Chemotypic variation of non-volatile constituents of Artemisia afra (African wormwood) from South Africa

The anthelmintic activity of the white wormwood (Artemisia herba Alba) against Haemonchus contortus in beef cattle

The objective of the study was to determine the efficacy of white wormwood on helminthes in beef cattle production. Water extracts of white wormwood of different levels of phytotoxicity were used to treat female adult H. contortus over 8 h under controlled laboratory conditions. The experiment was designed in a completely randomized design with six treatments replicated three times. Treatments 3-6 showed a reduction in worm motility over time (P < 0.05) while it did not change much for T1 and T2 (P < 0.05). Even after 8 h of incubation, more than 50% of the worms were still active in T1, T2 and T3. Meaningful reductions in activity were observed in T4 from 6 to 8 h, T5 form 4-8 h and T6 form 2-6 h. The highest mortality was observed in T4, T5 and T6, 8 h after incubation, however only T6 totally killed all worms 6 h after incubation. Treatments 4 and 5 only achieved 80 and 82% mortality respectively, 8 h post incubation. It is therefore concluded that wormwood aqueous extracts at 5 mg/mL and 10 mg/mL have the capability to immobilize, inactivate and kill mature H. contortus worms from beef cattle.

Future antimalarials from Artemisia? A rationale for natural product mining against drug-refractory Plasmodium stages

Covering: up to 2023Infusions of the plants Artemisia annua and A. afra are gaining broad popularity to prevent or treat malaria. There is an urgent need to address this controversial public health question by providing solid scientific evidence in relation to these uses. Infusions of either species were shown to inhibit the asexual blood stages, the liver stages including the hypnozoites, but also the sexual stages, the gametocytes, of Plasmodium parasites. Elimination of hypnozoites and sterilization of mature gametocytes remain pivotal elements of the radical cure of P. vivax, and the blockage of P. vivax and P. falciparum transmission, respectively. Drugs active against these stages are restricted to the 8-aminoquinolines primaquine and tafenoquine, a paucity worsened by their double dependence on the host genetic to elicit clinical activity without severe toxicity. Besides artemisinin, these Artemisia spp. contain many natural products effective against Plasmodium asexual blood stages, but their activity against hypnozoites and gametocytes was never investigated. In the context of important therapeutic issues, we provide a review addressing (i) the role of artemisinin in the bioactivity of these Artemisia infusions against specific parasite stages, i.e., alone or in association with other phytochemicals; (ii) the mechanisms of action and biological targets in Plasmodium of ca. 60 infusion-specific Artemisia phytochemicals, with an emphasis on drug-refractory parasite stages (i.e., hypnozoites and gametocytes). Our objective is to guide the strategic prospecting of antiplasmodial natural products from these Artemisia spp., paving the way toward novel antimalarial "hit" compounds either naturally occurring or Artemisia-inspired.

Secondary Metabolites Isolated from Artemisia afra and Artemisia annua and Their Anti-Malarial, Anti-Inflammatory and Immunomodulating Properties-Pharmacokinetics and Pharmacodynamics: A Review

There are over 500 species of the genus Artemisia in the Asteraceae family distributed over the globe, with varying potentials to treat different ailments. Following the isolation of artemisinin (a potent anti-malarial compound with a sesquiterpene backbone) from Artemisia annua, the phytochemical composition of this species has been of interest over recent decades. Additionally, the number of phytochemical investigations of other species, including those of Artemisia afra in a search for new molecules with pharmacological potentials, has increased in recent years. This has led to the isolation of several compounds from both species, including a majority of monoterpenes, sesquiterpenes, and polyphenols with varying pharmacological activities. This review aims to discuss the most important compounds present in both plant species with anti-malarial properties, anti-inflammatory potentials, and immunomodulating properties, with an emphasis on their pharmacokinetics and pharmacodynamics properties. Additionally, the toxicity of both plants and their anti-malaria properties, including those of other species in the genus Artemisia, is discussed. As such, data were collected via a thorough literature search in web databases, such as ResearchGate, ScienceDirect, Google scholar, PubMed, Phytochemical and Ethnobotanical databases, up to 2022. A distinction was made between compounds involved in a direct anti-plasmodial activity and those expressing anti-inflammatory and immunomodulating activities or anti-fever properties. For pharmacokinetics activities, a distinction was made between compounds influencing bioavailability (CYP effect or P-Glycoprotein effect) and those affecting the stability of pharmacodynamic active components.

Geographical and seasonal phytochemical variation of Artemisia afra Jacq. ex Willd

INTRODUCTION

Artemisia afra Jacq. ex. Willd. (Asteraceae) is a popular traditional medicine in South Africa, mainly used in the form of an infusion, for the treatment of respiratory ailments. Quality control methods are limited and phytochemical variation for the infusion is not well known.

OBJECTIVE

To develop a sensitive quality control method for A. afra infusions by validating a liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS) method and quantitatively comparing six marker compounds in A. afra samples collected from different locations and over a 12-month period.

MATERIAL AND METHODS

There was a multiple reaction monitoring method optimised and validated, according to ICH and FDA guidelines, to quantify the chemical markers present in infusions.

RESULTS

The chemistry differed significantly and interestingly, with an interchangeable trend between chlorogenic acid (CGA) and 4,5-dicaffeoylquinic acid (DCQA) observed in the samples collected monthly, elevated levels of CGA during winter and elevated levels of DCQA during summer. The remaining four markers showed a steady decrease as winter approached and a steady increase as summer approached. The ranges of the six markers were the following: CGA (0.68-14.68 μg/mg), DCQA (0.005-8.110 μg/mg), quercetin (0.01-0.65 μg/mg), luteolin (0.05-1.30 ng/mg), scopoletin (0.10-1.14 μg/mg), scopolin (0.03-1.21 μg/mg).

CONCLUSIONS

A sensitive LC-ESI-MS/MS method was developed, validated, and used to quantify six marker compounds. The results indicated a large degree of phytochemical variation occurred across all samples tested, which highlights the importance of producing herbal medicine under controlled conditions and the necessity of analytical quality control methods.

Anti-Salmonella activity of plant species in the Benin republic: Artemisia afra and Detarium senegalense with promising in vitro and in vivo activities

Non-typhoidal invasive Salmonella (NTiS) diseases are one of the most important zoonoses in the world. This study explored the antipathogenic potential of twenty-four plants used in Benin folk medicine against NTiS diseases. The in vitro antibacterial and antibiofilm activities of ethanolic plant extracts were screened against clinical resistant isolates and ATCC reference strains of Salmonella. Salmonella enterica serovar Typhimurium-infected rat model was used to examine the in vivo antibacterial potential of plant extracts. Of the 24 plants, 18 plants exhibited antibacterial activity against Salmonella enterica strains with minimum inhibitory concentrations (MICs) ranging from 0.156 to 1.25 mg/mL. Anacardium occidentale, Artemisia afra, Detarium microcarpum, Detarium senegalense, and Leucaena leucocephala were the most active plant species. Extracts from A. afra, D. microcarpum, and D. senegalense showed biofilm inhibition greater than 50% against Salmonella clinical isolates. In the rat model of infection, A. afra and D. senegalense extracts were found to have an effective dose of less than 100 mg/kg and to stop the salmonellosis after 10 days of treatment. Additionally, these extracts did not produce any toxic effects in the treated animals. These results indicate clear evidence supporting the anti-Salmonella activity of A. afra and D. senegalense. Further studies are now needed to isolate bioactive compounds and to ensure the safety of these plant species.

A Chewable Cure "Kanna": Biological and Pharmaceutical Properties of Sceletium tortuosum

Sceletium tortuosum (L.) N.E.Br. (Mesembryanthemaceae), commonly known as kanna or kougoed, is an effective indigenous medicinal plant in South Africa, specifically to the native San and Khoikhoi tribes. Today, the plant has gained strong global attraction and reputation due to its capabilities to promote a sense of well-being by relieving stress with calming effects. Historically, the plant was used by native San hunter-gatherers and Khoi people to quench their thirst, fight fatigue and for healing, social, and spiritual purposes. Various studies have revealed that extracts of the plant have numerous biological properties and isolated alkaloids of Sceletium tortuosum are currently being used as dietary supplements for medicinal purposes and food. Furthermore, current research has focused on the commercialization of the plant because of its treatment in clinical anxiety and depression, psychological and psychiatric disorders, improving mood, promoting relaxation and happiness. In addition, several studies have focused on the isolation and characterization of various beneficial bioactive compounds including alkaloids from the Sceletium tortuosum plant. Sceletium was reviewed more than a decade ago and new evidence has been published since 2008, substantiating an update on this South African botanical asset. Thus, this review provides an extensive overview of the biological and pharmaceutical properties of Sceletium tortuosum as well as the bioactive compounds with an emphasis on antimicrobial, anti-inflammatory, anti-oxidant, antidepressant, anxiolytic, and other significant biological effects. There is a need to critically evaluate the bioactivities and responsible bioactive compounds, which might assist in reinforcing and confirming the significant role of kanna in the promotion of healthy well-being in these stressful times.

Phytochemical Profiling and Quality Control of Terminalia sericea Burch. ex DC. Using HPTLC Metabolomics

Terminalia sericea is used throughout Africa for the treatment of a variety of conditions and has been identified as a potential commercial plant. The study was aimed at establishing a high-performance thin layer chromatography (HPTLC) chemical fingerprint for T. sericea root bark as a reference for quality control and exploring chemical variation within the species using HPTLC metabo3lomics. Forty-two root bark samples were collected from ten populations in South Africa and extracted with dichloromethane: methanol (1:1). An HPTLC method was optimized to resolve the major compounds from other sample components. Dichloromethane: ethyl acetate: methanol: formic acid (90:10:30:1) was used as the developing solvent and the plates were visualized using 10% sulfuric acid in methanol as derivatizing agent. The concentrations of three major bioactive compounds, sericic acid, sericoside and resveratrol-3-O-β-rutinoside, in the extracts were determined using a validated ultra-performance liquid chromatography-photodiode array (UPLC-PDA) detection method. The rTLC software (written in the R-programming language) was used to select the most informative retardation factor (Rf) ranges from the images of the analysed sample extracts. Further chemometric models, including principal component analysis (PCA) and hierarchical cluster analysis (HCA), were constructed using the web-based high throughput metabolomic software. The rTLC chemometric models were compared with the models previously obtained from ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS). A characteristic fingerprint containing clear bands for the three bioactive compounds was established. All three bioactive compounds were present in all the samples, although their corresponding band intensities varied. The intensities correlated with the UPLC-PDA results, in that samples containing a high concentration of a particular compound, displayed a more intense band. Chemometric analysis using HCA revealed two chemotypes, and the subsequent construction of a loadings plot indicated that sericic acid and sericoside were responsible for the chemotypic variation; with sericoside concentrated in Chemotype 1, while sericic acid was more abundant in Chemotype 2. A characteristic chemical fingerprint with clearly distinguishable features was established for T. sericea root bark that can be used for species authentication, and to select samples with high concentrations of a particular marker compound(s). Different chemotypes, potentially differing in their therapeutic potency towards a particular target, could be distinguished. The models revealed the three analytes as biomarkers, corresponding to results reported for UPLC-MS profiling and thereby indicating that HPTLC is a suitable technique for the quality control of T. sericea root bark.