Antioxidant Activities of Extracts and Main Components of Pigeonpea [Cajanus cajan (L.) Millsp.] Leaves

Abstract

Antioxidant activities of the aqueous and ethanol extracts of pigeonpea [Cajanus cajan (L.) Millsp.] leaves, as well as petroleum ether, ethyl acetate, n-butanol and water fractions and the four main compounds separated from the ethanol extract, i.e. cajaninstilbene acid (3-hydroxy-4-prenylmethoxystilbene-2-carboxylic acid), pinostrobin, vitexin and orientin, were examined by a DPPH radical-scavenging assay and a β-carotene-linoleic acid test. In the DPPH system, the antioxidant activity of the ethanol extracts was superior to that of the aqueous extracts, with IC50 values were 242.01 and 404.91 µg/mL, respectively. Among the four fractions, the ethyl acetate one showed the highest scavenging activity, with an IC50 value of 194.98 µg/mL. Cajaninstilbene acid (302.12 µg/mL) and orientin (316.21 µg/mL) showed more efficient radical-scavenging abilities than pinostrobin and vitexin. In the β-carotene-linoleic acid test, the inhibition ratio (%) of the ethyl acetate fraction (94.13%±3.41%) was found to be the highest, being almost equal to the inhibition capacity of the positive control BHT (93.89%±1.45%) at 4 mg/mL. Pinostrobin (>500 µg/mL) and vitexin (>500 µg/mL) showed insignificant antioxidant activities compared with cajaninstilbene (321.53 µg/mL) and orientin (444.61 µg/mL). In general, the ethyl acetate fraction of the ethanol extract showed greater activity than the main compounds in both systems, such results might be attributed to the synergistic effects of the components. The antioxidant activities of all the tested samples were concentration-dependent. Based on the results obtained, we can conclude that the pigeonpea leaf extracts may be valuable natural antioxidant sources and are potentially applicable in both medicine and the healthy food industry.

Assessment of anti-inflammatory, antinociceptive, immunomodulatory, and antioxidant activities ofCajanus cajanL. seeds cultivated in Egypt and its phytochemical composition

“…It is worthy to be mention that quercetin-3-O-b-Dglucopyranoside is isolated from C. cajan for the first time, while the other flavonoidal compounds were isolated from C. cajan seed for the first time. Quercetin, luteolin, apigenin, isorhamnetin, vitexin, and orientin were detected previously in C. cajan leaves (Wu et al, 2009;Zu et al, 2006). Chronic inflammation has been linked to a wide range of progressive diseases.…”

“…(Fabaceae) (in English: Pigeon pea, Arabic: Shakul, Hindi: Arhar, Bengali: Tur) is a perennial food crop (Pal et al, 2011). Other common names are red gram, congo pea, gungo pea, and no-eye pea (Wu et al, 2009).…”

“…Although traditional uses of C. cajan plant for treatment of different diseases (Pal et al, 2011;Wu et al, 2009), there has been less concern regarding phytochemical composition and biological activities of C. cajan seeds, which prompted us to study its chemical composition and anti-inflammatory, antinociceptive, immunomodulatory and antioxidant activities which may act as an important step towards the establishment of C. cajan as a medicinal drug.…”

Protective effect of aqueous extract of Feronia elephantum correa leaves on thioacetamide induced liver necrosis in diabetic rats

“…The major among them are flavonoids namely orientin and vitexin . Protective effects on many vital organs were reported by orientin [21,22] and vitexin [23] by virtue of antioxidant potential [24] . Therefore, protection shown by FE against TA-induced acute liver injury is at least partly contributed by antioxidant activity of orientin and vitexin.…”

The enhancement of drought tolerance for pigeon pea inoculated by arbuscular mycorrhizae fungi

“…Compared with other grain legumes, pigeon pea ranks only the sixth in area and production, but it is used in more diverse ways than others (Wu et al 2009, Domoguen et al 2010. Pigeon pea is a hardy, widely adapted and drought tolerant crop.…”