In-Vitro Antibacterial Activity of some Ganoderma Species: A Review

The rising significance of personal health and wellbeing has spurred scientific interest in natural research on products. Numerous phytochemicals that are found naturally in plants, fruits, and vegetables have been discovered to have biological activity and are frequently hailed as being good for human health. In addition to current treatment approaches, herbal medications may be a safe and effective way to treat infectious infections. Ganoderma has long been used for the management of incessant infectious conditions such diabetic foot ulcers, pneumonia, and chronic hepatitis. While there is little information on Ganoderma's antiviral and antibacterial properties in humans, preliminary ( in vitro and in vivo ) research show that the plant possesses a wide range of these properties. Furthermore, gram-positive and gram-negative bacteria are inhibited in vitro by antibacterial components found in Ganoderma species. The outcomes of preclinical ( in vitro ) and clinical investigations on the antibacterial and antifungal properties of Ganoderma species are brought to light in this review.

calluses or corns, trauma or pressure on the feet, inadequate foot care and Obesity.Reduced blood circulation hinders the body's ability to heal and fight infections and increases the risk of developing diabetic foot ulcers.
Diabetic foot ulcer's symptoms and signs may include an open sore, redness, swelling, warmth, drainage or pus or signs of infection.It can lead to severe complications if left untreated, including cellulitis (skin infection), osteomyelitis (bone infection), gangrene (tissue death) and the potential need for limb amputation.About 20% of individuals with DFU will need lower-extremity amputations, either major (above the ankle), minor (below the ankle), or both.Ten percent of DFU patients will die within a year of their first diagnosis [4] .In some cases, systemic infections can occur, which can be lifethreatening.Preventing DFU is a crucial aspect of diabetes care [5] .The healing process of a typical wound progresses through four stages: hemostasis, inflammation, proliferation, and remodelling.However, a diabetes patient's constant hyperglycaemia has an effect on a number of normal wound healing processes [6] .Wound healing in it can be a timeconsuming process and the time it takes for complete healing can vary significantly from person to person.It is crucial for individuals with diabetes to seek prompt medical attention for any foot ulcer and to follow the recommendations of their healthcare team to optimize the chances of successful wound healing and prevent complications [7] .This involves maintaining good blood sugar control, regularly examining the feet for any signs of injury or pressure points, wearing comfortable and properly fitting shoes, practising proper foot hygiene, avoiding walking barefoot and seeking professional podiatric care.In more severe cases, surgical intervention may be necessary.DFU requires careful monitoring and management [8] [9] , often involving a healthcare team that may include podiatrists, wound care specialists and endocrinologists.Preventive care and early detection are crucial in avoiding the development of diabetic foot ulcers and their complications.
Diabetic foot ulcer is a polymicrobial infection harbouring different bacteria.Diabetic foot infections (DFI) are composed of a mixture of Gram positive (Staphylococcus aureus, Bacillus subtilis, Streptococcus and Enterococcus spp.) and Gram negative (Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Entrobacter, Pseudomonas, Citrobacter, Salmonella and Proteus sp.) bacteria [10] .Among these multi drug resistance is one of the challenges faced by the therapists.In addition to determining the lesion's origin, the analysis is conducted to determine whether the ulcer is neuropathic, ischemic, or neuro-ischemic and provide details about its size, depth, appearance, and location.

Ganoderma and its species
Ganoderma is one of the most popular and important wild medicinal mushrooms Genus that has been therapeutically used since thousands of years [11] .Numerous studies and research have confirmed the multidirectional biological activity of extracts from various Ganoderma spp.and isolated compounds.The following properties have been proven antidiabetic [12] , hypoglycaemia, anti-cancer [13] , anti-inflammatory, anti-tumour [14] , anti-oxidant [15] , immunomodulatory, antiviral, anti-bacterial [16] , anticonvulsant, anti-fungal, antihypertensive, anti-atherosclerotic, anti-aging, anti-androgenic, antihepatotoxic, radical scavenging property, neuroprotection, sleep promotion, cholesterol synthesis inhibition, inhibition of lipid peroxidation/oxidative DNA damage, hepatoprotective properties, maintenance of gut health, prevention of obesity and stimulation of probiotics [17] .The most important groups of compounds found in Ganoderma spp.include triterpenes (Ganoderma triterpenes) and polysaccharides.Until now, more than 300 triterpenes and 200 polysaccharides Hypoglycemic activity is demonstrated by numerous compounds present in the extracts of G. lucidum: polysaccharides, proteoglycans, proteins, and triterpenes.It is presumed that G. lucidum extracts may be an alternative adjuvant treatment for diabetes.The mechanism of action of polysaccharides is by increasing insulin levels and lowering blood glucose levels.A study on mice with type 2 diabetes showed that Ganoderma spp. is effective in regulating blood glucose levels and has a positive effect on the lipid profile; therefore, it is considered a good candidate in the treatment of type 2 diabetes with comorbid metabolic disorders.Ganoderan A and B isolated from an aqueous extract of G. lucidum showed anti-glycaemic properties.The Ling-Zhi-8 protein is effective in type 1 diabetes due to its immunomodulatory properties [20] .Ganodermin is a protein with antifungal activity isolated from G. lucidum.

Antimicrobial activity
Genus Ganoderma has antimicrobial components that stop the growth of fungi, viruses and both gram-positive and gramnegative bacteria are inhibited from growing.Multidrug resistance (MDR) bacterial and fungal infections may be successfully treated with natural antimicrobial substances derived from a wide variety of medicinal plants [21] .Ganoderma extracts contain substances with antibacterial properties, which are caused by phytochemicals synthesised in the plant's secondary metabolism [22][23] .According to the World Health Organisation (WHO), medicinal plants would be the best source to obtain a range of medications.Plants include a number of secondary metabolites that have been shown to have antibacterial effects in vitro, including tannins, alkaloids, phenolic compounds and flavonoids [24][25] .
Ganoderma species, contain bioactive compounds such as polysaccharides, triterpenes and peptides, with demonstrated antibacterial properties.These compounds exhibit a broad-spectrum antimicrobial activity, making them effective against a range of bacterial strains.Studies have indicated that extracts from Ganoderma species can inhibit the growth and multiplication of pathogenic bacteria commonly found in diabetic foot ulcers.This includes both Gram-positive (Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, Enterococcus faecium and Streptococcus pneumoniae There are many different methods are used to extract different bioactive metabolite from Ganoderma.Some of the methods which we are discussing here, are being used in today's time: Numerous extracts obtained from Ganoderma with varying polarity (from non-polar to polar) have been utilised in scientific studies to explore the wide range of metabolites, including polysaccharides, triterpenoids, and phenols [26] , alkaloids etc., present within this fungus.These extracts possess distinct chemical profiles, enabling targeted exploration of specific metabolite classes and their associated biological activities [27] .
AgNO3 was reduced to produce silver nanoparticles via a green process mediated by mycelial extracts of G. lucidum have improved stability and excellent dispersion in an aqueous solution, (AgNPs).Compared to other metal NPs, AgNPs have more antibacterial activity against multidrug-resistant bacteria.Gram-positive and Gram-negative bacterial and yeast strains were used to assess the synthetic nanoparticles' antibacterial efficacy.Because the pathogens were inhibited in their multiplication, the environment and public health were less at danger due to the effectiveness of the silver nanoparticles [28] .
Using an environmentally friendly process, copper oxide nanoparticles (CuONPs) were created from the supernatant and extract of the fungus G. sessile, and their antibacterial and biocompatibility characteristics were identified.CuONPs showed antimicrobial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa.Further research might be done on the CuONPs created from the fungus G. sessile extract in order to see whether they are effective in treating superficial infectious illnesses. [29].
A green method was used to create new biogenic silver (AgNPs) and gold nanoparticles (AuNPs) using G. lucidum extract.B. subtilis showed the greatest growth suppression activity of GL-AgNPs, followed by B. cereus, P. aeruginosa, E.
Zinc oxide (ZnO) nanoparticles with different concentrations of G. lucidum extract have been biologically produced, and their optical, morphological, structural and elemental properties have been identified.The use of green generated ZnO with G. lucidum extracts as a nanonutrient is first documented in the study by Sedefoglu et al., 2022 [31] .
Novel anti-biofilm strategies must be designed to include natural bio products instead of common antibiotics.Mushrooms are a nutritionally functional foods and a source of pharmaceuticals functions such as antidiabetic, antitumor, immunomodulating, antioxidant, cardiovascular, anti-hypercholesterolemia, antimicrobial.Ganoderma, especially G.

Staphylococcus aureus
The nucleotide sequences obtained from all Ganoderma strains in this study were deposited in GenBank.
G. austral and G. applanatum extracts showed anti-proliferative activity against the tumor cell at concentration lower than 50 µg/mL G. curtisii and G.lucidum showed anti-proliferative activity and remarkable inhibition values for HeLa cell line G. curtisii show such growth inhibitory mechanisms in tumor cells [45]   Escherichia coli Triterpenoids, (ganoderic acids) responsible for its antitumor activity.

Staphylococcus aureus
AgNPs (silver nanoparticles) were successfully synthesized from G. lucidum crude extracts and these colloidal AgNPs demonstrated an extraordinary antimicrobial activity against all tested pathogens [61] [62]   Escherichia coli

Enterococcus faecalis
Methanolic extract of GL exhibited higher antibacterial activity against E. coli and P. aeruginosa Aqueous extract of GL exhibited higher antibacterial activity against B. subtilis and S. aureus

Staphylococcus aureus
Escherichia coli

Staphylococcus aureus
Antibacterial activity was weak against S. aureus All tested Ganoderma mushrooms have medicinal potential such as anti-inflammatory and anti-proliferative.

Ganoderma lucidum
Salmonella typhimurium compared to G. lucidum, G. neo-japonicum showed remarkable antibacterial and antioxidant properties

Escherichia coli
The synthesized AgNPs from methanolic extract of G. applanatumexhibit high antioxidant capacity, in vitro antibacterial activity against S.aureus and E. coli and invivoantifungal activity G. applanatum can be efficiently used in synthesis of AgNPs with potent antimicrobial properties, which can be used for both clinical and agrochemical purposes. [73]

Ganoderma atrum
Escherichia coli G. atrum is a popular remedy to treat conditions such as chronic hepatitis, hypertension,cancer, hyperlipemia, bronchitis, atherosclerosisand diabetes The antibacterial activity of each group was shown as G. atrum sterolcomponents> ergosterol>ergosterol ester.

Pseudomonas fluorescens
Water and methanol extracts of both Ganoderma exhibited strong antibiotic activity against all bacterial strains tested. [

Klebsiella pneumoniae
The ZnO nanoparticles synthesized from G. multipileum showed a strong antibacterial effect against gram-positive (K.pneumonia and S. aureus) and gram-negative (E.

Coli and P. aeruginosa) bacteria
The ZnO nanoparticles also showed a high antifungal effect against all different fungus

Staphylococcus aureus
Extracts of the fruiting bodies of the mushroom exhibited antibacterial activity against all tested bacteria Bacillus subtilis

Escherichia coli
The extracts of G. curtisiiinhibited the growth of S. aureus Ganoderic acids, phenolic compounds may also be responsible for antibacterial inhibition and antioxidant activity of all tested Ganoderma species

Staphylococcus aureus
Pseudomonas aeruginosa

Escherichia coli
A very low concentration of silver nanoparticles produced from the extract of G. sessile is required for the bacterial inhibition

Pseudomonas aeruginosa
Antimicrobial Activity of Ganoderma Species against Gram Positive Bacteria Fungi are particularly appealing for nano particle synthesis because they release huge amounts of enzymes and metabolites and are facile to manage in the laboratory.Copper and copper oxide NP synthesis has recently attracted attention, as recent research demonstrated that they are advantageous for biomedical applications due to their antibacterial, anticancer, antidiabetic and antioxidant characteristics [61] .Micro, quasi-spherical nanoparticles (NPs) with atypical size of 4.5 ± 1.9 nm and 5.2 ± 2.1 nm were obtained from the resulting supernatant and extract of the fungi Ganoderma sessile.CuONPs displayed antibacterial efficacy against Staphylococcus aureus (S. aureus).The halfmaximal inhibitory concentration (IC50) value for S. aureus, was 10.2 µg/mL.When bacteria were subjected to CuONPs, their ultrastructural examination confirmed that tiny CuONPs were present throughout the bacterial cells [33] .The mycelial extract of Ganoderma boninense was found to be effective in producing secondary metabolites with antibacterial efficacy against S.aureus and S. pyogenes.Methanol-extracted GBMA exhibited higher and broader ranges of antibacterial activity against S. aureus [34] .Additionally, the minimum inhibitory concentration (MIC) of Ganoderma sinense and Ganoderma multiplicatum extracts demonstrated bactericidal activity against S. aureus [52] .Gram-positive and gram-negative plant pathogenic bacteria were suppressed by G. lucidum culture fluids.Rathayibacter tritici which is a plant pathogen of wheat was inhibited by extracts of G.luicdum [39] .The biochemical function of the distillates derived from the in vitro culture of Mexican strains of Ganoderma viz.Ganoderma austral, Ganoderma applanatum, Ganoderma colossus, Ganoderma curtisii, Ganoderma lobatum, Ganoderma lucidum, Ganoderma oregonense and Ganoderma resinaceum.The growth of gram-positive S. aureus was suppressed by extracts of three strains of G. curtisii that exhibited anti-proliferative activity [45] .Research on G. lucidum extracts was evaluated on gram-positive and methicillin-resistant bacteria, including Streptococcus pyogenes, Pseudomonas aeruginosa and Staphylococcus aureus (MRSA).Streptococcus pyogenes (p = 0.05) and Staphylococcus aureus (MRSA) (p = 0.022) were significantly inhibited by hexane extract of Ganoderma lucidum.Streptococcus pyogenes was the most sensitive microorganism [46] .There are scanty researches on the physiological functions of G. mbrekobenum's fruiting bodies.Methanol extract of G. mbrekobenum demonstrated greater antibacterial activity against Bacillus cereus and Bacillus subtilis, measuring 14.13 ± 0.12 mm and 13.03 ± 0.12 mm, respectively.The majority of the test bacterial strains were resistant to the antibacterial effect of the aqueous extracts [49] .
The antibacterial activity of Ganoderma strains viz.G. tuberculosum, G. tornatum and G. weberianum against Clavibacter michiganensis, which causes tomato canker, is highlighted within the concentration range 31.5 to 1000 μg/mL is noteworthy [58] .Bacallao-Escudero et al. ( 2023) investigated the antibacterial activity of ethanolic extracts of Ganoderma oerstedii, G. weberianum and G. subincrustatum fruiting bodies against Staphylococcus aureus and Escherichia coli using the broth microdilution method.There was minimal antibacterial activity (MIC50 > 10 mg/mL) against S. aureus [67] .The strongest antibacterial activities against the studied pathogens were demonstrated by the "green synthesis" of silver nanoparticles (AgNPs) from Ganoderma applanatum.High antioxidant capacity, in vitro antibacterial activity against

Escherichia coli and Staphylococcus aureus, and in vivo antifungal capabilities against Colletotrichum gloeosporioides and
Botrytis cinerea are all displayed by the synthesised Ag nano particles [73] .ZnO nanoparticles synthesised from Ganoderma multipileum displayed significant antibacterial activity against gram-positive bacteria, including Staphylococcus aureus and Klebsilla pneumonia [88] .G. boninense is identified as an oil palm pathogen, although there is scanty information about its biological activity.In broth microdilution experiments, high susceptibility was reported in methicillin-resistant Staphylococcus aureus (MRSA) in the elute fraction, with a MIC value of 0.078 mg mL1.According to the findings, G. boninense extract causes irreversible damage to MRSA cell membranes, resulting in cellular lysis and death [85] .
Antimicrobial Activity of Ganoderma Species against Gram Negative Bacteria Gram-negative bacilli are the most common bacterial pathogens and are often resistant to medicinal products.Monitoring for antimicrobial resistance in this population is critical since resistance has been linked to increased morbidity and mortality.CuONPs extracted from the fungi Ganoderma sessile displayed antibacterial efficacy against gram-negative bacteria like Pseudomonas aeruginosa (P.aeruginosa) and Escherichia coli (E.coli).The half-maximal inhibitory concentration (IC50) values were 4.1µg/mL and 8.5µg/mL, respectively [33] .The mycelial extract of G. boninense was found to be effective in producing secondary metabolites with antibacterial activity against E. coli and P. aeruginosa and K.
pneumonia [36] .It was observed via liquid-liquid extractions (LLE) that mycelia extraction using a 1:1:1 combination of chloroform, methanol, and water was better at detecting antibacterial activity with the highest concentrations of antibacterial substances.Research have been conducted to isolate and distinguish the antibacterial activity of Ganoderma lucidum culture fluids against several gram-negative plant pathogenic bacteria like Acidovorax avenae, Agrobacterium exhibit any form of activity.There was a little inhibition seen with Brenneria quercina [39] .The remarkable antibacterial and anticancer activities of Ganoderma lucidum methanolic extract (GLME) have garnered significant interest.Screening the extract's antibacterial properties against four strains of both Gram-positive and Gram-negative bacteria revealed that it had more antibacterial properties against E. coli bacteria than streptomycin, resulting in a zone of inhibition measuring 44 ± 0.09 mm [66] .Furthurmore, colloidal AgNPs derived from G.lucidum displayed exceptional antibacterial efficacy against gram negative Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica and Candida albicans in biological assays, with IC50 values of 17.06, 1.32, 54.69 and 27.78 g/mL, respectively [61] .Crude extracts of G. lipiense, along with their dichloromethane (DCMf) and ethyl acetate (EAf) derivatives, demonstrated antibacterial activity at 500 µg mL−1 against Pseudomonas aeruginosa and Staphylococcus aureus [42] .El-Dein et.Al. (2023) demonstrated that the methanolic extract of G. mbrekobenum exhibited the strongest antifungal activity against F. oxysporum and F. oxysporum f. sp.
Lycopersici [49] .Experiments comparing the bioactivities of various Ganoderma species have been carried out.G. lucidum (GL) and G. neo-japonicum (GnJ) were extracted using hot water and their antimicrobial properties were contrasted.The pathogens Salmonella typhimurium, Salmonella Enteritidis and Escherichia coli had minimum inhibitory concentrations (MICs) of 1.25 mg/mL to 2.5 mg/mL for GL and 2.5 mg/mL to 5 mg/mL for GnJ.SEM demonstrated that the two extracts worked by lysing the cells and shrinking the pathogens' cell walls [71] .Investigations were conducted to evaluate the antimicrobial potential of the autochthonous Ganoderma species (G.resinaceum, G. pfeifferi, G. lucidum and G. applanatum).CHCl3 extract of G. resinaceum had the strongest antibacterial activity against P. aeruginosa, EtOH extracts of G. pfeifferi and G. resinaceum were shown to have the strongest antibacterial activity against A. niger, whereas G.
pfeifferi exhibited the maximum antibacterial activity against both E. coli and S. aureus [82] .ZnO nanoparticles that were isolated from Ganoderma multipileum had substantial antibacterial activity against gram-negative bacteria, such as Eschericia coli and Pseudomonas aeruginosa [88] .AgNPs were produced using Ganoderma sessile extracts and supernatants and their in vitro antibacterial efficacy against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus was assessed.Once the minimum inhibitory concentration (MIC) was established, the AgNPs demonstrated antibacterial activity against all employed bacteria.The MIC ranged from 1.26 to 5.0 µg/mL, contingent upon the type of bacterium [99] .

Conclusion
Ganoderma species are also known for their wound healing properties.By accelerating the wound healing process, they can indirectly contribute to reducing the risk of infection in diabetic foot ulcers and other wounds.Ganoderma species have immunomodulatory effects that can enhance the body's immune response.This can help the immune system combat bacterial infections more effectively, especially in individuals with diabetes, who may have compromised immune function.Inflammation is a key component of the body's response to bacterial infections.Ganoderma's anti-inflammatory properties can help reduce inflammation associated with diabetic foot ulcers and the corresponding infections.
This potential antimicrobial benefits of Ganoderma species for wound care in diabetic foot ulcers can be considered as complementary to standard medical treatment.Consulting with a healthcare professional is essential when using natural remedies like Ganoderma, as part of a comprehensive wound care plan.Furthermore, the quality and source of Ganoderma products can significantly impact their efficacy, so using reputable products is crucial.
Qeios, CC-BY 4.0 • Article, December 5, 2023 etc) and Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, salmonella typhimurium and Proteus vulgaris etc) bacteria.Bacterial biofilms are often implicated in chronic wound infections, including diabetic foot ulcers.Ganoderma extracts have demonstrated the ability to disrupt biofilms formed by pathogenic bacteria, making it easier for the immune system and antimicrobial agents to target and eliminate the bacteria.