ANTIMICROBIAL ACTIVITIES OF SOME SAUDI ARABIAN HERBAL PLANTS

Molecular docking analysis of some medicinal extracts for pro-apoptotic, antiinflammatory and antioxidative activities using HCC cell lines

We investigated the biological activities of 14 medicinal plants from Saudi Arabia as anti-inflammatory, antioxidant and anti-proliferative properties using hepatocellular carcinoma (HCC) cell lines. Hexane extracts exhibited the maximum inhibitory activities against albumin denaturation compared with those of other solvents. Baccharoides schimperi hexane extract showed the highest anti-inflammatory while Ocimum basilicum methanol extract showed significantly high hydroxyl radical scavenging activity (p < 0.001). B. schimperi methanol extract showed highest cytotoxicity and anti-proliferation activity (IC50; 25 µg/ml) in hepatocellular carcinoma cell line. Annexin V and caspase-9 activities were induced significantly (p < 0.001) by B. schimperi and the response increased in a dose dependent compared with untreated cells (p < 0.001). The docking scores showed a low docking energy binding of 2-Cyclohexylpiperidine of B. schimperi with COX-2, (-16.62 kcal/mol), high affinity for apoptotic and anti-inflammatory potency It can be concluded that, B. schimperi active ingredients as 2-Cyclohexylpiperidine and phytol contributed to its biological activity.

Effect of Ducrosia anethifolia methanol extract against methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa biofilms on excision wound in diabetic mice

Background

Ducrosia anethifolia is an aromatic desert plant used in Saudi folk medicine to treat skin infections. It is widely found in Middle Eastern countries.

Methods

A methanolic extract of the plant was prepared, and its phytoconstituents were determined using LC-MS. In-vitro and in-vivo antibacterial and antibiofilm activities of the methanolic extract were evaluated against multidrug-resistant bacteria. The cytotoxic effect was assessed using HaCaT cell lines in-vitro. Diabetic mice were used to study the in-vivo antibiofilm and wound healing activity using the excision wound method.

Results

More than 50 phytoconstituents were found in the extract after LC-MS analysis. The extract exhibited antibacterial activity against both the tested pathogens. The extract was free of irritant effects on mice skin, and no cytotoxicity was observed on HaCaT cells with an IC50 value of 1381 µg/ml. The ointment formulation of the extract increased the healing of diabetic wounds. The microbial load of both pathogens in the wounded tissue was also reduced after the treatment. The extract was more effective against methicillin-resistant Staphylococcus aureus (MRSA) than MDR-P. aeruginosa in both in vitro and in vivo experiments. Further, skin regeneration was also observed in histological studies.

Conclusions

The results showed that D. anethifolia methanol extract supports wound healing in infected wounds in diabetic mice through antibacterial, antibiofilm, and wound healing activities.

Studying the Bioactive Components and Phytochemicals of the Methanol Extract of Rhanterium epapposum Oliv

Rhanterium epapposum Oliv. (locally known as Al-Arfaj) belongs to the family Asteraceae. This study was designed to discover the bioactive components and phytochemicals of the methanol extract of the aerial parts of Rhanterium epapposum, using Agilent Gas Chromatography-Mass Spectrometry (GC-MS), while the mass spectra of the compounds found in the extract matched with the National Institute of Standards and Technology (NIST08 L). GC-MS analysis of the methanol extract of Rhanterium epapposum aerial parts showed presence of sixteen compounds. The major compounds among these were 9,12,15-octadecatrienoic acid, (Z, Z, Z)- (9.89), n-hexadecenoic acid (8.44), 7-hydroxy-6-methoxy-2H-1-benzopyran-2-one (6.60), benzene propanoic acid, β-amino-4-methoxy- (6.12), 1.4-isopropyl-1,6-dimethyl-1,2,3,4,4 a,7,8,8a-octahedron-1-naphthalenol (6.00), 1-dodecanol, 3,7,11-trimethyl- (5.64), and 9,12-octadecadienoic acid (Z, Z)- (4.84), whereas the minor compounds were 9-Octadecenoic acid, (2-phenyl-1,3-dioxolan-4-yl)methyl ester, trans- (3.63), Butanoic acid (2.93), Stigmasterol (2.92), 2-Naphthalenemethanol (2.66), (2,6,6-Trimethylcyclohex-1-phenylmethanesulfonyl)benzene (2.45), 2-(Ethylenedioxy) ethylamine, N-methyl-N-[4-(1-pyrrolidinyl)-2-butynyl]- (2.00), 1-Heptatriacotanol (1.69), Ocimene (1.59), and β-Sitosterol (1.25). Furthermore, the study was extended to determine the phytochemicals in the methanol extract of Rhanterium epapposum, which indicated the positive presence of saponins, flavonoids, and phenolic compounds. Moreover, quantitative analysis revealed the presence of high content of flavonoids, total phenolic, and tannins. This study outcome suggests a podium of using Rhanterium epapposum aerial parts as a herbal remedy for various diseases especially cancers, hypertension, and diabetes.

Stimulatory effects of Lycium shawii on human melanocyte proliferation, migration, and melanogenesis: In vitro and in silico studies

There is no first-line treatment for vitiligo, a skin disease characterized by a lack of melanin produced by the melanocytes, resulting in an urgent demand for new therapeutic drugs capable of stimulating melanocyte functions, including melanogenesis. In this study, traditional medicinal plant extracts were tested for cultured human melanocyte proliferation, migration, and melanogenesis using MTT, scratch wound-healing assays, transmission electron microscopy, immunofluorescence staining, and Western blot technology. Of the methanolic extracts, Lycium shawii L. (L. shawii) extract increased melanocyte proliferation at low concentrations and modulated melanocyte migration. At the lowest tested concentration (i.e., 7.8 μg/mL), the L. shawii methanolic extract promoted melanosome formation, maturation, and enhanced melanin production, which was associated with the upregulation of microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1 and TRP-2 melanogenesis-related proteins, and melanogenesis-related proteins. After the chemical analysis and L. shawii extract-derived metabolite identification, the in silico studies revealed the molecular interactions between Metabolite 5, identified as apigenin (4,5,6-trihydroxyflavone), and the copper active site of tyrosinase, predicting enhanced tyrosinase activity and subsequent melanin formation. In conclusion, L. shawii methanolic extract stimulates melanocyte functions, including melanin production, and its derivative Metabolite 5 enhances tyrosinase activity, suggesting further investigation of the L. shawii extract-derived Metabolite 5 as a potential natural drug for vitiligo treatment.

Antidesma thwaitesianum Müll. Arg. Fruit Juice, Its Phytochemical Contents, Antimicrobial Activity, and Application in Chiffon Cake

Antidesma thwaitesianum Müll. Arg. or Mao is well-known in Thailand for its use in soft drinks and wine. This study investigated the potential of its fruit juice as a food preservative based on its antimicrobial activity against food-borne pathogens and spoilage. The fruit juice had antibacterial activity against Bacillus cereus TISTR1527, Staphylococcus aureus TISTR2329, Listeria monocytogenes DMST17303, Pseudomonas aeruginosa TISTR357, Salmonella Typhimurium DMST562, and Escherichia coli TISTR074. The minimum inhibitory concentration ranged from 25 to 100 mg/ml. Of significance was that the juice had excellent antifungal activities against Aspergillus flavus TISTR3135 and Penicillium digitatum ATCC10030. Furthermore, the fruit juice increased the lag time of spore germination of P. digitatum. Analysis of the phytochemical contents of the juice showed that the total phenolic and flavonoid contents were 20.07 mg GAE/g and 3.57 mg QE/g, respectively. In antioxidant activity assay, the juice exhibited moderate DPPH and ABTS⁺ radical scavenging and ferric-reducing activities. The addition of 5% fruit juice extended the microbial shelf life of chiffon cake. The treated chiffon cake had a shelf-life of 7 days, compared to 3 days for the untreated control. These results support the possible use of Mao fruit juice as an antimicrobial agent and a natural food preservative.

In vitro antifungal and antibacterial potentials of organic extracts of Avicennia marina collected from Rabigh Lagoon, Red Sea Coasts in Saudi Arabia

Abstract Mangrove shrub Avicennia marina (Forsk.) Vierh was used to test the antifungal and antibacterial activities of aerial fractions in vitro. Aspergillus sp, Candida sp and Gram positive bacteria have all been found to be sensitive to mangrove extracts, whereas Gram negative bacteria have been found to be resistant to them. Agar disc diffusion and well-cut diffusion were employed to conduct antifungal and antibacterial activities. The MICs (minimum inhibitory concentrations) for each assay have been established. Several extracts from Mangrove reduced fungus growth (diameters fluctuated between 11 and 41 mm). The Ethyl acetate fraction showed particularly strong inhibition of C. tropicalis, C. albicanis, and A. fumigatus. They had 41, 40, and 25 mm-diameter inhibition zones, respectively. Nesoral, a synthetic antifungal medication, showed no significant changes in its MICs compared to different extracts. Enterococcus faecalis and Bacillus subtilis were inhibited by Petroleum Ether extracts at MICs of 0.78 and 0.35 mg/mL, respectively. It is possible that A. marina extracts may be exploited as a viable natural alternative that may be employed in the management of various infections, notably nosocomial bacterial infections, as anti-candidiasis and as anti-aspergillosis agents.

Potential synergistic effect of Alhagi graecorum ethanolic extract with two conventional food preservatives against some foodborne pathogens

The present study aims to screen the anti-bacterial activity and synergistic interaction of A. graecorum Boiss. ethanolic extract with two food preservatives against five strains of foodborne bacteria. Disk diffusion and minimum inhibitory concentration were used for anti-bacterial assay, checkerboard assay and time-kill curve were used for the combination studies. HPLC analysis and molecular docking study were performed to corroborate the in vitro results. The ethanolic extract showed anti-bacterial activity against all tested bacterial strains with inhibition zones from 7.5 to 9.3 mm and MIC values ranged between 1.2 and 1.8 mg mL⁻¹. The combination of the ethanolic extract with Na-benzoate or Na-propionate resulted in synergistic and additive interactions against the tested bacteria with fractional inhibitory concentration index (FICI) ranges 0.31–0.63 and no antagonism was shown. Time-kill curve assay showed that the synergistic and additive combinations have inhibitory effects on the tested strains. The ethanolic extract combination with Na-benzoate or Na-propionate can be used for development new sources of food preservatives. Testing new different natural plant extracts with food preservatives will help develop new anti-bacterial agents.

<i>In vitro</i> and <i>in vivo</i> Antibacterial effect of <i>Commiphora gileadensis</i> Methanolic Extract against Methicillin-Resistant <i>Staphylococcus aureus</i> (MRSA) and <i>Pseudomonas aeruginosa</i>

BACKGROUND AND OBJECTIVE

Commiphora gileadensis is a plant in the Burseraceae family that grows in the western area of Saudi Arabia. Traditionally, it is used in the treatment of some superficial infections.

MATERIALS AND METHODS

The methanolic extract of Commiphora gileadensis isolated from its leaves and branches. The in vitro study was conducted to determine the effect of this extract on Methicillin-Resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa using an agar diffusion and Minimum inhibitory concentration (MIC) methods. The in vivo study was conducted through two different methods. The first method, 20 male Balb c-1 mice were used for the determination of Commiphora gileadensis methanolic extract toxicity (LD50). In the second method, 40 male mice were used and were put into four groups. The first and second groups were injected subcutaneously with 108 CFU of MRSA 1 mL-1, while the third and fourth groups were injected with 108 CFU of Pseudomonas aeruginosa 1 mL-1. The comparison between groups was done by using a t-test (p<0.05).

RESULTS

The methanolic extract of Commiphora gileadensis had a greater sensitivity zone on MRSA and Pseudomonas aeruginosa, 7 and 3 mm respectively. The MIC of the extract was 1/8 and 1/2 for MRSA and Pseudomonas aeruginosa respectively. The in vivo study showed that the extract was non-toxic, it also showed that the extract decreased the mortality of mice induced by MRSA injection significantly (p<0.05) While insignificantly with Pseudomonas aeruginosa.

CONCLUSION

The total Commiphora gileadensis methanolic extract had an antibacterial effect on MRSA and Pseudomonas aeruginosa. This extract was non-toxic for the mice.

Efficacy and Mechanism of Traditional Medicinal Plants and Bioactive Compounds against Clinically Important Pathogens

Traditional medicinal plants have been cultivated to treat various human illnesses and avert numerous infectious diseases. They display an extensive range of beneficial pharmacological and health effects for humans. These plants generally synthesize a diverse range of bioactive compounds which have been established to be potent antimicrobial agents against a wide range of pathogenic organisms. Various research studies have demonstrated the antimicrobial activity of traditional plants scientifically or experimentally measured with reports on pathogenic microorganisms resistant to antimicrobials. The antimicrobial activity of medicinal plants or their bioactive compounds arising from several functional activities may be capable of inhibiting virulence factors as well as targeting microbial cells. Some bioactive compounds derived from traditional plants manifest the ability to reverse antibiotic resistance and improve synergetic action with current antibiotic agents. Therefore, the advancement of bioactive-based pharmacological agents can be an auspicious method for treating antibiotic-resistant infections. This review considers the functional and molecular roles of medicinal plants and their bioactive compounds, focusing typically on their antimicrobial activities against clinically important pathogens.

Antimicrobial Activity of Polyphenols and Alkaloids in Middle Eastern Plants

Antibiotic-resistant microorganisms have been an ever-growing concern over the past years. This has led researchers to direct their attention onto plants to be able to discover new possible antimicrobial compounds. The Middle East encompasses a wide spectrum of plant diversity with over 20,000 different species in habitats ranging from deserts to snow-capped mountains. Several plant secondary metabolites and their derivatives have been identified as possible antimicrobial agents. Among the secondary metabolites studied, alkaloids and polyphenols have shown strong antimicrobial activity. Polyphenols are one of the most numerous and diverse group of secondary metabolites; their antioxidant properties provide the basis for antimicrobial effects. Alkaloids provided the underlying structure for the development of several antibiotics with a diverse range of action. The ability of some plant secondary metabolites to act as resistance-modifying agents is a promising field in mitigating the spread of bacterial resistance.