Acute and Sub-Acute Toxicity Evaluation of the Crude Methanolic Extract of Justicia schimperiana Leaf in Wistar Albino Rats

A standardized chamuangone enriched extract from Garcinia cowa Roxb. leaves shows acute and sub-acute safety

ETHNOPHARMACOLOGICAL RELEVANCE

The safety assessment of herbal products is critical for their appropriate pharmacological applications. Garcinia cowa Roxb., commonly known as Cha-muang in Thai, has ethnopharmacological relevance for inflammation, infectious diseases, and diabetes. The leaf extracts of G. cowa have been extensively reported for their anticancer, anti-inflammatory, antimicrobial, and antioxidant effects. Notably, chamuangone is their major active constituent that contributes to various pharmacological properties.

AIM OF THE STUDY

The current study aims to establish a standardized chamuangone enriched extract (CEE) and assess its acute and sub-acute toxicities in animal models.

METHODOLOGY

CEE was established from G. cowa leaves using a microwave-assisted extraction (MAE), followed by fractionation and enrichment through silica gel vacuum and column chromatography. The concentration of chamuangone in the extract was quantified using a validated quantitative high-performance liquid chromatography (HPLC) method. The safety profiles of CEE were thoroughly evaluated in rodents according to the Organization for Economic Cooperation and Development (OECD) 425 and 407 guidelines. The effects on oxidative stress markers such as superoxide dismutase (SOD), reduced glutathione (GSH), catalase (CAT), and malondialdehyde (MDA) levels were also evaluated in various organs.

RESULTS

Based on the quantitative HPLC analysis, the CEE contained 73.0 ± 2.0% w/w of chamuangone. In the acute toxicity study, following up and down procedure the female rats were dosed with CEE at 1750 and 550 mg/kg body weight (b.w.), with CEE 1750 mg/kg b.w. was toxic, causing mortality, while CEE 550 mg/kg b.w. was deemed safe. An LD50 value was calculated according to the standard protocols, resulting in 970 mg/kg b.w. In histopathological examination, 550 mg/kg b.w. of CEE was safe in all the selected organs, while the 1750 mg/kg b.w. CEE treated rats exhibited toxic effects in histological tissues sections in the form of necrosis in the brain, cardiac muscle hypertrophy, liver inflammation, mild untoward effect in the spleen, fibrosis in the lungs, pancreatitis, pyelonephritis, and ovarian cyst. Administration of CEE at doses of 550 mg/kg b.w. (single dose) in the acute and 100 mg/kg b.w. (regularly 28-days) in the sub-acute toxicity studies significantly (p < 0.05) decreased levels of uric acid, triglycerides, and cholesterol. Importantly, the CEE (550 and 100 mg/kg b.w.) also significantly increased the levels of antioxidant enzymes (SOD, GSH, and CAT) and decreased MDA levels. Normal histopathology was observed in the sub-acute toxicity study in all treated groups.

CONCLUSION

This study successfully concludes that CEE at a dose of 100 mg/kg b.w. is safe for therapeutic application or use as a chemopreventive functional food utilizing green extraction methods. However, chronic toxicity studies are further recommended to validate safety concerns over an extended period.

Toxicological evaluation of chronic oral administration of Justicia schimperiana (Hochst. ex Nees) T. Anderson leaf 80% methanolic extract in Wistar albino rats

Background

Justicia schimperiana has been widely used for the treatment of various human ailments without scientific proof for chronic toxicity. Thus, this study is aimed to evaluate the chronic toxicity of 80% methanolic extracts of the leaves of Justicia schimperiana in rats.

Methods

An 80% crude methanolic extract of the plant leaves was orally administered to Wistar albino rats for 6 months. The experiment was conducted in accordance with the Organization for Economic Co-operation and Development's guideline number 452. Twenty rats per group and sex were randomly assigned to three treatment groups and a control group. Daily doses of 250 mg/kg, 500 mg/kg, and 1000 mg/kg of the extract diluted with distilled water were administered orally to the rats. Rats in the control group received distilled water orally. Weekly body weight and daily food intake were measured. At the end, rats were sacrificed for histopathological, biochemical and hematological tests. The statistical analysis was done using the Kruskal-Wallis test and one-way analysis of variance.

Results

Six months daily oral administration of the plant extract did not significantly affect the rats' food consumption, organ weight, and histopathology. Rats treated with 1000 mg/kg extract, however, significantly increased liver enzymes (aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase), and kidney function tests (creatinine and urea). Additionally, the high dose extract administered rats showed significantly lower red blood cell count, hemoglobin, and hematocrit compared to the control group.

Conclusion

Six months oral administration in Wistar albino rats in this experiment indicated that Justicia schimperiana is relatively safe at lower and medium doses. However, increased liver enzymes, increased kidney function tests and decreased red blood cell indices was observed in rats treated at higher doses. To obtain a thorough understanding of the plant's toxicity profile, it is advised that future studies be conducted on teratogenicity and reproductive toxicity.