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Antimicrobial activity and cytotoxicity of selected medicinal plants found in Nandi County, Kenya
(A KeSoBAP Publication, 2015-08) Nicholas Kimutai a, Elizabeth W. Njenga, Pascaline Jeruto, Janet Kosgey, Jonah N. Kipkorir, Charles Mutai, Lillian Ng’eny, and Richard Korir
Background: Medicinal plants are widely used by the local people to treat various human diseases cause by drug resistant microorganisms. For instance, Kigelia Africana fruits and barks are boiled in water and taken orally as a laxative in treating stomach ailments, Ekebergia capensis bark is boiled in water and use for the control of gonorrhea and tuberculosis while Fagaropsis angolensis stem bark is used to treat pneumonia, back ache and joins. The efficacy and safety of most of these plants has not been determined. Objective: The present study seeks to determine antimicrobial activities and cytotoxicity of the selected medicinal plants indicated above, that are commonly used to treat infectious diseases. Materials and Methods: Fresh plants were collected from the field; air dried ground and extracted using acetone and water. The extracts were screened for antibacterial and antifungal activities using Staphylococcus aureus, Methicillin resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Shigella dysentriae, Candida albicans, Cryptococcus neoformans, Microsporum gypseum and Trychophyton mentagrophytes. The methods were disc diffusion and broth dilution methods while in vitro cytotoxicity test was carried out following a modified rapid calorimetric assay, using actively dividing sub-confluent Vero E6 cells. Results: In disc diffusion assay, water extracts of E. capensis were the most active (14.7 mm) while those of Fagaropsis angolensis were the least (6.0 mm) against S. aureus. Acetone extracts of E. capensis and K. Africana had a Minimum Inhibitory Concentration of 3.125 mg/ml and 6.25 mg/ml respectively and were bactericidal. Cytotoxicity showed that K. africana was not cytotoxic against Vero cell lines while acetone extracts of E. capensis was moderately toxic with a CC 50(µg/ml) of 12.5. Conclusion: These results support the use of the plants in the traditional medicine as antimicrobials and they can be exploited for novel drugs. Key words: Antimicrobial activity, cytotoxicity, Kigelia africana, Ekebergia capensis, Fagaropsis angolensis,
IN-VITRO CYTOTOXICITY OF THREE SELECTED MEDICINAL PLANT EXTRACTS FROM KENYA.
(WORLD JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES, 2017-05-17) Kimutai Nicholas
In Kenya, medicinal plants have been used by the local people as traditional medicine to treat different human ailments from time immemorial. However, safety of most of these plants has not been determined hence the present study seeks to determine the in vitro cytotoxicity of the three medicinal plants namely; Ehretia cymosa Thonn, Dovyalis abyssinica (A. Rich.) Warb. and Periplocca linearifolia Dill & A. Rich that are commonly used to treat various diseases. The ethnobotanical survey was carried out using a structured questionnaire. Fresh plants were collected from the field and air dried under shade at 25oC and later ground into powder and extracted using acetone and water. In vitro cytotoxicity test was carried out following a modified rapid calorimetric assay using actively dividing sub-confluent Vero E6 cells. Cell toxicity showed that most of the plant extracts tested were not cytotoxic having a CC50(µg/ml) of ≥100 against Vero cell lines except the acetone extracts of P. linearifolia that were moderately toxic with a CC50(µg/ml) of 12.5, suggesting former extracts may be safe as antimicrobials.
Association of Phlebotomus guggisbergi with Leishmania major and Leishmania tropica in a complex transmission setting for cutaneous leishmaniasis in Gilgil, Nakuru county, Kenya
(PLOSNeglectedTropical Diseases, 2019-10-18) Barrack O.Owino Milkah Mwangi, DamarisMatoke-Muhia, Yasser Alraey, Jackline , Johnstone M.Ingonga Alvaro Acosta-Serrano, Philip M. Ngumbi , Daniel K. Masiga
Background Phlebotomus (Larroussius) guggisbergi is among the confirmed vectors for cutaneous leish maniasis (CL) transmission in Kenya. This scarring and stigmatizing form of leishmaniasis accounts for over one million annual cases worldwide. Most recent CL epidemics in Kenya have beenreported in Gilgil, Nakuru County, where the disease has become a public health issue. However, little is known about the factors that drive its transmission. Here, we sought to determine the occurrence, distribution and host blood feeding preference of the vectors, andto identify Leishmania species and infection rates in sandflies using molecular tech niques. This information could lead to a better understanding of the disease transmission andimprovement of control strategies in the area. Methodology/ Principal findings Anentomological survey of sandflies using CDC light traps was conducted for one week per month in April 2016, and in June and July 2017 from five villages of Gilgil, Nakuru county; Jaica, Sogonoi, Utut, Gitare and Njeru. Sandflies were identified to species level using mor phological keys and further verified by PCR analysis of cytochrome c oxidase subunit I (COI) gene. Midguts of female sandflies found to harbour Leishmania were ruptured and the isolated parasites cultured in Novy-MacNeal-Nicolle (NNN) media overlaid with Schneider’s insect media to identify the species. Leishmania parasite screening and identification in 198 randomly selected Phlebotomus females and parasite cultures was done by PCR-RFLP analysis of ITS1 gene, nested kDNA-PCR and real-time PCR-HRM followed by sequencing. Bloodmeal source identification was done by real-time PCR-HRM of the vertebrate cyto chrome-b gene. Atotal of 729 sandflies (males: n = 310; females: n = 419) were collected from Utut (36.6%), Jaica (24.3%), Sogonoi (34.4%), Njeru (4.5%), and Gitare (0.1%). These were found to consist of nine species: three Phlebotomus spp. and six Sergentomyia spp. Ph. guggisbergi was the most abundant species (75.4%, n = 550) followed by Ph. saevus sensu lato (11.3%, n = 82). Sandfly species distribution across the villages was found to be significantly different (p<0.001) with Jaica recording the highest diversity. The overall Leish mania infection rate in sandflies was estimated at 7.07% (14/198). Infection rates in Ph. gug gisbergi and Ph. saevus s.l. were 9.09% (12/132) and 3.57% (2/56) respectively. L. tropica wasfound tobethepredominant parasite in Gilgil with an overall infection rate of 6.91% (13/ 188) in Ph. guggisbergi (n = 11) and Ph. saevus s.l. (n = 2) sandflies. However, PCR analy sis also revealed L. major infection in one Ph. guggisbergi specimen. Bloodmeal analysis in the 74 blood-fed sandflies disclosed a diverse range of vertebrate hosts in Ph. guggisbergi bloodmeals, while Ph. saevus s.l. fed mainly on humans. Conclusions/ Significance Thehigh infection rates of L. tropica and abundance of Ph. guggisbergi in this study con firms this sandfly as a vector of L. tropica in Kenya. Furthermore, isolation of live L. tropica parasites from Ph. saevus s.l. suggest that there are at least three potential vectors of this parasite species in Gilgil; Ph. guggisbergi, Ph. aculeatus and Ph. saevus s.l. Molecular iden tification of L. major infections in Ph. guggisbergi suggested this sandfly species as a poten tial permissive vector of L. major, which needs to be investigated further. Sandfly host preference analysis revealed the possibility of zoonotic transmissions of L. tropica in Gilgil since the main vector (Ph. guggisbergi) does not feed exclusively on humans but also other vertebrate species. Further investigations are needed to determine the potential role of these vertebrate species in L. tropica and L. major transmission in the area.
ANTIBACTERIAL ACTIVITIES OF SELECTED MEDICINAL PLANTS FROM NANDI COUNTY, KENYA
(© Global Science Publications, 2020-08-13) NICHOLAS KIMUTAI K., PHILIP A. OGUTU AND CHARLES MUTAI
Medicinal plants are used by the local people to treat different human diseases since time immemorial. The efficacy of most of these plants has not been determined. The present study was therefore conducted at Nandi County to determine antimicrobial activities of seventeen selected medicinal plants that are commonly used to treat infectious diseases caused by bacteria. The plants were collected from the field and dried in a room at 25 oC. The samples were ground into powder and the components extracted using methanol. Plant extracts were tested against ten standard and clinical isolates of human pathogenic bacteria, using disc diffusion and broth dilution methods. The solvents used for extraction were used as negative control while Gentamycin was used as positive controls. In vitro antimicrobial assays indicated that four plant extracts exhibited antimicrobial activity in which the highest activity was observed from root bark extracts of Albicia coriaria, Acacia lahai, Olinia rochetiana, Leucas calostachys and stem bark of Sygium cordatum against S. aureus among others. This study demonstrated support for the claimed antimicrobial uses of the plants in the traditional medicine probably due to the phytochemicals present. Isolation and purification of bioactive chemical constituents from the active crude plant extracts can be obtained to supplement conventional drugs
Molecular detection of Leishmania donovani, Leishmania major, and Trypanosoma species in Sergentomyia squamipleuris sand flies from a visceral leishmaniasis focus in Merti sub-County, eastern Kenya
(BMC Parasites & Vectors, 2021) Barrack O. Owino, Jackline Milkah Mwangi, Steve Kiplagat, Hannah Njiriku Mwangi, Johnstone M. Ingonga, Alphine Chebet, Philip M. Ngumbi, Jandouwe Villinger, Daniel K. Masiga and Damaris Matoke‑Muhia
Background: Visceral leishmaniasis (VL) and zoonotic cutaneous leishmaniasis (ZCL) are of public health concern in Merti sub‑County, Kenya, but epidemiological data on transmission, vector abundance, distribution, and reservoir hosts remain limited. To better understand the disease and inform control measures to reduce transmission, we inves tigated the abundance and distribution of sand fly species responsible for Leishmania transmission in the sub‑County and their blood‑meal hosts. Methods: We conducted an entomological survey in five villages with reported cases of VL in Merti sub‑County, Kenya, using CDC miniature light traps and castor oil sticky papers. Sand flies were dissected and identified to the species level using standard taxonomic keys and PCR analysis of the cytochrome c oxidase subunit 1 (cox1) gene. Leishmania parasites were detected and identified by PCR and sequencing of internal transcribed spacer 1 (ITS1) genes. Blood‑meal sources of engorged females were identified by high‑resolution melting analysis of vertebrate cytochrome b (cyt‑b) gene PCR products. Results: We sampled 526 sand flies consisting of 8 species, Phlebotomus orientalis (1.52%; n = 8), and 7 Sergentomyia spp. Sergentomyia squamipleuris was the most abundant sand fly species (78.71%; n = 414) followed by Sergentomyia clydei (10.46%; n = 55). Leishmania major, Leishmania donovani, and Trypanosoma DNA were detected in S. squami pleuris specimens. Humans were the main sources of sand fly blood meals. However, we also detected mixed blood meals; one S. squamipleuris specimen had fed on both human and mouse (Mus musculus) blood, while two Ph. orien talis specimens fed on human, hyrax (Procavia capensis), and mouse (Mus musculus) blood. Conclusions: Our findings implicate the potential involvement of S. squamipleuris in the transmission of Leishma nia and question the dogma that human leishmaniases in the Old World are exclusively transmitted by sand flies of the Phlebotomus genus. The presence of Trypanosoma spp. may indicate mechanical transmission, whose efficiency should be investigated. Host preference analysis revealed the possibility of zoonotic transmission of leishmaniasis and other pathogens in the sub‑County. Leishmania major and L. donovani are known to cause ZCL and VL, respectively. However, the reservoir status of the parasites is not uniform. Further studies are needed to determine the reservoir hosts of Leishmania spp. in the area. Keywords: Leishmania, Leishmaniasis, Sand fly, Trypanosoma, Sergentomyia, Phlebotomus, Zoonotic cutaneous leishmaniasis, Visceral leishmaniasis, Kenya
Antibacterial Activities Investigation of Leucas calostachys Root Extracts
(CrossMark, 2021) Nicholas K. Kimutai, Philip A. Ogutu and Charles Mutai
Background and Objective: Traditional healers have long used plants to treat bacterial infections caused by resistant bacteria. Hence, there is an increased interest in the ethnopharmacological approach to identify new novel compounds from plants to treat these infections. The objective of this study, therefore, was to test successive extracts and their fractions. Materials and Methods: The roots of Leucas calostachys were obtained, dried and ground. The total methanol extract was obtained and screen for antibacterial activities. Successive extracts were extracted using four different solvents hexane, dichloromethane, ethyl acetate and methanol. The bioactive solvent extracts were fractionated. Successive extracts and fractions were then screened for antibacterial activities against ten pathogenic bacteria in vitro using the disk diffusion method. Results: The results indicated the solvent extracts and fractions were active against both gram-negative and gram-positive bacteria with the lowest MIC value of 3.15 mg mLG1 obtained from total methanol extract against methicillin-resistant Staphylococcus aureus. Conclusion: This demonstrated that hexane extracts and fractions could be helpful in the management of resistant bacterial infections. This work is the first attempt to fractionate and test fractions of L. calostachys, which can be used for the development of phytomedicine
Bioprospecting for Phytochemical Repellents and bio-pesticides of the Jigger Flea Tunga penetrans from the Western Kenya Flora.
(WIPO International Publication, 2022-03-03) Maurice V. Omolo, Paul K. Tarus, Joseph Owino, Regina Bwire, Vitman M. Wafula, Judith V. Adhiambo, Regina J. Cheptum, Vincent C. Terer, Anderson Misati, James Nonoh, John Muoma, Dennis Ochieno and Consolata Ngala
Discloses a composition comprising for treating jigger infestation, comprising Nicotine and related compounds present in Nicotiana tobaccum as bio-pesticides and antitungiasis of the jigger flea, Tunga penetrans. A single application of 10% formulation of Nicotine, nornicotine, Anabasine, Anatabine, Continine and myosmine in the ratio of 85: 2: 4: 7: 1: 1 respectively in petroleum jelly base of 90% and lemon Eucalyptus oil of 1 g on a jigger (6) infested victim's feet (6) gives 100% pesticide activity within 5-7 days as demonstrated by recovered foot (2B) and jigger scars (8). The said bio-chemicals, alone or in combination with one another and/ or other natural or synthetic pesticides exhibit activity against the jigger flea among other blood feeding insect & arachnid pests of humans and animals. Also discloses a method of formulating the bio-pesticide composition consisting of Nicotine and other biomolecules extracts from Nicotiana tobaccum.
Natural Infection of Sandfly Vector and Reservoir Hosts Species with Leishmania Parasites in Mt. Elgon Cave Habitats in Kenya
(International Journal of TROPICAL DISEASE & Health, 2023-02-15) Kennedy Ombula Ombaka, Moses M. Ngeiywa and Judith Makwali
Leishmaniasis is a major public health problem caused by a parasite of the genus Leishmania which is transmitted through the bite of an infected female phlebotomine sandfly. However, the disease epidemiology on interactions of causative agents, reservoir hosts, and vectors in areas where there is a high prevalence of the disease needs to be properly understood to inform effective control. The present study was conducted to determine natural infection by Leishmania parasites in phlebotomine sandfly vectors and suspected reservoir hosts found in caves in Mount Elgon in Kenya. Sandflies, bats and rock hyraxes were found inhabiting the assessed caves in the study area. A total of 5688 sandflies collected from caves were morphologically identified and analyzed for infectivity with Leishmania parasites by molecular characterization sequencing using Cytochrome c oxidase subunit 1 (COI). Giemsa-stained blood smears and spleen and liver impression smears prepared from bats, and hyraxes collected from the same caves were examined microscopically for Leishmania amastigotes. The sandflies, bats, and hyraxes were identified morphologically using taxonomic keys. The results showed that randomly selected COI sequences (n = 5) of three different morphologically identified Phlebotomus species were positive for Leishmania based on their molecular characteristics. Five species of bats were identified, and they were significantly more abundant compared to hyraxes (χ2 = 16.7845, df = 7, P = 0.0002). The bats’ species had a higher prevalence of Leishmania parasites compared to hyraxes (F = 7.342, P = 0.0043). Cardioderma cor, Chaerephon pumilus and Rhinolophus clivosus bat species had more than 5% Leishmania parasite prevalence rate. Leishmania amastigote density was significantly higher in the liver (F = 39.232, P < 0.001) compared to the density in the blood (F = 75.1124, P < 0.001) of bats and hyraxes. This study has shown that transmission of Leishmania parasites in Mt. Elgon caves involves vertebrate reservoir hosts (bats and hyraxes) and the insect vector species (sandfly). Therefore, disruption of the life cycle of the Leishmania parasites should be done by targeting these reservoir animals and the sandfly vector.
Strengthening primary care systems for prevention & control of cardiovascular diseases in Kenya: feasibility study of health kiosks in markets “HEKIMA Study”
(BMJ GROUP, 2024-09-30) Lydia Kaduka, Jaymima Mbuka, Joanna Olale, Joseph Mutai, Elia Christelle, Rodgers Ochieng, Boniface Oyugi, Chrispine Oduor, Majella O’Keeffe, Harriet Boulding, Jamie Murdoch, Divya Parmar, Gilbert Kokwaro, Elijah Ogola, Seeromanie Harding
Objectives The increasing burden of cardiovascular diseases (CVDs) in Kenya threatens its healthcare system. There is a need for innovative models that improve equitable access to CVD prevention services. Community markets are social establishments with untapped potential to promote public health. This is a multiphased feasibility study that explores the potential of Health Kiosks in Markets (HEKIMA) to improve access to CVD prevention services. In this formative phase, the aim was to assess the readiness of primary healthcare centres (HCs) and community markets to jointly deliver CVD prevention services. Design Mixed methods using concept mapping and readiness surveys. Concept mapping with 35 stakeholders from different sectors (health and non-health) to identify feasible priorities for HEKIMA. The readiness questionnaire contained 193 items which were based on the guidance of the WHO Handbook for Monitoring the Building Blocks of Health Systems and adapted to suit the context of a single HC. Setting Vihiga County is located in western Kenya and has a population of 590 013. A total of 18 HCs and 19 markets were assessed, with 10 HCs and 15 markets included in the evaluation. Results 91 statements were generated from concept mapping and distilled into 8 clusters, namely equipment and supplies, access and referral, communication, manpower, networks and linkages, practice, service delivery and health promotion. Agreed actions for HEKIMA were provision of efficient quality services, health promotion and partnerships sensitive to the local context. HCs and markets had established governance systems and basic infrastructure. The majority of the HCs lacked essential CVD medications. No HC–market interface existed but there was willingness for a partnership. Conclusion There was strong consensus that an HC–market interface via community health worker manned kiosks could have a positive impact on health systems, markets and CVD prevention in vulnerable communities. However, significant infrastructural, technical and resource gaps were observed that need to be addressed.
Resurgence of Visceral and Cutaneous Leishmaniasis in Kajiado County, Kenya: A Coordinated Response and Entomological Survey.
(The Lancet Global Health, 2025) Matoke-Muhia, Damaris and Owino, Barrack and Kiplagat, Stephen and Mwangi, Hannah N. and Ingonga, Johnstone M. and Njenga, Daniel and Septer, Benny and Kitondo, Mwatela and Mwiti, Daniel and Magiri, Charles and Nyakundi, Hellen and Onditi, Juliet Akoth and Weihl, Sarah and Wenger, Catherine and Wamai, Richard and Satoskar, Abhay R. and Villinger, Jandouwe and Kamhawi, Shaden and Ndungu, Joseph and Masiga, Daniel,
Background: Leishmaniasis is of major global health concern with global elimination targets set for 2030. East Africa accounts for ~75% of global visceral leishmaniasis (VL) cases. Hence, attention to endemic, recurrent or emerging foci is critical to meeting global elimination targets. In 2021, Kajiado County, on the southern border of Kenya with Tanzania, emerged with cases of local transmission that necessitated this investigation. Methods: This was a mixed methods coordinated response. We conducted a training for clinicians, sensitised communities, and set up medical camps in four villages. Here we screened the community for VL and other common ailments and undertook an entomological survey for sandfly vector species in the same villages. We screened 100 individuals (males: 56; females: 44) for leishmaniasis using the rK39 rapid antibody test and by microscopic examination. Dry blood spots (DBS) were collected from suspected cases. The samples were further analyzed using PCR targeting the internal transcribed spacer 1 (ITS1) region, followed 1 Preprint not peer reviewed This preprint research paper has not been peer reviewed. Electronic copy available at: https://ssrn.com/abstract=5242611 by sequencing for Leishmania species identification. For entomological surveys, sandfly sampling was done in the four villages where medical camps were implemented, and another four adjacent villages using CDC miniature or Silverbullet 2.0 light traps. Sandflies were identified morphologically using taxonomic keys and the speciation confirmed by PCR analysis of the cytochrome c oxidase subunit 1 (Cox1) gene and sequencing. We characterized sandfly blood feeding preference by PCR analysis of the vertebrate cytochrome-b (Cyt-b) gene, followed by HRM analysis and sequencing. Results: Ten people (10/100; 10%) tested positive for VL (eight below 15 years old - six males and two females). Of the 22 suspected cases with lesions suspected of cutaneous leishmaniasis (CL), eight were confirmed as being infected with Leishmania tropica. We trapped 4,781 sandflies and identified 1,624 specimens, consisting of 422 males and 1202 females, to species. They represented four Phlebotomus spp. and eight Sergentomyia spp. The Phlebotomus spp. included Ph. martini (8.4%; n = 136), Ph. saevus (2.2%; n = 35), Ph. orientalis (1.2%; n = 19), and Ph. guggisbergi (0.1%; n = 1). Overall, Sergentomyia species (62.7%, 1019 specimens) were abundant. Of the 450 sandflies examined for presence of Leishmania parasites by PCR, we detected DNA of Leishmania donovani in Sergentomyia clydei (n = 13), Sergentomyia adleri (n = 4), S. antennatus (n = 2), and Ph. saevus (n = 1), while L. tropica DNA was detected in Ph. saevus (n = 1). Analysis of the blood meal sources of the 68 engorged sand flies showed that most fed on humans followed by goats. We also detected blood from donkeys, mongoose and rock hyraxes. Conclusion: We confirmed L. donovani and L. tropica as the main Leishmania species responsible for VL and CL, respectively, in Kajiado. The presence of the parasites in humans and the high human blood indices in sandflies indicate active transmission and high vector human contact in the area. The co-occurrence of VL and CL is unusual and complicates case management as the two forms are managed differently, and raises the possibilities of genetic recombination in Leishmania parasites. Since access to diagnostic and treatment facilities are at the core of infectious diseases management, and elimination efforts, the establishment of two treatment Centres in Kajiado, for the first time, constitutes an important step in enhancing community access to treatment and stemming the spread of leishmaniasis in the region. This study thus contributes to global and national VL elimination targets, and demonstrates the value of coordinated outbreak preparedness.

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