Acute and subchronic toxicity profile of methanol extract of leaves of Fimbristylis miliacea (L.) Vahl

Ethnopharmacological relevance

Fimbristylis miliacea (L.) Vahl (Cyperaceae) is a grass like herb habitually breeds as weed in paddy fields and mostly disseminated in tropical or sub-tropical countries of south and south-east Asia, northern Australia, and west Africa. The plant has been traditionally used to treat fever as a form of poultice. However, no scientific study regarding its toxicity profile has been testified.

Aim of the study

The study has been carried out to determine the potential toxicity of the methanol extract from leaves of the Fimbristylis miliacea, employing the technique of acute and subchronic oral administration in mice.

Materials and methods

In the acute toxicity study according to OECD guideline 425, oral administration of FM methanol extract at single doses of 2000 and 5000 mg/kg in both sexes of Swiss albino mice was performed. Toxic symptoms, abnormal behavior, changes in body weight, and mortality were observed for 14 consecutive days. In subchronic toxicity study according to OECD guideline 407, plant extract was administered orally at doses of 100, 500, 1000, and 2000 mg/kg daily for 28 days. The general toxic symptoms, abnormal behavior, changes in body weight were observed daily. Biochemical analysis of serum, and histopathological examination of liver were performed at the end of the study.

Results

No mortality, abnormal behavior and urination, changes in sleep, food intake, adverse effect, and non-linearity in body weight have been recorded during acute toxicity study at the doses of 2000 and 5000 mg/kg. Also, in subchronic toxicity study, FM extract produced no mortality or any kind of adverse effects in regards of general behavior, body weight, urination, sleeping routine, and food intake. In case of analysis of thirteen different biochemical parameters, concentrations of aspartate transaminase (AST) and glucose were altered significantly in male and female mice in both acute and subchronic study. Total cholesterol and triglycerides at 5000 mg/kg.bw were changed in male mice in acute toxicity study. On the other hand, female mice had altered triglycerides in subchronic test. All other critical parameters were found unaffected. In subchronic test, histopathological examination of liver demonstrated cellular necrosis at 2000 mg/kg.bw in both male and female mice while minor necrosis was observed at 1000 mg/kg.bw. Thus, the no observed adverse effect level (NOAEL) can be assumed around 1000 mg/kg.bw.

Conclusion

The present study suggests that treatment with FM extract does not reveal significant toxicity.

A facile and universal method to achieve liposomal remote loading of non-ionizable drugs with outstanding safety profiles and therapeutic effect

Liposomes have made remarkable achievements as drug delivery vehicles in the clinic. Liposomal products mostly benefited from remote drug loading techniques that succeeded in amphipathic and/or ionizable drugs, but seemed impracticable for nonionizable and poorly water-soluble therapeutic agents, thereby impeding extensive promising drugs to hitchhike liposomal vehicles for disease therapy. In this study, a series of weak acid drug derivatives were designed by a simplistic one step synthesis, which could be remotely loaded into liposomes by pH gradient method. Cabazitaxel (CTX) weak acid derivatives were selected to evaluate regarding its safety profiles, pharmacodynamics, and pharmacokinetics. CTX weak acid derivative liposomes were superior to Jevtana® in terms of safety profiles, including systemic toxicity, hematological toxicity, and potential central nerve toxicity. Specifically, it was demonstrated that liposomes had capacity to weaken potential toxicity of CTX on cortex and hippocampus neurons. Significant advantages of CTX weak acid derivative-loaded liposomes were achieved in prostate cancer and metastatic cancer therapy resulting from higher safety and elevated tolerated doses.

Remote loading paclitaxel-doxorubicin prodrug into liposomes for cancer combination therapy

The combination of paclitaxel (PTX) and doxorubicin (DOX) has been widely used in the clinic. However, it remains unsatisfied due to the generation of severe toxicity. Previously, we have successfully synthesized a prodrug PTX-S-DOX (PSD). The prodrug displayed comparable in vitro cytotoxicity compared with the mixture of free PTX and DOX. Thus, we speculated that it could be promising to improve the anti-cancer effect and reduce adverse effects by improving the pharmacokinetics behavior of PSD and enhancing tumor accumulation. Due to the fact that copper ions (Cu²⁺) could coordinate with the anthracene nucleus of DOX, we speculate that the prodrug PSD could be actively loaded into liposomes by Cu²⁺ gradient. Hence, we designed a remote loading liposomal formulation of PSD (PSD LPs) for combination chemotherapy. The prepared PSD LPs displayed extended blood circulation, improved tumor accumulation, and more significant anti-tumor efficacy compared with PSD NPs. Furthermore, PSD LPs exhibited reduced cardiotoxicity and kidney damage compared with the physical mixture of Taxol and Doxil, indicating better safety. Therefore, this novel nano-platform provides a strategy to deliver doxorubicin with other poorly soluble antineoplastic drugs for combination therapy with high efficacy and low toxicity.

Evaluation and analytical validation of a handheld digital refractometer for urine specific gravity measurement

Objectives

Refractometers are commonly used to determine urine specific gravity (SG) in the assessment of hydration status and urine specimen validity testing. Few comprehensive performance evaluations are available demonstrating refractometer capability from a clinical laboratory perspective. The objective of this study was therefore to conduct an analytical validation of a handheld digital refractometer used for human urine SG testing.

Design and methods

A MISCO Palm Abbe™ refractometer was used for all experiments, including device familiarization, carryover, precision, accuracy, linearity, analytical sensitivity, evaluation of potential substances which contribute to SG (i.e. “interference”), and reference interval evaluation. A manual refractometer, urine osmometer, and a solute score (sum of urine chloride, creatinine, glucose, potassium, sodium, total protein, and urea nitrogen; all in mg/dL) were used as comparative methods for accuracy assessment.

Results

Significant carryover was not observed. A wash step was still included as good laboratory practice. Low imprecision (%CV, <0.01) was demonstrated using low and high QC material. Accuracy studies showed strong correlation to manual refractometry. Linear correlation was also demonstrated between SG, osmolality, and solute score. Linearity of Palm Abbe performance was verified with observed error of ≤0.1%. Increases in SG were observed with increasing concentrations of albumin, creatinine, glucose, hemoglobin, sodium chloride, and urea. Transference of a previously published urine SG reference interval of 1.0020–1.0300 was validated.

Conclusions

The Palm Abbe digital refractometer was a fast, simple, and accurate way to measure urine SG. Analytical validity was confirmed by the present experiments.