The effects of supplementation of noni (Morinda citrifolia L.) fruit polysaccharides-rich extract on antioxidant status and immune function in cashmere goats

Lay Summary Due to the limited pasture supply and the seasonal imbalance of nutrients in grazed pastures in China, cashmere goats are commonly raised in a confined yard-feeding system, which may result in oxidative stress from a lack of green pastures. Noni (Morinda citrifolia L.) fruit polysaccharides contain various biological compounds that function as anti-inflammatory, antitumor, and to enhance immune responses, hence likely to relieve oxidative stress in animals. Previous researches in our laboratory have shown that polysaccharides-rich extract from noni fruit (NFP) enhanced rumen fermentation in cashmere goats. This experiment was designed to evaluate the effect of NFP supplementation on serum antioxidant status and immune function in cashmere goats. The results showed that dietary supplementation of 0.40% NFP enhanced the immune signaling molecule levels and antioxidant enzyme activities by upregulating the expression of related genes in blood and reduced the levels of lipid peroxides and free radicals in serum, while mature goats improved body weight. Therefore, NFP could be a viable source of antioxidants for cashmere goats. This experiment was designed to examine the effects of a dietary supplementation of polysaccharides-rich noni (Morinda citrifolia L.) fruit extract (NFP) on the anti-oxidant enzyme activities, cytokines level, and expression of corresponding genes in blood of cashmere goats. Twelve castrated, 2-yr-old male cashmere goats (45.44 +/- 3.30 kg of BW +/- SD) were used in a 2 x 2 crossover design: the basal diet with or without (CON) supplementation of NFP at 4 g per kg DM (0.4%). Each period lasted for 29 d, including 1 wk for diet transition, 20 d for adaptation, and the last 2 d for sampling. The results showed that NFP supplementation increased (P < 0.05) the levels of nitric oxide, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), and the activities of catalase (CAT), glutathione peroxidase (GPx), thioredoxin reductase (TrxR), and total superoxide dismutase (T-SOD) in serum. The expressions of CAT, GPx4, TrxR, SOD1, IL-6, and TNF-alpha genes were upregulated (P < 0.05), whereas the levels of malondialdehyde (P = 0.015) and reactive oxygen species (P = 0.051) in serum were reduced. The body weight gain of goats was increased (P = 0.006) with a nonsignificant increase of feed intake with NFP supplementation. In conclusion, dietary NFP supplementation enhanced the antioxidant status and immune function in blood of cashmere goats. Polysaccharides-rich extract from noni fruit has potential as an immunomodulator for cashmere goats.

Automated summary

Dietary supplementation of polysaccharides-rich extract from noni fruit (NFP) can enhance the immune function and antioxidant status in cashmere goats, alleviating oxidative stress.