merah (Allium cepa L) pada media gambut telah dilaksanakan di Kebun percobaan Universitas Islam Indragiri UNISI Kabupaten Indragiri Hilir Propinsi Riau selama 3 bulan dari bulan Janurai sampai Maret Tahun 2020. Penelitian ini bertujuan untuk mengetahui pengaruh konsentrasi mikroorganisme lokal (MOL) feses walet terhadap pertumbuhan bawang merah (Allium cepa L) pada media gambut Penelitian ini menggunakan rancangan acak lengkap (RAL) non factorial yang terdiri dari 6 perlakuan dengan 3 kali ulangan yaitu terdiri dari 0%, 5%, 10%, 15 %, 20 %, 25 % Parameter pengamatan pada penelitian ini yaitu, tinggi tanaman, jumlah umbi per rumpun, berat basah umbi per rumpun, berat kering umbi per rumpun, bobot umbi per rumpun. Data pengamatan dianalisis dengan sidik ragam (ANNOVA) dan dilanjutkan dengan uji lanjut tukey HSD dengan taraf 5% Hasil penelitian menunjukkan bahwa perlakuan 25% mampu meningkatkan parameter yaitu Tinggi tanaman, Berat basah umbi per rumpun, Berat kering umbi perrumpun, bobot kering umbi, dan buah layak jual, kecuali pada perlakuan jumlah umbi perrumpun;

Antiproliferative, genotoxic and mutagenic potential of synthetic chocolate food flavoring

Flavoring additives are of great technological importance for the food industry. However, there is little information regarding the toxicological properties of these micro-ingredients, especially at the cellular level. The present study used meristematic root cells of Allium cepa L. to evaluate the toxicity of a liquid, aroma and flavor synthetic chocolate additive, manufactured and widely marketed throughout Brazil and exported to other countries in South America. The flavoring concentrations evaluated were 100.00; 50.00; 25.00; 1.00; 0.50 and 0.25 µL/L, where the highest concentration established was one-hundred times lower than that commercially suggested for use. The concentration 100 µL/L substantially reduced cell division of meristems within 24- and 48-hours exposure. Concentrations from 100.00 to 0.50 µL/L resulted in a significant number of prophases to the detriment of the other phases of cell division, indicating an aneugenic activity, and induced a significant number of cellular changes, with emphasis on micronuclei, nuclear buds and chromosomal breaks. Under the established analysis conditions, with the exception of concentration 0.25 µL/L, the flavoring of chocolate caused cytotoxicity, genotoxicity and mutagenicity to root meristems.