Low Dose of Fluoride in the Culture Medium of Cordyceps militaris Promotes Its Growth and Enhances Bioactives with Antioxidant and Anticancer Properties

Abstract

Cordyceps militaris possesses several compounds with medicinal properties, and is commonly used in traditional Chinese functional food and medicine for a variety of health benefits. Because of its rare occurrence in nature, the market demand for artificial C. militaris is on the rise. Furthermore, efforts to increase its bioactive ingredients have also been considered in research. In this study, we aimed to investigate the effect of fluoride on the growth and enrichment of bioactive compounds in C. militaris. A wide range of potassium fluoride concentrations (0, 0.001, 0.01, 0.1, and 1 mM) were added to the culture media as a source of fluoride during the cultivation of C. militaris fruiting bodies. The contents of fluorine and bioactive substances of the fruiting bodies in normal (NM) and fluorine-supplemented (FM) media were measured and compared. C. militaris raised in the growth medium supplemented with 0.01 mM potassium fluoride led to a 44.86% (1.55 ± 0.14 g/bottle) increase in biomass and a 23.43% (3161.38 ± 35.71 µg/g) increase in total carotenoid content in the fruiting bodies. Furthermore, a remarkable increase in superoxide dismutase-like activity (84.75 U/mg) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (IC50 = 2.59 mg/mL) was recorded. In human cancer cell-based assays, C. militaris raised in FM caused stronger cytotoxicity, apoptosis, and cell cycle arrest in human osteosarcoma cells. These results demonstrated that a low dose of fluoride could stimulate the growth of C. militaris fruiting bodies and enhance the production of bioactive ingredients that possess useful antioxidant and anticancer activities.

Biomass and Cordycepin Production by the Medicinal Mushroom Cordyceps militaris—A Review of Various Aspects and Recent Trends towards the Exploitation of a Valuable Fungus

“…These effects are yet to be evaluated for C. militaris, but existing results have already proven a positive impact of insect-based compounds on its growth and productivity. Cottonseed shells, corn cobs particles at ratios of 8:1:1 (w/w/w) with rice and wheat -Increased fruit body yield and improved cordycepin levels [12] Vegetable oils Addition in liquid culture Cell growth and cordycepin production enhancement [15] Fluoride Addition of 0.01 mM Growth promotion and bioactive substance enhancement; stronger anti-proliferation effects of ascomata extracts on U2OS cancer cells [35] Aerial mycelia scratching Scratching C. militaris degenerated mycelia before stromata differentiation Shortening growth periods of C. militaris fruit bodies by at least 5 days [36] Considering fruit bodies production, a cost-effective substrate is mandatory in the development of relevant commercial applications. By-products of the agricultural and agro-industrial sectors are cheap, abundant, and suitable resources for the cultivation of edible and medicinal mushrooms [72][73][74][75].…”

“…Furthermore, the outcome of ongoing studies revealed the beneficial effect of using rice-based substrates supplemented with insect tissues in the production of C. militaris ascomata (Figure 1) [76]. Other factors that influence C. militaris productivity include the use of low concentrations of fluoride (0.01 mM), which promoted fungal growth, increased superoxide dismutase-like activity, and enhanced biomass content in bioactive substances, including carotenoids [35] (Table 2). Moreover, extracts from C. militaris fruit bodies produced with the addition of fluoride exhibited a stronger anti-proliferation effect on U2OS cancer cells [35] (Table 2).…”

“…As stated before, a breeder has to overcome several obstacles when attempting to improve C. militaris cultivation aspects, e.g., cultures degeneration, optimization of biomass and cordycepin production, reduction in time needed for fruit body maturation, determination of nutritional and environmental requirements, and assessment of fruit body composition. So far, C. militaris can be selectively improved by using traditional breeding techniques, and these are mainly restricted to re- Other factors that influence C. militaris productivity include the use of low concentrations of fluoride (0.01 mM), which promoted fungal growth, increased superoxide dismutase-like activity, and enhanced biomass content in bioactive substances, including carotenoids [35] (Table 2). Moreover, extracts from C. militaris fruit bodies produced with the addition of fluoride exhibited a stronger anti-proliferation effect on U2OS cancer cells [35] (Table 2).…”

“…Furthermore, in order to optimize C. militaris productivity, many parameters have already been examined through numerous pertinent studies that will be suitably outlined and discussed in the present review. Most of them focused on developing suitable methodologies and interventions to avoid (or minimize) culture degeneration [21][22][23][24][25][26][27][28][29][30][31], on improving ascomata and mycelia production [12,15,[32][33][34][35][36], and/or on enhancing cordycepin output by adopting various approaches and the use of both solid and liquid substrates [12,15,23,32,[37][38][39][40][41][42][43][44][45][46][47]. In addition, the application of genetic engineering breakthrough technologies has resulted in a considerable improvement in C. militaris biomass content in various metabolites, including cordycepin [37,[48][49][50][51].…”

Cordyceps militaris as a Bio Functional Food Source: Pharmacological Potential, Anti-Inflammatory Actions and Related Molecular Mechanisms

“…Similarly, methanolic extracts showed good cytotoxic activity via the MTT assay against Hep-2 cancer cell lines with an IC 50 value of 20 µg/mL [74]. In another study, the effect of fluoride was monitored in the culture medium of C. militaris, and positive effects were observed on the synthesis of secondary bioactive metabolites and growth of fruiting bodies, which eventually caused reduced proliferation and apoptosis in a human osteosarcoma (U2OS) cell line [88]. Another study discussed the decreased apoptotic activity of aqueous extract of C. militaris (AECM) on MDA-MB-231 cells.…”