Helichrysum Odoratissimum Research Articles

Chemical Composition, Repellent, and Oviposition Deterrent Potential of Wild Plant Essential Oils against Three Mosquito Species.

In this study, the chemical composition, repellent, and oviposition deterrent effects of five plant essential oils (EOs) extracted from Lantana camara (Verbenaceae), Schinus terebinthifolia (Anacardiaceae), Callistemon viminalis (Myrtaceae), Helichrysum odoratissimum (Asteraceae), and Hyptis suaveolens (Lamiaceae) were evaluated against Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus. When tested at 33.3 µg/cm2, L. camara, S. terebinthifolia, C. viminalis, and H. odoratissimum were effective repellents against Ae. aegypti (89%, 91%, 90%, and 51% repellency, respectively), but they were less repellent against An. gambiae (66%, 86%, 59%, and 49% repellency, respectively). Interestingly, L. camara, S. terebinthifolia, C. viminalis, and H. odoratissimum exhibited 100% repellency against Cx. quinquefasciatus at 33.3 μg/cm2. In time-span bioassays performed at 333 μg/cm2, the EO of L. camara exhibited 100% repellence against Ae. aegypti and An. gambiae for up to 15 min and against Cx. quinquefasciatus for 75 min. The oviposition bioassays revealed that L. camara exhibited the highest activity, showing 85%, 59%, and 89% oviposition deterrence against Ae. aegypti, An. gambiae, and Cx. quinquefasciatus, respectively. The major compounds of L. camara, S. terebinthifolia, and C. viminalis were trans-β-caryophyllene (16.7%), α-pinene (15.5%), and 1,8-cineole (38.1%), respectively. In conclusion, the L. camara and S. terebinthifolia EOs have the potential to be natural mosquito repellents.

Anti-inflammatory and antiproliferative activity of Helichrysum odoratissimum Sweet. against lung cancer

Lung cancer remains the top killing cancer worldwide despite advances in treatment. Seven ethanolic plant extracts were selected and evaluated for their antiproliferative activity against the two main types of lung cancers: non-small cell (A549) and small cell lung cancer cells (SHP-77). An ethanolic extract of Helichrysum odoratissimum Sweet (HO) showed significant antiproliferative activity against lung cancer, with a fifty percent inhibitory concentration (IC50) of 83.43 ± 1.60 µg/mL (A549), 49.46 ± 0.48 µg/mL (SHP-77) and 50.71 ± 2.27 µg/mL, against normal lung epithelial cells (MRC-5), resulting in a selectivity index (SI) value of 0.61 on A549 cells and 1.03 on SHP-77 cells, which was compared to the positive drug control, actinomycin D where the SI values were found to be 2 and 0.25 against A549 and SHP-77 cells, respectively. Against murine macrophages (RAW 264.7) and hepatocytes (HepG2), the HO ethanolic extract showed IC50 values of 60.15 ± 1.98 µg/mL and 23.61 ± 1.06 µg/mL, respectively. Microscopy showed that the HO ethanolic extract induced apoptosis in the A549 and HepG2 cells at 50 µg/mL and 300 µg/mL, respectively. The HO ethanolic extract, furthermore, inhibited the pro-inflammatory enzymes, cyclooxygenase 2 (COX-2) and 5-lipoxygenase (5-LOX) with IC50 values of 7.94 ± 3.84 µg/mL and 2.08 ± 1.35 µg/mL, respectively, whereas the positive controls Ibuprofen (COX-2) and Zileuton (5-LOX) showed IC50 values of 0.85 ± 0.14 µg/mL and 0.06 ± 0.05 µg/mL, respectively. The activity of NAD(P)H quinone oxidoreductase-1 (NQO1), which is a direct target of nuclear factor erythroid-2-related factor-2 (NRF2), was significantly inhibited in the A549 cells by the HO ethanolic extract (at 125 µg/mL) when compared to the positive control, brusatol (at 500 nM). Using the ex ovo yolk sac membrane (YSM) assay, the HO ethanolic extract (at 18.5 µg/egg) showed a 31.65 ± 12.80% inhibition of blood vessel formation. This is the first report of the noteworthy antiproliferative activity of the HO ethanolic extract on lung cancer cells including its potential to target several enzymes associated with inflammation and therefore, should be considered for further analysis.

Seed germination and vegetative propagation of Helichrysum odoratissimum

Helichrysum odoratissimum is a popular indigenous herb of South Africa, well known for its aromaticity. It offers potential as a source of extracts for the development of cosmeceutical products as it has been reported to be a natural antibiotic, and has antifungal, antimicrobial, antioxidant and antiviral properties. In order to be commercialized, a sustainable production system is required to ensure a consistent supply of good quality material. Therefore, the production of H. odoratissimum by seed and stem cutting was evaluated. The interactive effect of different seed priming methods and temperature levels were investigated on germination indices of H. odoratissimum seeds. A randomized complete block design with three replicates was used to evaluate the effect of season, cutting position, rooting hormone and growth media on survival percentage, number of buds, number of leaves, rooting percentage, number of roots per cutting and root length of H. odoratissimum stem cuttings. Data for both aspects was analysed using ANOVA and means with significant differences were separated with a t-test at 5% level of significance. Smoke treated seeds incubated at 20 °C had a significantly higher germination percentage (91,7%), mean germination rate (0.59) and coefficient velocity of germination (59.5) compared to most other treatments. Almost all factors tested in vegetative propagation significantly affected parameters measured. Apical cuttings taken during autumn resulted in significantly higher survival (78.5) and rooting percentages (71.1%) compared to other seasons. Cuttings planted in a perlite, vermiculite and sand mixture during autumn significantly outperformed all other season/media combinations with regards to rooting percentage (75%). PGR application improved the number of roots obtained significantly in autumn and winter, but not in summer and spring, compared to the control. It was therefore concluded that, for higher seed germination H. odoratissimum seeds must be primed with smoke water and incubated at 15–20 °C and cuttings may be taken autumn for higher rooting and survival rates as well as improved root length. A PGR application can be beneficial depending on the type of medium used.

Plants of Commercial Importance in Lesotho: Ethnobotanical and Pharmacological Insights

Several plants have been processed in Lesotho to manufacture various commercial prodcts, ranging from cosmetics and beverages (juice, tea) to traditional herbal mixtures and crafts. Even though plants of commercial importance have been documented in different regions and countries, this is not the case in Lesotho. Therefore, the aim of the study is to record plant species commonly used in the country for development of commercial products. A physical survey was undertaken in different places in the Maseru District of Lesotho between January 2019 and October 2021, taking a record of existing commercial products and identifying plants used in their development. A total of 15 plants of commercial importance in the country are recorded in the current study, namely Agave americana, Aloe ferox, Artemisia afra, Cannabis sativa, Helichrysum odoratissimum, Hemannia depressa, Hypoxis hemerocallidea, Leudeboria cooperi, Mentha spp., Merxmuellera spp., Pelargonium sidoides, Opuntia ficus-indica, Rosa rubiginosa and Urtica urens. Most of the plants are used for production of commercial products in the country, whereas some are exported as raw materials, mainly to countries such as Germany, South Africa, Australia and America. The latter are C. sativa, Merxmuellera spp., P. sidoides and R. rubiginosa. Profiling of the plants provides important information about their commercial potential. However, conservation of the plants is encouraged to ensure their sustainable utilisation.

Bioprospecting of Helichrysum Species: Chemical Profile, Phytochemical Properties, and Antifungal Efficacy against Botrytis cinerea.

Variation in plant species and extraction solvents play a crucial role in the recovery of their bioactive compounds and antifungal efficacy. Thus, in this study, a comparative investigation was carried out using extraction solvents: 70% acetone and 95% ethanol to obtain crude aqueous extracts from Helichrysum odoratissimum and H. patulum. Crude aqueous extracts were screened using gas chromatography-mass spectrometry (GC-MS), to gain insight into their chemical composition. Phytochemical properties (total polyphenols (TP) and radical scavenging capacity via 2,2-diphenyl-1-picrylhydrazyl (DPPH)), and antifungal activity against Botrytis cinerea of the crude extracts were evaluated. Fungicide (Rovral® WP) and extraction solvents were used as controls. Variation in Helichrysum spp. and extraction solvent had influence on the chemical composition, phytochemicals, and antifungal activities. Metabolites such as γ-terpinene (≈0.1%), α-amorphene (≈0.6%) α-gurjunene (≈1.4%), β-selinene (2.2-3.2%), γ-gurjunene (≈3.3%), and methyl cinnamate (≈20%) were detected only in extracts of H. patulum. Crude extract of H. odoratissimum using 70% acetone had the highest TP (19.3 ± 0.76 g GA 100 g-1), and DPPH capacity (13,251.5 ± 700.55 µmol Trolox g-1) compared to H. patulum (p ≤ 0.05). Ethanolic extracts of H. patulum showed highest antifungal efficacy (≈65%) against B. cinerea (p ≤ 0.05) compared to other crude extracts. This study showed that Helichrysum spp. differ in their potential as a source for bioactive compounds and antifungal treatments/formulations.

Proximate, Vitamins, Minerals and Anti-Nutritive Constituents of the Leaf and Stem of Helichrysum odoratissimum (L.) Sweet: A Folk Medicinal Plant in South Africa

Helichrysum odoratissimum (L.) Sweet (Asteraceae) is a perennial shrub used in South African folk medicine to combat human diseases such as diabetes, coughs, asthma, and diarrhoea, and for wound treatment. This study evaluated the leaf and stem of H. odoratissimum for their nutritive and anti-nutritive qualities using the standard methods of the Association of Official Analytical Chemists (AOAC), atomic absorption spectrometry (AAS) and colorimetry. Crude fat and protein were high in the leaf (7.61% and 7.82% DW), but low in the stem (2.25% and 3.4%), respectively. The neutral detergent fibre (NDF) content was significantly higher in the stem (68.5%) compared to the leaf (43.6%), while non-fibre carbohydrate (NFC) in the leaf (24.93%) was higher than in the stem (15.67%). Mineral analysis showed that both the leaf and stem of H. odoratissimum are good sources of potassium, calcium, sodium, magnesium, phosphorus and iron. Appreciable amounts of vitamins B2, C and E in the leaf and stem supports the folkloric utility of the plant in the traditional treatment of wounds, coughs and colds. A tolerable amount of phytate in both leaf (0.36%) and stem (1.06%) might be a factor for safer consumption of the plant as food and medicine. These findings suggest the use of the plant as a source for dietary supplementation and ethnomedicinal applications.

Comparing Crop Yield, Secondary Metabolite Contents, and Antifungal Activity of Extracts of Helichrysum odoratissimum Cultivated in Aquaponic, Hydroponic, and Field Systems.

The overexploitation of wild plants for medicinal uses and conventional agricultural farming methods, which use high amounts of water, fertilizers, and pesticides, have had devastating environmental consequences. This study aimed to evaluate the prospects of using aquaponics and hydroponics as alternative approaches to soil cultivation by comparing the crop yields, secondary metabolite contents, and the antifungal activities of ethanol extracts of Helichrysum odoratissimum (L.) Sweet, a widely used medicinal plant species in Southern Africa. Six-week-old H. odoratissimum seedlings were grown in aquaponic and hydroponic systems. The growth parameters, secondary metabolite contents, and antifungal activity against Fusarium oxysporum were assessed. The results for crop yield (plant height, fresh and dry weights) and the tissue nutrient contents did not change substantially (p > 0.05) between aquaponic and hydroponic treatments. Gas chromatography–mass spectrometry (GC–MS) analysis showed that monoterpenes and sesquiterpenes were the most abundant compounds in H. odoratissimum; however, no statistical difference was observed among the field, hydroponic, and aquaponic plants (DF = 2; χ2 = 2.67; p > 0.05). While there was no significant difference in polyphenol contents among the three treatments, remarkably, the flavonol contents in the leaves varied significantly (DF = 2; χ2 = 6.23; p < 0.05) among the three treatments. A higher flavonol content occurred in leaves from the hydroponic system than in leaves from the aquaponic (p < 0.05) and field (p > 0.05) systems. The MIC results showed that the ethanolic extract of H. odoratissimum was fungistatic against F. oxysporum; however, this effect was more prominent in the ethanol extracts of plants grown in the aquaponic system, with a mean MIC value of 0.37 ± 0.00 mg/mL The key findings of this study are that aquaponically cultivated plants exhibited the best antifungal activity, while higher total flavonol contents occurred in the hydroponically cultivated plants. In conclusion, aquaponics and hydroponics performed better or similar to field cultivation and are viable alternative methods for cultivating H. odoratissimum plants.

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.

Impact of spatial variation and extraction solvents on bioactive compounds, secondary metabolites and antifungal efficacy of South African Impepho [Helichrysum odoratissimum (L.) Sweet

Extracts of indigenous plants have been explored to control several plant diseases and fruit pathogens, as well as in the development of bioactive compounds. This study investigated the impact of spatial variation and application of different extraction solvent on the antioxidant properties (total polyphenols (TP), and radical scavenging capacity via 2,2-diphenyl-1-picrylhydrazyl (DPPH)), secondary metabolite profile and the inhibitory activity (against Botrytis cinerea) of South African Impepho (Helichrysum odoratissimum L.). Fresh H. odoratissimum were harvested from two different agro-climatic sites of South Africa: Western Cape (WC) and Kwazulu Natal (KZN) provinces. Crude extracts were obtained using 95% ethanol and 70% acetone. Rovral® WP was used as control in antifungal study. Secondary metabolites of these extracts were relatively quantified using gas chromatography-mass spectroscopy (GC-MS). Extracts obtained via acetone had the highest soluble solids (SS), TP and DPPH capacity, for H. odoratissimum from WC and KZN (p ≤ 0.05). All extracts of H. odoratissimum provided considerable inhibition against B. cinerea in comparison to the controls. A total of 18 chemical classes of secondary metabolite were identified across all samples. Sesquiterpenoids were found to be the most relatively abundant class of compounds (31%–40%), followed by sesquiterpenes (9%–40%) and alkanes (7%–12%). Acetone extract of H. odoratissimum from KZN had the highest relative amount of sesquiterpenes. Higher relative abundance in viridiflorol (26% and 16.8% for acetone and ethanol extracts, respectively), were obtained for samples collected from WC compared to KZN province (p ≤ 0.05).

Ethanolic extracts of South African plants, Buddleja saligna Willd. and Helichrysum odoratissimum (L.) Sweet, as multifunctional ingredients in sunscreen formulations

Exposure to solar ultraviolet (UV) radiation is a major contributing factor to the increasing number of skin cancer cases. Interest has grown to use plant extracts as natural ingredients in cosmetic formulations due to their photoprotective effect, antioxidant and anti-inflammatory activity, as well as other biological activities. The aim of this study was to evaluate the biological activity of two South African plant extracts, Helichrysum odoratissimum (L.) Sweet. and Buddleja saligna Willd., and to successfully incorporate these extracts into sunscreen formulations (o/w emulsions) due to their reported biological activity. Ethanolic extracts were prepared from the leaves and stems of H. odoratissimum and B. saligna and evaluated for their antioxidant activity, mutagenic potential and antiproliferative activity against human dermal fibroblasts (MRHF). The extracts were further characterized using gas chromatography-mass spectrometry (GC-MS). Thereafter, the extracts were incorporated into separate sunscreen formulations to evaluate the in vivo dermal irritancy potential, in vivo sun protection factor, in vitro UVA protection, photostability and long term stability of the formulation, to confirm that by incorporating the extracts, the stability or photoprotective effect of the sunscreen formulation was not reduced and that these formulation were considered safe for topical application. Three separate sunscreen formulations were prepared; the base sunscreen formulation (formulation A), the base sunscreen formulation containing B. saligna (formulation B) and H. odoratissimum (formulation C) respectively. Both extracts showed significant radical scavenging activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with a fifty percent inhibitory concentration (IC50) of 5.13 ± 0.07 and 8.16 ± 0.34 µg/mL for H. odoratissimum and B. saligna respectively. No mutagenic activity was observed when the extracts were tested in the Ames assay using Salmonella typhimurium (TA98 and TA100). The PrestoBlue® cell viability assay was used to determine the antiproliferative activity of the extracts against MRHF cells, both extracts showed an IC50 value >90 µg/mL. Photoprotective activity was measured using in vivo sun protection factor (SPF) test method according to South African (SANS 1557) and International (ISO 24444) standards as well as the in vitro UVA SPF testing procedure (ISO 24443). The SPF results showed that the formulations had broad-spectrum UV protection with SPF values of 15.8±0.41, 16.1±0.66 and 16.0±0.49 and UVAPF values of 6.47±0.06, 6.45±0.06 and 6.47±0.07 for formulation A, B and C respectively. Furthermore, the formulations remained stable under normal and extreme conditions and the plant extracts did not affect the photoprotective effect of the sunscreen formulations and contributed towards the formulations stability. Additionally, each of the formulations were photostable, whereas the formulations with the addition of the extracts showed an incremental increase in photostability when compared to the base formulation. Both these extracts have been previously reported to display antiproliferative activity against skin cancer cell lines (previously published data), with an IC50 value of 31.80 ± 0.35 µg/mL (human malignant melanoma, UCT-MEL-1) for B. saligna and IC50 values of 15.50 ± 0.20 (human epidermoid carcinoma, A431) and 55.50 ± 6.60 µg/mL (human malignant melanoma, A375) for H. odoratissimum, contributing towards the medicinal benefit of using these extracts as ingredients into sunscreen formulations. Therefore, Helichrysum odoratissimum and Buddleja saligna could be considered as useful and viable additives to sunscreen formulations due to their reported biological activity.

Comparative chemical profiling and antimicrobial activity of two interchangeably used ‘Imphepho’ species (Helichrysum odoratissimum and Helichrysum petiolare)

Helichrysum petiolare and Helichrysum odoratissimum, collectively known as ‘Imphepho’, are popular medicinal herbs that are indigenous to South Africa. The species are used interchangeably to relieve gastrointestinal and respiratory conditions, fever and urinary tract infections, implying that they produce antibacterial compounds. Although these herbs are sold in informal markets, they have not been commercialized. The aim of this study was to compare the chemical profiles and the antimicrobial activities of solvent extracts of the two species. The profiles of the smoke condensates were also compared, since the smoke from both species is inhaled during cultural rituals to induce central nervous system effects. After optimizing the extractant, the chemical profiles of aqueous methanol extracts of the aerial parts of twelve H. odoratissimum and fifteen H. petiolare samples, collected from several different localities, were obtained using ultra performance liquid chromatography-mass spectrometry (UPLC-MS). Three isomeric compounds were found to be present in both species. The construction of chemometric models from the data indicated a large degree of inter-population variation within H. odoratissimum, with the samples loosely clustering into two main groups. In contrast, the chemistry of H. petiolare was highly conserved. Discriminant analysis identified four distinguishing marker compounds for each species. One of the isomers common to both species, was isolated from H. odoratissimum and identified as 4,5-dicaffeoylquinic acid using nuclear magnetic resonance (NMR) spectroscopy, and is herein reported for the first time from the two species. Following validation of a developed UPLC-photodiode array (PDA) detection method, it was determined that the concentrations of the compound ranged from 3.89 - 31.1 µg/g in H. odoratissimum and from 2.3 to 13.4 µg/g in H. petiolare. High performance thin layer chromatography (HPTLC) fingerprints also indicated a greater degree of chemical variation within H. odoratissimum than in H. petiolare. This was confirmed through multivariate analysis of densitograms obtained from images of the fingerprints through the application of rTLC software, effectively mirroring the UPLC-MS results. The antibacterial activity of extracts of all the samples was determined using the minimum inhibitory concentration (MIC) serial dilution assay against selected Gram-positive (Staphylococcus saprophyticus, Enterococcus faecalis, Streptococcus agalactiae) and Gram-negative (Proteus mirabilis, Escherichia coli, Moraxella catarrhalis) pathogens that affect the urinary, respiratory and gastro-intestinal tracts. The MICs obtained for H. odoratissimum extracts indicated that these were more effective towards a larger range of bacteria than extracts of H. petiolare. The methanol extracts yielded average MICs denoting noteworthy or moderate activity towards three pathogens (E. coli, M. catarrhalis and S. agalactiae), while the chloroform:methanol extracts displayed noteworthy or moderate activity towards the same three pathogens, but also towards E. faecalis. These results justify to some degree the traditional use of H. odoratissimum to treat conditions of the gastro-intestinal, respiratory and urinary tracts. The UPLC-PDA profiles of smoke condensates of the two species, obtained under controlled conditions, revealed five major compounds that were common to both species. Although the similarity of the smoke profiles rationalises their interchangeable use for inhalation, the solvent extracts displayed little congruence regarding their chemical profiles or antibacterial activities.

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

ObjectiveCyclophosphamide (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. MethodsIn 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. ResultsThe 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. ConclusionH. odoratissimum might be considered as an alternative drug to alleviate/prevent reproductive damage in cancer patients receiving CP chemotherapy.

A SYNTHESIS AND REVIEW OF MEDICINAL USES, PHYTOCHEMISTRY AND BIOLOGICAL ACTIVITIES OF HELICHRYSUM ODORATISSIMUM (L.) SWEET

Helichrysum odoratissimum is an important medicinal plant species in tropical Africa. The current study critically reviewed the medicinal uses, phytochemistry and biological activities of H. odoratissimum. Information on medicinal uses, phytochemistry and biological activities of H. odoratissimum were collected from multiple internet sources which included Scopus, Google Scholar, Elsevier, Science Direct, Web of Science, PubMed, SciFinder, and BMC. Additional information was gathered from pre-electronic sources such as journal articles, scientific reports, theses, books, and book chapters obtained from the university library. This study showed that H. odoratissimum is mainly used as an herbal medicine for insomnia, menstrual pain and sterility, and wounds and respiratory problems. Pharmacological research revealed that H. odoratissimum extracts and compounds isolated from the species have antibacterial, antimycobacterial, antifungal, anti-inflammatory, antioxidant, hepatoprotection, and hypoglycemic and cytotoxicity activities. There is a need to validate the documented ethnomedicinal uses of H. odoratissimum through phytochemical and pharmacological studies. Therefore, future studies should address these knowledge gaps through experimental animal studies, randomized clinical trials, and target-organ toxicity studies involving H. odoratissimum crude extracts and compounds isolated from the species.

The Effect of Helichrysum odoratissimum (L.) Sweet on Cancer Cell Proliferation and Cytokine Production

The cytotoxicity of Helichrysum odoratissimum against human epidermoid carcinoma (A431), malignant melanoma (A375), cervical epithelial carcinoma (HeLa) and human embryonic kidney (HEK-293) cells was investigated. The cytokine production and antioxidant activity was also determined. H odoratissimum was selected based on its traditional usage as a dressing for wounds. In this study the cytotoxicity was performed on skin and cervical cancer which are associated with the presence of wounds. H. odoratissimum showed inhibitory activity against A431 cells, with a fifty percent inhibitory concentration (IC50) of 15.5±0.2 µg/ml, and a high DPPH inhibition with an IC50 of 5.13±0.07 µg/ml. A431 cells treated with the extract showed an increase in morphological characteristics associated with apoptosis. The extract induced IL-12 in U937 cells and inhibited IL-8 at the tested concentrations, with the highest levels being 12.4±7 pg/ml and 103±6.1 pg/ml respectively. IL-2 was inhibited by 56 % and 52 % in naive and PHA induced murine splenocytes respectively. Furthermore, 2 lipophilic fractions and 3 compounds were isolated from the extract. The lipophilic fractions showed relative cytotoxicity on A431 cells with IC50 values of 175±13.5 µg/ml and 61.3±0.16 µg/ml. The extract showed significant hepatoprotection at 25 µg/ml on HepG2 cells exposed to D-Galactosamine. This is the first report of the activity of H. odoratissimum ethanolic leaf stem extract on A431, A375, HeLa and HEK-293 cell lines as well as the isolation of two promising lipophilic fractions.

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.

Genomic differences may drive speciation in South African Helichrysum odoratissimum

Genomic differences may drive speciation in South African Helichrysum odoratissimum

Hypoglycemic effect of Helichrysum odoratissimum in alloxan induced diabetic mice

Diabetes mellitus is a disease of antiquity with worrying global incidence and prevalence. Conventional management and/or treatment interventions have been hampered by drawbacks like high costs, inaccessibility, likelihood of potential adverse and toxic effects among others. Use of antidiabetic phytodrugs has been on the rise, particularly in the developing countries, perhaps due to cost implications and accessibility advantages. In this study, an aqueous leaf extract of the medicinal plant Helichrysum odoratissimum was bioscreened for their hypoglycemic potential in alloxan-induced diabetic mice. Three dose ranges were used viz; 50 mg/kgbwt, 100 mg/kgbwt and 150 mg/kgbwt. Results indicate that the extract appreciably lowered blood glucose level in the diabetic mice. The glucose lowering potency of this extract was dose dependent. Preliminary in vivo toxicity assessment revealed that the plant has no discernible toxicity on the major organs of the study animals. The study results confirm the folklore reports from traditional medical practitioners that the extract has safe bioactivity against diabetes mellitus. It avails an impetus for further bioscreening efforts with a view to the development of more hypoglycemic agents in future.

Chemical Composition, Antibacterial and Cytotoxic Activities of Essential Oil from the Leaves of Helichrysum odoratissimum grown in South Africa

The chemistry of Helichrysum odoratissimum (L) Sweet., (family Asteraceae) volatiles grown in South Africa has been studied. The essential oil was obtained by hydrodistillation and analyzed by GC and GC-MS. The main compounds were β-pinene (51.6 %) and limonene (16.9 %) among the monoterpenes, while α-humulene (5.6 %) and β-caryophyllene (4.7 %) are the prominent among the sesquiterpenes. The abundance of β-pinene is not a common occurrence when compared with previously reported data on the oil constituents of H. odoratissimum. The volatile oil showed potential antibacterial activities towards some tested microorganisms with mean zones of inhibition and minimal inhibitory concentrations ranging from 14.0±1.3 -17.0±1.7 mm and 0.6-2.5 mg/mL, respectively. The oil exhibited moderate cytotoxicity against brine shrimp larvae with LC50 of 31.16 µg/mL.

Essential Oils from Ugandan Aromatic Medicinal Plants: Chemical Composition and Growth Inhibitory Effects on Oral Pathogens.

The study assessed the growth inhibitory effects of essential oils extracted from ten Ugandan medicinal plants (Bidens pilosa, Helichrysum odoratissimum, Vernonia amygdalina, Hoslundia opposita, Ocimum gratissimum, Cymbopogon citratus, Cymbopogon nardus, Teclea nobilis, Zanthoxylum chalybeum, and Lantana trifolia) used traditionally in the management of oral diseases against oral pathogens. Chemical compositions of the oils were explored by GC-MS. Inhibitory effects of the oils were assessed on periodontopathic Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans and cariogenic Streptococcus mutans and Lactobacillus acidophilus using broth dilution methods at concentrations of 1%, 0.1%, and 0.01%. The most sensitive organism was A. actinomycetemcomitans. Its growth was markedly inhibited by six of the oils at all the concentrations tested. Essential oil from C. nardus exhibited the highest activity with complete growth inhibition of A. actinomycetemcomitans and P. gingivalis at all the three concentrations tested, the major constituents in the oil being mainly oxygenated sesquiterpenes. Most of the oils exhibited limited effects on L. acidophilus. We conclude that essential oils from the studied plants show marked growth inhibitory effects on periodontopathic A. actinomycetemcomitans and P. gingivalis, moderate effects on cariogenic S. mutans, and the least effect on L. acidophilus. The present study constitutes a basis for further investigations and development of certain oils into alternative antiplaque agents.