Dichrostachys cinerea (L.) Wight et Arn (Mimosaceae) hydro-alcoholic extract action on the contractility of tracheal smooth muscle isolated from guinea-pig

Medicinal Uses of the Fabaceae Family in Zimbabwe: A Review

The current study is aimed at providing a systematic review of the ethnomedicinal, phytochemical and pharmacological properties of Fabaceae species used as sources of traditional medicinies in Zimbabwe. Fabaceae is one of the well-known plant families of ethnopharmacological importance. Of the approximately 665 species of the Fabaceae family occurring in Zimbabwe, about 101 are used for medicinal purposes. Many communities in the country, mainly in peri-urban, rural and marginalized areas with limited access to healthcare facilities, rely on traditional medicines as their primary healthcare. The study reviewed research studies undertaken on Zimbabwe's Fabaceae species during 1959 to 2022. Information was gathered from literature sourced from Google Scholar, Science Direct, Scopus, PubMed, books, dissertations, theses and scientific reports. This study showed that 101 species are traditionally used to manage human and animal diseases in Zimbabwe. The genera with the highest number of medicinal uses are Indigofera, Senna, Albizia, Rhynchosia and Vachellia. Species of these genera are used as traditional medicines against 134 medical conditions, mainly gastrointestinal conditions, female reproductive conditions, respiratory conditions and sexually transmitted infections. Shrubs (39.0%), trees (37.0%) and herbs (18.0%) are the primary sources of traditional medicines, while roots (80.2%), leaves (36.6%), bark (27.7%) and fruits (8.9%) are the most widely used plant parts. Many of Zimbabwe's Fabaceae species used as sources of traditional medicines have been assessed for their phytochemical and pharmacological properties, corroborating their medicinal uses. However, there is a need to unravel the therapeutic potential of the family through further ethnopharmacological research focusing on toxicological studies, in vitro and in vivo models, biochemical assays and pharmacokinetic studies.

Medicinal plants used for the management of respiratory diseases in Zimbabwe: Review and perspectives potential management of COVID-19

Respiratory diseases have in the recent past become a health concern globally. More than 523 million cases of coronavirus disease (COVID19), a recent respiratory diseases have been reported, leaving more than 6 million deaths worldwide since the start of the pandemic. In Zimbabwe, respiratory infections have largely been managed using traditional (herbal) medicines, due to their low cost and ease of accessibility. This review highlights the plants' toxicological and pharmacological evaluation studies explored. It seeks to document plants that have been traditionally used in Zimbabwe to treat respiratory ailments within and beyond the past four decades. Extensive literature review based on published papers and abstracts retrieved from the online bibliographic databases, books, book chapters, scientific reports and theses available at Universities in Zimbabwe, were used in this study. From the study, there were at least 58 plant families comprising 160 medicinal plants widely distributed throughout the country. The Fabaceae family had the highest number of medicinal plant species, with a total of 21 species. A total of 12 respiratory ailments were reportedly treatable using the identified plants. From a total of 160 plants, colds were reportedly treatable with 56, pneumonia 53, coughs 34, chest pain and related conditions 29, asthma 25, tuberculosis and spots in lungs 22, unspecified respiratory conditions 20, influenza 13, bronchial problems 12, dyspnoea 7, sore throat and infections 5 and sinus clearing 1 plant. The study identified potential medicinal plants that can be utilised in future to manage respiratory infections.

Pharmacological Modulation of Smooth Muscles and Platelet Aggregation by Psidium cattleyanum

Traditionally, in the Southern Asian countries, Psidium cattleyanum is a widely used plant for the management of various ailments such as gastrointestinal, respiratory, and cardiac disorders, but it lacks proof on a scientific basis, and therefore, this is the major emphasis of the current research work. Crude extract of Psidium cattleyanum (Pc.Cr) was preliminary analyzed for the presence of different classes of bioactive molecules. The aqueous and dichloromethane fractions of Pc.Cr were subjected to in vitro and in vivo studies. It was applied at variable concentrations (0.1-10 mg/ml) to isolated rabbit jejunum to investigate spasmolytic effect. Concentration dependent curves of calcium were constructed to check the calcium channel antagonistic activity. For the evaluation of tracheorelaxant activity, isolated tracheal tissue was treated with High-K⁺ (80 mM) and carbachol (CCh) and then challenged cumulatively with Pc.Cr. To study the antidiarrheal effect of the plant extract, castor oil-induced diarrhea model was adopted. For evaluation of the hypotensive effect of Pc.Cr, it was given intravenously to preanesthetized normotensive rats, and the response was recorded using pressure transducer. Platelet rich plasma was used for the assessment of the antiplatelet activity when challenged with purinergic and adrenergic agonists. Concentration-dependent inhibition of spontaneous and High-K⁺ mediated contractions in isolated jejunum was observed by the application of Pc.Cr. Contractions induced in isolated tracheal tissue by High-K⁺ and CCh were inhibited by application of Pc.Cr to these tissues. Similarly, application of Pc.Cr to High-K⁺ and phenylephrine (PE) treated aortic strips resulted in vasodilation. Platelet aggregation inhibition was shown by Pc.Cr against adenosine diphosphate (ADP) only. The antidiarrheal effect was observed as a reduction in the total number of feces in Pc.Cr-treated mice when given castor oil. Dose-dependent hypotension was seen in normotensive rats when treated with Pc.Cr intravenously. This study showed the spasmolytic, tracheorelaxant, vasodilator, platelet aggregation inhibitory, antidiarrheal, and hypotensive activities of P. cattleyanum which may be due to the blockage of calcium channels, but the involvement of any other pathway cannot be ignored.

Antibacterial activity of aqueous and methanol extracts of selected species used in livestock health management

CONTEXT

Salvadora persica L. (Salvadoraceae), Colophospermum mopane (J.Kirk ex Benth.) J. Léonard (Leguminosae) and Dichrostachys cinerea (L.) Wight & Arn. (Leguminosae) crude extracts are used by local farmers against many livestock infections with little or no side effects usually associated with synthetic antimicrobials. However, their efficacy has rarely been tested.

OBJECTIVE

These plants were tested for potential antibacterial activity against clinical isolates of Staphylococcus aureus ATCC33862 and Escherichia coli ATCC25922. Minimal inhibitory concentrations (MIC) of the crude plant extracts were determined.

MATERIALS AND METHODS

Aqueous and methanol extraction of 100 g each of the bark of C. mopane, roots of D. cinerea and leaves of S. persica was done by placing the samples in 250 mL of either water or methanol. Nutrient broth was used as growth medium for the bacteria, and McFarland standard for bacterial standardization. 2,3,5-Triphenyltetrazoliumchloride (TTC) was the indicator salt. Each of the aqueous and methanol extracts (100 μL) was tested. Gentamycin and ampicillin were the controls.

RESULTS

MIC of aqueous extracts ranged from 1.03-14.6 mg/mL against S. aureus, and from 12.1-34.3 mg/mL against E. coli. Methanol extracts ranged between 5.31 and 9.64 mg/mL against S. aureus, and between 7.86 and 13.6 mg/mL against E. coli. Aqueous and methanol extracts of S. persica were significantly higher (p < 0.05) than C. mopane and D. cinerea.

DISCUSSION AND CONCLUSION

Colophospermum mopane, S. persica and D. cinerea exhibited antibacterial activity, with methanol extracts performing better than aqueous extracts, justifying use as ethnoveterinary medicine. Further study to isolate the active components should be pursued.

Arctigenin exhibits relaxation effect on bronchus by affecting transmembrane flow of calcium

Arctigenin, a lignan extract from Arctium lappa (L.), exhibits anti-inflammation, antioxidation, vasodilator effects, etc. However, the effects of arctigenin on bronchus relaxation are not well investigated. This study aimed to investigate how arctigenin regulates bronchus tone and calcium ion (Ca(2+)) flow. Trachea strips of guinea pigs were prepared for testing the relaxation effect of arctigenin to acetylcholine, histamine, KCl, and CaCl2, respectively. Furthermore, L-type calcium channel currents were detected by patch-clamp, and intracellular Ca(2+) concentration was detected by confocal microscopy. The results showed that arctigenin exhibited relaxation effect on tracheae to different constrictors, and this was related to decreasing cytoplasmic Ca(2+) concentration by inhibiting Ca(2+) influx partly through L-type calcium channel as well as promoting Ca(2+) efflux. In summary, this study provides new insight into the mechanisms by which arctigenin exhibits relaxation effect on bronchus and suggests its potential use for airway disease therapy.

Tracheal relaxation of five Ivorian anti-asthmatic plants: role of epithelium and K⁺ channels in the effect of the aqueous-alcoholic extract of Dichrostachys cinerea root bark

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves of Boerhavia diffusa (Nyctaginaceae), Baphia nitida, Cassia occidentalis, Desmodium adscendens (Fabaceae), and root bark of Dichrostachys cinerea (Fabaceae) are used in Ivory Coast for the treatment of asthma. The aim of this study was to evaluate the potential airway relaxant activity of different extracts of these plants.

MATERIALS AND METHODS

Extracts of different polarities (H(2)O, EtOH/H(2)O, MeOH and CH(2)Cl(2)) were obtained from these five plants. Their ex vivo relaxant activity was tested in mice isolated trachea precontracted with carbachol (1 μM).

RESULTS

Cumulative concentrations of most extracts induced moderate to strong relaxation, the methanolic extracts being the most potent and the polar extracts the most active at the concentrations used, supporting the traditional use of these five plants as anti-asthmatic remedies. We further investigated the molecular and cellular mechanisms of the mouse trachea relaxant effect of the aqueous-alcoholic extract of Dichrostachys cinerea root bark, the most potent extract. Its effect was not modified in the presence of β-adrenoceptor antagonists (propranolol or ICI 118,551) or a PKA inhibitor (H89). By contrast, it was decreased after depolarization-induced precontraction (with 80 mM KCl), in the presence of some K(+) channels blockers [4-aminopyridine as voltage-dependent K(+) (K(v)) channel blocker and tetraethylammonium chloride as large conductance Ca(2+)-activated K(+) (BK(Ca)) channel blocker, but not with glibenclamide, an ATP-sensitive K(+) (K(ATP)) channel blocker] or after epithelium removal.

CONCLUSIONS

The mouse tracheal relaxant effect of Dichrostachys cinerea EtOH/H(2)O extract was independent of β(2)-adrenoceptors activation and cAMP/PKA pathway, but dependent on epithelium and K(+) channels, namely K(v) and BK(Ca) channels. Further investigation will be required to identify the component(s) responsible for this airways relaxant activity.

Differential phenolic profiles in six African savanna woody species in relation to antiherbivore defense

Low molecular weight phenolics are suggested to have a role in mediating diet selection in mammalian herbivores. However, very little is known about low molecular weight phenolic profiles of African savanna woody species. We determined low molecular weight phenolic profiles of six woody species with different life history, morphological and functional traits. We investigated interspecific phytochemical variation between species and found that: (1) related Acacia species were chemically dissimilar; (2) similarity percentage analysis revealed that Acacia grandicornuta was most dissimilar from other species and that the evergreen and unpalatable Euclea divinorum had a qualitatively similar chemical profile to the deciduous and palatable Acacia exuvialis and Combretum apiculatum; (3) C. apiculatum had the highest chemical diversity; (4) relative to spineless plants, spinescent plants contained significantly less HPLC phenolics and condensed tannins; and (5) the major quantitative difference between the evergreen and unpalatable E. divinorum and other species was its high myricitrin concentration.