تاثير روش هاي مختلف استخراج بر فعاليت آنتي اكسيداني و فعاليت آنتي باكتريال گياه Nonnea lutea

Influence of Different Extraction Methods on Antioxidant and Antibacterial Activities of Nonnea lutea

سابقه و هدف: از گياه چشم گربه‌اي تا‌كنون هيچ اثر بيولوژيكي گزارش نشده است. اين مطالعه به منظور بررسي فعاليت آنتي اكسيداني و ضد ميكروبي آن انجام شده است. مواد و روش‌ها: اندام‌هاي هوايي به سه روش خيساندن، سوكسله و التراسونيك با متانول عصاره‌گيري شد. فعاليت آنتي اكسيداني با چهار روش مورد ارزيابي قرار گرفت. محتواي تام فنلي و فلاونوئيدي آن نيز اندازه‌گيري شد. فعاليت ضد ميكروبي بر روي چهار باكتري به روش ديسك ديفيوژن انجام شد. يافته‌ها: بيش‌ترين ميزان فنل و فلاونوئيد تام مربوط به عصاره سوكسله و عصاره اولتراسونيك بود. IC50 بدام اندازي راديكال DPPH در استخراج به روش سوكسله 3/0 ± 14/99µg/ml بود كه اختلاف معني‌داري با دو عصاره ديگر داشت (01/0p<). در تست احيا كنندگي، عصاره‌ها فعاليت مشابه‌اي از خود نشان دادند (05/0p>). عصاره‌ها توانايي كمي در شلاته كردن آهن و به دام‌اندازي راديكال آزاد نيتريك اكسايد از خود نشان دادند و بين آن‌ها اختلاف معني‌داري وجود نداشت (05/0

Background and purpose: No reports are found on biological activities of Nonea lutea (boraginaceae). The aim of this study was to investigate the antioxidant and antibacterial activities of this plant. Materials and methods: The aerial parts were extracted by three different methods, i.e. meceration (MA), ultrasonic assisted (US), and soxhlet assisted (SO) extractions with methanol. Antioxidative capacity was assessed by utilizing four methods: DPPH and nitric oxide (NO) free radicals scavenging, reducing power and iron chelating activity. The total phenolic and flavonoid contents were also determined. Antibacterial activities were evaluated by disc diffusion method against four bacteria. Results: The highest amount of total phenolic and flavonoid contents were found in SO and US extracts, respectively. In DPPH radical scavenging activity, SO extract (IC50 = 99.14 ± 0.3 µg ml-1) had a higher activity which was significantly different from that of other extracts (P< 0.01). In reducing power, the extracts showed similar activities (P>0.05). The extracts showed weak iron chelating and nitric oxide radical scavenging activities indicating no significant differences (P> 0.05). Findings showed that all extracts had the highest activity against B. subtilis and the least activity against S. aureus. SO extract showed the highest activity against B. subtilis, US extract showed the highest activity against E coli and P. aeruginosa, and MA extract showed the highest activity against S. aureus. Conclusion: The results indicated that extraction methods significantly affect antioxidant and antibacterial capacities and total phenolic and flavonoid contents. For this plant, SO extraction method was found to be more efficient.