Search Results (5)

Ralstonia solanacearum is an important pathogen causing bacterial wilt in pepper (Capsicum annuum L.). The concurrent infection of R. solanacearum and root-knot nematodes (Meloidogyne spp.) exacerbates the severity of bacterial wilt in pepper. Utilizing plant endophytic bacteria to control these mixed diseases is a viable strategy. Waltheria indica L. (Sterculiaceae) is a traditional medicine plant. A total of 209 endophytic bacteria were isolated from W. indica, and Pseudomonas aeruginosa W-126 showed an efficient antagonistic effect against R. solanacearum. Based on active compound tracking principles, a compound was isolated through silica gel column chromatography and preparative HPLC combined with TLC analysis. It was identified as phenazine-1-carboxamide (PCN) by spectral techniques (ESI-MS, ¹H-NMR, ¹³C-NMR). PCN displayed excellent inhibitory activity against R. solanacearum, with an EC₅₀ of 64.16 μg/mL in vitro. In addition, it showed certain nematocide activity, with an LC₅₀ value of 118.63 μg/mL at 72 h. PCN also showed certain inhibitory activity against five other phytopathogenic bacteria. The structure−activity relationship indicated that the phenazine skeleton and acylamide groups were the key pharmacophores for the activity of phenazine-related compounds against R. solanacearum. PCN controlled the complex diseases of R. solanacearum and M. incognita in a pot experiment, with respective 51.41 and 39.80% inhibitory rates. The exploration of secondary metabolites of biocontrol bacteria can provide reference for the development of novel and efficient pesticides. Full article

Waltheria, a genus within the Malvaceae family, is abundantly distributed in tropical and subtropical areas worldwide. Many species of this genus are widely utilized in various ways, including chewing, in folk medicine, acting as an anti-inflammatory agent, and treating gastrointestinal disorders, rheumatism, and asthma, among other conditions. These applications are largely due to their secondary metabolites, primarily quinolone alkaloids and cyclopeptides. Several biological activities have been reported for Waltheria species, including antifungal, anticancer, trypanocidal, acetylcholinesterase inhibitory, potential anti-HIV, antinociceptive, analgesic, anti-inflammatory, antibacterial, antioxidant, and leishmanicidal activities. This review not only presents information on isolated alkaloids and their biological activities but also delves into biosynthetic, chemosystematic, medicinal chemistry, and total synthesis aspects. Additionally, the manuscript highlights other applications of alkaloids of the genus, such as a study on their herbicidal activity, which shows significant potential for agricultural use. Full article

Seven new coumarinolignans, walthindicins A–F (1a, 1b, 2–5, 7), along with five known analogs (6, 8–11), were isolated from the roots of Waltheria indica. The structures of the new compounds are determined by detailed nuclear magnetic resonance (NMR), circular dichroism (CD) with extensive computational support, and mass spectroscopic data interpretation. Compounds were tested for their antioxidant activity in Human Cervical Cancer cells (HeLa cells). Compounds 1a and 6 showed higher reactive oxygen species (ROS) inhibitory activity at 20 μg/mL when compared with other natural compound-based antioxidants such as ascorbic acid. Considering the role of ROS in nuclear-factor kappa B (NF-κB) activation, compounds 1a and 6 were evaluated for NF-κB inhibitory activity and showed a concentration-dependent inhibition in Human Embryonic Kidney 293 cells (Luc-HEK-293). Full article

Traditional medicine is typically the most accessible primary healthcare for a large proportion of the people in Nigeria. However, its potential remains under-explored, especially with regards to their documentation. This research investigated and documented the use of medicinal plants in the management of various health conditions/diseases among local populations in Lagos State. This study was conducted in five (5) locations of Lagos State i.e., Alimosho, Badagry, Eti-Osa, and Epe (including Ijebu and Imota). Ethnobotanical information from 100 participants was obtained using semi-structured questionnaires. Frequency of citation (FC), relative frequency of citation (RFC), fidelity level (FL), and informant consensus factor (ICF) were used to assess the importance of plants utilised for various health conditions/diseases. We identified 183 plants from 61 plant families with the highest number (24) of plants belonging to Fabaceae. Based on the high FC, the top-five popular plants used for managing health conditions/diseases in the study areas were Mangifera indica (95%), Waltheria indica (93%), Zingiber officinale (87%), Alchornea cordifolia (83%) and Ipomoea involucrata (81%). Furthermore, Rauvolfia vomitoria, Urena lobata and Waltheria indica were recognised as the most adaptable plants, as they were used to treat five different health conditions/diseases. The most commonly used life-forms were herbs (34%) and woody species (shrubs; 30%, and trees; 22%). The most regularly used plant parts were leaves. The calculated RFC values for all medicinal plant species ranged from 0.01 to 0.95, while FL values ranged from 7.14 to 100%. We found 14 health conditions/diseases, with ICF values ranging from 0.88 to 0.95. Insomnia, insanity, convulsion, nervousness, and muscle relaxants had the lowest (ICF = 0.88) agreement, while malaria/fevers, stomach, and respiratory-related diseases had the most (ICF = 0.95) agreement. The documented therapeutic uses of the plants provide basic data for further research aimed at pharmacological and conservation studies of the most important flora existing in the study areas. Full article

Inflammation is the body’s response to infection or tissue injury in order to restore and maintain homeostasis. Prostaglandin E2 (PGE-2) derived from arachidonic acid (AA), via up-regulation of cyclooxygenase-2 (COX-2), is a key mediator of inflammation and can also be induced by several other factors including stress, chromosomal aberration, or environmental factors. Targeting prostaglandin production by inhibiting COX-2 is hence relevant for the successful resolution of inflammation. Waltheria indica L. is a traditional medicinal plant whose extracts have demonstrated COX-2 inhibitory properties. However, the compounds responsible for the activity remained unknown. For the preparation of extracts with effective anti-inflammatory properties, characterization of these substances is vital. In this work, we aimed to address this issue by characterizing the substances responsible for the COX-2 inhibitory activity in the extracts and generating prediction models to quantify the COX-2 inhibitory activity without biological testing. For this purpose, an extract was separated into fractions by means of centrifugal partition chromatography (CPC). The inhibitory potential of the fractions and extracts against the COX-2 enzyme was determined using a fluorometric COX-2 inhibition assay. The characterizations of compounds in the fractions with the highest COX-2 inhibitory activity were conducted by high resolution mass spectrometry (HPLC-MS/MS). It was found that these fractions contain alpha-linolenic acid, linoleic acid and oleic acid, identified and reported for the first time in Waltheria indica leaf extracts. After analyzing their contents in different Waltheria indica extracts, it could be demonstrated that these fatty acids are responsible for up to 41% of the COX-2 inhibition observed with Waltheria indica extract. Additional quantification of secondary metabolites in the extract fractions revealed that substances from the group of steroidal saponins and triterpenoid saponins also contribute to the COX-2 inhibitory activity. Based on the content of compounds contributing to COX-2 inhibition, two mathematical models were successfully developed, both of which had a root mean square error (RMSE) = 1.6% COX-2 inhibitory activity, demonstrating a high correspondence between predicted versus observed values. The results of the predictive models further suggested that the compounds contribute to COX-2 inhibition in the order linoleic acid > alpha linolenic acid > steroidal saponins > triterpenoid saponins. The characterization of substances contributing to COX-2 inhibition in this study enables a more targeted development of extraction processes to obtain Waltheria indica extracts with superior anti-inflammatory properties. Full article