Evaluation of acute and sub-chronic toxicity of lithothamnion sp. in mice and rats

In silico, in vitro, and in vivo acute and sub-acute toxicity profiling of whole plant methanol extract of Equisetum diffusum D. Don from the sub-Himalayan West Bengal, India, having ethnobotanical uses

BACKGROUND

Equisetum diffusum D. Don commonly known as 'Himalayan horsetail', has been traditionally used in the treatment of back pain, bone fracture and dislocation, and arthritis by various tribal communities of India. Our previous study confirmed the anti-inflammatory efficacy of the plant through in silico, in vitro, and in vivo model studies. Therefore, the current research is focused on safety dose evaluation for the first-time of the whole-plant methanol extract (EDME) of E. diffusum through appropriate in silico, in vitro, and in vivo approaches.

METHOD

The whole plant, along with its rhizomes, was collected, and the methanol extract was prepared. The in silico ADMET study was performed to predict the pharmacokinetics profile and toxicity of all the identified phyto-compounds of EDME previously screened by GC-MS study. In vitro cytotoxicity study of EDME was performed using two cell lines: kidney (HEK293) and liver (Huh7) cell lines. The in vivo toxicity study of EDME was validated by the acute toxicity (OECD 423, 2002) and sub-acute toxicity assays (OECD 407, 2008) in the Wistar Albino rat model.

RESULTS

The in silico ADMET study of all 47 bioactives predicted good pharmacokinetic and low toxicity profiles. In vitro cytotoxicity showed higher IC50 values of EDME viz., 672 ± 15.7 μg/mL and 1698 ± 6.54 μg/mL for both kidney (HEK293) and liver (Huh7) cell lines, respectively, which were considered as low-toxic. Based on acute oral toxicity, the LD50 value of the extract was considered "non-toxic" up to a feeding range of 2000 mg/kg of body weight. The regular consumption of the extract for an extended period (28 days) was also qualified as safe based on the body and organ weight, hematological, biochemical, and histoarchitecture results in the sub-acute toxicity assay.

CONCLUSION

The detailed in silico, in vitro, in vivo (acute and sub-acute oral toxicity) studies gave us a new insight to the safety dose evaluation of Equisetum diffusum, which may serve as a reliable documentation for undertaking the experimental validation of the ethnobotanical uses of the plant which would help in the field of drug development for the treatment of inflammation related complications.

Acute and subacute hepatotoxicity of genipin in mice and its potential mechanism

Gardenia, as a medicinal and edible herb, has the pharmacological activity of protecting the liver and cholagogue, but the hepatotoxicity induced by the chemical component genipin (GP) limits its application. The aim of this study was to evaluate the acute and subacute hepatotoxicity of genipin in normal mice and mice with α-naphthalene isothiocyanate (ANIT)-induced liver injury. The results of the acute study showed that the LD50 of genipin was 510 mg/kg. Genipin exhibited hepatotoxicity in normal and jaundiced mice at doses of 125 mg/kg, 250 mg/kg, and 500 mg/kg, which increased with dose. In a 28-day subacute study, the 50 mg/kg and 100 mg/kg dose groups showed some pharmacodynamic effects at 7 days but exhibited hepatotoxicity that increased with time and improved after drug withdrawal. In addition, based on proteomics, the mechanism of liver injury induced by genipin may be related to the disruption of the UDP-glucuronosyltransferase system and cytochrome P450 enzyme activity. In conclusion, this study showed that genipin hepatotoxicity was time- and dose dependent, but it is worth mentioning that hepatotoxicity was reversible. It is hoped that this study will provide a scientific basis for circumventing the adverse effects of genipin.

Evaluation of physicochemical parameters, acute and subchronic toxicities, and anti-diabetic activity of Spondias venulosa (Engl.) Mart. ex Engl. leaf extract on alloxan-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Spondias venulosa is a medicinal plant whose leaves are popularly used for decades in Northeast Nigeria as a first-choice medicinal plants for the treatment of diabetes. This claim has not been proven scientifically.

AIM OF THE STUDY

The present study was carried out to determine the physicochemical profiles, acute, sub-chronic toxicities, and antidiabetic activity the leaf extract in alloxan-induced diabetic rats.

MATERIALS AND METHODS

The physicochemical parameters of S. venulosa leaves, acute, subchronic toxicities, and antidiabetic activity in alloxan-induced diabetic rats were determined using standard procedures. All physicochemical parameters were carried out triplicate. Acute and subchronic toxicity studies were carried out following OECD guidelines by administering maximum extract dose of 2000 mg/kg orally to Wistar rats. Subchronic toxicity and antidiabetic studies were carried out in rats of opposite sexes at doses 300, 600, and 1200 mg/kg (orally).

RESULTS

Results obtained showed that the moisture content, water soluble extractive, and organic matter had values of 4.98 ± 1.01, 12.04 ± 1.24 and 1.01 ± 0.01% w/w respectively. The metallic contents of the methanol leaf extract revealed the presence of zinc with value of 12.01 ± 1.01 ppm (normal range:< 100 mg/kg DM) and copper with value of 6.24 ± 2.14 ppm (normal range:< 30 mg/kg DM). Oral median lethal dose (LD₅₀) was estimated to be greater than 2000 mg/kg since the extract did not produce any sign of toxicity or death in short term while, subchronic toxicity study showed that there was no significant weight loss in the rats after 28 days of extract administration. All hematology and biochemical parameters showed no elevated values when compared to the control group (p < 0.05). Histopathological examinations of major organs do not show signs of organ damages which indicate that the extract was safe at the doses administered. Oral administration of extract doses for 30 days reduced blood glucose levels in alloxan-induced diabetic rats in dose-dependent manner compared (p < 0.05) to standard drug (Glibenclamide).

CONCLUSIONS

Our study showed some physicochemical parameters of S. venulosa leaf which are essential for its identification from closely related species in traditional medicine. The study further showed that S. venulosa methanol leaf extract possessed antidiabetic activity, thus, justifying its use for the treatment of diabetes in Nigeria. However, there is need to identify and investigate the bioactive compound(s) responsible for the activity towards drug discovery.

Assessment of the acute and sub-acute toxicity of the ethanolic extract of the aerial parts of Crassocephalum rabens (Asteraceae) in rats

This pioneering study was to assess the acute and sub-acute toxicity of the ethanolic extract of the aerial parts of Crassocephalum rabens (Asteraceae) in rats. C. rabens is a common vegetable and herb for treating inflammation-related syndromes in Taiwan. Pharmacological studies have unveiled that the extracts of C. rabens have potential to become hepatoprotective, anti-inflammatory, or anti-cancer agents. The toxicological effects of the aerial parts of C. rabens in rodents are still elusive. For the acute toxicity study, rats were administrated with a single dose of 5,000 mg/kg body weight (BW) and observed for 14 days in accordance with the Organization for Economic Cooperation and Development (OECD) guideline No. 420. For the sub-acute toxicity study, animals were orally treated with daily doses of 0, 416.7, 833.3, and 1,666.7 mg/kg BW for 28 days based on the OECD guideline No. 407. The toxicity of the repeated dose was observed with anthropometric, hematological, and biochemical parameters as well as histology. The mortality and critical pathological and biochemical abnormalities were not observed in the acute and/or sub-acute toxicity studies. The oral median lethal dose (LD₅₀) of the extract was greater than 5000 mg/kg BW. The no-observed-adverse-effect-level (NOAEL) in male and female rats was greater than 1,666.7 mg/kg BW. As such, the extract of the aerial parts of C. rabens is considered a non-toxic substance.

Applying Seaweed Compounds in Cosmetics, Cosmeceuticals and Nutricosmetics

The interest in seaweeds for cosmetic, cosmeceutics, and nutricosmetics is increasing based on the demand for natural ingredients. Seaweeds offer advantages in relation to their renewable character, wide distribution, and the richness and versatility of their valuable bioactive compounds, which can be used as ingredients, as additives, and as active agents in the formulation of skin care products. Bioactive compounds, such as polyphenols, polysaccharides, proteins, peptides, amino acids, lipids, vitamins, and minerals, are responsible for the biological properties associated with seaweeds. Seaweed fractions can also offer technical features, such as thickening, gelling, emulsifying, texturizing, or moistening to develop cohesive matrices. Furthermore, the possibility of valorizing industrial waste streams and algal blooms makes them an attractive, low cost, raw and renewable material. This review presents an updated summary of the activities of different seaweed compounds and fractions based on scientific and patent literature.

Antioxidant mediated protective effect of Bridelia tomentosa leaf extract against carbofuran induced oxidative hepatic toxicity

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Bridelia tomentosa is a traditional medicinal plant that is used against colitis, traumatic injury, diarrhea, and diabetes.

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Gallic acid, Tannic acid, salicylic acid, and naringin were isolated from the leaf of B. tomentosa for the first time.

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B. tomentosa extract amended serum biochemical markers, MDA levels, and improved the levels of hepatic antioxidant enzymes.

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Phenolic and flavonoid compounds of the B. tomentosa can be used as nutraceuticals for treating oxidative hepatic ailments.

Bridelia tomentosa (B. tomentosa) is a traditional medicinal plant for treating diverse ailments. Hence, we designed our study to scrutinize the protective effect of the methanol extract of B. tomentosa leaf (BTL) against carbofuran-induced oxidative stress-mediated hepato-toxicity in Sprague-Dawley rats for the first time, along with the identification and quantification of phenolic acids and flavonoids by high-performance liquid chromatography (HPLC) and evaluation of antioxidant and antiradical activities of this extract. HPLC analysis confirmed the existence of tannic acid, gallic acid, salicylic acid, and naringin in B. tomentosa leaf extract which showed in-vitro antioxidant potentialities with DPPH, nitric oxide, hydrogen peroxide, and hydroxyl radical scavenging properties. Co-administration of B. tomentosa leaf extract with carbofuran showed dose-dependent significant protective effects of hepatic toxicity on serum markers such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl-transferase, lactate dehydrogenase, total bilirubin, total protein, albumin, globulin, lipid profile, urea, uric acid, and creatinine. Carbofuran intoxication also revealed an upsurge in malondialdehyde (MDA) and a decline in cellular endogenous antioxidant enzyme levels in rats compared with the control group. However, B. tomentosa leaf extract co-treatment increased the levels of hepatic antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, and amended the MDA level. Similarly, histopathological evaluation further assured that BTL could keep the hepatocyte from carbofuran-induced damage. Therefore, all of our findings may conclude that the phenolic acids and flavonoids of B. tomentosa leaf extract are responsible to neutralize the toxic free radical-mediated oxidative hepatic damages.

Acute oral toxicity assessment of ethanolic extracts of Antidesma bunius (L.) Spreng fruits in mice

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In treated mice, mortality during 14-day experimental period was not observed.

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Bignay extract did not cause behavioral, respiratory and neurologic changes.

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Liver, kidney, stomach, intestines and esophagus remained intact post Bignay treatment.

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16 volatile compounds and 10 secondary metabolites were identified.

The aim of the study is to assess the acute oral toxicity of ethanolic extracts of Antidesma bunius (L.) Spreng [Bignay] in ICR mice in accordance to OECD guideline 423. Single doses of Bignay fruit extracts ranging from 500 mg/kg to 2000 mg/kg, as well as a vehicle control, were given orally and monitored for 14 days. We observed that there is no mortality or adverse effects after treatment of mice indicating that Bignay extracts are safe for use in laboratory animals. Behavioral, respiratory, and neurologic changes, as well as changes in body weight, food and water consumption, did not occur during the experimental period. Hematological- (total-red and -white blood cells) and biochemical-profile analysis (alanine transaminase, blood urea nitrogen, and creatinine) remained within normal concentrations in treated mice regardless of sex. The morphology of visceral organs in all treated mice was typical in appearance when stained with H&E. It is assumed that the LD₅₀ is greater than 2000 mg/kg and there is no mortality at the maximum dose used (2000 mg/kg). We have also determined the active components of dried Bignay by headspace GC–MS and by phytochemical analysis of ethanolic Bignay extracts. We have identified 16 compounds by GC–MS and 10 secondary metabolites. In this study, the assessment of extracted Antidesma bunius (L.) Spreng fruits [Bignay] on the value of safety measures in mice is described.

Oral acute and sub-chronic toxicity assessment of aqueous leaf extract of Simarouba glauca DC (Paradise tree)

Simarouba glauca has been widely reported to be effective against a number of diseases and possesses medicinal benefits. Thus, the study was conducted to evaluate the toxic effect of aqueous leaf extract of Simarouba glauca (AESG) on relevant organs of male Wistar rats. The oral acute toxicity of AESG was evaluated according to the method described by Lorke. Sub-chronic toxicity of AESG was carried out in line with the guidelines of the Organization for Economic Co-operation and Development (OECD), using a total of twenty-four (24) male Wistar rats divided into four groups of six rats each. Test rats were orally administered AESG at doses of 500, 1000 and 2000 mg /kg body weight, respectively, daily for thirty (30) days. At the end of the study, rats were fasted overnight and sacrificed; the relevant biochemical and histopathology evaluation was carried out. Statistical analysis was conducted using the GraphPad Prism®, version 7. The data obtained indicated that the LD50 exceeded 5000 mg/kg. There were significant increases (P < 0.05) in percentage (%) body weight of test rats. There were no significant differences (P < 0.05) in mean liver, kidney, and heart weight/body weight (IOW/BWT) ratios. The AST activity was significantly lowered (P < 0.05) in rats administered AESG 2000 mg/kg. The ALP activities were significantly elevated (P < 0.05), while the GGT activities were significantly lowered (P < 0.05) in all groups of rats administered AESG. Plasma conjugated and unconjugated bilirubin were significantly lowered and elevated (P < 0.05), respectively in rats administered AESG 1000 and 2000 mg/kg. Plasma urea was significantly elevated (P < 0.05) in rats given AESG 1000 mg/kg. Test rats given AESG 2000 mg/kg recorded significant reduction (P < 0.05) in plasma sodium ions concentration. Rats given AESG 500 mg/kg recorded significant reduction (P < 0.05) in plasma bicarbonate ion levels. The findings suggest that AESG was not significantly toxic to the liver, kidney, and heart.

A study of the genetic and prenatal developmental toxicity potential of lithothamnion sp

Due to its calcium-rich and diverse multimineral profile, Aquamin (derived from the red seaweed Lithothamnion sp.) is used globally as a dietary food supplement. Published reports on the genetic and prenatal developmental toxicity of Lithothamnion sp. do not exist. In accordance with the standardized protocols set by the Ministry of Health of the People's Republic of China (GB-15193), the following studies were performed: the Ames test, the mammalian erythrocyte micronucleus test, the mammalian spermatocyte chromosome test, and prenatal developmental toxicity testing. The results showed that Lithothamnion sp. did not induce a significant increase in the following: revertant colony numbers for Salmonella typhimurium strains TA 97, 98, 100, 102 and 1535; frequency of micronucleated polychromatic erythrocytes (MNPCE); spermatocyte chromosomal aberration rate. In the prenatal developmental toxicity study, no mortality, no abnormal changes in behavior and activities, and the absence of toxic symptoms and abnormalities in macroscopic autopsy were observed in each dam/all pups. Compared to the negative control group, Lithothamnion sp. at all tested doses had no effects on body weight gain, number of corpora lutea and implantations, fetal body weight and length, external, visceral and skeletal malformations. In conclusion, Lithothamnion sp. did not cause genetic toxicity. Furthermore, the prenatal developmental toxicity no observed adverse effect level (NOAEL) was determined to be greater than 2000  mg/kg.bw.