Clinical trial to analyze the effects of oral intake of Phellinus linteus (sanghuang) extract on immune function: a study protocol for a randomized, double-blind controlled trial

Polyphenolic Hispolon Derived from Medicinal Mushrooms of the Inonotus and Phellinus Genera Promotes Wound Healing in Hyperglycemia-Induced Impairments

Background: This study investigated the wound-healing potential of hispolon, a polyphenolic pigment derived from medicinal mushrooms, under diabetic conditions using both in vitro and in vivo models. Methods: In the in vitro assays, L929 fibroblast cells exposed to high glucose (33 mmol/L) were treated with hispolon at concentrations of 2.5, 5, 7.5, or 10 μmol/L. In the in vivo assays, streptozotocin-induced diabetic rats with excision wounds received daily topical applications of 0.2 g of 5% (w/w) hispolon ointment. Results: Hispolon improved cell viability; suppressed oxidative stress by reducing reactive oxygen species, lipid peroxidation, and oxidative DNA damage; and restored the reduced glutathione/oxidized glutathione ratio. The scratch assay demonstrated that hispolon at 10 μmol/L enhanced fibroblast migration impaired by high-glucose conditions. Treatment with 5% (w/w) hispolon ointment accelerated wound contraction, reduced the epithelialization time, and enhanced tissue regeneration with an efficacy comparable to that of Fespixon® cream, as shown by histological findings of increased fibroblast activity, collagen deposition, and capillary growth. Hispolon ointment also modulated macrophage polarization in diabetic wounds by reducing M1 markers and enhancing M2 markers. In a diabetic rat dead-space-wound model, 5% (w/w) hispolon ointment reduced the levels of pro-inflammatory cytokines, increased those of anti-inflammatory cytokines and growth factors, and stimulated Type I and III collagen synthesis, effectively promoting wound healing. In incisional wounds, hispolon ointment improved the wound-breaking strength, showing results comparable to that of Fespixon® cream. Safety assessments confirmed that hispolon ointment showed no acute dermal toxicity. These findings underscore hispolon's potential as a promising candidate for diabetic wound management by mitigating oxidative stress, enhancing tissue regeneration, and accelerating wound healing.

Initial report on the multiple biological and pharmacological properties of hispolon: Exploring stochastic mechanisms

The development of natural substances derived from nature poses a significant challenge as technologies for the extraction and characterization of active principles advance. Hispolon has received a lot of attention in recent years, ascribable to its wide range of biological activities. It is a phenolic molecule that was extracted from several mushroom species such as Phellinus igniarius, Phellinus linteus, Phellinus lonicerinus, Phellinus merrillii, and Inonotus hispidus. To provide a comprehensive overview of the pharmacological activities of hispolon, this review highlights its anticancer, anti-inflammatory, antioxidant, antibacterial, and anti-diabetic activities. Several scientific research databases, including Google Scholar, Web of Science, PubMed, SciFinder, SpringerLink, Science Direct, Scopus, and, Wiley Online were used to gather the data on hispolon until May 2024. The in vitro and in vivo studies have revealed that hispolon exhibited significant anticancer properties through modifying several signaling pathways including cell apoptosis, cycle arrest, autophagy, and inhibition of angiogenesis and metastasis. Hispolon's antimicrobial activity was proven against many bacterial, fungal, and viral pathogens, highlighting its potential use as a novel antimicrobial agent. Additionally, hispolon displayed potent anti-inflammatory activity through the suppression of key inflammatory mediators, such as inducible NO synthase (iNOS), tumor necrosis factor-α (TNF-α), and cyclooxygenases-2 (COX-2), and the modulation of mitogen-activated protein kinases (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways. The antioxidant potential of hispolon was attributed to its capacity to neutralize reactive oxygen species (ROS) and to increase the activity of antioxidant enzymes, indicating a possible involvement in the prevention of oxidative stress-related illnesses. Hispolon's antidiabetic activity was associated with the inhibition of aldose reductase and α-glucosidase. Studies on hispolon emphasized its potential use as a promising scaffold for the development of novel therapeutic agents targeting various diseases, including cancer, infectious diseases, inflammatory disorders, and diabetes.

Effects of Phellinus linteus extract on immunity improvement: A CONSORT-randomized, double-blinded, placebo-controlled trial

BACKGROUND

Immunity protects the body from external threats and prevents the development of cancer. Biological response modifiers extracted from natural sources are being actively studied, and the immunostimulatory and anticancer effects of various types of fungi have been reported. However, there are no previous clinical studies on the immune-enhancing effect of Phellinus linteus (PL). Lactate dehydrogenase cytotoxicity assay is a prerequisite in order to get approval for using PL as a raw material in functional supplements and medicines in Korea. However, due to the absence of precedent clinical trials, the use of PL in supplements has been hindered. but there is no precedent clinical trial using it. We conducted a randomized, double-blinded, placebo-controlled trial to confirm the efficacy and safety of PL extract for the improvement of immunity using the lactate dehydrogenase cytotoxicity assay.

METHODS

A total of 98 subjects were enrolled and randomly assigned to 2 groups. Subjects in the PL and placebo groups received 1000 mg of PL extract and 1000 mg of dextrin per day, respectively (one capsule, twice every day for 8 weeks). The primary outcome measured was the activity of natural killer cells. Secondary outcomes were the levels of TNF-α, IFN-γ, IL-1β, IL-2, IL-6, IL-12, IgG1, IgG2, and IgM. Safety was evaluated using laboratory tests.

RESULTS

NK cell activity was significantly increased in the PL group compared to the placebo group (P < .05). Despite the absence of significant changes in secondary outcomes, there was a tendency for improvement in the PL group. PL extract-related adverse outcomes, particularly in liver and renal function, were not observed.

CONCLUSION

PL extract may improve immunity and is safe to be consumed orally.