Comparative SELDI-TOF-MS profiling of low-molecular-mass proteins from Lignosus rhinocerus (Cooke) Ryvarden grown under stirred and static conditions of liquid fermentation

Phytochemical Screening and Antibacterial Activity of Lignosus rhinocerotis (Cooke) Ryvarden Grown in Open Field and Indoor

Lignosus rhinocerotis (Cooke) Ryvarden, known as tiger milk mushroom, is a rare and valuable medicinal mushroom that is widely used throughout Southeast Asia and South China for treating several ailments. This study was conducted to screen the phytochemicals present in L. rhinocerotis (Cooke) Ryvarden sclerotium grown from two different environments, open field and indoor, and evaluate the antibacterial activity. In this study, phytochemical screening of ethyl acetate and methanolic extract of L. rhinocerotis (Cooke) Ryvarden sclerotium were done using various chemical tests to identify the compounds present in the extracts. All the extracts were then tested for antibacterial activity against three different bacteria including Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa at the concentrations of 20 and 30 mg/mL using disc diffusion method. Based on the phytochemical screening result, extracts of L. rhinocerotis (Cooke) Ryvarden demonstrated the presence of steroids, terpenoids, alkaloids, and flavonoids. The antibacterial assays revealed that the ethyl acetate extracts from open field and indoor cultivations exhibited moderate activities against S. aureus at 30 mg/mL with the values of the inhibition zone being 13.3 ± 0.67 mm and 11.0 ± 0.58 mm, respectively.

A Status Review of the Bioactive Activities of Tiger Milk Mushroom Lignosus rhinocerotis (Cooke) Ryvarden

Edible and medicinal mushrooms are regularly used in natural medicines and home remedies since antiquity for ailments like fever, inflammation, and respiratory disorders. Lignosus rhinocerotis (Cooke) Ryvarden is a polypore found in Malaysia and other regions in South East Asia. It can be located on a spot where a tigress drips milk while feeding, hence the name “tiger's milk mushroom.” The sclerotium of L. rhinocerotis is highly sought after by the native communities in Malaysia to stave off hunger, relieve cough and asthma, and provide stamina. The genomic features of L. rhinocerotis have been described. The pharmacological and toxicity effects, if any, of L. rhinocerotis sclerotium have been scientifically verified in recent years. In this review, the validated investigations including the cognitive function, neuroprotection, immune modulation, anti-asthmatic, anti-coagulation, anti-inflammatory, anti-microbial/ anti-viral, anti-obesity, anti-cancer/ anti-tumor, and antioxidant properties are highlighted. These findings suggest that L. rhinocerotis can be considered as an alternative and natural medicine in the management of non-communicable diseases. However, there is a paucity of validation studies including human clinical trials of the mycochemicals of L. rhinocerotis.

Ethnomedicinal uses, pharmacological activities, and cultivation of Lignosus spp. (tiger׳s milk mushrooms) in Malaysia - A review

ETHNOPHARMACOLOGICAL RELEVANCE

Several members of the genus Lignosus, which are collectively known as cendawan susu rimau (in Malay) or tiger׳s milk mushrooms (TMM), are regarded as important local medicine particularly by the indigenous communities in Malaysia. The mushroom sclerotia are purportedly effective in treating cancer, coughs, asthma, fever, and other ailments. The most commonly encountered Lignosus spp. in Malaysia was authenticated as Lignosus rhinocerotis (Cooke) Ryvarden (synonym: Polyporus rhinocerus), which is also known as hurulingzhi in China and has been used by Chinese physicians to treat liver cancer, gastric ulcers, and chronic hepatitis. In spite of growing interest in the therapeutic potential of TMM, there is no compilation of scientific evidence that supports the ethnomedicinal uses of these mushrooms. Therefore, the present review is intended (i) to provide a comprehensive, up-to-date overview of the ethnomedicinal uses, pharmacological activities, and cultivation of TMM in general and L. rhinocerotis in particular, (ii) to demonstrate how recent scientific findings have validated some of their traditional uses, and (iii) to identify opportunities for future research and areas to prioritize for TMM bioprospecting.

MATERIALS AND METHODS

A detailed literature search was conducted via library search (books, theses, reports, newspapers, magazines, and conference proceedings) and electronic search (Web of Science, PubMed, and Google Scholar) for articles published in peer-reviewed journals. These sources were scrutinized for information on TMM and specifically for L. rhinocerotis.

RESULTS

Ethnomycological knowledge about TMM, with an emphasis on cultural associations and use as local medicine, has been comprehensively and systematically compiled for the first time. Some of the reported medicinal properties of TMM have been validated by scientific studies. The anti-tumor, immuno-modulatory, anti-inflammatory, anti-oxidative, anti-microbial, neurite outgrowth stimulation, and other pharmacological activities of L. rhinocerotis sclerotial extracts have been explored. The nature of sclerotial bioactive components, such as proteins, polysaccharides, and/or polysaccharide-protein complexes, has been identified, whereas the low-molecular-weight constituents remain poorly studied. The artificial cultivation of L. rhinocerotis via solid substrate and liquid fermentations successfully yielded fruiting bodies, sclerotium, mycelium, and culture broth that could be exploited as substitutes for the wild resources. The cultivated sclerotium and mycelium were shown to be safe from a toxicological point of view. Other research areas, e.g., chemical studies, genomics, and proteomics, have been employed to gain insights into the medicinal properties of TMM.

CONCLUSIONS

This review clarified the medicinal properties of TMM as recorded in various ethnomycological records, and it simultaneously highlighted the current efforts to provide scientific evidence by using various in vitro and in vivo models. Thus far, only the anti-tumor and immuno-modulatory effects of L. rhinocerotis sclerotial aqueous extracts have been extensively investigated, and other medicinal properties relevant to their traditional uses, e.g., anti-tussive and anti-pyretic properties, have yet to be validated. Further studies focusing on (i) the isolation and characterization of active components, (ii) the elucidation of their modes of action, and (iii) an evaluation of their safety and efficacy, when compared with the crude aqueous preparations, are warranted to accelerate potential drug discovery from TMM.

Genome-based proteomic analysis of Lignosus rhinocerotis (Cooke) Ryvarden sclerotium

Lignosus rhinocerotis (Cooke) Ryvarden (Polyporales, Basidiomycota), also known as the tiger milk mushroom, has received much interest in recent years owing to its wide-range ethnobotanical uses and the recent success in its domestication. The sclerotium is the part with medicinal value. Using two-dimensional gel electrophoresis coupled with mass spectrometry analysis, a total of 16 non-redundant, major proteins were identified with high confidence level in L. rhinocerotis sclerotium based on its genome as custom mapping database. Some of these proteins, such as the putative lectins, immunomodulatory proteins, superoxide dismutase, and aegerolysin may have pharmaceutical potential; while others are involved in nutrient mobilization and the protective antioxidant mechanism in the sclerotium. The findings from this study provide a molecular basis for future research on potential pharmacologically active proteins of L. rhinocerotis.

The potential of mycelium and culture broth of Lignosus rhinocerotis as substitutes for the naturally occurring sclerotium with regard to antioxidant capacity, cytotoxic effect, and low-molecular-weight chemical constituents

Previous studies on the nutritional and nutraceutical properties of Lignosus rhinocerotis focused mainly on the sclerotium; however, the supply of wild sclerotium is limited. In this investigation, the antioxidant capacity and cytotoxic effect of L. rhinocerotis cultured under different conditions of liquid fermentation (shaken and static) were compared to the sclerotium produced by solid-substrate fermentation. Aqueous methanol extracts of the mycelium (LR-MH, LR-MT) and culture broth (LR-BH, LR-BT) demonstrated either higher or comparable antioxidant capacities to the sclerotium extract (LR-SC) based on their radical scavenging abilities, reducing properties, metal chelating activities, and inhibitory effects on lipid peroxidation. All extracts exerted low cytotoxicity (IC50>200 µg/ml, 72 h) against selected mammalian cell lines. Several low-molecular-weight compounds, including sugars, fatty acids, methyl esters, sterols, amides, amino acids, phenolics, and triterpenoids, were identified using GC-MS and UHPLC-ESI-MS/MS. The presence of proteins (<40 kDa) in the extracts was confirmed by SDS-PAGE and SELDI-TOF-MS. Principal component analysis revealed that the chemical profiles of the mycelial extracts under shaken and static conditions were distinct from those of the sclerotium. Results from bioactivity evaluation and chemical profiling showed that L. rhinocerotis from liquid fermentation merits consideration as an alternative source of functional ingredients and potential substitute for the sclerotium.

Chemical composition and cellular toxicity of ethnobotanical-based hot and cold aqueous preparations of the tiger's milk mushroom (Lignosus rhinocerotis)

ETHNOPHARMACOLOGICAL RELEVANCE

The sclerotium of the "tiger's milk mushroom" (Lignosus rhinocerotis) is used as tonic and folk medicine for the treatment of cancer, fever, cough and asthma by the local and indigenous communities. It is traditionally prepared by either boiling or maceration-like methods; however, there is no attempt to understand how different processing methods might affect their efficacies as anticancer agents.

AIM OF THE STUDY

This investigation was undertaken to evaluate the cytotoxicity of the hot and cold aqueous extracts of Lignosus rhinocerotis and to deduce the nature of the chemical component(s) that might be responsible for differential cellular toxicity of the extracts.

MATERIALS AND METHODS

The hot (LR-HA) and cold (LR-CA) aqueous extracts of the sclerotium of Lignosus rhinocerotis were prepared. The levels of bioactive components in the extracts were determined and chemical profiling was performed using UPLC-ESI-MS, SDS-PAGE and SELDI-TOF MS. Cytotoxicity of LR-HA and LR-CA against a panel of human cancer and normal cell lines was assessed by the MTT and trypan blue exclusion assays. Changes in cell morphology upon treatment with the extracts were observed. The chemical composition and bioactivities data were correlated to explain the nature of the cytotoxic component(s).

RESULTS

LR-HA and LR-CA were particularly abundant in polar components. Both extracts exhibited varying degree of cytotoxicity against the cancer cell lines with LR-CA showed significantly stronger cytotoxicity (IC50: 37-355 µg/ml) than LR-HA (IC50>500 µg/ml); however, LR-CA lacked selectivity in that it also has cytotoxic effect on the normal cell lines. Based on the results of protein profiling of heat-treated LR-CA (40-100°C) coupled to the MTT assay, the cytotoxic component(s) in LR-CA were deduced to be thermo-labile, water-soluble protein/peptide(s).

CONCLUSION

Our findings have shown that the use of different preparation methods (hot and cold aqueous extraction) for Lignosus rhinocerotis has resulted in extracts with distinctively different cellular toxicity in which the cytotoxic constituents were present only in LR-CA.

Antidiabetic and antioxidant properties of Ficus deltoidea fruit extracts and fractions

Background

Diabetes is a serious metabolic disorder affecting the metabolism of carbohydrate, protein and fat. A number of studies have shown that diabetes mellitus is associated with oxidative stress, leading to an increased production of reactive oxygen species. Ficus deltoidea is traditionally used in Malaysia for regulating blood sugar, blood pressure and cholesterol levels. The use of F. deltoidea as an alternative medicinal herb is increasingly gaining popularity with the sale of F. deltoidea tea bags and capsules in the local market. The present study was undertaken to investigate the antidiabetic and antioxidant activities of the fruits from different varieties of F. deltoidea, employing in vitro methods.

Method

Two fruit varieties of F. deltoidea (var. angustifolia (SF) and var. kunstleri (BF)) were extracted separately using double-distilled water. The resulting aqueous extracts were partitioned using ethyl acetate to obtain the ethyl acetate and water fractions. The crude aqueous extracts and the corresponding fractions were evaluated for their phenolic, flavonoid, sugar and protein contents. Protein profiling of the extracts and fractions were also carried out by means of SDS-PAGE and SELDI-TOF MS. Antidiabetic activities were assessed based on the ability of the samples to inhibit yeast and mammalian α-glucosidase as well as α-amylase. Antioxidant capacities were examined by measuring the ability of the samples to reduce ferric ions and to scavenge DPPH, superoxide anion, ABTS and nitric oxide radicals.

Results

The crude extracts and fractions of SF and BF inhibited both yeast and rat intestinal α-glucosidases in a dose-dependent manner, but did not inhibit porcine pancreatic α-amylase. The water fraction of BF showed the highest percentage of α-glucosidase inhibition while having the highest amount of protein (73.33 ± 4.99 μg/mg fraction). All the extracts and fractions exhibited antioxidant activities, with SF crude extract showing the highest antioxidant activity and phenolic content (121.62 ± 4.86 mg/g extract). Fractionation of the crude extracts resulted in loss of antioxidant activities. There was no positive correlation between phenolic and flavonoid content with α-glucosidase inhibitory activities. However, phenolic content correlated well with antioxidant activities of the crude extracts but not with the fractions.

Conclusions

The antioxidant activities of the fruits of F. deltoidea might be asserted by the phenolic content but other polar plant components were possibly involved in the antidiabetic properties. The study of these compounds having both antihyperglycemic and antioxidant activities may provide a new approach in the treatment of diabetes mellitus.

Chemical composition of the tiger's milk mushroom, Lignosus rhinocerotis (Cooke) Ryvarden, from different developmental stages

The chemical composition of the tiger's milk mushroom (Lignosus rhinocerotis) from different developmental stages, i.e., the fruit body, sclerotium, and mycelium, was investigated for the first time. The fruit body and sclerotium of L. rhinocerotis were rich in carbohydrates and dietary fibers but low in fat. Protein levels in L. rhinocerotis were moderate, and all essential amino acids, except tryptophan, were present. The mycelium contained high levels of potassium, phosphorus, magnesium, riboflavin, and niacin and appreciable amounts of essential fatty acids. The results indicated that the sclerotium of L. rhinocerotis that was used in ethnomedicine was not superior to the fruit body and mycelium with regard to the nutritional content and bioactive constituents. Our findings provide some insights into the selection of appropriate mushroom part(s) of L. rhinocerotis and proper cultivation techniques for the development of new nutraceuticals or dietary supplements.