Lignosus rhinocerotis has a long history of use by the indigenous community within East Asia to treat a range of health conditions including asthma and chronic cough. To date, there is limited scientific evidence to support its therapeutic effects in relieving these airways conditions. In this study, we examined the effects of the different molecular weight fractions [high-molecular-weight (HMW), medium-molecular-weight (MMW), and low-molecular-weight (LMW)] obtained from the cold water sclerotial extract (CWE) of L. rhinocerotis on airways patency using airway segments isolated from Sprague Dawley rat in an organ bath set-up. It is demonstrated that the HMW and MMW fractions exhibited higher efficacy in relaxing the pre-contracted airways when compared to the CWE and LMW fraction. In addition, the HMW fraction markedly supressed carbachol-, 5-hydroxytrptamine-, and calcium-induced airway contractions. CWE demonstrated a lower efficacy than the HMW fraction but it also significantly attenuated carbachol- and calcium-induced airway contractions. Results showed that the bronchorelaxation effect of CWE and fractions is mediated via blockade of extracellular Ca2+ influx. The composition analysis revealed the following parts of carbohydrate and proteins, respectively: HMW fraction: 71 and 4%; MMW fraction: 35 and 1%; and LMW fraction: 22 and 0.3%. Our results strongly suggest that the polysaccharide-protein complex or proteins found in the HMW and MMW fractions is likely to contribute to the bronchorelaxation effect of CWE.
Ophiocordyceps sinensis (=Cordyceps sinensis) has been known for its various medicinal properties, in particular immunomodulatory activities associated with its polysaccharides. In this study, the fruiting body of O. sinensis cultivar OCS02® was investigated for its chemical composition and monosaccharide profile. Cold water extract (CWE) obtained from this fruiting body was fractionated by molecular weight (MW) into high (HMW), medium (MMW), and low (LMW) fractions. Polysaccharides in the extract and fractions were identified as heteroglycans containing mostly glucose and mannose with small amounts of galactose, fucose, arabinose, and xylose. The immunomodulatory potential of these heteroglycans was evaluated by induction of cytokine/chemokine secretion using murine macrophage RAW 264.7. All treatments showed significant modulation of IL-6, IL-9, MIP-2, and TIMP-1, especially for CWE, HMW, and MMW, which might be due to their high ratios of glucose and the presence of protein. Further investigation on the structure-function relationship of these fruiting body polysaccharide fractions is needed to delineate the underlying mechanism of their immunomodulatory effect both in vitro and in vivo.