Antibacterial Activity of Psoralea cordifolia Linn.: A Systematic Review

Psoralea corylifolia Linn. is an annual herb with alternate unifoliolate leaves. The fruit is ovoid, glabrous, black, pitted and mucronate and the inflorescence is a peduncled raceme. It is a member of the Fabaceae family and develops throughout India, particularly in the plains of Central and Eastern India. The plant has been used to cure a range of maladies, including leucoderma, heart and vascular problems, nephritis, osteoporosis and cancer.¹ Plant extracts have anti, bacterial, anti, cancer, antioxidant, anti-inflammatory, anti, fungal and immune-modulating properties.² Because of its efficiency against a wide range of bacteria, extract from the leaves, seeds and fruit of P. cordifolia L. may provide a natural alternative to antibiotics.³ This plant’s principal identified components are coumarins, flavonoids and meroterpenes. The main active chemicals in the seeds have mostly been identified. It can be used to treat Type II Diabetes mellitus when there is insulin resistance.⁴ The fruit constitutes psoralenoside, isopsoralenoside, corylinin, isopsoralen, psoralen, neobavaisochin, methylcorylifol A, isoprenylcorylifol A, isoprenylneobavaisoavone, isobavachromene, psoralidin, neobavaiso avone, corylifol A, bakuchiol, coumestan, sophoracoumestan A, dihydroxybakuchiol, bisbakuchiol C, geranyliso avone and corylifols. This activity could be caused by phytochemicals. The antibacterial activity of psoralidin, bakuchicin, psoralin, prenyl avonoid and angelicin is significant. Isopsoralen, psoralen, isobavachalcone, bavachin, corylifol A, neobavaisoavone and bakuchiol make up the chemical content of the plant’s leaves.⁵ Bacteria are ubiquitous, mainly free-living creatures with only one biological cell. They have both gram-negative and positive characteristics. Gram-positive bacteria are bacteria that pass the Gram stains test, which is commonly used to classify bacteria into two basic groups based on cell wall type. The crystal violet stain used in the Gram-staining method of bacterial differentiation is absent in Gram-negative bacteria. Klebsiella, Acinetobacter, Pseudomonas aeruginosa and E. coli infections are examples of Gram-negative infections. All staphylococci, streptococci and a few listeria species are Gram-positive bacteria.⁶

The study’s goal is to establish the greatest potential of P. cordifolia L. by examining its various sections, extraction methods and phytochemicals that yield the best outcomes. The goal of this brief review is to analyse and summarise the antibacterial activity of phytochemical components of P. cordifolia L. from diverse chemical groups. Based on information obtained from published and peer-reviewed research articles, the classes of phenolic acids, tannins and flavonoids exhibit antibacterial activity against diverse bacteria strains. The global problem of drug usage, along with the pharmaceutical industry’s lack of novel antibiotic therapies, has resulted in the rise of drug-resistant bacteria, putting standard antibiotic results in jeopardy. Given the severity of this ailment, it is critical to research plant extracts as preventive and therapeutic approach.⁷ Ensured knowledge may supply future schemes for responsive assistance for medical technologists’ practises in determining the effect of distinct components of the P. cordifolia L. on various gram-negative and gram-positive bacteria. Furthermore, the findings of this study will assist researchers in gaining more relevant and thorough knowledge that will be valuable in their future practice.

The study papers and journal papers utilised in the mini-review were gathered from online resources such as Google Scholar, PubMed, etc., using search phrases such as “Bakuchi,” “Psoralea cordifolia L.”, “Antibacterial,” and “Extract.” These databases serve as a basis for the quick reviewing method’s evaluation of research articles and journals.

The following are the experimental research criteria for this work: (1) Presented in English, (2) Released within 2001 and today, (3) Obtained from reputable sources such as PubMed, Goggle scholar and (4) Addresses the antibacterial activity of phyto-chemicals discovered in Psoralea cordifolia L. roots, leaves, tender stem, seeds and fruits. The following are the exclusion criteria: (1) Review papers, (2) Non-English publications and studies, (3) published before 2001, (4) From untrustworthy sources and P. cordifolia L. activity against bacteria.

The flowchart in Figure 1 depicts the process of selecting articles.

The research’ eligibility was assessed and determined by each author independently based on the previously stated criteria for acceptance and elimination. The title and abstract were evaluated first, accompanied by the believability. The papers’ full texts were then studied for further evaluation.

The researchers extracted eligible articles based on research characteristics such as the first writer’s last name, year of the publication’s release part of P. cordifolia L. used, category of compounds and specific substances extracted, targeted bacteria, the Minimal Inhibitory Concentration (MIC), Minimum bactericidal concentration, Zone of Inhibition (ZOI) of the extract and study results.

During the initial search, 200 literature papers and journals were found using PubMed (50) and Google Scholar (150). The data extracted from the collected literature papers and journals resulted data that did not satisfy the criteria were eliminated. The rejected publications have been eliminated. Using compilation, inclusion and exclusion criteria. Due to the exclusion of three investigations, a total of 200 papers and journals were kept. The 50 kinds of literature were screened based on title, abstract, relevancy, availability of full-text articles, language of research and year of publication. The screening technique returned 150 assessed articles, which were then excluded based on their relevance to the antibacterial capabilities of P. cordifolia L., yielding a total of 130 discarded publications. Following the screening, 20 studies were obtained. The publications and studies that were retained were included in the review. Table 1 shows the data retrieved for each publication.

Figure 1:
Schematic Diagram for study Selection.

Figure 2:
Different Chemical compounds of Psoralea cordifolia Linn. that have antibacterial activity.[National Centre for Biotechnology Information. PubChem Compounds Summary. https://pubchem.ncbi.nlm.nih.gov/compound/name of compound].

The phytochemical substances found in P. cordifolia L. differ depending on the part of the plant they are found in. Alkaloids, sugars, flavonoids, glycosides, phenolics, tannins, steroids and saponins are the most prevalent phytochemical elements. Psoralen, coumarins, isopsorale, neobavaislfoavone and bovachin compounds were found in extracts of the roots of P. cordifolia L. in methanol, water and ethanol. Seed ethanol extract contains Bavachin, corylin, corylifol, isobavachalcone, 4-0-methylbrousso, Isobavachin, Corylifolinin, Bakuchiol, Psoralen, Isopsoralen, Psolaridine, Cadinene, Isopsoralen and Psoraledin.^4–6

Overall, the chemical compounds present in P. cordifolia L. are Coumarins psoralidin, psoralen, bakuchiol, bavachinin, baldachin, corylin, corylifol, corylifolin, flavanones, isoflavones, chalcones, meroterpenes, coumarins, isobavachalcone, bakuchiol, Corylifol C, neobavaisoflavone and corylifol B.⁷ The chemical compounds structure shown in Figure 2 and collected from different articles shown Figure 3.

P. cordifolia L. antibacterial activity yielded MIC (Minimum Inhibitory Concentrations) values of 9-32 μg/mL, MBC (Minimum Bactericidal Concentrations) values of 25-313 μg/ mL and ZOI (Zone of Inhibition) values of 10-42 mm. These findings are from different studies of different parts of P. cordifolia L. and the methanol extract showed more effectiveness against gram-negative and gram-positive.⁸ Furthermore, it can inhibit biofilm growth by disturbing microbial viability, lowering the expression of genes related to biofilm development and destroying enzymes and polysaccharides that aid in biofilm formation. Bavachin has the strongest antibacterial activity, with a MIC of 31 μg/mL.⁹

Figure 3:
Diagrammatic presentation of chemical compounds present in P. cordifolia L.^{2,8,9,13,19,21,23,27}

After screening, 20 articles that met the requirements were chosen. The antibacterial activity of P. cordifolia L. was demonstrated in many articles and plant leaves, fruits, roots and seeds were employed to detect the various activities. It contains a variety of phenolic chemicals that are responsible for its antibacterial action against various bacteria. Experimental research discovered the many kinds of substances found in the plant including flavonoids, polyphenols, tannins, phenolic acids and so on. Various antibacterial mechanisms have been proposed for the chemicals present in each section.¹⁰

Flavonoids, polyphenols, phenolic acid and tannins are among the substances found in P. cordifolia L. and they are thought to be the cause of microbe inhibition. By disrupting the cell membrane, flavonoids and phenolic acids cause cell lysis, which lowers DNA synthesis. Tannins particularly ellagitannins, trap metal ions essential for bacterial development. The inhibitory mechanisms of polyphenols, notably ellagic acid are still unclear.¹¹ The chemical structure of phenol molecules is linked to their antibacterial function. It can easily infiltrate the pathogen’s membrane and disrupt its enzymatic activity, resulting in cell death because it is lipophilic.¹²

P. cordifolia L. is an excellent source of bioactive components that have significant antibacterial effects on bacterial population growth, implying that the researched P. cordifolia L. plant could be an herbal remedy for minimising the formation of bacteria pathogen strains, which are frequently involved in food-borne illnesses. The polyphenol content of the fruits, roots, seeds and leaves varied according to the extraction methods, solvents used and dosage formulation. The MIC/MBC values of P. cordifolia L. Extract found in several studies differ significantly. The mechanism of antibacterial effects essentially involves damaging the cell membrane and bacterial cell wall to modify bacterial membrane permeability; effect on protein and nucleotide synthesis; and reduction of bacterial enzymatic activity.¹³ Corylifolinin exhibited specific effects on bacterial cell membranes. The mechanism of antibacterial effects mostly included the destruction of the cell membrane and bacterial cell wall to alter bacterial membrane permeability; effect on protein and nucleotide synthesis; and suppression of bacterial enzymatic activity.¹⁴ Even a study on seeds leaves and aerial parts of P. cordifolia L. showed antibacterial activity.^15,16

Bakuchiol had equal antibacterial action against adhering bacterial cells within water-insoluble glucan with the addition of sucrose. Bakuchiol has been reported to have a cytotoxic effect against cells in culture, which has been connected to cell membrane disintegration using microscopy of electrons and haemolytic activity.

Bakuchiol’s biological actions have lately been reported to include anti-inflammatory properties, inhibition of mitochondrial lipid peroxidation, immune system activation, inhibition of DNA polymerase, suppression of papilloma development and diabetes prevention. As a result, Bakuchiol could be a suitable lead chemical for the development of antibacterial drugs against human oral infections.^9,17 Psoralen inhibits the growth of bacteria such as M canis, M gypseum, T rubrum, T. mentagrophytes, S. aureus, C. albicans and E. coli.¹⁸ The MIC of methanol extract of P. corylifolia L. seeds was reported to be in the 2.5 to 5 mg/mL range for the majority of pathogens.¹⁰

The marker compounds (bakuchiol, psoralen, isopsoralen and psolaridin) concluded that antimicrobial activity of the extracts of P. corylifolia L. was due to the presence of Bakuchiol.¹⁹ Antimicrobial screening of P. corylifolia L. Leaf, Seed and Stem in different solvents such as hexane, chloroform and methanol against appropriate pathogens demonstrates that methanolic extraction has the best suppression of pathogen activity.²⁰ Bakuchiol’s MIC range was determined to be 9.76-19.5 g/ mL.²¹ P. cordifolia L. seeds extracted in alcohol and diethyl ether have revealed wide-spectrum antibacterial action against cutaneous pathogens, with a maximum zone of inhibition against gram-negative and gram-positive pathogens and a zone of inhibition against gram-positive pathogens and a zone of inhibition against gram-positive pathogens inhibition 21mm in diameter and a Maximum Inhibitory Concentration (MIC) of 2.5-5mg/mL. Out of all the compounds examined, Bakuchiol was found to have significant antibacterial activity.

According to a specific concept, the two the coumarin chemicals might trigger cell disintegration and death by destroying the cell membrane. Because psoralen and angelicin are both liposoluble, they can pass the plasma membrane and disrupt the cytomembrane’s integrity.²² The presence of tannins in P. cordifolia L. oil is responsible for its antibacterial activity against Enterococcus sp., as demonstrated by a TLC bio autography experiment. P. cordifolia L. essential oil has demonstrated strong antibacterial activity against Enterococcus sp., P. aeruginosa, E. coli and S. aureus, making it a promising candidate for development into the next generation of antimicrobials to tackle Multidrug Resistance (MDR) in pathogenic bacteria.²³ Six Plant Essential Oils’ Antibacterial Activity against Pathogenic Bacterial Strains, this study focuses on the antibacterial properties of plant essential oils against human pathogenic pathogens. When evaluated in vitro, all essential oils were found to have substantially stronger bacteriostatic and bactericidal activity than synthetic antibiotics. Other Gram (-) and Gram (+) bacteria may be affected by these essential oils. More importantly, because of their great antibacterial potential and few side effects, these might be included in the list of herbal medications. As a result, essential oils and their constituents might be prescribed for therapeutic purposes and utilised as an alternative medication.^24,25 Standard chemical compound analysis was performed on extracts from plants, which revealed the existence of a variety of secondary metabolites such as reducing sugars, tannins, flavonoids, terpenoids, glycosides and phenolics.^26,27

Only corylifol (MIC 16 g/mL) showed an antibacterial effect on the two MRSA strains tested. Bavachin exhibited the lowest bactericidal impact (MIC 32 g/mL), while the other flavanones, bakuflavanone and bavachinin, did not have antibacterial characteristics at the levels tested. Except for neobavaisoflavone, which had a MIC of 16 g/mL, other isoflavones had little bactericidal activity (MICs>32 g/mL). Isobavachalcone and corylifol B, two chalcones, showed significant antibacterial activity against MRSA (Methicilin-Resistant staphylococcus aureus) (MIC 8 or 16 g/mL). Bakuchiol, a phenolic meroterpene, demonstrated a notable bactericidal activity (MIC, 8 g/mL), while the other meroterpenes and coumarins had minor effects. Corylifol C, neobavaisoflavone and corylifol B all showed significant antibacterial activity. The MIC value of 30 μg/mL of P. cordifolia L. seeds contains a considerable amount of polyphenols and has been demonstrated to produce the highest antibacterial activity.^28,29 According to the review’s summary, the authors found extraordinary promise, notably in extracts produced from various components of P. cordifolia L., such as roots, seeds, fruits, leaves and dosage formulations. The separation of bioactive substances, especially those with antibacterial activity, might be used to produce medications and help combat resistant to antibiotics.

The research aims to determine the antibacterial activity of different portions of the P. cordifolia L. Plant, especially the phytochemical elements found in different kinds of compounds. A study of multiple studies showed that polyphenols, which include flavonoids and tannins are the most prevalent class of compounds found in many P. cordifolia L. The components, particularly the leaves, roots, fruits, seeds and dosage form formulations with antibacterial properties. Finally, the phytochemical components of P. cordifolia L. have antimicrobial activity. Among all investigations, Bavachin and Bakuchiol exhibit stronger antibacterial action than other chemical ingredients.