Chemical and Biological Properties of an Arabinogalactan from Phyllanthus niruri

Abstract

Phyllanthus niruri is a well-known herb widely used medicinally in Asia, Africa, and South America. Aqueous extraction of the intact plant provided an acidic arabinogalactan, which was characterized chemically, and its effects on peritoneal macrophage activation were determined. Methylation analyses and (13)C NMR spectroscopy showed it to have a complex structure with a (1-->4)-linked beta-Galp main chain, substituted by rhamnose, galacturonic acid, arabinose, xylose, galactose, and glucose-containing side chains, with nonreducing end-units of arabinofuranose, xylopyranose, galactopyranose, and glucopyranose. In immunological studies, the arabinogalactan stimulated superoxide anion production, when tested using peritoneal macrophages of mice, but did not interfere with the nitric oxide pathway. Thus, traditional aqueous extraction methods, such as decoction and infusion, provide a major polysaccharide, which stimulates an intense biological response in macrophages: this could represent an interesting approach in phytotherapeutic treatments.

Phytochemicals fromPhyllanthus niruriLinn. and their pharmacological properties: a review

“…These xylans have immunomodulatory and anti-tussive properties (Ebringerova et al 2002;Kardosova et al 2002). An aqueous extract of P. niruri contained an acidic arabinogalactan, which belongs to the polysaccharide category, and has shown immunostimulatory activity by stimulating macrophages from mouse peritoneal cavity to produce superoxide (O 2 − ) (Mellinger et al 2005b). This type of agent, collectively known as biological response modifiers, are able to mediate many therapeutic effects, including anti-tumour activity.…”

Immunomodulatory activity of polysaccharides isolated from Alchornea cordifolia

“…Among the high molecular weight components of medicinal herbs, polysaccharides have been shown to possess a variety of pharmacological activities (Schepetkin and Quinn, 2011). Although, there are several reports on the medicinal properties of polysaccharides isolated from plants belonging to the Euphorbiaceae family (Milo et al , 2002; Mellinger et al , 2005; Yu et al , 2006), there are no reports regarding isolation and characterization of polysaccharides from any of the seventy known tropical Alchornea species. Thus, we performed studies to investigate the immunomodulatory properties of Alchornea polysaccharides isolated by hot water extraction, which is the most frequently used preparation reported in our ethnopharmacological analysis.…”

Antidiabetic property of some Nigerian medicinal plants

“…The morphology of the plant has been described (Bagalkotkar, 2006). It is popularly used in Asia, Africa and South America (Mellinger et al, 2005) as a stomachic, aperitive, anti-hyperglycemic, antispasmodic, anti-hepatotoxic, antiviral, antibacterial, laxative, diuretic, carminative, in the management of diabetes, constipation, fever including malaria, jaundice, hepatitis B, dysentery, gonorrhea, syphilis, tuberculosis, cough, influenza, diarrhea, vaginitis, tumors, kidney stones (Syamasundar et al, 1985;Oliver-Bever, 1986;Chopra et al, 1986;Unander et al, 1995;Paranjape, 2001;Lin et al, 2003;Mellinger et al, 2005). Studies on extracts from various parts of the plant have revealed the antioxidant (Tasaduq et al, 2003) and nitric oxide scavenging (Jagetia and Baliga, 2004), antimalarial (antiplasmodial) (Tona et al, 1999;Tona et al, 2001;Tona et al, 2004;Subeki et al, 2005;Mustofa et al, 2007), antihyperuricemic (Murugaiyah and Chan, 2006), antinociceptive/analgesic (Santos et al, 1994;Santos et al, 1995), diuretic, hypotensive, hypoglycemic (Ramakrishnan et al, 1982), hepatoprotective (Syamasundar et al, 1985;Bhattacharjee and Sil, 2006;Sarkar and Sil, 2007;Bhattacharjee and Sil, 2007;Manjrekar et al, 2008) activities.…”

“…Studies on extracts from various parts of the plant have revealed the antioxidant (Tasaduq et al, 2003) and nitric oxide scavenging (Jagetia and Baliga, 2004), antimalarial (antiplasmodial) (Tona et al, 1999;Tona et al, 2001;Tona et al, 2004;Subeki et al, 2005;Mustofa et al, 2007), antihyperuricemic (Murugaiyah and Chan, 2006), antinociceptive/analgesic (Santos et al, 1994;Santos et al, 1995), diuretic, hypotensive, hypoglycemic (Ramakrishnan et al, 1982), hepatoprotective (Syamasundar et al, 1985;Bhattacharjee and Sil, 2006;Sarkar and Sil, 2007;Bhattacharjee and Sil, 2007;Manjrekar et al, 2008) activities. Constituents isolated from the plant include compounds such as the alkaloids -4-methoxy-securinine (Phyllanthine) and 4-methoxy-nor-securinine (Mulchandani and Hassarajani, 1984), arabinogalactan (Mellinger et al, 2005;Mellinger et al, 2008), ellagic acid, brevifolin carboxylic acid and ethyl brevifolin carboxylate (Shimizu et al, 1989) (Subeki et al, 2005), the lignans -phyllanthin, hypophyllanthin, phyltetralin (Murugaiyah and Chan, 2006), cubebin dimethyl ether, urinatetralin (Elfahmi et al, 2006), and niranthin (Murugaiyah and Chan, 2007).…”