Comparative pharmacokinetics and safety evaluation of high dosage regimens of Andrographis paniculata aqueous extract after single and multiple oral administration in healthy participants

Background: The prolonged situation of the COVID-19 pandemic, with the emergence of new variants of SARS-CoV-2, not only imposes a financial burden on healthcare supports but also contributes to the issue of medication shortages, particularly in countries with limited access to medical resources or developing countries. To provide an alternative therapeutic approach during this crisis, there is an increasing research that has investigated the potential uses of Andrographis paniculata in supporting the application of herbal medicine for COVID-19.Purpose: This study aimed to investigate the safety profiles and clinical pharmacokinetics, specifically focusing on dose proportionality of the four major active diterpenoids of Andrographis paniculata aqueous extract following oral administration of two different high doses of andrographolide.Methods: The participants received the aqueous extract capsules equivalent to 60 or 120 mg of andrographolide; and as multiple doses administered three times daily, calculated as 180 or 360 mg/day of andrographolide. Safety evaluation was assessed following the oral administration of the multiple doses.Results: The results indicated a dose-dependent effect observed between the respective two doses. A twofold increase in the dose of the extract demonstrated twofold higher plasma concentrations of the four major parent compounds; 1) andrographolide, 2) 14-deoxy-11, 12-didehydroandrographolide, 3) neoandrographolide, and 4) 14-deoxyandrographolide, as well as their conjugated metabolites. The observed diterpenoids are biotransformed partly through a phase II metabolic pathway of conjugation, thus reducing in the parent compounds in the plasma and existing the majority as conjugated metabolites. These metabolites are then excreted through the hepatobiliary system and urinary elimination. For the results of the safety evaluation, the occasional adverse events experienced by individuals were of mild intensity, infrequent in occurrence, and reversible to the normal baseline. Safety consideration should be given to the individual patient’s pertinent health conditions when using this extract in patients with hepatic or kidney dysfunction.Clinical Trial Registration:https://www.thaiclinicaltrials.org/show/TCTR20210201005; Identifier: TCTR20210201005

Andrographolide, an Antioxidant, Counteracts Paraquat- Induced Mutagenesis in Mammalian Cells

© This work is licensed under a Creative Commons Attribution-Non Commercial 4.0 International License. Paraquat (1,1’-dimethyl, 4,4’-bipyridinium dichloride; PQ), a commonly used herbicide worldwide, is both toxic and mutagenic. The mutagenic effect of PQ stems from its ability to redox-cycle, generating oxidative stress and subsequently oxidative DNA damage, which miscodes when replication is attempted. Andrographolide (AP1), the major constituent in the leaves of the herbaceous plant Andrographis paniculata, is a diterpenoid with reported antioxidant activity. The present study employed the mammalian cell line AS52 to investigate the protective effect of AP1 against PQ-induced mutagenesis. AP1 induced cytotoxicity in AS52 cells in a dose-dependent manner (IC50 = 15.7 µM), which allowed the selection of a non-lethal dose for the mutagenesis studies. While PQ was mutagenic in AS52 cells as evidenced by the increased levels of 6-TGr mutants, AP1 by itself did not increase the mutation frequency. However, co-treatment with AP1 (1-5 µM) or the antioxidant N-acetylcysteine (2 mM) almost completely counteracted the mutagenicity of PQ (10-100 µM) in AS52 cells. Taken together, these findings suggest that AP1, and likely by extension, A. paniculata extracts, are effective antioxidants that can protect against PQ-induced mutations, and thus could be a promising alternative treatment for PQ poisoning.National Institutes of Health (Grants P30-ES002109, R01-CA080024 and P01- CA26731

An engineered cell line lacking OGG1 and MUTYH glycosylases implicates the accumulation of genomic 8-oxoguanine as the basis for paraquat mutagenicity

Paraquat (1,1′-dimethyl, 4,4′-bipyridinium dichloride; PQ), a widely used herbicide, is toxic to mammals through ingestion, inhalation and skin contact. Epidemiological data suggest that PQ is also mutagenic and carcinogenic, especially in high doses. The toxic and mutagenic properties of PQ are attributed to the ability of the molecule to redox-cycle, which generates reactive oxygen species (ROS) and subsequent oxidative stress. ROS also cause oxidative DNA damage such as 8-oxoguanine (8OG), a mutagenic base that, when replicated, causes G to T transversion mutations. The present study employed the CHO-derived cell line AS52 to quantify the mutagenic properties of low doses of PQ. By containing a functional, chromosomally-integrated copy of the bacterial gpt gene, AS52 cells a facile system for evaluating the mutagenic properties of genotoxicants. To bolster the sensitivity of this system for detecting mutagenesis of weak mutagens like PQ, and to provide a tool for mechanistic evaluation of the mutagenic process, we constructed a new AS52-derived cell line defective for 8OG DNA repair. Specifically, we employed CRISPR-Cas9 technology to knock out 8-oxoguanine DNA glycosylase (OGG1) and MUTYH glycosylase, two key enzymes involved in the base excision repair of 8OG. The double knock-out (DKO) AS52 cells were found to be more sensitive to PQ toxicity than the parental (WT) AS52 cell line. They experienced higher levels of ROS, which translated into more DNA double-strand breaks, which explained the PQ toxicity. The increased ROS levels also led to more 8OG genomic accumulation, and a higher level of mutations in the DKO cells, suggesting that PQ mutagenesis is mediated primarily by 8OG genomic accumulation. Consistent with this view, antioxidant co-treatment lowered induced cellular ROS and PQ-induced mutagenesis. Taken together, our data demonstrate the strong protective role of OGG1 and MUTYH against PQ-induced mutagenesis. Moreover, our experiments establish the engineered OGG1 MUTYH AS52 cell line and associated methods as a versatile cellular system for studying in quantitative terms the mutagenesis of other agents, environmental or endogenous, that induce oxidative stress. -/- -/

DataSheet1_Comparative pharmacokinetics and safety evaluation of high dosage regimens of Andrographis paniculata aqueous extract after single and multiple oral administration in healthy participants.PDF

Background: The prolonged situation of the COVID-19 pandemic, with the emergence of new variants of SARS-CoV-2, not only imposes a financial burden on healthcare supports but also contributes to the issue of medication shortages, particularly in countries with limited access to medical resources or developing countries. To provide an alternative therapeutic approach during this crisis, there is an increasing research that has investigated the potential uses of Andrographis paniculata in supporting the application of herbal medicine for COVID-19.Purpose: This study aimed to investigate the safety profiles and clinical pharmacokinetics, specifically focusing on dose proportionality of the four major active diterpenoids of Andrographis paniculata aqueous extract following oral administration of two different high doses of andrographolide.Methods: The participants received the aqueous extract capsules equivalent to 60 or 120 mg of andrographolide; and as multiple doses administered three times daily, calculated as 180 or 360 mg/day of andrographolide. Safety evaluation was assessed following the oral administration of the multiple doses.Results: The results indicated a dose-dependent effect observed between the respective two doses. A twofold increase in the dose of the extract demonstrated twofold higher plasma concentrations of the four major parent compounds; 1) andrographolide, 2) 14-deoxy-11, 12-didehydroandrographolide, 3) neoandrographolide, and 4) 14-deoxyandrographolide, as well as their conjugated metabolites. The observed diterpenoids are biotransformed partly through a phase II metabolic pathway of conjugation, thus reducing in the parent compounds in the plasma and existing the majority as conjugated metabolites. These metabolites are then excreted through the hepatobiliary system and urinary elimination. For the results of the safety evaluation, the occasional adverse events experienced by individuals were of mild intensity, infrequent in occurrence, and reversible to the normal baseline. Safety consideration should be given to the individual patient’s pertinent health conditions when using this extract in patients with hepatic or kidney dysfunction.Clinical Trial Registration:https://www.thaiclinicaltrials.org/show/TCTR20210201005; Identifier: TCTR20210201005.</p

An engineered cell line lacking OGG1 and MUTYH glycosylases implicates the accumulation of genomic 8-oxoguanine as the basis for paraquat mutagenicity

Paraquat (1,1′-dimethyl, 4,4′-bipyridinium dichloride; PQ), a widely used herbicide, is toxic to mammals through ingestion, inhalation and skin contact. Epidemiological data suggest that PQ is also mutagenic and carcinogenic, especially in high doses. The toxic and mutagenic properties of PQ are attributed to the ability of the molecule to redox-cycle, which generates reactive oxygen species (ROS) and subsequent oxidative stress. ROS also cause oxidative DNA damage such as 8-oxoguanine (8OG), a mutagenic base that, when replicated, causes G to T transversion mutations. The present study employed the CHO-derived cell line AS52 to quantify the mutagenic properties of low doses of PQ. By containing a functional, chromosomally-integrated copy of the bacterial gpt gene, AS52 cells a facile system for evaluating the mutagenic properties of genotoxicants. To bolster the sensitivity of this system for detecting mutagenesis of weak mutagens like PQ, and to provide a tool for mechanistic evaluation of the mutagenic process, we constructed a new AS52-derived cell line defective for 8OG DNA repair. Specifically, we employed CRISPR-Cas9 technology to knock out 8-oxoguanine DNA glycosylase (OGG1) and MUTYH glycosylase, two key enzymes involved in the base excision repair of 8OG. The double knock-out (DKO) AS52 cells were found to be more sensitive to PQ toxicity than the parental (WT) AS52 cell line. They experienced higher levels of ROS, which translated into more DNA double-strand breaks, which explained the PQ toxicity. The increased ROS levels also led to more 8OG genomic accumulation, and a higher level of mutations in the DKO cells, suggesting that PQ mutagenesis is mediated primarily by 8OG genomic accumulation. Consistent with this view, antioxidant co-treatment lowered induced cellular ROS and PQ-induced mutagenesis. Taken together, our data demonstrate the strong protective role of OGG1 and MUTYH against PQ-induced mutagenesis. Moreover, our experiments establish the engineered OGG1 MUTYH AS52 cell line and associated methods as a versatile cellular system for studying in quantitative terms the mutagenesis of other agents, environmental or endogenous, that induce oxidative stress. -/- -/