The Activity of Gold Nanoparticles Synthesized Using Helichrysum odoratissimum Against Cutibacterium acnes Biofilms.

The human skin is home to millions of bacteria, fungi, and viruses which form part of a unique microbiome. Commensal microbes, including Cutibacterium acnes can occasionally become opportunistic resulting in the onset of dermatological diseases such as acne. Acne is defined as a chronic inflammatory disorder based on its ability to persist for long periods throughout an individual's life. The synthesis of gold nanoparticles (AuNPs) was performed using the bottom-up approach by reduction of a gold salt (HAuCl4.3H2O) by the methanol extract (HO-MeOH) and aqueous decoction prepared from the dried aerial parts of Helichrysum odoratissimum (HO-Powder). The HO-MeOH and HO-Powder AuNPs were prepared as unstabilised (-GA) or stabilized (+GA) by the omission or addition of Gum Arabic (GA) as the capping agent. The characterization of the AuNPs was performed using Transmission Electron Microscopy (TEM), dynamic light scattering (DLS), Ultraviolet-Visual spectroscopy (UV-Vis), Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD) and Zeta-potential. The MBIC50 values for HO-MeOH - GA and HO-MeOH + GA were 1.79 ± 0.78% v/v and 0.22 ± 0.16% v/v, respectively. The HO-Powder AuNPs showed potent inhibition of C. acnes cell adhesion to the 96-well plates. The HO-MeOH - GA and HO-Powder + GA exhibited IC50 of 22.01 ± 6.13% v/v and 11.78 ± 1.78% v/v, respectively. The activity of the AuNPs validated the anti-adhesion activity of the methanol extract in the crude form. The study emphasizes the selectivity of H. odoratissimum AuNPs for the prevention of C. acnes cell adhesion and not antimicrobial activity, which may prevent the emergence of resistant strains of C. acnes through reduced bactericidal or bacteriostatic activity, while targeting mechanisms of pathogenesis.

Cyclophosphamide-induced reproductive toxicity: Beneficial effects of Helichrysum odoratissimum (Asteraceae) in male Wistar rats.

OBJECTIVE: Cyclophosphamide (CP) is commonly used to treat some cancers, but its clinical efficacy is also linked with testicular toxicity. We investigated the effects of aqueous extract (AE) and methanolic extract (ME) of Helichrysum odoratissimum for reducing CP-induced reproductive toxicity in male rats. METHODS: In addition to a normal control (group 1), drugs or vehicles were administered orally to seven groups (n = 5) of rats that had already received 4-weeks of pre-treatment with CP (5 mg/[kg·d], per oral administration); group 2 received CP + distilled water (10 mL/[kg·d]); group 3 received CP + 5% tween 80 (10 mL/[kg·d]); group 4 received CP + clomiphene citrate (0.25 mg/[kg·d]); groups 5 and 6 received CP + AE (50 and 100 mg/[kg·d]) and groups 7 and 8 received CP + ME (50 and 100 mg/[kg·d]). Animals were sacrificed on day 15, and body and sexual organ weights, sperm characteristics, testosterone level and testicular histology were evaluated. RESULTS: The CP-treated group showed a significant reduction (P < 0.001) in the body and seminal vesicle weights, testosterone level, sperm count, sperm motility and sperm viability, but elevated (P < 0.001) sperm morphological abnormalities and testicular structure alterations, compared to the control group. Interestingly, these detrimental effects of CP were reversed by treatment with H. odoratissimum extracts. For instance, both extracts and all doses of H. odoratissimum significantly increased the sperm count (P < 0.001), sperm motility (AE, 50 mg/kg, P < 0.05; ME, 50 and 100 mg/kg, P < 0.05) and sperm viability (AE, 50 mg/kg, P < 0.001; ME, 50 and 100 mg/kg, P < 0.001) compared to the CP group. H. odoratissimum also improved plasmatic and intratesticular testosterone levels and prevented histological alterations of the testes. CONCLUSION: H. odoratissimum might be considered as an alternative drug to alleviate/prevent reproductive damage in cancer patients receiving CP chemotherapy.

Exploring the Anti-Acne Potential of Impepho [Helichrysum odoratissimum (L.) Sweet] to Combat Cutibacterium acnes Virulence.

The Gram-positive bacterium Cutibacterium acnes (previously Propionibacterium acnes), plays an important role in the pathogenesis and progression of the dermatological skin disorder acne vulgaris. The methanolic extract of Helichrysum odoratissimum (L.) Sweet (HO-MeOH) was investigated for its ability to target bacterial growth and pathogenic virulence factors associated with acne progression. The gas chromatography-mass spectrometry (GC-MS) analysis of HO-MeOH identified α-humulene (3.94%), α-curcumene (3.74%), and caryophyllene (8.12%) as major constituents, which correlated with previous reports of other Helichrysum species. The HO-MeOH extract exhibited potent antimicrobial activity against C. acnes (ATCC 6919) with a minimum inhibitory concentration (MIC) of 7.81 µg/ml. It enhanced the antimicrobial activity of benzoyl peroxide (BPO). The extract showed high specificity against C. acnes cell aggregation at sub-inhibitory concentrations, preventing biofilm formation. Mature C. acnes biofilms were disrupted at a sub-inhibitory concentration of 3.91 µg/ml. At 100 µg/ml, HO-MeOH reduced interleukin-1α (IL-1α) cytokine levels in C. acnes-induced human keratinocytes (HaCaT) by 11.08%, highlighting its potential as a comedolytic agent for the treatment of comedonal acne. The extract exhibited a 50% inhibitory concentration (IC50) of 157.50 µg/ml against lipase enzyme activity, an enzyme responsible for sebum degradation, ultimately causing inflammation. The extract's anti-inflammatory activity was tested against various targets associated with inflammatory activation by the bacterium. The extract inhibited pro-inflammatory cytokine levels of IL-8 by 48.31% when compared to C. acnes-induced HaCaT cells at 7.81 µg/ml. It exhibited cyclooxygenase-II (COX-II) enzyme inhibition with an IC50 of 22.87 µg/ml. Intracellular nitric oxide (NO) was inhibited by 40.39% at 7.81 µg/ml when compared with NO production in lipopolysaccharide (LPS)-induced RAW264.7 cells. The intracellular NO inhibition was potentially due to the 2.14 fold reduction of inducible nitric oxide synthase (iNOS) gene expression. The HO-MeOH extract exhibited an IC50 of 145.45 µg/ml against virulent hyaluronidase enzyme activity, which is responsible for hyaluronan degradation and scar formation. This study provides scientific validation for the traditional use of H. odoratissimum as an ointment for pimples, not only due to its ability to control C. acnes proliferation but also due to its inhibitory activity on various targets associated with bacterial virulence leading to acne progression.

Cyclophosphamide-induced reproductive toxicity: Beneficial effects of Helichrysum odoratissimum (Asteraceae) in male Wistar rats / 中西医结合学报

OBJECTIVE@#Cyclophosphamide (CP) is commonly used to treat some cancers, but its clinical efficacy is also linked with testicular toxicity. We investigated the effects of aqueous extract (AE) and methanolic extract (ME) of Helichrysum odoratissimum for reducing CP-induced reproductive toxicity in male rats.@*METHODS@#In addition to a normal control (group 1), drugs or vehicles were administered orally to seven groups (n = 5) of rats that had already received 4-weeks of pre-treatment with CP (5 mg/[kg·d], per oral administration); group 2 received CP + distilled water (10 mL/[kg·d]); group 3 received CP + 5% tween 80 (10 mL/[kg·d]); group 4 received CP + clomiphene citrate (0.25 mg/[kg·d]); groups 5 and 6 received CP + AE (50 and 100 mg/[kg·d]) and groups 7 and 8 received CP + ME (50 and 100 mg/[kg·d]). Animals were sacrificed on day 15, and body and sexual organ weights, sperm characteristics, testosterone level and testicular histology were evaluated.@*RESULTS@#The CP-treated group showed a significant reduction (P < 0.001) in the body and seminal vesicle weights, testosterone level, sperm count, sperm motility and sperm viability, but elevated (P < 0.001) sperm morphological abnormalities and testicular structure alterations, compared to the control group. Interestingly, these detrimental effects of CP were reversed by treatment with H. odoratissimum extracts. For instance, both extracts and all doses of H. odoratissimum significantly increased the sperm count (P < 0.001), sperm motility (AE, 50 mg/kg, P < 0.05; ME, 50 and 100 mg/kg, P < 0.05) and sperm viability (AE, 50 mg/kg, P < 0.001; ME, 50 and 100 mg/kg, P < 0.001) compared to the CP group. H. odoratissimum also improved plasmatic and intratesticular testosterone levels and prevented histological alterations of the testes.@*CONCLUSION@#H. odoratissimum might be considered as an alternative drug to alleviate/prevent reproductive damage in cancer patients receiving CP chemotherapy.

Microsatellite primers for a species of South African everlasting daisy (Helichrysum odoratissimum; Gnaphalieae, Asteraceae).

PREMISE OF THE STUDY: Microsatellites were developed for the widespread Helichrysum odoratissimum (Asteraceae) to estimate gene flow across diploid populations and to test if gene flow occurs among other closely related lineages within this genus. METHODS AND RESULTS: Ten primer pairs were developed and tested using populations across South Africa; however, only seven primer pairs were polymorphic for the target species. The seven polymorphic primers amplified di- and trinucleotide repeats with up to 16 alleles per locus among 125 diploid individuals used for analyses. CONCLUSIONS: These markers can be used to estimate gene flow among populations of known ploidy level of H. odoratissimum to test evolutionary hypotheses. Furthermore, these markers amplify successfully in other Helichrysum species, including the other three taxonomic Group 4 species, and therefore can be used to inform taxonomic work on these species.