Identification of Bioactive Phytochemicals from Six Plants: Mechanistic Insights into the Inhibition of Rumen Protozoa, Ammoniagenesis, and α-Glucosidase
Authors
Aurele Ayemele
State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; [email protected] (A.G.A.); [email protected] (L.M.)
Lu Ma
State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; [email protected] (A.G.A.); [email protected] (L.M.)
Xiumei Li
Feed Research Institute, Chinese Academy of Agricultural Science, Beijing 100081, China; [email protected] (X.L.); [email protected] (P.Y.)
Peilong Yang
Feed Research Institute, Chinese Academy of Agricultural Science, Beijing 100081, China; [email protected] (X.L.); [email protected] (P.Y.)
Jianchu Xu
State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; [email protected] (A.G.A.); [email protected] (L.M.)
Zhongtang Yu
Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA; [email protected]
Dengpan Bu
State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; [email protected] (A.G.A.); [email protected] (L.M.)
Simple Summary
Rumen protozoa have some contribution to feed digestibility in the rumen, but Entodinium, the most predominant genus, is the main culprit of inefficient nitrogen utilization in ruminants. Using chemical drugs, many studies have attempted to inhibit the rumen protozoa, but few of the approaches are either effective or practical. In this study, we investigated the nutritional and functional properties of Adansonia digitata (baobab), Flemingia macrophylla (waras tree), Kalimeris indica (Indian aster), Brassica rapa subsp. chinensis (bok choy), Portulaca oleracea (common purslane), and Calotropis gigantea (giant milkweed) for their potential as feed additives in animal husbandry. The plants were also analyzed for their major phytochemicals using reversed phase-high performance liquid chromatography (HPLC) and then evaluated for their ability to inhibit rumen protozoa, ammoniagenesis, and microbial α-glucosidase activity in vitro. C. gigantea inhibited the rumen protozoa and reduced the wasteful ammoniagenesis, thereby indicating improved nitrogen utilization. A. digitata also reduced the microbial α-glucosidase activity that can potentially contribute to rumen acidosis. The tested plants, especially C. gigantea and A. digitata, could be used as potential alternatives to chemicals or antibiotics to ensure sustainable and green animal husbandry.
Rumen protozoa prey on feed-degrading bacteria synthesizing microbial protein, lowering nitrogen utilization efficiency in ruminants. In this in vitro study, we evaluated six plants (Adansonia digitata, Flemingia macrophylla, Kalimeris indica, Brassica rapa subsp. chinensis, Portulaca oleracea, and Calotropis gigantea) for their potential to inhibit rumen protozoa and identified the phytochemicals potentially responsible for protozoa inhibition. Rumen protozoa were anaerobically cultured in vitro in the presence of each plant at four doses. All of the tested plants reduced total rumen protozoa (p ≤ 0.05), but C. gigantea and B. rapa were the most inhibitory, inhibiting rumen protozoa by 45.6 and 65.7%, respectively, at the dose of 1.1 mg/mL. Scanning electron microscopy revealed a disruption of the extracellular structure of protozoa cells. Only C. gigantea also decreased the wasteful ammoniagenesis (p ≤ 0.05). Moreover, the A. digitata extract inhibited α-glucosidase activity by about 70% at 100 µg/mL. Reversed-phase high-performance liquid chromatography analysis detected quercetin, anthraquinone, 3-hydroxybenzoic acid, astragaloside, and myricetin in the tested plant leaves. These plants may hold potential as feed additives to reduce rumen protozoa and α- glucosidase activity. Future research is needed to identify the specific anti-protozoal compound(s), the effects on the rumen microbiome, and its fermentation characteristics.
Keywords: bioactive phytochemicals, feed efficiency, microbial α-glucosidase, protozoa inhibition
Author Biographies
Aurele Ayemele, State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; [email protected] (A.G.A.); [email protected] (L.M.)
Honghe Center for Mountain Futures, Kunming Institute of Botany, Chinese Academy of Sciences, Honghe County, Kunming 654400, China
Jianchu Xu, State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; [email protected] (A.G.A.); [email protected] (L.M.)
World Agroforestry Center, East and Central Asia, Kunming 650201, China
Dengpan Bu, State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; [email protected] (A.G.A.); [email protected] (L.M.)
Joint Laboratory on Integrated Crop-Tree-Livestock Systems of the Chinese Academy of Agricultural Sciences (CAAS), Ethiopian Institute of Agricultural Research (EIAR) and World Agroforestry Center (ICRAF), Beijing 100193, China
Click on "Archives" to access the full archive of scientific preprints. You may use the categories and the search functionality to find select preprints you're interested in.
