GC-MS analysis of esterified fatty acids obtained from leaves of wild and cultivated specimens of Leonotis nepetifolia

Phytochemical Analysis, GC-MS Profiling, and In Vitro Evaluation of Biological Applications of Different Solvent Extracts of Leonotis nepetifolia (L.) R.Br. Flower Buds

Leonotis nepetifolia (L.) R.Br. is a medicinally important herb belonging to the family Lamiaceae. The plant is typically found in tropical regions, and its leaf and root extracts are renowned for their ethno-botanical and therapeutic applications. This study was designed to determine the presence of various bioactive components, and to evaluate antibacterial, antifungal, antioxidant, and anti-proliferative activities. The preliminary phytochemical screening and gas chromatography-mass spectrometry (GC-MS) analysis of different solvent extracts revealed the presence of various bioactive compounds, of which methanol extract showed 24 compounds, petroleum ether extract revealed 26 compounds, and 24 compounds in hexane extracts. The major bioactive components including λ-sitosterol (16.20 %) in methanol extract, 1-nonadecanol (15.48 %) in petroleum extract, and eicosane (13.22 %) in hexane extract have been reported with various bio-therapeutic applications. In addition, the flower bud methanolic extract of L. nepetifolia exhibited inhibitory potential against all tested bacterial and fungal pathogens. The DPPH radical scavenging assay revealed that methanolic extract possessed the highest antioxidant activity. The scavenging activity increased in a concentration-dependent manner, as indicated by a 74 % inhibition rate at 1000 µg/ml. Furthermore, the in vitro cytotoxic effects of the methanolic extract on the HepG2 cell line were evaluated. The IC₅₀ value of methanolic extract against HepG2 cells was determined to be 83.28 µg/ml. The findings reveal that different solvent extracts of L. nepetifolia flower buds contain a significant amount of various bioactive phytochemicals with antioxidant and anticancer activities; and thus, the plant could serve as a potential source of pharmacological applications.

Analysis of Streptomyces Volatilomes Using Global Molecular Networking Reveals the Presence of Metabolites with Diverse Biological Activities

Streptomyces species produce a wide variety of specialized metabolites, some of which are used for communication or competition for resources in their natural environments. In addition, many natural products used in medicine and industry are derived from Streptomyces, and there has been interest in their capacity to produce volatile organic compounds (VOCs) for different industrial and agricultural applications. Recently, a machine-learning workflow called MSHub/GNPS was developed, which enables auto-deconvolution of gas chromatography-mass spectrometry (GC-MS) data, molecular networking, and library search capabilities, but it has not been applied to Streptomyces volatilomes. In this study, 131 Streptomyces isolates from the island of Newfoundland were phylogenetically typed, and 37 were selected based on their phylogeny and growth characteristics for VOC analysis using both a user-guided (conventional) and an MSHub/GNPS-based approach. More VOCs were annotated by MSHub/GNPS than by the conventional method. The number of unknown VOCs detected by the two methods was higher than those annotated, suggesting that many novel compounds remain to be identified. The molecular network generated by GNPS can be used to guide the annotation of such unknown VOCs in future studies. However, the number of overlapping VOCs annotated by the two methods is relatively small, suggesting that a combination of analysis methods might be required for robust volatilome analysis. More than half of the VOCs annotated with high confidence by the two approaches are plant-associated, many with reported bioactivities such as insect behavior modulation. Details regarding the properties and reported functions of such VOCs are described. IMPORTANCE This study represents the first detailed analysis of Streptomyces volatilomes using MSHub/GNPS, which in combination with a routinely used conventional method led to many annotations. More VOCs could be annotated using MSHub/GNPS as compared to the conventional method, many of which have known antimicrobial, anticancer, and insect behavior-modulating activities. The identification of numerous plant-associated VOCs by both approaches in the current study suggests that their production could be a more widespread phenomenon by members of the genus, highlighting opportunities for their large-scale production using Streptomyces. Plant-associated VOCs with antimicrobial activities, such as 1-octen-3-ol, octanol, and phenylethyl alcohol, have potential applications as fumigants. Furthermore, many of the annotated VOCs are reported to influence insect behavior, alluding to a possible explanation for their production based on the functions of other recently described Streptomyces VOCs in dispersal and nutrient acquisition.

Genus Triplaris (Polygonaceae): A review on traditional medicinal use, phytochemistry and biological activities

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Triplaris (Polygonaceae) comprises approximately 25 species distributed throughout South and Central America. Some species have been used in folk medicine, mainly, to treat malaria, leishmaniasis, diarrheia, dysenteria, pain and inflammation.

AIM OF THE STUDY

The purpose of this review is to provide information on the traditional uses, phytochemistry and known biological activities of Triplaris, an important genus for South America research groups on medicinal plants, in order to explore its therapeutic potential to direct future research in the search for new bioactive molecules.

MATERIALS AND METHODS

The available information on the genus Triplaris was gathered from scientific databases (LILACS, Pubmed, SciELO, Science Direct, Scopus, CAPES Periodicals Portal and Theses and Dissertations Catalog) before March 2020 using the keyword "Triplaris". Works related to traditional uses, phytochemistry and biological activities of plants were included in this review.

RESULTS

Most of the studies involving Triplaris were conducted by research groups located in Brazil, Peru e Bolivia. Probably, because the genus has been used in folk medicine only by these countries. Regarding the annual evolution of the publications, a larger number of articles published in 2010 were observed. Flavonols represent the main classe of secondary metabolites from Triplaris. In terms of the pharmacological investigations, T. americana and T. gardneriana are considered the most studied species, with extensive promising biological activities. The pharmacological activities can be attributed to bioactive phytochemicals.

CONCLUSIONS

All findings indicate that Triplaris is an important genus of the Polygonaceae family. However, considering its chemical and pharmacological importance, the studies developed with Triplaris species are still limited, representing an opportunity to investigate new bioactive molecules and extracts. The review shows that little pre-clinical or in vivo research is available to prove the ethnopharmacological records in the genre. Therefore, this review encourages further studies on Triplaris in the search for a wide range of therapeutic products.

Medicinal plants used to treat "African" diseases by the local communities of Bwambara sub-county in Rukungiri District, Western Uganda

ETHNOPHARMACOLOGICAL RELEVANCE

In Africa, traditional medicine encompasses a diverse range of practices, including herbalism and spiritualism, where some diseases are believed to be "African" since they can only be traditionally treated. Indigenous knowledge on the management of "African" diseases using medicinal plants is still handed down orally from generation to generation by tribal societies of tropical Africa, and with the rapid westernization of these societies there is a pressing need to record local knowledge before it is lost forever.

AIM

This study documented medicinal plant species associated with the management of "African" diseases by the local communities of Bwambara sub-county in Rukungiri district, Western Uganda.

METHODS

A cross-sectional study was conducted using semi-structured questionnaires and interviews. The data collected included names of plant species, plant parts used, diseases treated, methods of preparation, and mode of administration of the herbal remedies. A total of 196 informants participated in the study. Data were analyzed and presented using descriptive statistics and the Informant consensus factor.

RESULTS

We documented 67 medicinal plant species distributed over 27 families and 62 genera. The most commonly reported species belong to Asteraceae family. The most frequently used medicinal species were Chenopodium opulifolium (27), Sesbania sesban (26), Thevetia peruviana (25), Leonotis nepetifolia (23), Momordica foetida (23), Euphorbia hirta (21) and Cassia mimosoides (20). Leaves were the most commonly used plants parts and decoctions were the main method of preparation. Water was the main medium used for the preparation of the remedies which were administered orally while petroleum jelly was the main medium for those which were used as ointments. The medicinal plant species reported are used to treat 39 conditions which were clustered into 10 International Classification of Primary Care (ICPC) disease categories. There is a high degree of consensus among the informants on which medicinal plant species they use for different diseases especially disorders in the following categories: neurological (FIC = 0.90), general and unspecified (FIC = 0.87), digestive (FIC = 0.86) and female genital (FIC = 0.82).

CONCLUSION

Local communities of Bwambara sub-county in Rukungiri district, Western Uganda use a rich diversity of medicinal plant species in the management of various "African" diseases. Therefore, collaboration between users of medicinal plants and scientists is paramount, to help in the discovery of new drugs based on indigenous knowledge.

Dietary Compounds Influencing the Sensorial, Volatile and Phytochemical Properties of Bovine Milk

The main aim of this study was to evaluate the volatile profile, sensory perception, and phytochemical content of bovine milk produced from cows fed on three distinct feeding systems, namely grass (GRS), grass/clover (CLV), and total mixed ration (TMR). Previous studies have identified that feed type can influence the sensory perception of milk directly via the transfer of volatile aromatic compounds, or indirectly by the transfer of non-volatile substrates that act as precursors for volatile compounds. In the present study, significant differences were observed in the phytochemical profile of the different feed and milk samples. The isoflavone formonoetin was significantly higher in CLV feed samples, but higher in raw GRS milk, while other smaller isoflavones, such as daidzein, genistein, and apigenin were highly correlated to raw CLV milk. This suggests that changes in isoflavone content and concentration in milk relate to diet, but also to metabolism in the rumen. This study also found unique potential volatile biomarkers in milk (dimethyl sulfone) related to feeding systems, or significant differences in the concentration of others (toluene, p-cresol, ethyl and methyl esters) based on feeding systems. TMR milk scored significantly higher for hay-like flavor and white color, while GRS and CLV milk scored significantly higher for a creamy color. Milk samples were easily distinguishable by their volatile profile based on feeding system, storage time, and pasteurization.