Acute and subchronic toxicities of the ethanol and hot-water extracts from Chinese sumac (Rhus chinensis Mill.) fruits by oral administration in rats

The investigation on an ethnic medicinal plant of Elsholtiza bodinieri Vaniot: Chemical constituents, acute, 28-day subacute and 90-day subchronic toxicity evaluation

ETHNOPHARMACOLOGICAL SIGNIFICANCE

Elsholtiza bodinieri Vaniot, belonging to the family Lamiaceae, has important medicinal value in Yunnan province of China. Traditionally, its aerial parts have been used as an ethnomedicine to treat diaphoresis, headache, fever, cough, pharyngitis, dyspepsia, and hepatitis. However, the safety assessment of E. bodinieri is still unexplored.

AIM OF THE STUDY

This study aimed to investigate the phytochemical constituents of the hot water extract from E. bodinieri (HEEB) and evaluate the 14-day acute, 28-day subacute and 90-day subchronic toxicity by oral administration in Sprague-Dawley (SD) rats.

MATERIALS AND METHODS

The chemical constituents of HEEB were analyzed by UHPLC-ESI-HRMS/MS. Firstly, SD rats were chosen for a single oral administration of the maximum dose of 5000 mg/kg to evaluate toxicity. Subsequently, consecutive 28-day subacute and 90-day subchronic toxicity assessments of HEEB were conducted on Sprague-Dawley (SD) rats through repeated doses of 2500, 1250, 625, and 312.5 mg/kg for the former, and 1500, 1000, and 500 mg/kg for the latter. For toxicity evaluation, hematology and serum biochemical indicators were determined, and major organs of the rats were collected to calculate organ coefficients. Additionally, hematoxylin-eosin (H&E) staining was performed on the collected tissues to assess histopathological changes induced by repeated oral administration of HEEB.

RESULTS

A total of 23 compounds were identified by UHPLC-ESI-HRMS/MS analysis. Acute toxicity assessment revealed that oral administration of HEEB did not induce mortality and unnormal behavior changes in female rats over a 14-day period, suggesting that the approximate lethal dose (ALD) was higher than 5000 mg/kg. In consecutive 28-day and 90-day toxicity evaluations, HEEB doses of 2500 mg/kg and 1500 mg/kg resulted in hepatic and kidney tissue damage in both female and male rats, which was verified by the increased levels of AST, ALT, BUN, Na+, and Cl-.

CONCLUSIONS

After the acute, 28-day subacute and 90-day subchronic toxicity evaluation, the No Observed Adverse Effect Level (NOAEL) was determined as 1000 mg/kg/day. These findings not only provided a safety information for its medicinal and edible application, but also promoted the further comprehensive development of this plant.

Chemical analysis and biological activities on solvent extracts from different parts of Rhus chinensis mill

The present research is focused on the preparation of a variety of solvent extracts using different parts of Rhus chinensis Mill. for the estimation of phytochemicals and to perform biological activities. The highest phenolic and flavonoid contents were recorded as 141.48 ± 0.67 mg GAE/g in methanol root extract and 54.34 ± 0.28 mg QE/g in ethyl acetate root extract. Ethyl acetate root extract displayed an IC50 of 7.83 ± 0.18 µg/mL in the DPPH assay. TPC and TFC were found moderately correlated with antioxidant activity. The root and leaf extracts showed antibacterial activities comparable to those of standard drugs against the gram-positive and gram-negative bacteria. The MIC and MBC for root extract against Staphylococcus aureus were 7.8125 mg/mL and 15.625 mg/mL respectively. Similarly, the MIC and MBC for leaf extract against Escherichia coli were 15.625 mg/mL and 31.25 mg/mL respectively.

Testing of acute and sub-acute toxicity profile of novel naproxen sodium nanoformulation in male and female mice

Nanodrugs offer promising alternatives to conventionally used over the counter drugs. Compared to its free form, therapeutic benefits, and gastric tissue safety of naproxen sodium nanoformulation (NpNF) were recently demonstrated. Essential regulatory safety data for this formulation are, however, not available. To address this, male and female BALB/c mice were subjected to acute and 14-day repeated-oral dose assessments. Our data indicate that NpNF was well tolerated up to 2000 mg/kg b.w. A 14-day subacute toxicity testing revealed that the oral administration of low dose (30 mg/kg) NpNF did not produce any adverse effects on blood profile and serum biochemical parameters. Levels of oxidative stress markers and antioxidant enzymes neared normal. Histology of selected tissues also showed no evidence of toxicity. In contrast, a ten-fold increase in NpNF dosage (300 mg/kg), demonstrated, irrespective of gender, mild to moderate toxicity (p < 0.05) in the brain, stomach, and heart tissues, while ROS, LPO, CAT, SOD, POD, and GSH levels remained unaffected in the liver, kidney, spleen, testis, and seminal vesicles. No effect on serum biochemical parameters, overall indicated a no-observed-adverse-effect level (NOAEL) is 300 mg/kg. Further increase in dosage (1000 mg/kg) significantly altered all parameters demonstrating that high dose is toxic.

Blood-Pressure-Lowering and Endothelium-Dependent Vasorelaxant Effects of Nutgall Tree in Rats

Hypertension is the crucial modifiable risk factor for cardiovascular diseases, and efforts to identify functional foods that are effective for hypertension control are increasing. The nutgall tree (NT, Rhus chinensis Mill.) is used in traditional medicine and food because of its medicinal value. However, the role of NT in hypertension has not been investigated. Therefore, the hypotensive effect of NT leaf ethanol extract (NTE) was investigated in spontaneously hypertensive rats (SHRs). SHRs were allocated to three groups (control, 300, or 1000 mg/kg NTE), and blood pressure was measured before and after oral administration. Systolic and diastolic blood pressure significantly decreased in the NTE 1000 mg/kg group and was the lowest at 2 h after administration (-26.4 ± 10.3, -33.5 ± 9.8%, respectively). Daily NTE administration for five days also resulted in a similar effect. Further, the vasorelaxant effects and related mechanisms were investigated in the aortas of Sprague Dawley rats. NTE showed the dose-dependent blood-vessel-relaxing effect, and its mechanism involves the NO-sGC-cGMP pathway, activation of K+ channels, and reduction in the vasoconstrictive action of angiotensin II. Therefore, our study provides basic data indicating the potential use of NTE as a functional food for high blood pressure.

Safety evaluation of a proprietary ayruveda-based polyherbal preparation (arthralgex) used for arthritis

Arthralgex is a proprietary polyherbal preparation used in clinics to treat rheumatoid arthritis for decades. Its safety evaluation has not been reported. The study is aimed at evaluating the safety of arthralgex using Wistar rats, as per OECD guidelines. According to OECD 407, rats of either gender were separated into six groups (n= 6 each). The dose of arthralgex was decided based on an acute toxicity study. Under the treatment group, separate set of rats received arthralgex in three dose levels like - low, medium, and high (200, 400 & 800 mg/kg/day; p.o for 28 days). Satellite groups received high dose (800 mg/kg/day, p.o for 28 days), and control group received equal volume of vehicle. On day 28, blood samples were collected to estimate hematology and biochemistry parameters. Subsequently, rats were euthanized to collect organs for weighing and histopathology. Satellite groups were maintained for an additional 14 days post-treatment to assess toxicity reversibility and euthanized on day 43. Arthralgex did not show any signs of toxicity or major change in body weight in the acute toxicity study. Arthralgex has no significant adverse effect on general health status as confirmed by body weight, feed intake, hematology, biochemistry, urine analysis, internal organs, relative organ weight, and histopathological evaluation after 28 day treatment. Arthralgex could be considered safe for short-term treatment. Present findings may help researchers in dose fixing for sub-chronic and chronic toxicity studies, which is essential for safety evaluation for long-term use.

Chinese Sumac Fruits (Rhus chinesis Mill.) Alleviate Type 2 Diabetes in C57BL/6 Mice through Repairing Islet Cell Functions, Regulating IRS-1/PI3K/AKT Pathways and Promoting the Entry of Nrf2 into the Nucleus

This research aimed to probe the potential alleviative effects of ethanol extracts of Chinese sumac (Rhus chinesis Mill.) fruits against type 2 diabetes mellitus (T2DM) in C57BL/6 mice induced by high-fat/high-fructose diet (HFFD) and streptozotocin. The results showed that the ethanol extracts could significantly regulate blood glucose levels, glycosylated hemoglobin, blood lipids, insulin, and insulin resistance, while also restoring endogenous oxidative stress. Pathological and immunohistochemical analyses revealed that the extracts partially restored the physiological function of islet cells. Furthermore, Western blotting results suggested that the extracts could regulate the protein expression in IRS-1/PI3K/AKT signaling pathway, and immunofluorescence findings demonstrated their potential to promote the translocation of Nrf2 into the nucleus. This study elucidated a novel finding that ethanol extracts derived from Chinese sumac fruits have the potential to alleviate symptoms of T2DM in mice. Moreover, these findings could offer valuable scientific insights into the potential utilization of R. chinensis fruits as nutritional supplement and/or functional food to prevent or ameliorate diabetes.

Assessment of the acute and subacute toxicity of the aqueous extract of Moroccan Ferula communis fruit in a mouse model

Ferula communis L. is thought to possess a wide range of therapeutic qualities. This plant's safety is critical regarding its potential uses as a medicine. Using the techniques outlined in the OECD recommendations, the present study aimed to assess the acute and subacute toxicity profiles of Ferula communis aqueous extract (FC-Ext) in mice. In the acute study, the FC-Ext was administered to adult male and female Swiss albino mice through oral and intraperitoneal routes at doses of 0-4 g/kg. The general behavioral effects, mortality rates, and latency of mortality were evaluated for a period of 14 days. For the sub-acute dose study, the FC-Ext was administered orally to adult mice at doses of 125, 250, and 500 mg/kg on a daily basis for 28 days. Body weight and selected biochemical and hematological parameters were measured, and histological examinations of the liver, kidney, and spleen were conducted to assess any signs of organ damage at the end of the treatment period. The results of the acute toxicity study demonstrated that the LD50 values for the oral and intraperitoneal administration of FC-Ext were 3.6 g/kg and 2.3 g/kg, respectively. In the subacute toxicity study of FC-Ext, no significant changes in body weight were observed. However, a substantial increase in the weights of the liver, kidney, and spleen was observed in male mice. The administration of FC-Ext to mice at doses higher than 250 mg/kg resulted in a decrease in white blood cells and platelets in both sexes and a reduction in red blood cells and mean corpuscular hemoglobin concentration in males and hemoglobin in females. No changes in biochemical parameters were observed. Microscopic examination of vital organs such as the liver, kidney, and spleen revealed no significant injuries. Based on the current results, the aqueous extract of Ferula communis has low toxicity. These findings provide important information about the toxicity profile of the traditional medicine plant Ferula communis.

Rhus chinensis Mill. fruits alleviate liver injury induced by isoniazid and rifampicin through regulating oxidative stress, apoptosis, and bile acid transport

ETHNOPHARMACOLOGICAL RELEVANCE

Rhus chinensis Mill. is a species of the genus Rhus belonging to the family Anacardiaceae. Its fruits used to treat/prevent liver related diseases (e.g., jaundice and hepatitis) in folk medicine. Otherwise, the effects and underlying mechanisms of the fruits on the prevention of isoniazid and rifampicin-caused liver injury have not been investigated.

AIM OF THE STUDY

To study the preventive effects and mechanisms of the Rhus chinensis Mill. fruits on isoniazid and rifampicin-caused liver injury.

MATERIALS AND METHODS

This experiment was based on rifampicin (75 mg/kg/day) and isoniazid (75 mg/kg/day)-induced liver damage model to explain the pharmacological effects of Rhus chinensis Mill. fruits. The prevention of the extract from Rhus chinensis Mill. fruits on isoniazid and rifampicin-caused liver injury were evaluated using biochemical parameters, histopathological analysis, and immunofluorescence technique. Apart from that, the potential molecular mechanisms were elucidated by analyzing the expression of such crucial proteins participated in oxidative stress, apoptosis, and bile acid transport.

RESULTS

The extract from Rhus chinensis Mill. fruits significantly reduced the levels of ALT, AST, TBIL, ALP and MDA. Besides, the extract, especially 800 mg/kg b.w., was remarkably decreased the content of TNF-α,IL-6 and IL-1β, restored the levels of GSH and SOD. The results of Western blot also presented that the extract could activate the Nrf2 protein pathway and inhibit the expression of CYP2E1 to reduce oxidative stress. Meanwhile, the extract significantly up-regulated the expressions of BSEP and Mrp2 to regulate the transport of bile acid, and alleviated the cellular apoptosis via adjusting the expression of Bax and Bcl-2 proteins.

CONCLUSIONS

Rhus chinensis Mill. fruits can prevent the liver injury induced by isoniazid and rifampicin in mice through adjusting the expressions of multiple proteins in oxidative stress, apoptosis, and bile acid transport pathways. This paper may provide scientific basis for the fruits as a Chinese medicine to prevent/cure liver injury.

Safety assessment of oil extracted from lacquer (Toxicodendron vernicifluum (Stokes) F.A. Barkley) seed: acute and subchronic toxicity studies in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Toxicodendron vernicifluum (Stokes) F.A. Barkley (RVS) is an economic tree species and widely distributed in East Asia. Wood parts and raw lacquers of RVS have been used in coatings, herbal medicines or food supplements, and the leaves, flowers, roots, and fruits of RVS are also widely used in medicine traditionally. Lacquer seed oil (LSO) has potential health benefits and has not previously been evaluated for safety.

AIM OF THE STUDY

The aim of the present study was to investigate the toxicological potential of LSO by acute and subchronic toxicity tests.

MATERIALS AND METHODS

The characterization of fatty acids of the LSO was carried out by gas chromatography. In the acute toxicity study, LSO was administered at single doses of 5000 or 10000 mg/kg by oral gavage. The subchronic toxicity study was conducted by daily oral administration of LSO at doses of 1250, 2500 and 5000 mg/kg/day for 30 consecutive days. The animals were evaluated for clinical observations, body weight, organ weight, feed consumption, biochemical and hematological parameters, and liver, lung, and kidney histology.

RESULTS

There were no mortality and toxic changes were observed in acute toxicity study. The results of subchronic toxicity showed no toxicologically significant changes in clinical observations, body weight, organ weight, biochemical or hematological parameters. Histopathologic results indicated slight hepatic steatosis and inflammatory infiltration in the rats of 5000 mg/kg/day LSO treated group. However, the histopathologic observation was not confirmed by hepatic biochemical analysis.

CONCLUSIONS

These results suggested that the LD₅₀ of LSO is over 10000 mg/kg and LSO is non-toxic for SD rats in acute toxicity study. The no observed adverse effect level (NOAEL) of LSO in rats is considered to be 5000 mg/kg/day, and liver is the potential target organ of LSO for 30-day subchronic toxicity study.

Acute and Subacute Toxicity Studies of Erodium guttatum Extracts by Oral Administration in Rodents

The present study aimed to evaluate the acute and subacute toxicity profiles of Erodium guttatum extracts in mice using the methods described in the guidelines of the OECD. In the acute toxicity study, the LD₅₀ value was greater than 2000 mg/kg. The subacute toxicity study of E. guttatum extracts showed no significant changes in body or organ weights. The administration of E. guttatum extracts to mice at a dose of 200 mg/kg led to an increase in white blood cells, platelets and hemoglobin. Moreover, the aqueous extract of E. guttatum only decreased liver aspartate aminotransferase (ASAT) levels at a dose of 200 mg/kg, and creatinine and urea levels did not show any significant alterations compared to the control group. Our results showed that the extracts of E. guttatum caused a slight increase in alanine aminotransferase (ALAT) and triglycerides. The histological study showed that mice treated with E. guttatum extracts experienced some histopathological changes in the liver, particularly with the methanolic extract, and slight changes in the kidneys and pancreas. Regarding the renal profile, no toxicity was observed. These results provide basic information on the toxicological profile of E. guttatum used in traditional medicine.

Water Caltrop (Trapa quadrispinosa Roxb.) Husk Improves Oxidative Stress and Postprandial Blood Glucose in Diabetes: Phenolic Profiles, Antioxidant Activities and α-Glycosidase Inhibition of Different Fractions with In Vitro and In Silico Analyses

The aim of this study was to investigate the phenolic profiles, antioxidant activities and α-glycosidase inhibitory activities of three different phenolic fractions from water caltrop (Trapa quadrispinosa Roxb.) husk and to further explore the predominant compounds and their mechanisms on α-glycosidase inhibition by virtual screening and molecular dynamics. A total of 29 substances were identified and quantified in this study. Tannins were the main constituents of water caltrop husk extract. All of the free phenolic (FP), esterified phenolic (EP) and insoluble-bound phenolic (BP) fractions exhibited good antioxidant activities, and the BP had the highest radical scavenging ability with IC50 values of 0.82 ± 0.12 μg/mL (ABTS) and 1.15 ± 0.02 μg/mL (DPPH), respectively (p < 0.05). However, compared with the EP and BP, the FP showed the strongest inhibition towards the α-glycosidase and the IC50 value of FP was 1.43 ± 0.12 μg/mL. The 1,2,6-trigalloylglucose and α-glycosidase complex had better root mean square deviations (RMSD) stability via molecular dynamics simulation study. Results obtained from this study may provide a good potential natural resource for the improvement of oxidative stress injury and blood glucose control in diabetes mellitus, which could expand the use of water caltrop husk and improve its economic value.

A comprehensive review on ethnobotanical, phytochemical and pharmacological aspects of Rhus chinensis Mill

ETHNOPHARMACOLOGICAL RELEVANCE

Rhus chinensis Mill., firstly recorded as herbal medicine in Shan Hai Jing, have been used for thousands of years to treat various diseases.

AIM OF THIS REVIEW

This review targets on the ethnomedicinal applications of R. chinensis and to gather the phytochemical, pharmacological and toxicological data which support the therapeutic potential of R. chinensis in treatment on different diseases, with emphasis on the naturally occurring compounds and detailed pharmacological developments.

MATERIALS AND METHODS

The information of R. chinensis was collected based on a variety of popular databases such as Scifinder, PubMed, Web of Science, ScienceDirect, Springer, Wiley, ACS, CNKI, Baidu Scholar, Google Scholar and other published materials (books and Ph.D. and M. Sc. Dissertations). The keywords "Rhus chinensis", "Rhus amela", "Rhus javanica", "Rhus osbeckii", "Rhus semialata", and "Schinus indicus" were applied to search the literature related in this review.

RESULTS

152 natural compounds of R. chinensis belong to different classes are presented in this review, including flavonoids, lignans, coumarins, simple phenolics, urushiols, tannins, triterpenoids, steroids and other types of constituents. Among them, flavonoids, lignans, and triterpenoids are most frequently reported components. The pharmacological effects of R. chinensis were numerous and complicated, including anti-viral, anti-bacterial, anti-diarrheal, hepatoprotective, anti-proliferation, enzyme-inhibiting, anti-oxidants and so on.

CONCLUSION

In order to discover more compounds with novel structures to both enrich chemical context of genus Rhus and expand the variety of constituents, the phytochemical research is urgent and indispensable. Anti-diarrhea, the most widely application of R. chinensis traditionally, is insufficient in underlying mechanism exploration. And for other activities, in-depth studies on the mechanism of pharmacological effects in vivo and in vitro are both needed. Meanwhile, pharmacokinetics, toxicology, quality control and preclinical and clinical data are urgent to assess the rationale and safety of the medicinal and food application of R. chinensis.

E Se tea alleviates acetaminophen-induced liver injury by activating the Nrf2 signaling pathway

E Se tea is a traditional herbal tea used in the prevention of liver diseases. However, the hepatoprotective effect of E Se tea has not been investigated. This study aimed to determine the protective effect of E Se tea on acetaminophen (APAP)-induced acute liver injury and its potential mechanism. Hot water extracts and aqueous-ethanol extracts of E Se tea were obtained, which were analyzed to determine the chemical constituents of the tea. Phlorizin and phloretin were found to be the dominant chemical compounds. Histopathological analysis showed that E Se tea extract inhibited APAP-induced inflammatory infiltration, necrosis, and cellular vacuolization of hepatocytes in the liver tissue. The E Se tea extract could significantly ameliorate liver injury, inhibit an inflammatory response, and reduce oxidative stress. Western blot analysis revealed that E Se tea extract upregulated the expressions of nuclear Nrf2, HO-1 and NQO1 proteins and downregulated the expressions of cytoplasmic Nrf2 and Keap1 proteins in the hepatocyte. qPCR results showed that E Se tea extract also increased the expression of antioxidant genes (SOD2, Gpx1, GCLC and GCLM). These findings exhibited that E Se tea, enriched in dihydrochalcones, can be used to effectively prevent and manage liver dysfunction.

Rhus chinensis Mill. Fruits Ameliorate Hepatic Glycolipid Metabolism Disorder in Rats Induced by High Fat/High Sugar Diet

Hepatic glycolipid metabolism disorder is considered as one of the key factors in the pathogenesis of many chronic diseases. The objective of this study was to investigate the protective effect and underlying mechanisms of Rhus chinensis Mill. fruits against hepatic glycolipid metabolic disorders in rats induced by a high fat/high sugar diet. Results showed that ethanol extract, especially at a dose of 600 mg/kg b.w., could effectively ameliorate glycolipid metabolic disorders in rats. The biochemical indexes, including CAT, GSH and HOMA-IR, were significantly improved by the administration of ethanol extract. Immunohistochemistry and Western blot analysis revealed that ethanol extract up-regulated the expression levels of PI3K/AKT, PPAR-α, and the phosphorylation of IRS1 and AMPK proteins, and down-regulated the expressions of SREBP-1 and FAS proteins in the liver, which are closely related to hepatic glycolipid metabolism. Those findings suggested that R. chinensis Mill. fruits could be developed as functional foods and/or nutraceuticals for preventing or controlling some chronic diseases related to hepatic glycolipid metabolism disorder.

Safety evaluation and hypolipidemic effect of aqueous-ethanol and hot-water extracts from E Se tea in rats

E Se tea, processed by the fresh leaves of Malus toringoides (Rehd.) Hughes, is a traditional herbal tea with various human benefits. The present study was aimed to evaluate the toxicity and hypolipidemic effect of aqueous-ethanol extract (EE) and hot-water extract (WE) from E Se tea. Eight main chemical constituents in EE and WE were respectively identified and quantified by UHPLC-HRMS/MS. EE is rich in TPC and TFC, while WE had higher TPS content. Both EE and WE exhibited strong antioxidant activity with no significant difference. The acute toxicity study revealed that the LD₅₀ values were higher than 5000 mg/kg, while both WE and EE had no significant adverse effect in rats by subacute toxicity assay. However, the triglyceride (TG) content in experiment groups (male) and highest doses groups (female) significantly decreased. Furthermore, the hypolipidemic effect of WE and EE were performed on high fat diet induced hyperlipidemic rats. The result exhibited that either WE or EE could effectively regulate lipid droplet accumulation in liver, and reduce the adipocyte size. These results demonstrated that these two extracts from E Se tea could be regarded as a potential functional dietary supplement in preventing and treating diet induced metabolic diseases.

Genotoxic risk in humans and acute toxicity in rats of a novel oral high-dose coenzyme Q10 oleogel

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An oral high-dose CoQ₁₀ oleogel was assessed in its genotoxicity and acute toxicity.

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There was no genotoxic risk associated with the use of CoQ₁₀ oleogel in volunteers.

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Biochemical parameters remained within reference values after oleogel treatment.

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No signs of toxicity or mortality were observed in the rats exposed to the oleogel.

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The novel high-dose CoQ₁₀ oleogel formulation designed is safe for oral consumption.

Coenzyme Q₁₀ (CoQ₁₀) supplementation has demonstrated to be safe and effective in primary and secondary CoQ₁₀ deficiencies. Previously, we have designed a high-dose CoQ₁₀ oleogel (1 g/disk) with excipients used in quantities that do not represent any toxic risk. However, it was necessary to demonstrate their safety in the final formulation. Following this purpose, an acute toxicity study of the oleogel in rats was performed. Furthermore, the genotoxic risk was evaluated in human volunteers after CoQ₁₀ supplementation with oleogel and compared to the solid form (1 g/three 00-size-capsules). In addition, the general health status and possible biochemical changes of the participants were determined using serum parameters. Results suggested the absence of adverse effects caused by the interaction of the components in the oleogel formulation. Therefore, we conclude that the designed novel high-dose CoQ₁₀ oleogel was safe for oral consumption.

Acute and subacute toxicity evaluation of Houttuynia cordata ethanol extract and plasma metabolic profiling analysis in both male and female rats

Houttuynia cordata has been used as a traditional medicine for more than 1500 years. It has aroused wide public concern about its safety in the past few years, for it contains various aristolactams. However, the safety of H. cordata extract remains unclear. In the present study, single dose (2000 mg/kg) and subacute (250, 500, and 1000 mg/kg/day for 28 days) oral toxicity studies of the 95% ethanol extract of H. cordata (HCE) were performed in both male and female Sprague-Dawley (SD) rats. Hematological, biochemical, histopathological parameters, and plasma metabolic profiling were assessed. The single-dose toxicity of HCE was more than 2000 mg/kg. The subacute toxicity results showed that no significant adverse effect of HCE was observed at 250 mg/kg/day. However, five rats died in 500 and 1000 mg/kg/day groups and exhibited toxicities to liver and kidney. Plasma metabolic profiling analysis suggested that a number of metabolic disturbances were induced by oral administration of HCE, focusing on energy metabolism, amino acid metabolism, and lipids metabolism. Moreover, it appeared that male rats were more susceptible to the toxic effects of HCE than female rats. Therefore, in this preliminary study, oral administration of HCE 250 mg/kg/day can be regarded as the no observed adverse effect level in rats over 28 days. However, long-term use of HCE with large doses exhibited some hepatotoxicity and nephrotoxicity in rats.

Phytochemicals of Rhus spp. as Potential Inhibitors of the SARS-CoV-2 Main Protease: Molecular Docking and Drug-Likeness Study

Background

The outbreak of coronavirus disease 2019 (COVID-19) induced by the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in China and spread to cover the entire world with an ongoing pandemic. The magnitude of the situation and the fast spread of the new and deadly virus, as well as the lack of specific treatment, led to a focus on research to discover new therapeutic agents.

Aim

In this study, we explore the potential inhibitory effects of some active polyphenolic constituents of Rhus spp. (sumac) against the SARS-CoV-2 main protease enzyme (M^pro; 6LU7).

Methods

26 active polyphenolic compounds of Rhus spp. were studied for their antiviral activity by molecular docking, drug likeness, and synthetic accessibility score (SAS) as inhibitors against the SARS-CoV-2 M^pro.

Results

The results show that all tested compounds of sumac provided good interaction with the main active site of SARS-CoV-2 M^pro, with better, lower molecular docking energy (kcal/mol) compared to the well-known drugs chloroquine and favipiravir (Avigan). Only six active polyphenolic compounds of Rhus spp. (sumac), methyl 3,4,5-trihydroxybenzoate, (Z)-1-(2,4-dihydroxyphenyl)-3-(3,4-dihydroxyphenyl)-2-hydroxyprop-2-en-1-one, (Z)-2-(3,4-dihydroxybenzylidene)-6-hydroxybenzofuran-3(2H)-one, 3,5,7-trihydroxy-2-(4-hydroxyphenyl)chroman-4-one, 2-(3,4-dihydroxyphenyl)-3,5-dihydroxy-7-methoxy-4H-chroman-4-one, and 3,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one, were proposed by drug likeness, solubility in water, and SAS analysis as potential inhibitors of M^pro that may be used for the treatment of COVID-19.

Conclusion

Six phenolic compounds of Rhus spp. are proposed for synthesis as potential inhibitors against M^pro and have potential for the treatment of COVID-19. These results encourage further in vitro and in vivo investigations of the proposed ligands and research on the preventive use of Rhus spp. against SARS-CoV-2.

Protective effect of Que Zui tea hot-water and aqueous ethanol extract against acetaminophen-induced liver injury in mice via inhibition of oxidative stress, inflammation, and apoptosis

The tender leaves and buds of Vaccinium dunalianum Wight have been traditionally processed as folk tea, known as Que Zui tea (QT), with a wide range of benefits to humans. In this study, Que Zui tea hot-water extract (QTW) and aqueous-ethanol extract (QTE) were tested for their effectiveness to alleviate acetaminophen (APAP)-induced liver damage. QTW and QTE significantly inhibited the alanine aminotransaminase, aspartate aminotransaminase, tumor necrosis factor-α, interleukin-6, and interleukin-1β levels in the serum. Both extracts also ameliorated pathological damage and inhibited oxidative stress in the liver of APAP-induced mice. In addition, QTW and QTE activated the nuclear erythroid related factor 2 signal pathway, and inhibited mitogen-activated protein kinase activation. QTW and QTE also suppressed hepatocyte apoptosis by improvement of Bcl-2/Bax and inhibition of caspase-3 and caspase-9 expression. The results demonstrated that QTW and QTE could effectively protect APAP hepatotoxicity, which might be attributed to their antioxidant, anti-inflammatory and anti-apoptosis activities.

Toxicity assessment of saline extract and lectin-rich fraction from Microgramma vacciniifolia rhizome

Microgramma vacciniifolia is broadly used in folk medicine but safety information is unavailable. Therefore, we evaluated the toxicity of a saline extract and a lectin-rich fraction of M. vacciniifolia rhizome. The extract showed hemolytic activity on mice erythrocytes at 1000 μg/mL, whereas the fraction promoted hemolysis (8.57-26.15%) at all tested concentrations (10-1000 μg/mL). Acute toxicity test in mice indicated an LD₅₀ of >5000 mg/kg. Hematological alterations and increased serum alkaline phosphatase level were observed in the treated animals. Transaminases and urea levels increased in the groups treated with the extract or fraction at 5000 mg/kg. Leukocyte infiltration was observed in the liver of extract-treated animals and in the liver and lungs of mice treated with the fraction. The kidneys of animals treated with the fraction at 5000 mg/kg presented hydropic degeneration. The extract and fraction did not induce oxidative stress in the liver and did not show genotoxicity, as examined by micronucleus and comet assays. In conclusion, the preparations were not lethal to mice but caused some signs of toxicity, mainly the fraction. The results indicated the need to evaluate the toxicity of M. vacciniifolia rhizome in other models and in chronic assays.

Could Sumac Be Effective on COVID-19 Treatment?

Sumac is an herbal product, commonly consumed as a spice and was used for medical treatment for centuries. The phytochemical structure of Sumac was studied extensively, and it was established that the herb contained tannins, polyphenols, flavonoids, organic acids, and essential oils. Various scientific studies demonstrated that Sumac had a free oxygen radical-scavenging effect, a protective effect against liver damage, antihemolytic, leukopenia, and antifibrogenic effects, along with its antiviral, antimicrobial, anti-inflammatory, and antioxidant properties. Recently, several scientific studies described the pathophysiology, clinical course, and the treatment of COVID-19 infection. The examination of the characteristics of COVID-19 infection revealed via the clinical studies suggests that Sumac extract could be useful in the treatment of COVID-19. Given the scientific studies focusing on the beneficial effects of Sumac, the present review aims to provide an encouraging viewpoint to investigate whether Sumac is effective in treating COVID-19 infection.

Acute and Sub-Acute Toxicological Evaluations of Bioactive Alkaloidal Extract from Melodinus henryi and Their Main Chemical Constituents

Melodinus henryi is a good source of terpenoid indole alkaloids, and traditionally used as a folk medicine in the treatment of meningitis and fracture. In order to further exploit their potential uses, its anti-inflammatory and immunosuppressive activities, safety evaluations and chemical profiles have been illustrated. Compared to the crude methanol extract from M. henryi and its non-alkaloidal fraction, the total alkaloidal fraction (MHTA) had the strongest anti-inflammatory and immunosuppressive activities. In the acute oral toxicity assay, the half lethal dose (LD50) of MHTA was more than 2000 mg/kg. The sub-acute toxicity assay for consecutive 28 days exhibited MHTA at a lower concentrations of less than 500 mg/kg might be regarded as safe, and might damage spleen, liver, kidney, and heart when the dose is higher than 1000 mg/kg. In addition, a phytochemical investigation on MHTA led to the isolation of 15 monoterpenoid indole alkaloids. Thus, in regard with the potent side effects of MHTA, it should be used with caution in the development of phytomedicine.

The preventive effect of phenolic-rich extracts from Chinese sumac fruits against nonalcoholic fatty liver disease in rats induced by a high-fat diet

The objective of this study is to investigate the preventive effect of phenolic-rich extracts from Chinese sumac (Rhus chinensis Mill.) fruits against NAFLD in rats induced by a high-fat diet and to clarify the underlying mechanisms.

Safety evaluation of syringic acid: subacute oral toxicity studies in Wistar rats

Syringic acid (SA) is a phenolic acid and have been investigated for diverse pharmacological activities, but the safety and/or mechanism of toxicity is still lacking in the literature. Subacute toxicity studies will add value to its pharmacological profile and support its exploration as a future medicine. According to OECD TG 407 (OECD, 2008), rats were divided into 3 groups (n = 12). The dose of SA was decided by limit test. Treatment and satellite groups received SA (1000 mg/kg/day, p.o for 14 days), whereas an equal volume of vehicle was given to control groups. In order to access reversibility, satellite groups were kept for another 14 days post-treatment. The toxic signs, mortality and body weight changes were recorded. On day 15 and 29 the rats were anesthetized to collect blood for estimation of hematological and biochemical parameters and then sacrificed to collect internal body organ for weighing and histopathological studies. SA has no major adverse effect on the body weight, food intake, erythropoiesis, leucopoiesis and on internal body organs which was confirmed by evaluating various biochemical and hematological parameters, relative body organ weight and histopathological studies. Therefore, SA could be considered safe over limited period of time and this study may help researchers in establishing the doses for the longer-term subchronic studies. Further, subchronic and chronic toxicity studies are required to evaluate safety on long term use.

Pharmacological, phytochemical and in-vivo toxicological perspectives of a xero-halophyte medicinal plant: Zaleya pentandra (L.) Jeffrey

This study endeavours to investigate the phytochemical composition, biological properties and in vivo toxicity of methanol and dichloromethane extracts of Zaleya pentandra (L.) Jeffrey. Total bioactive contents, antioxidant (phosphomolybdenum and metal chelating, DPPH, ABTS, FRAP and CUPRAC) and enzyme inhibition (cholinesterases, tyrosinase α-amylase, and α-glucosidase) potential were assessed utilizing in vitro bioassays. UHPLC-MS phytochemical profiling was carried out to identify the essential compounds. The methanol extract was found to contain highest phenolic (22.60 mg GAE/g) and flavonoid (31.49 mg QE/g) contents which correlate with its most significant radical scavenging, reducing potential and tyrosinase inhibition. The dichloromethane extract was most potent for phosphomolybdenum, ferrous chelation, α-amylase, α-glucosidase, and cholinesterase inhibition assays. UHPLC-MS analysis of methanol extract unveiled to identify 11 secondary metabolites belonging to five sub-groups, i.e., phenolic, alkaloid, carbohydrate, terpenoid, and fatty acid derivatives. Additionally, in vivo toxicity was conducted for 21 days and the methanol extract at different doses (150, 200, 250 and 300 mg/kg) was administered in experimental chicks divided into five groups each containing five individuals. Different physical, haematological and biochemical parameters along with the absolute and relative weight of visceral body organs were studied. Overall, no toxic effect was noted for the extract at tested doses.

Acute and subacute toxicity evaluation of ethanol extract from aerial parts of Epigynum auritum in mice

Acute and subacute toxicities of the ethanol extract from Epigynum auritum (EAE) wereperformed by oral administration in pathogen-free mice. Acute toxicity study was performed at a single dose of 5000 mg/kg for 14 consecutive days, while subacute toxicity test was conducted by daily oral administration of EAE at doses of 312, 625, 1250, and 2500 mg/kg for 28 days. Acute toxicity study showed that LD₅₀ of EAE was over 5000 mg/kg. The results of subacute toxicity showed no significant adverse effect of EAE at 312 mg/kg. Moreover, EAE exhibited toxicities to liver, spleen and kidney in mice determined by hematological, serum biochemical and histological analyses during daily oral administration of 1250 mg/kg and 2500 mg/kg EAE. The results revealed that the dose of EAE lower than 625 mg/kg can be regarded as safe.