In VitroandIn VivoImmunomodulatory Activity of Okra (Abelmoschus esculentus L.) Polysaccharides

Abstract

Crude okra (Abelmoschus esculentus L.) polysaccharide (RPS) was obtained by water extraction and alcohol precipitation. Three purified fractions of RPS, designated RPS-1, RPS-2, and RPS-3, were fractioned by diethylaminoethyl (DEAE)-cellulose chromatography. Their molecular weights, monosaccharide compositions, infrared (Fourier transform infrared [FT-IR]) spectra, and nuclear magnetic resonance (NMR) spectra were analyzed. Their immunomodulatory activity was evaluated with an in vitro cell model (RAW264.7 cells). In vivo immunomodulatory activity of RPS-2 was evaluated in normal and cyclophosphamide-induced immunosuppressed mice. The results showed that the molecular weights of RPS-1, RPS-2, and RPS-3 were 600, 990, and 1300 kDa, respectively. RPS-1 and RPS-2 were mainly composed of galactose, rhamnose, galacturonic acid, and glucuronic acid, while RPS-3 was mainly composed of galactose, rhamnose, galacturonic acid, glucuronic acid, and glucose. FT-IR and NMR spectrum data indicated a rhamnogalacturonan I characteristic of polysaccharide. Both RPS and its purified fractions RPS-1, RPS-2, and RPS-3 significantly increased RAW264.7 cell proliferation, nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression, and tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-10 secretion (P< .05). The purified fraction RPS-2 also increased the spleen index, splenocyte proliferation, and cytokine secretion in vivo. These results indicate that okra polysaccharides may potentially serve as novel immunomodulators.

Okra Polysaccharides Improves Spleen Weight and B-Lymphocytes Proliferation in Mice Infected by Staphylococcus aureus

“…Similar with study conducted by Zha et al (2014), Dendrobium huoshananse polysaccharides at doses of 50, 100, and 200 mg/kg BW increased splenocyte proliferation of 140%, 165%, and 196% respectively. Chen et al (2016) also revealed that administration of okra polysaccharides at doses of 25, 50, and 100 mg/kg BW significantly increase splenocyte proliferation induced by LPS and okra polysaccharide at dose of 100 mg/kg BW showed highest rising of splenocyte proliferation. We can state that higher doses of polysaccharides help in rising the proliferation of B-lymphocytes.…”

“…Similarly, study conducted by Chen et al (2016) showed that highest dose of okra polysaccharides (100 mg/kg BW) increased the spleen index significantly with cyclophosphamide as an antigen. Our present result suggested that okra polysaccharides enhance spleen weight and induce the increase in number of splenocytes in spleen.…”

“…In the last few decades, many polysaccharide-protein complexes with immunomodulatory activity from medicinal herbs have become primary concern of researchers to prevent the disease (Schepetkin & Quinn, 2006). Okra pods have long been used both as a food source and as traditional medicine for many disease (Chen et al, 2016). Okra (Abelmoschus esculentus) is a vegetable plant known as bendi in Malaysia, kra jeab khiew in Thailand, lender in Riau, or Arab nuts in West Kalimantan (Nadira et al, 2009).…”

“…The pellet was dissolved in distilled water and centrifuged. The supernatant was collected and lyophilized (Chen et al, 2016).…”

“…The active compounds of okra are flavonoids and vitamine C as antioxidant (Arapitsas, 2008;Lim, 2012). Meanwhile, okra polysaccharides acts were used as immunomodulator (Chen et al, 2016).…”