Community interventions in Low-And Middle-Income Countries to inform COVID-19 control implementation decisions in Kenya: A rapid systematic review.

Globally, public health measures like face masks, hand hygiene and maintaining social distancing have been implemented to delay and reduce local transmission of COVID-19. To date there is emerging evidence to provide effectiveness and compliance to intervention measures on COVID-19 due to rapid spread of the disease. We synthesized evidence of community interventions and innovative practices to mitigate COVID-19 as well as previous respiratory outbreak infections which may share some aspects of transmission dynamics with COVID-19. In the study, we systematically searched the literature on community interventions to mitigate COVID-19, SARS (severe acute respiratory syndrome), H1N1 Influenza and MERS (middle east respiratory syndrome) epidemics in PubMed, Google Scholar, World Health Organization (WHO), MEDRXIV and Google from their inception until May 30, 2020 for up-to-date published and grey resources. We screened records, extracted data, and assessed risk of bias in duplicates. We rated the certainty of evidence according to Cochrane methods and the GRADE approach. This study is registered with PROSPERO (CRD42020183064). Of 41,138 papers found, 17 studies met the inclusion criteria in various settings in Low- and Middle-Income Countries (LMICs). One of the papers from LMICs originated from Africa (Madagascar) with the rest from Asia 9 (China 5, Bangladesh 2, Thailand 2); South America 5 (Mexico 3, Peru 2) and Europe 2 (Serbia and Romania). Following five studies on the use of face masks, the risk of contracting SARS and Influenza was reduced OR 0.78 and 95% CI = 0.36-1.67. Equally, six studies on hand hygiene practices reported a reduced risk of contracting SARS and Influenza OR 0.95 and 95% CI = 0.83-1.08. Further two studies that looked at combined use of face masks and hand hygiene interventions showed the effectiveness in controlling the transmission of influenza OR 0.94 and 95% CI = 0.58-1.54. Nine studies on social distancing intervention demonstrated the importance of physical distance through closure of learning institutions on the transmission dynamics of disease. The evidence confirms the use of face masks, good hand hygiene and social distancing as community interventions are effective to control the spread of SARS and influenza in LMICs. However, the effectiveness of community interventions in LMICs should be informed by adherence of the mitigation measures and contextual factors taking into account the best practices. The study has shown gaps in adherence/compliance of the interventions, hence a need for robust intervention studies to better inform the evidence on compliance of the interventions. Nevertheless, this rapid review of currently best available evidence might inform interim guidance on similar respiratory infectious diseases like Covid-19 in Kenya and similar LMIC context.

Risk of Fungi Associated with Aflatoxin and Fumonisin in Medicinal Herbal Products in the Kenyan Market.

Utilization of herbal products is a major concern due to the possibility of contamination by toxigenic fungi that are mycotoxin producers such as Aspergillus species during processing and packaging. Research was carried out to determine the presence of aflatoxins and fumonisins in herbal medicinal products sold in Eldoret and Mombasa towns in Kenya. The study employed both exploratory and laboratory experimental design. The herbal products were purchased from the market and transported to Kenya Medical Research Institute for processing and analysis. Fungal contaminants were determined according to Pharmacopoeia specifications. The toxins were quantified using ELISA based technique. The genus Aspergillus was the most dominant followed by Penicillium. Fungal counts ranged between 1 CFU/g and >1000 cfu/g. Analysis of variance showed that the rate of fungal contaminants for Eldoret and Mombasa samples had significant association (p ≤ 0.001). Aflatoxin levels ranged from 1 to 24 ppb, while fumonisin levels ranged from 1 to >20 ppb. Only 31% of samples met the standards for microbial limits as specified in Pharmacopoeia. There is need for product microbial quality improvement through proper harvesting, processing, storage, and marketing. It is recommended that a policy be enacted to enable regulation of herbal products in Kenya.

Antimalarial actions of Lawsonia inermis, Tithonia diversifolia and Chromolaena odorata in combination.

ETHNOPHARMACOLOGICAL RELEVANCE: Chromolaena odorata, Tithonia diversifolia and Lawsonia inermis are medicinal plants used in treating malaria in traditional medicine system. Previous studies however showed that their dichloromethane, methanol (1:1) extracts were more active against Plasmodium parasite than the aqueous extracts. AIM OF THE STUDY: To determine the in vitro and in vivo antiplasmodial activity of dichloromethane, methanol (1:1) extracts of Chromolaena odorata, Tithonia diversifolia and Lawsonia inermis in combination and evaluate their safety using acute limit toxicity test. MATERIALS AND METHODS: Dichloromethane, methanol (1:1) extracts of Chromolaena odorata, Tithonia diversifolia and Lawsonia inermis leaves were combined at ratios 1:1, 1:3, 3:1, 1:5 and 5:1 using in vitro semi-automated microdilution technique against P. falciparum Chloroquine sensitive (D6) and Chloroquine resistant (W2) strains, with chloroquine and artemisinin as controls. The in vivo antiplasmodial activity of the crude extracts was carried out singly, and in combination at the different combination ratios on Plasmodium berghei Anka infected Swiss albino mice using Peters' 4-day suppressive test. Acute toxicity test was done in mice at 5000mg/kg. RESULTS: The in vitro combination of L. inermis and T. diversifolia (1:1) extracts against P. falciparum showed the highest synergy with IC50 of 0.43±0.02µg/mL and 2.55±0.19µg/mL against D6 and W2 respectively; while the combination of C. odorata with T. diversifolia and L. inermis were antagonistic. A synergy with chemosuppression of 83.6% against P. berghei infected mice was observed in L. inermis and T. diversifolia (1:1) treated animals. In contrast to the in vitro result, combination of C. odorata with T. diversifolia and L. inermis showed some degrees of synergy in vivo. Extracts were not toxic at the concentration tested. CONCLUSION: These findings rationalized the use of these plants in combination as antimalarials in traditional medicine. However, the combination of Chromolaena odorata with other medicinal plants should be used with caution because of its possible antagonistic effect.

Antiplasmodial and cytotoxic activities of the constituents of Turraea robusta and Turraea nilotica.

ETHNOPHARMACOLOGICAL RELEVANCE: Turraea robusta and Turraea nilotica are African medicinal plants used for the treatment of a wide variety of diseases, including malaria. The genus Turraea is rich in limonoids and other triterpenoids known to possess various biological activities. MATERIALS AND METHODS: From the stem bark of T. robusta six compounds, and from various parts of T. nilotica eleven compounds were isolated by the use of a combination of chromatographic techniques. The structures of the isolated compounds were elucidated using NMR and MS, whilst the relative configuration of one of the isolated compounds, toonapubesin F, was established by X-ray crystallography. The antiplasmodial activities of the crude extracts and the isolated constituents against the D6 and W2 strains of Plasmodium falciparum were determined using the semiautomated micro dilution technique that measures the ability of the extracts to inhibit the incorporation of (G-(3)H, where G is guanine) hypoxanthine into the malaria parasite. The cytotoxicity of the crude extracts and their isolated constituents was evaluated against the mammalian cell lines African monkey kidney (vero), mouse breast cancer (4T1) and human larynx carcinoma (HEp2). RESULTS: The extracts showed good to moderate antiplasmodial activities, where the extract of the stem bark of T. robusta was also cytotoxic against the 4T1 and the HEp2 cells (IC50<10 µg/ml). The compounds isolated from these extracts were characterized as limonoids, protolimonoids and phytosterol glucosides. These compounds showed good to moderate activities with the most active one being azadironolide, IC50 2.4 ± 0.03 µM and 1.1 ± 0.01 µM against the D6 and W2 strains of Plasmodium falciparum, respectively; all other compounds possessed IC50 14.4-40.5 µM. None of the compounds showed significant cytotoxicity against vero cells, yet four of them were toxic against the 4T1 and HEp2 cancer cell lines with piscidinol A having IC50 8.0 ± 0.03 and 8.4 ± 0.01 µM against the 4T1 and HEp2 cells, respectively. Diacetylation of piscidinol A resulted in reduced cytotoxicity. CONCLUSION: From the medicinal plants T. robusta and T. nilotica, twelve compounds were isolated and characterized; two of the isolated compounds, namely 11-epi-toonacilin and azadironolide showed good antiplasmodial activity with the highest selectivity indices.

Piperaquine and Lumefantrine resistance in Plasmodium berghei ANKA associated with increased expression of Ca2+/H+ antiporter and glutathione associated enzymes.

We investigated the mechanisms of resistance of two antimalarial drugs piperaquine (PQ) and lumefantrine (LM) using the rodent parasite Plasmodium berghei as a surrogate of the human parasite, Plasmodium falciparum. We analyzed the whole coding sequence of Plasmodium berghei chloroquine resistance transporter (Pbcrt) and Plasmodium berghei multidrug resistance gene 1(Pbmdr-1) for polymorphisms. These genes are associated with quinoline resistance in Plasmodium falciparum. No polymorphic changes were detected in the coding sequences of Pbcrt and Pbmdr1 or in the mRNA transcript levels of Pbmdr1. However, our data demonstrated that PQ and LM resistance is achieved by multiple mechanisms that include elevated mRNA transcript levels of V-type H(+) pumping pyrophosphatase (vp2), Ca(2+)/H(+) antiporter (vcx1), gamma glutamylcysteine synthetase (ggcs) and glutathione-S-transferase (gst) genes, mechanisms also known to contribute to chloroquine resistance in P. falciparum and rodent malaria parasites. The increase in ggcs and gst transcript levels was accompanied by high glutathione (GSH) levels and elevated activity of glutathione-S-transferase (GST) enzyme. Taken together, these results demonstrate that Pbcrt and Pbmdr1 are not associated with PQ and LM resistance in P. berghei ANKA, while vp2, vcx1, ggcs and gst may mediate resistance directly or modulate functional mutations in other unknown genes.

Constituents of the roots and leaves of Ekebergia capensis and their potential antiplasmodial and cytotoxic activities.

A new triterpenoid, 3-oxo-12ß-hydroxy-oleanan-28,13ß-olide (1), and six known triterpenoids 2-7 were isolated from the root bark of Ekebergia capensis, an African medicinal plant. A limonoid 8 and two glycoflavonoids 9-10 were found in its leaves. The metabolites were identified by NMR and MS analyses, and their cytotoxicity was evaluated against the mammalian African monkey kidney (vero), mouse breast cancer (4T1), human larynx carcinoma (HEp2) and human breast cancer (MDA-MB-231) cell lines. Out of the isolates, oleanonic acid (2) showed the highest cytotoxicity, i.e., IC50's of 1.4 and 13.3 µM against the HEp2 and 4T1 cells, respectively. Motivated by the higher cytotoxicity of the crude bark extract as compared to the isolates, the interactions of oleanonic acid (2) with five triterpenoids 3-7 were evaluated on vero cells. In an antiplasmodial assay, seven of the metabolites were observed to possess moderate activity against the D6 and W2 strains of P. falciparum (IC50 27.1-97.1 µM), however with a low selectivity index (IC50(vero)/IC50(P. falciparum-D6)<10). The observed moderate antiplasmodial activity may be due to general cytotoxicity of the isolated triterpenoids.

Sequencing of bacitracin A and related minor components by liquid chromatography/electrospray ionization ion trap tandem mass spectrometry.

A selective reversed-phase liquid chromatography/mass spectrometry (LC/MS(n)) method is described for the characterization of related compounds in commercial bacitracin samples. Mass spectral data for these polypeptide antibiotics were acquired on a LCQ ion trap mass spectrometer equipped with an electrospray ionization probe operated in the positive and negative ion mode. The LCQ ion trap is ideally suited for the sequencing of those linear side-chain cyclized peptides because it provides on-line LC/MS(n) capability. Using this method bacitracin A, 1-epibacitracin A, bacitracins B(1), B(2), B(3) and bacitracin F were sequenced and previous sequencing was confirmed. Bacitracins C(1), C(2), C(3), D, H(2) and H(3) were resolved chromatographically and their ring portion was sequenced for the first time. Four components not described in the literature (1-epibacitracin B(1), 1-epibacitracin B(2), 1-epibacitracin C(1) and H(4)) were sequenced completely for the first time. The main advantage of this hyphenated LC/MS(n) technique is the characterization of the related substances without time-consuming isolation and purification procedures.

Liquid chromatography-ion trap tandem mass spectrometry for the characterization of polypeptide antibiotics of the colistin series in commercial samples.

A selective reversed-phase liquid chromatography-tandem mass spectrometry method is described for the characterization of related substances in the colistin complex. Mass spectral data were acquired on an LCQ ion trap mass spectrometer equipped with an electrospray ionization probe operated in the positive ion mode. The main advantage of this technique is the characterization of novel related substances without time-consuming isolation and purification procedures. Using this method seven new related substances were partially identified in colistin bulk sample and tablets. Four components were assigned as isomers of the main components of colistin.

Mass spectrometric fragmentation of cyclic peptides belonging to the polymyxin and colistin antibiotics studied by ion trap and quadrupole/orthogonal-acceleration time-of-flight technology.

Electrospray ionization linked to quadrupole/orthogonal-acceleration time-of-flight (Q/oaTOF) and ion trap equipment was used to study the fragmentation behavior of the linear side-chain cyclized peptides of the polymyxin B and E antibiotics. This study exemplifies both the benefits and the drawbacks of mass spectrometric techniques for the determination of the sequence of such complex linear side-chain cyclized peptides. Q/oaTOF accurate mass measurements did not help sufficiently to assign the product ions observed in the product ion spectra. An ion trap mass spectrometer providing MS(n) capability was used to eliminate ambiguities encountered with a single MS/MS approach. The complex fragmentation behavior of these compounds of well-established structure is described which could be useful for structural characterization of unknown substances related to polymyxin B and E in the future.

Characterization of polypeptide antibiotics of the polymyxin series by liquid chromatography electrospray ionization ion trap tandem mass spectrometry.

A selective reversed phase liquid chromatography/mass spectrometry (LC/MSn) method is described for the identification of related compounds in commercial polymyxin B samples. Mass spectral data for these polypeptide antibiotics were acquired on a LCQ ion trap mass spectrometer equipped with an electrospray ionization probe operated in the positive ion mode. The LCQ ion trap is ideally suited for the identification of the related substances because it provides on-line LC/MSn capability. The main advantage of this hyphenated LC/MSn technique is the characterization of novel related substances without time-consuming isolation and purifications procedures. Using this method six novel related substances were partially identified in a polymyxin B bulk sample.