Antioxidant potential of common leafy vegetables in Bangladesh

Abstract

Amount of polyphenols, flavonoids, anthocyanins in ethanol extracts and antioxidant activity of both ethanol and lipophilic extracts of common leafy vegetables in Bangladesh were compared. Among the 12 leafy vegetables, Ipomoea aquatica Forssk. showed the highest content of total polyphenols (38.9 mg gallic acid equivalent (GAE)/g extract) and flavonoids (23.2 mg (+)-catechin equivalent (CE)/g extract). Highest anthocyanins content was found in Amaranthus gangeticus L. (1.15 ?mol/g extract) followed by Pisum sativum L. (0.85 ?mol/g extract). Ethanol extracts of Brassica campestris L., Enhydra fluctuans Lour., I. aquatica, Lagenaria siceraria (Mol.) Standl. and P. sativum exhibited high DPPH free radical scavenging activity with IC50 of 104.2, 85.5, 26.9, 125 and 68.5 ?g/ml, respectively whereas for the same lipophilic pentane extracts of Basella alba L. showed the lowest (68.4 ?g/ml) IC50 followed by I. aquatica (70.4 ?g/ml), E. fluctuans (75.7 ?g/ml), L. siceraria (78.3 ?g/ml) and B. campestris (80.6 ?g/ml). I. aquatica also showed the highest NO free radical scavenging followed by B. campestris and B. alba. Highest reducing power (O.D. = 1.7) was observed for I. aquatica followed by P. sativum (O.D. = 1.12), B. alba (O.D. = 0.86) and L. siceraria (O.D. = 0.72) at 400 ?g/ml extract. They also displayed high total antioxidant capacity. Therefore, the top five potential leafy vegetables consist of both hydrophilic and lipophilic antioxidant(s), the order being I. aquatica > B. campestris > B. alba > P. sativum > and L. siceraria. DOI: http://dx.doi.org/10.3329/bjb.v44i1.22723 Bangladesh J. Bot. 44(1): 51-57, 2015 (March)

Chemical composition and in vitro antioxidant properties of water‐soluble extracts obtained from Bangladesh vegetables

“…Ridge gourd (62.96 ± 0.73%) and snake gourd (62.54 ± 1.39%) also showed values that are comparable to the Indian spinach. The results differ from a previous work, which reported 100.9 ± 0.6% DRSA at 200 µg/ml for kangkong and 71.6 ± 0.6% for Indian spinach (Hossain et al., 2015). Apart from brinjal and bitter gourd, all the other vegetable extracts had more than 50% DRSA.…”

“…The results are similar to those reported by Hossain et al. (2015), which showed that kangkong had the highest TFC when compared to 11 other vegetables. Noticeably, there was no direct correlation between the TPC and TFC values, which indicates varied levels of polyphenolic compounds in the samples.…”

“…The highest DPPH radical scavenging activity (DRSA) was observed for BHT at 0.5 mg/ml (81.08 ± 0.65%) when compared to the vegetable extracts ( Figure 2). fer from a previous work, which reported 100.9 ± 0.6% DRSA at 200 µg/ml for kangkong and 71.6 ± 0.6% for Indian spinach (Hossain et al, 2015). Apart from brinjal and bitter gourd, all the other vegetable extracts had more than 50% DRSA.…”

“…The results are in contrast to a previous work, which reported that kangkong had a higher TPC value of 27.65 ± 1.45 mg GAE/g when compared to 7.65 ± 0.47 mg/GAE for Amaranth gangeticus , 7.22 ± 0.31 mg GAE/g for Amaranth viridis and 2.71 ± 0.05 mg GAE/g for brinjal (Sharmin, Nazma, Mohiduzzaman, & Cadi, 2011). Similarly, Hossain, Sultana, Iftekharuzzaman, Hossain, and Taleb (2015) also reported that kangkong had a higher TPC value of 38.9 ± 1.7 mg GAE/g when compared to amaranth with 16.6 ± 0.7 mg GAE/g. The differences between our work and previous studies may be due to the type of extraction solvent used because some of the previous studies used solvents and not water.…”

Antibacterial and antioxidant activities of Agaricus bisporus (J.E. Lange) imbach from Pakistan

“…Antioxidants are the compounds that protect the cell from destruction caused by free radicals through redox reaction carried out by peroxide or oxygen (Hossain et al 2015). Free radicals destroy the proteins, DNA and sugars present in the plants and antioxidants are the chemicals that delay or stop the formation of these radicals by scavenging effect (Hussein et al 2015).…”