Novel Iridoid Derivatives Isolated from the Roots of Patrinia scabra with Potential Anti-Renal Fibrosis Activity In Vitro.

Scabrol B and Scabrol C, two newly identified iridoid derivatives (1 and 2) and six known compounds (3-8), were extracted from the roots of Patrinia scabra. The structures of these derivatives, including their absolute configurations, were elucidated via comprehensive NMR analysis, chemical derivatization, and quantum chemical ECD calculations. All isolated compounds were evaluated for their anti-renal fibrosis activity. The results demonstrate that compounds 1 and 2 showed dose-dependent protective effects against renal fibrosis in vitro by reducing the expression of fibronectin, collagen I, and alpha-smooth muscle actin (α-SMA) in NRK-49f cells mediated by TGF-ß1.

Effects of exogenous amylolytic or fibrolytic enzymes inclusion on in vitro fermentation of lactating dairy cow diets in a dual-flow continuous-culture system.

The objective of this study was to determine the effects of including exogenous amylolytic or fibrolytic enzymes in a diet for high-producing dairy cows on in vitro ruminal fermentation. Eight dual-flow continuous-culture fermentors were used in a replicated 4 × 4 Latin square. The treatments were control (CON), a xylanase and glucanase mixture (T1), an α-amylase mixture (T2), or a xylanase, glucanase, and α-amylase mixture (T3). Treatments were included at a rate of 0.008% of diet dry matter (DM) for T1 and T2 and at 0.02% for T3. All treatments replaced the equivalent amount of soybean meal in the diet compared with CON. All diets were balanced to have the same nutrient composition [30.2% neutral detergent fiber (NDF), 16.1% crude protein (CP), and 30% starch; DM basis], and fermentors were fed 106 g/d divided into 2 feedings. At each feeding, T2 was pipetted into the respective fermentor and an equivalent amount of deionized water was added to each fermentor to eliminate potential variation. Experimental periods were 10 d (7 d for adaptation and 3 d for sample collection). Composite samples of daily effluent were collected and analyzed for volatile fatty acids (VFA), NH3-N, and lactate concentrations, degradability of DM, organic matter, NDF, CP, and starch, and flow and metabolism of N. Samples of fermentor contents were collected from each fermentor at 0, 1, 2, 4, 6, and 8 h after feeding to determine kinetics of pH, NH3-N, lactate, and VFA concentrations over time. All data were analyzed using PROC GLIMMIX of SAS (SAS Institute Inc.), and the repeated variable of time was included for kinetics measurements. Treatment did not affect mean pH, degradability, N flow and metabolism, or the concentrations of VFA, NH3-N, or lactate in the effluent samples. Treatment did not affect pH, acetate:propionate ratio, or the concentrations of lactate, NH3-N, total VFA, acetate, propionate, butyrate, isobutyrate, valerate, or caproate. However, the concentration of total VFA tended to change at each time point depending upon the treatment, and T2 tended to have a greater proportion of 2-methylbutyrate and isovalerate than CON, T1, or T3. As 2-methylbutyrate and isovalerate are branched-chain VFA that are synthesized from branched-chain amino acids, T2 may have an increased fermentation of branched-chain amino acids or decreased uptake by fibrolytic microorganisms. Although we did not observe changes in N metabolism due to the enzymes, there could be changes in microbial populations that utilize branched-chain VFA. Overall, the tested enzymes did not improve in vitro ruminal fermentation in the diet of high-producing dairy cows.

The Prognostic Biomarkers of Plasma Trimethylamine N-Oxide and Short-Chain Fatty Acids for Recanalization Therapy in Acute Ischemic Stroke.

Bidirectional communication of the microbiota-gut-brain axis is crucial in stroke. Recanalization therapy, namely intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT), are recommended for eligible patients with acute ischemic stroke (AIS). It remains unclear whether gut microbiota metabolites, namely trimethylamine N-oxide (TMAO) and short-chain fatty acids (SCFAs), can predict the prognosis after recanalization therapy. This prospective study recruited patients with AIS receiving IVT, EVT, or both. The National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) scores were used to assess the severity and functional outcomes of AIS, respectively. A functional outcome of mild-to-moderate disability was defined as a mRS score of 0-3 at discharge. Plasma TMAO and SCFA levels were measured through liquid chromatography with triple-quadrupole mass spectrometry. Fifty-six adults undergoing recanalization therapy for AIS were enrolled. Results showed that TMAO levels were not associated with stroke severity and functional outcomes, while isovalerate levels (one of the SCFAs) were negatively correlated with NIHSS scores at admission and discharge. In addition, high isovalerate levels were independently associated with a decreased likelihood of severe disability. The study concluded that an elevated plasma isovalerate level was correlated with mild stroke severity and disability after recanalization therapy for AIS.

Typical Aroma of Merlot Dry Red Wine from Eastern Foothill of Helan Mountain in Ningxia, China.

Aroma is an important aspect of wine quality and consumer appreciation. The volatile organic compounds (VOCs) and olfactory profiles of Merlot dry red wines from the Eastern Foothill of Helan Mountain (EFHM) were analyzed using gas chromatography-mass spectrometry and quantitative descriptive analysis. The results showed that Merlot wines from EFHM were characterized by intense flavors of drupe and tropical fruits compared with the Gansu region. Nineteen VOCs were defined as essential compounds contributing to the aroma characteristics of the Merlot wines through gas chromatography-olfactometry/mass spectrometry and odor activity value analysis. Predominantly, geranyl isovalerate, which contributed to the herbal odors of the Merlot wines, was detected in the grape wine of EFHM for the first time. The addition experiment revealed that geranyl isovalerate influenced the aroma quality of wine by increasing herbal odors and enhancing the olfactory intensities of tropical fruits. These results are helpful for further understanding the aroma of Merlot wines from EFHM and improving the quality of wine aromas.

Effects of Macleaya cordata extract supplementation on digestive parameters of ponies.

High amounts of grains in the equine diet led to high starch intake, causing gut alterations. Aimed at reducing harmful effects, Macleaya cordata extract (MCE) is a phytogenic additive that stands out for its antibiotic and anti-inflammatory effects proven in different species. However, there is no useful information for horses. The objective of this study was to evaluate the effects of different levels of the inclusion of commercial MCE on body weight (BW), body condition score (BCS), total apparent digestibility (AD) of nutrients, faecal pH and fermentative products, on ponies fed a high-starch diet. Eight healthy gelding Mini Horse ponies were used. The study design was contemporary double Latin-square 4 × 4 in the experimental unit, with the animal inside each experimental period (n = 8 experimental units per group). The experiment was conducted over four 20-d periods. Basal diet attended 1.75% BW dry matter daily and starch intake was 2.2 g/kg BW/meal. The experimental groups were as follows: control - without food additive; S1-1 mg/kg BW MCE; S1.5-1.5 mg/kg BW MCE and S2-2 mg/kg BW MCE. The data were analysed by PROC MIXED of SAS (p < 0.05). Tendency was considered when 0.05 < p < 0.1. Our results showed higher ether extract (EE) AD for S2 group (63.75%) when compared with the control (54.55%) (p = 0.0377). Lactate was lower (p = 0.0391) in S1 (3.27 mmol/l) and S2 (3.24 mmol/l) groups, although pH was not different between groups. Iso-valerate was greater in S1 group (2.29 mmol/l; p = 0.0289), and a tendency of higher butyrate values was found for S1 and S2 groups (p = 0.0980). We concluded that MCE supplementation probably positively influences equine resident microbiota, improving EE AD and increasing iso-valerate concentration. It can also minimise harmful high-starch impact. We recommend further studies using MCE in horses for a better understanding of its local activity and possible benefits.

Origin of the 3-methylglutaryl moiety in caprazamycin biosynthesis.

BACKGROUND: Caprazamycins are liponucleoside antibiotics showing bioactivity against Gram-positive bacteria including clinically relevant Mycobacterium tuberculosis by targeting the bacterial MraY-translocase. Their chemical structure contains a unique 3-methylglutaryl moiety which they only share with the closely related liposidomycins. Although the biosynthesis of caprazamycin is understood to some extent, the origin of 3-methylglutaryl-CoA for caprazamycin biosynthesis remains elusive. RESULTS: In this work, we demonstrate two pathways of the heterologous producer Streptomyces coelicolor M1154 capable of supplying 3-methylglutaryl-CoA: One is encoded by the caprazamycin gene cluster itself including the 3-hydroxy-3-methylglutaryl-CoA synthase Cpz5. The second pathway is part of primary metabolism of the host cell and encodes for the leucine/isovalerate utilization pathway (Liu-pathway). We could identify the liu cluster in S. coelicolor M1154 and gene deletions showed that the intermediate 3-methylglutaconyl-CoA is used for 3-methylglutaryl-CoA biosynthesis. This is the first report of this intermediate being hijacked for secondary metabolite biosynthesis. Furthermore, Cpz20 and Cpz25 from the caprazamycin gene cluster were found to be part of a common route after both individual pathways are merged together. CONCLUSIONS: The unique 3-methylglutaryl moiety in caprazamycin originates both from the caprazamycin gene cluster and the leucine/isovalerate utilization pathway of the heterologous host. Our study enhanced the knowledge on the caprazamycin biosynthesis and points out the importance of primary metabolism of the host cell for biosynthesis of natural products.

Nematicidal Volatiles from Bacillus atrophaeus GBSC56 Promote Growth and Stimulate Induced Systemic Resistance in Tomato against Meloidogyne incognita.

Bacillus volatiles to control plant nematodes is a topic of great interest among researchers due to its safe and environmentally friendly nature. Bacillus strain GBSC56 isolated from the Tibet region of China showed high nematicidal activity against M. incognita, with 90% mortality as compared with control in a partition plate experiment. Pure volatiles produced by GBSC56 were identified through gas chromatography and mass spectrometry (GC-MS). Among 10 volatile organic compounds (VOCs), 3 volatiles, i.e., dimethyl disulfide (DMDS), methyl isovalerate (MIV), and 2-undecanone (2-UD) showed strong nematicidal activity with a mortality rate of 87%, 83%, and 80%, respectively, against M. incognita. The VOCs induced severe oxidative stress in nematodes, which caused rapid death. Moreover, in the presence of volatiles, the activity of antioxidant enzymes, i.e., SOD, CAT, POD, and APX, was observed to be enhanced in M. incognita-infested roots, which might reduce the adverse effect of oxidative stress-induced after infection. Moreover, genes responsible for plant growth promotion SlCKX1, SlIAA1, and Exp18 showed an upsurge in expression, while AC01 was downregulated in infested plants. Furthermore, the defense-related genes (PR1, PR5, and SlLOX1) in infested tomato plants were upregulated after treatment with MIV and 2-UD. These findings suggest that GBSC56 possesses excellent biocontrol potential against M. incognita. Furthermore, the study provides new insight into the mechanism by which GBSC56 nematicidal volatiles regulate antioxidant enzymes, the key genes involved in plant growth promotion, and the defense mechanism M. incognita-infested tomato plants use to efficiently manage root-knot disease.

Butyrate, but not propionate, reverses maternal diet-induced neurocognitive deficits in offspring.

BACKGROUND: Maternal diet plays a beneficial role in the health, including the neurodevelopment, of offspring. Insufficient fibre consumption among the general population has increased concern about neurocognitive diseases. However, the association between maternal low-fibre diet (MLFD) and neurocognitive function in offspring is still unclear. METHODS: Mice were fed diets containing diverse levels of fibre or administered short-chain fatty acids (SCFAs) during gestation. The neurocognitive functions of the offspring and synaptic plasticity-related protein levels were measured. Gene expression was disrupted by siRNA interference. Samples from pregnant women and paired umbilical cord blood (UCB) samples were analysed by the general linear model. RESULTS: We found that MLFD impaired cognitive function and synaptic plasticity in offspring and that the impairments were reversed by butyrate intake but not propionate intake. Mechanistic studies showed that histone deacetylase (HDAC)-4 is the most likely mediator of butyrate-dependent neurocognitive improvement. In addition, using human maternal serum and paired UCB samples, we demonstrated that SCFA levels in offspring were positively correlated with levels in the maternal serum. CONCLUSION: These results provide solid evidence that fibre in the maternal diet regulates neurocognitive functions in offspring through altering SCFA levels and supports the use of SCFA-dependent perinatal intervention for improving offspring health in the clinic.

Tracing the biosynthetic origin of limonoids and their functional groups through stable isotope labeling and inhibition in neem tree (Azadirachta indica) cell suspension.

BACKGROUND: Neem tree serves as a cornucopia for triterpenoids called limonoids that are of profound interest to humans due to their diverse biological activities. However, the biosynthetic pathway that plant employs for the production of limonoids remains unexplored for this wonder tree. RESULTS: Herein, we report the tracing of limonoid biosynthetic pathway through feeding experiments using 13C isotopologues of glucose in neem cell suspension. Growth and development specific limonoid spectrum of neem seedling and time dependent limonoid biosynthetic characteristics of cell lines were established. Further to understand the role of mevalonic acid (MVA) and methylerythritol phosphate (MEP) pathways in limonoid biosynthesis, Ultra Performance Liquid Chromatography (UPLC)- tandem mass spectrometry based structure-fragment relationship developed for limonoids and their isotopologues have been utilized. Analyses of labeled limonoid extract lead to the identification of signature isoprenoid units involved in azadirachtin and other limonoid biosynthesis, which are found to be formed through mevalonate pathway. This was further confirmed by treatment of cell suspension with mevinolin, a specific inhibitor for MVA pathway, which resulted in drastic decrease in limonoid levels whereas their biosynthesis was unaffected with fosmidomycin mediated plastidial methylerythritol 4-phosphate (MEP) pathway inhibition. This was also conspicuous, as the expression level of genes encoding for the rate-limiting enzyme of MVA pathway, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR) was comparatively higher to that of deoxyxylulose-phosphate synthase (DXS) of MEP pathway in different tissues and also in the in vitro grown cells. Thus, this study will give a comprehensive understanding of limonoid biosynthetic pathway with differential contribution of MVA and MEP pathways. CONCLUSIONS: Limonoid biosynthesis of neem tree and cell lines have been unraveled through comparative quantification of limonoids with that of neem tree and through 13C limonoid isotopologues analysis. The undifferentiated cell lines of neem suspension produced a spectrum of C-seco limonoids, similar to parental tissue, kernel. Azadirachtin, a C-seco limonoid is produced in young tender leaves of plant whereas in the hard mature leaves of tree, ring intact limonoid nimocinol accumulates in high level. Furthermore, mevalonate pathway exclusively contributes for isoprene units of limonoids as evidenced through stable isotope labeling and no complementation of MEP pathway was observed with mevalonate pathway dysfunction, using chemical inhibitors.

The Structure of LiuC, a 3-Hydroxy-3-Methylglutaconyl CoA Dehydratase Involved in Isovaleryl-CoA Biosynthesis in Myxococcus xanthus, Reveals Insights into Specificity and Catalysis.

Myxobacteria are able to produce the important metabolite isovaleryl coenzyme A by a route other than leucine degradation. The first step into this pathway is mediated by LiuC, a member of the 3-methylglutaconyl CoA hydratases (MGCH). Here we present crystal structures refined to 2.05 and 1.1 Šof LiuC in the apo form and bound to coenzyme A, respectively. By using simulated annealing we modeled the enzyme substrate complex and identified residues potentially involved in substrate binding, specificity, and catalysis. The dehydration of 3-hydroxy-3-methylglutaconyl CoA to 3-methylglutaconyl CoA catalyzed by LiuC involves Glu112 and Glu132 and likely employs the typical crotonase acid-base mechanism. In this, Tyr231 and Arg69 are key players in positioning the substrate to enable catalysis. Surprisingly, LiuC shows higher sequence and structural similarity to human MGCH than to bacterial forms, although they convert the same substrate. This study provides structural insights into the alternative isovaleryl coenzyme A biosynthesis pathway and might open a path for biofuel research, as isovaleryl-CoA is a source for isobutene, a precursor for renewable fuels and chemicals.

Crystal Structure of the HMG-CoA Synthase MvaS from the Gram-Negative Bacterium Myxococcus xanthus.

A critical step in bacterial isoprenoid production is the synthesis of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) catalyzed by HMG-CoA synthase (HMGCS). In myxobacteria, this enzyme is also involved in a recently discovered alternative and acetyl-CoA-dependent isovaleryl CoA biosynthesis pathway. Here we present crystal structures of MvaS, the HMGCS from Myxococcus xanthus, in complex with CoA and acetylated active site Cys115, with the second substrate acetoacetyl CoA and with the product of the condensation reaction, 3-hydroxy-3-methylglutaryl CoA. With these structures, we show that MvaS uses the common HMGCS enzymatic mechanism and provide evidence that dimerization plays a role in the formation and stability of the active site. Overall, MvaS shows features typical of the eukaryotic HMGCS and exhibits differences from homologues from Gram-positive bacteria. This study provides insights into myxobacterial alternative isovaleryl CoA biosynthesis and thereby extends the toolbox for the biotechnological production of renewable fuel and chemicals.

Two New Cinnamyl Isovalerate Derivatives from Sabina gaussenii.

Chemical investigation of the 90% acetone extract of the branches and leaves of Sabina gaussenii led to the isolation of two new cinnamyl isovalerate derivatives (1-2) and eighteen known compounds (3-20). Their structures were determined mainly by means of MS, 1D- and 2D-NMR data, and this is the first time these compounds have been reported from this plant. The biological activity test results indicated that the 90% acetone extract showed cytotoxicity against the human lung adenocarcinoma (A549) cell line (IC50 = 0.98 ± 0.1 µg/mL), compound 6 showed cytotoxicities against human cervical carcinoma (HeLa) (IC50 = 0.4 ± 0.1 µM ) and human gastric carcinoma (BGC-823) (IC50 = 0.9 ± 0.2 µM) cancer cell lines, and compound 19 showed cytotoxicities against HeLa (IC50 = 1.5 ± 0.4 µM), BGC-823 (IC50 = 7.0 ± 0.8 µM ), and A549 (IC50 = 10.6 ± 1.5 µM ) cancer cell lines.

Floral scent of eastern skunk cabbage (Symplocarpus foetidus: Araceae).

Symplocarpus foetidus (L.) Salisb. (eastern skunk cabbage) occurs across a broad geographic range of northeastern North America, blooming in winter between December and March. The inflorescences are well-known for their thermogenic and thermoregulatory metabolic capabilities. The perceptual qualities of their fetid floral aroma have been described widely in the literature, but to date the floral volatile composition remained largely unknown. Here we present a detailed study of the floral scent produced by S. foetidus collected from intact female- and male-stage inflorescences and from dissected floral parts. Our results show a large range of biosynthetically diverse volatiles including nitrogen- and sulfur-containing compounds, monoterpenes, benzenoids, and aliphatic esters and alcohols. We document high inter-individual variation with some organ-specific volatile trends but no clear strong variation based on sexual stage. Multivariate data analysis revealed two distinct chemotypes from our study populations that are not defined by sexual stage or population origin. The chemotype differences may explain the bimodal perceptual descriptions in earlier work which vary between highly unpleasant/fetid and pleasant/apple-like. We discuss the results in ecological contexts including potential for floral mimicry, taking into account existing pollination studies for the species. We also discuss the results in evolutionary contexts, comparing our scent data to published scent data from the close sister species Symplocarpus renifolius. Future work should more closely examine the chemotype occurrence and frequency within these and other populations, and the impact these chemotypes may have on pollinator attraction and reproductive success.

Effects of steam explosion-modified rice bran dietary fiber on volatile flavor compounds retention and release of red date-flavored naan (ethnic specialty food of Xinjiang) during storage.

This study explored the effects of steam explosion-modified rice bran dietary fiber (S-RBDF) on red date-flavored naan quality and flavor characteristics. The results revealed that the rheological properties of the dough were improved with the incremental addition of S-RBDF (0-5%). The microstructure revealed that adding an appropriate amount of S-RBDF (1-5%) enabled more starch granules to be embedded in the dough network. Notably, the addition of 5% S-RBDF resulted in naan with an optimum specific volume and texture, which consumers preferred. Additionally, gas chromatography-mass spectrometry analysis showed that adding S-RBDF to naan contributed to the retention and sustained release of pleasant volatile compounds (e.g. red date flavor, etc.), while inhibiting the development of unpleasant volatile compounds by delaying the oxidation and decomposition of lipids and preserving the antioxidant phenolic compounds, thus contributing to flavor maintenance of naan during storage. Overall, these results provided a foundation for developing high-quality flavored naan.

Ethnobotany, phytochemistry, pharmacology and quality control of Peucedanum decursivum (Miq.) Maxim: A critical review.

ETHNOPHARMACOLOGICAL RELEVANCE: Dried roots of Peucedanum decursivum, a traditional Chinese medicine (TCM), has historically respiratory diseases such as cough, thick phlegm, headache, fever, and gynecological diseases, rheumatoid arthritis, and nasopharyngeal carcinoma. AIM OF THE STUDY: Made an endeavor to evaluate the research trajectory of P. decursivum, comprehensively discern its developmental status, and offer a guideline for future investigations. MATERIALS AND METHODS: A meticulous search of literatures and books from 1955 to 2024 via databases like PubMed, Web of Science and CNKI was conducted, including topics and keywords of " P. decursivum" "Angelica decursivum" and "Zihua Qianhu". RESULTS: P. decursivum and its prescriptions have traditionally been used for treating phlegm-heat cough, wind-heat cough, gastrointestinal diseases, pain relief and so on. It contains 234 identified compounds, encompassing coumarins, terpenes, volatile oils, phenolic acids, fatty acids and derivatives. It exhibits diverse pharmacological activities, including anti-asthmatic, anti-inflammatory, antioxidant effects, anti-hypertensive, anti-diabetic, anti-Alzheimer, and anti-cancer properties, primarily attributed to coumarins. Microscopic identification, HPLC fingerprinting, and bioinformatics identification are the primary methods currently used for the quality control. CONCLUSION: P. decursivum demonstrates anti-asthmatic, anti-inflammatory, and antioxidant effects, aligning with its traditional use. However, experimental validation of its efficacy against phlegm and viruses is needed. Additionally, analgesic effects mentioned in historical texts lack modern pharmacological studies. Numerous isolated compounds exhibit highly valuable medicinal properties. Future research can delve into exploring these substances further. Rigorous of heavy metal contamination, particularly Cd and Pb, is necessary. Simultaneously, investigating its pharmacokinetics and toxicity in humans is crucial for the safety.

A 'low-level' chemotaxonomic analysis of the plant family Apiaceae: the case of Scandix balansae Reut. ex Boiss. (tribe Scandiceae).

Analyses by GC and GC/MS of an essential-oil sample obtained from dry fruits of Scandix balansae Reut. ex Boiss. allowed the identification of 81 components, comprising 91.4% of the total oil composition. Interestingly, the major identified volatile compounds were medium-chain-length n-alkanes, i.e., tridecane (6.7%), pentadecane (13.4%), and heptadecane (19.3%), and a long-chain homolog nonacosane (7.6%). A number of minor oil constituents, among them tetradecyl 3-methylbutanoate, and octadecyl 2-methylpropanoate, 3-methylbutanoate, and pentanoate, turned out to have a restricted natural occurrence not only in umbellifers but also in the Plant Kingdom, whereas the last ester is a new natural compound in general. The identity of these rare plant constituents that present excellent chemotaxonomic marker candidates for Scandix species was unambiguously confirmed by co-injection of the oil sample with appropriate standards, which were synthesized for this purpose and fully characterized ((1) H- and (13) C-NMR, IR, MS). To explore the possible applicability of the essential oils' compositional data in the taxonomy of Apiaceae, the herein studied and additional 58 oils obtained from Scandiceae taxa were compared using multivariate statistical analyses (MVA). MVA demonstrated that the evolution of the volatiles' metabolism of Scandiceae taxa was neither genera-specific nor follows their morphological evolution.

Effect of pH and medium composition on chain elongation with Megasphaera hexanoica producing C4-C8 fatty acids.

Introduction: Chain elongation technology, which involves fermentation with anaerobic bacteria, has gained attention for converting short and medium chain substrates into valuable and longer-chain products like medium chain fatty acids (MCFAs). In the recent past, the focus of studies with pure chain elongating cultures was on species of other genera, mainly Clostridium kluyveri. Recently, other chain elongators have been isolated that deserve further research, such as Megasphaera hexanoica. Methods: In this study, batch studies were performed in bottles with two different media to establish the optimal conditions for growth of M. hexanoica: (a) a medium rich in different sources of nitrogen and (b) a medium whose only source of nitrogen is yeast extract. Also, batch bioreactor studies at pH values of 5.8, 6.5 and 7.2 were set up to study the fermentation of lactate (i.e., electron donor) and acetate (i.e., electron acceptor) by M. hexanoica. Results and discussion: Batch bottle studies revealed the yeast extract (YE) containing medium as the most promising in terms of production/cost ratio, producing n-caproate rapidly up to 2.62 ± 0.24 g/L. Subsequent bioreactor experiments at pH 5.8, 6.5, and 7.2 confirmed consistent production profiles, yielding C4-C8 fatty acids. A fourth bioreactor experiment at pH 6.5 and doubling both lactate and acetate concentrations enhanced MCFA production, resulting in 3.7 g/L n-caproate and 1.5 g/L n-caprylate. H2 and CO2 production was observed in all fermentations, being especially high under the increased substrate conditions. Overall, this study provides insights into M. hexanoica's behavior in lactate-based chain elongation and highlights optimization potential for improved productivity.

Short-Chain Fatty Acid Levels after Fecal Microbiota Transplantation in a Pediatric Cohort with Recurrent Clostridioides difficile Infection.

Though antibiotics are the mainstay treatment for Clostridioides difficile, a large population of individuals infected will experience recurrence. In turn, fecal microbiota transplantation (FMT) has emerged as a promising treatment for recurrent C. difficile infection (rCDI). Mechanistically, by providing a healthy, diverse flora to the infected individual, FMT "resets" the underlying gut microbiome dysbiosis associated with rCDI. A proposed mechanism through which this occurs is via microbiome metabolites such as short-chain fatty acids (SCFAs); however, this has not been previously studied in pediatric patients. Using mass spectroscopy, we quantified pre- and post-transplant levels of acetate, isovalerate, butyrate, formate, and propionate in pediatric patients diagnosed with rCDI (n = 9). We compared pre- and post-transplant levels within the rCDI cohort at 1, 3, 6, and 12 months post-transplant and correlated these levels with healthy controls (n = 19). We witnessed a significant difference in the combined SCFA levels and the individual levels of acetate, butyrate, isovalerate, and propionate in the pre-treatment rCDI cohort compared to the healthy controls. In addition, there was a significant increase in combined SCFA levels at 12 months post-transplant within the rCDI group compared to that of their pre-transplant levels, and, more specifically, acetate, propionate, and isovalerate increased from pre-transplant to 12 months post-transplant. The longitudinal aspect of this study allowed us to identify mechanisms that contribute to the durability of responses to FMT, as well as characterize the unique patterns of short-chain fatty acid level recovery in rCDI pediatric patients.

Short-chain fatty acids reprogram metabolic profiles with the induction of reactive oxygen species production in human colorectal adenocarcinoma cells.

Short-chain fatty acids (SCFAs) exhibit anticancer activity in cellular and animal models of colon cancer. Acetate, propionate, and butyrate are the three major SCFAs produced from dietary fiber by gut microbiota fermentation and have beneficial effects on human health. Most previous studies on the antitumor mechanisms of SCFAs have focused on specific metabolites or genes involved in antitumor pathways, such as reactive oxygen species (ROS) biosynthesis. In this study, we performed a systematic and unbiased analysis of the effects of acetate, propionate, and butyrate on ROS levels and metabolic and transcriptomic signatures at physiological concentrations in human colorectal adenocarcinoma cells. We observed significantly elevated levels of ROS in the treated cells. Furthermore, significantly regulated signatures were involved in overlapping pathways at metabolic and transcriptomic levels, including ROS response and metabolism, fatty acid transport and metabolism, glucose response and metabolism, mitochondrial transport and respiratory chain complex, one-carbon metabolism, amino acid transport and metabolism, and glutaminolysis, which are directly or indirectly linked to ROS production. Additionally, metabolic and transcriptomic regulation occurred in a SCFAs types-dependent manner, with an increasing degree from acetate to propionate and then to butyrate. This study provides a comprehensive analysis of how SCFAs induce ROS production and modulate metabolic and transcriptomic levels in colon cancer cells, which is vital for understanding the mechanisms of the effects of SCFAs on antitumor activity in colon cancer.

Evaluation of the Anticancer Properties of Geranyl Isovalerate, an Active Ingredient of Argyreia nervosa Extract in Colorectal Cancer Cells.

Chemotherapy is a general treatment procedure for cancer. The diversity in cancer incidence and the failure of therapy due to chemoresistance lead to increased cancer-related deaths. Therefore, new drugs with fewer secondary complications targeting diverse pathways are the need of the hour. Geranyl isovalerate (GIV), one of the active ingredients of ethyl acetate fraction of Argyreia nervosa is routinely used as a food flavoring agent. In this study, we found that GIV also exhibits anticancer activity when tested against the HCT116 cell line. It influenced the viability of the cells in a dose- and time-dependent manner. We examined whether GIV could induce oxidative stress and affect the mitochondrial membrane potential, thereby leading to apoptosis induction. Moreover, GIV could suppress the expression of antiapoptotic genes, such as BCl2 and PARP, and induce the expression of proapoptotic genes, such as Caspase 3 and 9. This is the first study demonstrating the anticancer activity of GIV and providing evidence for its mechanism of action. In conclusion, this study proposes GIV as a potential lead or supplementary molecule in treating and preventing colorectal cancer (CRC). Based on our findings, we conclude that GIV may be a viable lead or supplementary molecule for treating and preventing CRC.