Myrrh, a resin derived from the damaged bark of Commiphora genus, has traditionally been used for treatment of various human diseases, such as amenorrhea, ache, tumors, fever, and stomach pains. In spite of this widespread use of the myrrh in Ethiopia, the pharmacological activity and chemical composition have not been studied in detail. A new tricyclic triterpene acid (3S,4S,14S,7E,17E,21Z)-3,30-dihydroxypodioda-7,17,21-trien-4-carboxylic acid (commafric A) has been isolated from a crude methanolic extract of Commiphora africana (A. Rich.) Engl. resin along with the known pentacyclic triterpene α-amyrin. The structure of commafric A was characterized using different spectroscopic techniques such as 1D and 2D NMR, IR, and VCD combined with computations. The anti-proliferative activity of both isolated compounds was evaluated using SRB based colorimetric cellular assay against four human cancer cell lines. Etoposide was used as a positive control. Commafric A showed significant anti-proliferative effects against non-small cell lung cancer (A549) with IC₅₀ values of 4.52 μg/ml. The pentacyclic triterpene α-amyrin showed a weak anti-proliferative activity against A2780 (ovarian cancer), MIA-PaCa-2 (pancreatic cancer), and SNU638 (stomach cancer) cell lines tested with IC₅₀ values ranging 9.28 to 28.22 μg/ml. Commafric A possessed anti-proliferative activity against non-small cell lung cancer (A549), which suggests that commafric A has potential to be further optimized being a lead compound in the search for new drugs against cancer diseases.

Hydnora johannisis a medicinal plant traditionally used to treat various ailments. Chemical investigation of the dichloromethane (DCM)/methanol (MeOH) (1:1) roots extract ofHydnora johannisafforded three compounds (1–3), reported herein for the first time from the species. The structures of the isolated compounds1–3were elucidated using 1D and 2D NMR spectroscopic analysis and comparison with literature data. The highest zone of inhibition value was measured for DCM/MeOH extract (10.75 ± 0.25 mm) againstStaphylococcus aureusat concentration of 0.25 mg/mL, promising in comparison to the standard amoxicillin (16.0 ± 0.0 mm, 0.25 mg/mL). At concentration of 0.25 mg/mL, the largest mean inhibition zone of 12.0 ± 0.0 mm was measured for compound2againstPseudomonas aeruginosa, comparable to the standard drug amoxicillin (16.0 ± 0.0 mm, 0.25 mg/mL). Compound2displayed better binding affinity with minimum binding energy of − 8.7 kcal/mol (PqsA), − 7.6 kcal/mol (DNA gyrase), and − 7.4 kcal/mol (S aureusPK) than amoxicillin (− 7.3, − 6.1, and − 7.0 kcal/mol, respectively). This suggests that compound2may act as potential inhibitor of the tested bacterial proteins. Compound1satisfies the Lipinski’s rule of five with zero violations. Compound2obey the MW (452.4 g/mol) and iLogP (< 5) rules, and compound3obey the NHD (4) and NHA (6) rules. Compounds2recorded iLogP value less enough than five (1.55), implying its optimal lipophilicity. Compounds1and3satisfy the veber’s rule (NRB < 12, and TPSA < 140 unit). Compound2and3exhibited negligible acute toxicity (LD₅₀ > 5000, Toxicity class > 5. Compound2demonstrated maximum scavenging activity (67.87%) with IC₅₀value of 0.190 µg/mL, compared to ascorbic acid (78.21%) with IC₅₀value of 0.014 µg/mL at concentration of 12.5 µg/mL. Overall, the in vitro antibacterial activity of the extracts and compounds, molecular docking analysis and radical scavenging activity results of the isolated compounds suggest DCM/MeOH crude extract and compound2are promising antibacterial agents whereas compound2and3are promising antioxidants which corroborates with the traditional uses of the roots ofH. johannis.

Eicosanoids mediate both cellular and humoral immune responses in insects. Phospholipase A₂ (PLA₂) catalyzes the first committed step in eicosanoid biosynthesis. It is a common pathogenic target of two entomopathogenic bacteria, Xenorhabdus and Photorhabdus. The objective of this study was to identify novel PLA₂ inhibitors from X. hominickii and determine their immunosuppressive activities. To identify novel PLA₂ inhibitors, stepwise fractionation of X. hominickii culture broth and subsequent enzyme assays were performed. Eight purified fractions of bacterial metabolites were obtained. Gas chromatography and mass spectrometry (GC-MS) analysis predicted that the main components in these eight fractions were 2-cyanobenzoic acid, dibutylamine, 2-ethyl 1-hexanol, phthalimide (PM), dioctyl terephthalate, docosane, bis (2-ethylhexyl) phthalate, and 3-ethoxy-4-methoxyphenol (EMP). Their synthetic compounds inhibited the activity of PLA₂ in hemocytes of a lepidopteran insect, Spodoptera exigua, in a dose-dependent manner. They also showed significant inhibitory activities against immune responses such as prophenoloxidase activation and hemocytic nodulation of S. exigua larvae, with PM and EMP exhibiting the most potent inhibitory activities. These immunosuppressive activities were specific through PLA₂ inhibition because an addition of arachidonic acid, a catalytic product of PLA₂, significantly rescued such suppressed immune responses. The two most potent compounds (PM and EMP) showed significant insecticidal activities after oral administration. When the compounds were mixed with Bacillus thuringiensis (Bt), they markedly increased Bt pathogenicity. This study identified eight PLA₂ inhibitors from bacterial metabolites of X. hominickii and demonstrated their potential as novel insecticides.

Open access peer-reviewed chapter

Background. Shigellosis is the most common cause of epidemic dysentery found worldwide, particularly in developing countries, where it causes infant diarrhea and mortality. The prevalence of Shigella species resistant to commonly used antimicrobial drugs has steadily increased. The purpose of this review is to describe the prevalence and antimicrobial resistance (AMR) characteristics of Shigella species in East Africa between 2015 and 2022. Methods. Studies were identified using a computerized search of Medline/PubMed, Google Scholar, and Web of Science databases, with a detailed search strategy and cross-checking of reference lists for studies published between 2015 and 2022. Articles presenting data on prevalence and AMR, accessibility of the full-length article, and publication dates between 2015 and 2022 were the eligibility criteria for inclusion in the review. Original research reports written in English were considered. The heterogeneities of the studies were examined, and a meta-analysis was performed to estimate the pooled prevalence and AMR using a random effects model. Results. The pooled prevalence of Shigella species in East Africa was 6.2% (95% CI −0.20–12.60), according to an analysis of 22 studies. Shigella species prevalence was 4.0% in Ethiopia, 14.6% in Kenya, 0.7% in Sudan, 5.2% in South Sudan, and 20.6% in Somalia. The association of Shigella infection significantly varied among the countries ( ). Among the antibiotics tested, most Shigella isolates were susceptible to ciprofloxacin, norfloxacin, nalidixic acid, and ceftriaxone. Despite the fact that the reports varied in study sites and time, Shigella species were resistant to tetracycline, ampicillin, amoxicillin, chloramphenicol, and co-trimoxazole. Conclusion. The pooled estimate indicates high burden of Shigella infection in East Africa, as well as a high proportion of drug resistance pattern to tetracycline, ampicillin, chloramphenicol, and amoxicillin. Therefore, initiating and scale-up of performing drug susceptibility test for each shigellosis case need to be considered and strengthened.

Propolis, such as is used as bio-cosmetics and in functional materials, is increasing because of its antioxidant medicinal benefits. However, its pharmacological and chemical composition is highly variable, relative to its geography and botanical origins. Comparative studies on three propolis samples collected from different regions in Korea have been essential for linking its provenance, chemical composition, and biological activity, thereby ensuring the efficient utilization of its beneficial properties. Here, we report the chemical composition and biological activities such as the antioxidant, wound healing, and anti-inflammatory effects of the ethanolic extract of Korean propolis collected from two regions. We compared the chemical constituents of three 70% ethanol-extracted (EE) samples, including the Andong, Gongju field (GF), and Gongju mountain (GM)-sourced propolis using Gas chromatography–mass spectrometry (GC–MS). The major and common components of these EE Korean propolis were flavonoids such as pinocembrin (12.0–17.7%), chrysin (5.2–6.8%), and apigenin (5.30–5.84%). The antioxidant property using a 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity assay of EEP showed substantial differences among samples with the highest from Andong. The sample 10% GM levigated in simple ointment was found to be the most active in wound healing activity based on the excision, incision, and dead space wound models. The potential of propolis for wound healing is mainly due to its evidenced properties, such as its antimicrobial, anti-inflammatory, analgesic, and angiogenesis promoter effects, which need further study. The anti-inflammatory activity and NO production inhibitory effect were highest in GM samples. However, GM and GF samples demonstrated similar inhibitory effects on the expression of inflammatory mediators such as iNOS, IL-1β, and IL-6. The presence of a higher concentration of flavonoids in Korean EE propolis might be responsible for their promising wound healing, anti-inflammatory, and antioxidant properties.