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.

The effect of increased mobility on SARS-CoV-2 transmission: a descriptive study of the trends of COVID-19 in Zimbabwe between December 2020 and January 2021.

INTRODUCTION: when the first cases of COVID-19 were reported in Zimbabwe in March 2020, the local outbreak was characterised by an insidious increase in national caseload. This first wave was mainly attributable to imported cases, peaking around July 2020. By October 2020, the number of cases reported daily had declined to less than 100 cases per day signalling the end of the first wave. This pattern mirrored the global trends. In December 2020, reports of new COVID-19 variants emerged and coincided with the beginning of the second wave within the ongoing pandemic. This paper reports on the analysis conducted on the new wave of COVID-19 beginning December 2020 to January 2021. The objective of this study was to document the evolving presumptive second wave of the COVID-19 pandemic in Zimbabwe from December 2020 to January 2021. METHODS: this is a retrospective analysis of secondary data extracted from the daily situation reports published by the Ministry of Health and Child Welfare, Zimbabwe and World Health Organization Country Office, Zimbabwe. The period under consideration started from 1st December 2020 to 31st January 2021. RESULTS: there was a 333% increase in the number of confirmed COVID-19 cases starting 1st December 2020, to 31st January 2021. These new cases were mainly attributed to community transmission though there were a few imported cases. There was a 439% increase in the absolute number of deaths; however, the case fatality rate remained low at 3.6%, and comparable to that from other countries. Harare, Bulawayo and Manical and provinces accounted for 60% of the case burden, with the other seven provinces only accounting for 40%. By mid-January, the number of incident COVID-19 cases started to decline significantly, to levels similar to the residual levels seen during the first wave. CONCLUSION: the second wave, which lasted a period of less than 2 months, had a steep rise and sharp decline in the incident cases and fatalities. The steep rise was attributable to increased mobility, with a consequent increase in the chains of community transmission. The declines, noted from mid-January 2021, may be partly attributable to a strict national lockdown, though more in-depth exploration of the drivers of transmission is needed to tailor effective interventions for future control. Differentiated strategies maybe needed according to the case burdens in the different provinces. In anticipation of further waves, the introduction of safe and effective vaccines might be the game changer if the vaccines are widely availed to the population to levels adequate to achieve herd immunity. Meanwhile, infection prevention and control guidelines must continue to be observed.

A descriptive study of the trends of COVID-19 in Zimbabwe from March-June 2020: policy and strategy implications.

INTRODUCTION: the first cases of COVID-19 were reported in China in December 2019. Since then, the disease has evolved to become a global pandemic. Zimbabwe reported its first case on 20th March 2020, and the number has been increasing steadily. However, Zimbabwe has not witnessed the exponential growth witnessed in other countries so far, and the trajectory seems different. We set out to describe the epidemiological trends of COVID-19 in Zimbabwe from when the first case was confirmed to June 2020. METHODS: data were collected from daily situation reports that were published by the Zimbabwean Ministry of Health and Child Care from 20th March to 27th June 2020. Missing data on the daily situation reports was not imputed. RESULTS: as of 27th June 2020, Zimbabwe had 567 confirmed COVID-19 cases. Eighty-two percent of these were returning residents and 18% were local transmission. The testing was heavily skewed towards returnees despite a comprehensive testing strategy. Of the confirmed cases, 142 were reported as recovered. However, demographic data for the cases were missing from the reports. It was not possible to estimate the probable period of infection of an active case, and case fatality in Zimbabwe was about 1% for the first 4 months of the pandemic. CONCLUSION: the epidemiological trends of COVID-19 experienced in Zimbabwe between March and June 2020 are somewhat different from what has been observed elsewhere. Further research to determine the reasons for the differences is warranted, to inform public health practice and tailor make suitable interventions.

Effects of a hydroethanolic extract of Boophone disticha bulb on anxiety-related behaviour in naive BALB/c mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Boophone disticha is one of the most important medicinal bulbs of Southern Africa. Previous in vitro studies have shown that it's crude ethanolic extracts and some alkaloidal phytoconstituents possesses high affinity for the serotonin transporter protein (SERT) and serotonin receptor 1a (5HT1a) which are both implicated in the pathogenesis and treatment of anxiety disorders. However, there are no in vivo studies that validates the anxiolytic actions of the plant. AIM OF THE STUDY: This study was therefore set to determine the anxiolytic-like activity of an orally administered hydroethanolic extract of B. disticha bulbs in naive mice using the behavioural tests of anxiety. MATERIALS AND METHODS: Naïve adult male BALB/c mice were randomly placed into five treatment groups (n=6-10): vehicle control (10ml/kg 0.9% NaCl), positive control (1mg/kg diazepam) and the hydroethanolic extract of B. disticha (10, 25 and 40mg/kg p.o.). Souk test, elevared plus maze and open field tests were used to evaluate the anxiolytic-like activity of the B. disticha extract. RESULTS: Diazepam-treated mice exhibited higher number of sector visits and line crossings in the ST, rearings in the OF and head dips in the EPM than the control (p<0.05). B. disticha extract treated groups expressed higher sector visits at 10mg/kg, and, unprotected head dips at 25mg/kg in the ST, as well as, open arm time entries at 10mg/kg dose, and unprotected head dips at all doses in the EPM than the control group (p<0.05). The 25mg/kg B. disticha dose group exhibited highest anxiolytic-like activity in both the ST and OF, while the 10mg/kg was most active in the EPM. CONCLUSION: The extract of B. disticha exerted good anxiolytic-like activity in both the ST and OF at medium dose (25mg/kg), while the low dose (10mg/kg) showed prominent anxiolytic-like activity in the EPM.

Antiamnesic Effects of a Hydroethanolic Extract of Crinum macowanii on Scopolamine-Induced Memory Impairment in Mice.

Crinum macowanii has been found to contain alkaloids that have activity against acetylcholinesterase enzyme in vitro. The present study was undertaken to investigate the in vivo ability of hydroethanolic crude extract of Crinum macowanii to ameliorate memory impairment induced by scopolamine. Thirty-six male Balb/c mice weighing around 25-35 g were employed in the present investigation. Y-maze and novel object recognition apparatus served as the exteroceptive behavioural models, and scopolamine-induced amnesia served as the interoceptive behavioural model. C. macowanii (10, 20, and 40 mg/kg p.o.) was administered in single doses to the mice. Donepezil (3 mg/kg p.o.) was used as a positive control agent. C. macowanii extract reversed the amnesia induced by scopolamine as indicated by a dose-dependent increase in spontaneous alternation performance in the Y-maze task. C. macowanii 40 mg/kg showed significant activity (p < 0.05 versus negative control), comparable to that of the positive control. C. macowanii also showed memory-enhancing activity against scopolamine-induced memory deficits in the long-term memory novel object recognition performance as indicated by a dose-dependent increase in the discrimination index. The results indicate that the hydroethanolic extract of C. macowanii may be a useful memory restorative mediator in the treatment of cognitive disorders such as Alzheimer's disease.

Application of osmometry in quality analysis of milk.

The aim of this study was to evaluate osmometry as a tool in quality analysis of milk. The osmolality of raw milk, sterilized milk, skimmed UHT (ultra-high temperature-treated) milk, pasteurized milk, standardized UHT milk and fermented milk (Lactococcus lactis culture) was determined by freezing point osmometry. The relationship between osmolality and pH of fermented milk was further investigated during spontaneous fermentation of UHT milk at 37 °C for 48 h. Average osmolality values (mean ± SD) were raw milk-290.2 ± 7.98, sterilized milk-290.2 ± 5.84, skimmed UHT milk-290.8 ± 3.31, pasteurized milk-283.6 ± 2.28, standardized UHT milk-281 ± 4.59 and fermented milk-466.0 ± 17.30 mOsmoles kg(-1). For fresh milk samples, 88 % showed normal osmolality, 8 % were hypo-osmotic and 4 % hyper-osmotic. Fermentation studies revealed a high negative correlation between osmolality and pH, with a correlation coefficient of -97.49 %. Hypo-osmotic milk shows mixing of milk with water along the production chain. Hyper-osmotic milk indicates fermentation of milk at high ambient temperatures or with prolonged storage. It may also reveal adulteration of fresh milk with a soluble substance. Osmolality was highest for fermented milk owing to production of lactic acid during fermentation. This was confirmed by the high negative correlation between osmolality and pH of milk in fermentation studies. Hence the osmolality of fermented milks may be used as an index of the extent of fermentation.

Cardiovascular effects of Boophone disticha aqueous ethanolic extract on early maternally separated BALB/C mice.

ETHNOPHARMACOLOGICAL RELEVANCE: There are a number of reports from traditional medical practice in Zimbabwe and neighboring countries and few in vitro studies suggesting an effect with extracts of Boophone disticha in some forms of anxiety disorder. AIM OF THE STUDY: In order to validate the use of Boophone disticha in treatment of anxiety, this study was set to determine the effects of the plant extracts on blood pressure (BP) and heart rate (HR) in adult BALB/c mice subjected to repeated early maternal separation (MS) stress. MATERIALS AND METHODS: To test whether early life stress increases anxiety in mice, non-invasive tail cuff method was used to examine the autonomic nervous system activity by assessing cardiovascular reactivity and response to acute mixing stress (AMS) and restraint stress (RS) in adult mice subjected to early postnatal stress as compared to control. AMS-induced cardiovascular response was then evaluated in adult MS mice treated with Boophone disticha as compared to vehicle and diazepam. RESULTS: Comparisons of the BP and HR measurements indicated that MS significantly reduced AMS-induced HR responses in BALB/c mice when compared with control. Boophone disticha treatment significantly reduced AMS-induced BP response in BALB/c MS mice as compared to vehicle and diazepam treatments. CONCLUSIONS: Our findings demonstrate for the first time that postnatal stress can induce short-term changes in the sensitivity of the cardiovascular system to subsequent stress which can be reduced by treatment with a freeze dried aqueous ethanolic extract of Boophone disticha.