Acute and sub-acute oral toxicity of aqueous whole leaf and green rind extracts of Aloe vera in Wistar rats

Background Several local communities in Central, Western, Eastern, and Northern regions of Uganda have been using the whole leaf extracts of Aloe vera (L.) Burm. f. (Asphodelaceae) in the treatment of various ailments. Also, several commercial companies sell A. vera as soft drinks in Uganda. However, there are inadequate reports on the toxicities of such preparations. This paper reports the acute and sub-acute oral toxicity of aqueous extracts of whole leaf and green rind of A. vera in Wistar rats. Methods Acute oral toxicity test was carried out in female Wistar rats at doses of 175, 550, 1750, and 5000 mg/kg, p.o. The animals were observed for signs of toxicity for 14 days. Similarly, a sub-acute oral toxicity test was performed in both sexes of rats at doses of 200, 400, and 800 mg/kg, p.o. daily for 28 days. All the groups of animals were monitored for behavioral, morphological, biochemical, and physiological changes, including mortality and compared with respective controls. Body weights were measured weekly while the animals’ relative organ weights, hematological, biochemical, gross, and microscopic pathology were examined on day 29. Results There was no mortality or apparent behavioral changes at the doses tested in acute and sub-acute oral toxicity tests. Thus, the Median Lethal Dose (LD50) of green rind and whole leaf aqueous extracts was above 5000 mg/kg. Gross anatomy revealed that the rats’ relative spleen weight in green rind extract at 200 mg/kg significantly decreased compared to the control group. The creatinine levels in female rats that received green rind extract and the chloride ion levels in male rats administered whole leaf extract were significantly elevated. Conversely, Mean Corpuscular Hemoglobin Concentration (MCHC) levels significantly decreased at lower doses of the green rind extract compared to the control. Histopathology of the kidney revealed the renal interstitium’s inflammation at doses of 200 and 800 mg/kg of the whole leaf extract. Conclusion The findings demonstrated that A. vera green rind and whole leaf extracts are non-toxic at relatively high doses when used for a short duration. Prolonged use of the aqueous whole leaf extract might be associated with kidney toxicity.

Excess serum Na level in rats administered with high doses of (−)-epigallocatechin gallate-casein nanoparticles prepared with sodium caseinate

The 28-day oral toxicity test of 5.0 g per kg BW FD-EGCG-NPs on rats did not show any adverse effect. However, Na level in the serum of females and males treated with 10.0 g per kg BW FD-EGCG-NPs or FD-NPs significantly increased (P < 0.05).

Evaluation of acute and subchronic toxicity of “Tran Chau Nguu Hoang Hoan” in experimental animals

“Tran chau nguu hoang hoan” was prepared from 12 herbal ingredients. So far, the safety of this product, has not been reported yet. Thus, this study aimed to evaluate the acute and subchronic toxicity of “Tran chau nguu hoang hoan” through oral administration in experimental animals. The acute toxicity was determined by the method of Litchfield Wilcoxon in mice at the doses of 2.42 g/kg b.w/day to 6.04 g/kg b.w/day. The subchronic toxicity was evaluated followed the Guideline of WHO and OECD in rats with oral doses of 58.0 mg/kg b.w/day and 174.0 mg/kg b.w/day for 12 consecutive weeks. As a result, in the course of the acute toxicity test, the mice showed no abnormal sign or death. In terms of the subchonic toxicity test, hematological indexes, hepato-renal functions and microscopic images of liver and kidney were unchanged. In conclusion, “Tran chau nguu hoang hoan” does not appear to produce acute and subchronic toxicities in mice and rats.

Acute and subchronic oral toxicity assessments of BTL tea in experimental animals

Tobacco smoking remains a leading cause of preventable diseases and premature death in many countries. Many smokers want to quit smoking but are not offered the highly effective treatments available to manage tobacco dependency. There has been a current trend for researchers to find new natural ingredients that were safe and still effective in treating tobacco dependence. BTL tea was a herbal-derived product prepared from Herba Menthae, Pogos cablin (Blanco) Benth., Zingiber Officinale Rosc., Flos Chrysanthemi, Radix Glycyrrhizae, Pericarpium Citri deliciosa, and Flos Lonicera. At this time, the safety of this product has not been reported. Thus, this study aimed to evaluate BTL tea’s acute and subchronic toxicity through oral administration in experimental animals. The acute toxicity was determined by Litchfield-Wilcoxon method in mice at the doses of 45.0 g/kg b.w/day to 112.5 g/kg b.w/day. The subchronic toxicity was evaluated following WHO and OECD’s Guidelines in rats with oral doses of 1.08 g/kg b.w/day (equal to recommended human dose) and 3.24 g/kg b.w/day (three times as high as recommended human dose) for four consecutive weeks. As a result, in the acute toxicity test, the mice showed no abnormal sign or death. The subchronic toxicity test, hematological indexes, hepato-renal functions, and microscopic images of liver and kidney were unchanged. However, compared with the control group, there were significant differences in various indexes, including total WBC, lymphocytes, neutrophils, and AST level, but the levels were still safe. In conclusion, BTL tea does not appear to produce acute and subchronic toxicities in mice and rats.

Preclinical toxicity test results of a new antiviral–immune-modulator compound consisting of flavonoid molecules (COVID-19 clinical trial preliminary data)

Aim: Isolated specific glycone–aglycone conjugated flavonoids which are investigated for their effect of bioavailability and molecular concentrations. The specific formula is then tested via in vitro and in vivo cytotoxicity tests. Methods: Considering the higher affinity for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), quercetin, quercetin 3-sambubioside-3’-glucoside, luteolin, apigenin-7-4’alloside, kaempferol-7-O-glucoside, epicatechin-epigallocatechin-3-O-gallate, and hesperetin were selected to investigate the effects of a new combination of the formula. Specific chemical analyses, such as high-performance liquid chromatography (HPLC), liquid chromatography–mass spectrometry (LC–MS), quadrupole time of flight mass spectrometry (QTOF–MS) analysis and ultraviolet–visible (UV–VIS) spectrophotometry, were performed for molecular qualification and quantification. Results: In silico molecular docking analyses have shown that flavonoids can bind strongly to the spike protein and main protease of the SARS-CoV-2 virus. Flavonoids also have anti-inflammatory and immune-modulating activity by inhibiting cytokines. Although flavonoids may be a treatment alternative for coronavirus disease 2019 (COVID-19), an effective flavonoid compound has yet to be developed. The main problem here is that the absorption rate of flavonoids is very low (2–10%) in the intestines, and these compounds are metabolized rapidly. In contrast, according to recent literature, a conjugated flavonoid mixture is better absorbed in the small intestine, and its toxic effects are relatively fewer. Conclusions: It is found that the new formula has no cytotoxic or genotoxic effects. Furthermore, oral administrations of the new compound did not produce any toxicity symptoms or any mortality in male and female rats. The pre-clinical in vitro and in vivo toxicity test results indicated that the new flavonoid formula can be safely used for clinical trials.

Assessment of Potential Toxicity of Onion-like Carbon Nanoparticles from Grilled Turbot Scophthalmus maximus L.

Although the presence of foodborne nanoparticles was confirmed in grilled fish in a previous study, the evaluation of potential health risks of these NPs was insufficient. In the present study, the potential toxicity of onion-like carbon nanoparticles (OCNPs) separated from grilled turbot Scophthalmus maximus L. was evaluated using mouse osteoblasts cells model and zebrafish (Danio rerio) model. Cytotoxicity evaluation revealed that the OCNPs penetrated into the MC3T3-E1 cells without arousing cell morphology changes. No evident apoptosis or damage of cells was observed with increasing OCNPs’ concentration to 20 mg/mL. In the hemolysis test, OCNPs did not show an obvious hemolysis effect on red blood cells. In the acute toxicity test, the LC50 value (212.431 mg/L) of OCNPs to zebrafish showed a weak acute toxicity. In subacute toxicity test, after exposure to OCNPs (30 mg/L, 40 mg/L) for 10 days, a significant increase of reactive oxygen species level of zebrafish was observed. Meanwhile, redundant ROS content caused inhibition to several antioxidant enzymes and induced lipid and protein peroxidation damages according to the upregulation of malondialdehyde and protein carbonyl levels. The chronic toxicity test results indicated that oxidative stress was only observed in the high concentration group of OCNPs-treated zebrafish.

Toxicity Studies of Centella asiatica for Drug Development: Mini Review

Toxicity studies' quality control of drug plant-based products is an important aspect of pharmacological research. The purpose of this literature review is to extract about toxicity test on Centella asiatica. The plant component utilized, the test animals used, the type of toxicity test, evaluation, the findings, and conclusions of each test are all included in this review—the database used in PubMed. Most of the literature results obtained from this review indicate high safety in C. asiatica plants. The acute toxicity test is that the most frequently used toxicity test. The use varies from plant parts to whole plants, with minimal side effects reported and high in safety, so it can be concluded that C. asiatica is very prospective to be developed as a medicine.