A comprehensive review on disposition kinetics and dosage of oral administration of Andrographis paniculata, an alternative herbal medicine, in co-treatment of coronavirus disease

Non-linear oral bioavailability and clinical pharmacokinetics of high-dose Andrographis paniculata ethanolic extract: relevant dosage implications for COVID-19 treatment

AIM

Insufficient quality control and limited dissolution of Andrographis paniculata extract capsules restricts their bioavailability and hinder the clinical use for treating mild coronavirus disease 2019 (COVID-19) patients.

OBJECTIVE

This study aims to investigate pharmacokinetics and safety of high-dosage A. paniculata ethanolic extract (equivalent to 180 or 360 mg/day of andrographolide), relevant dosages used for mild COVID-19 treatment.

METHODS

An open-label, single-dose, and repeated-dose conducted in healthy volunteers. Subjects received capsules containing ethanolic extract equivalent to andrographolide dosage of either 60 or 120 mg per dose, taken every eight hours daily (totaling 180 or 360 mg/day). Safety was assessed through blood chemical analysis and adverse event monitoring after 7 days of ethanolic extract administration.

RESULTS

Pharmacokinetics of ethanolic extract indicated low plasma levels of the major diterpenoids. The maximum plasma concentration (Cmax) of andrographolide did not exhibit a dose-proportional increase, reaching 6.44 and 11.62 µg/L for single and repeated doses of 60 mg/day, respectively. Doubling the dose (120 mg/day) only resulted in slightly higher Cmax (6.97 and 15.03 µg/L for single and repeated doses, respectively). Safety evaluation revealed mild, transient adverse events, but all parameters remained within normal ranges.

CONCLUSIONS

This study highlights limitations in the pharmacokinetics of the ethanolic extract of A. paniculata. It indicated non-linear proportionality in the oral bioavailability of andrographolide. These findings suggest that current extraction process of ethanolic extract may hinder its effectiveness. Further research is warranted to explore alternative extraction methods or formulation developments that can enhance the bioavailability of andrographolide and its potential therapeutic effects for COVID-19 treatment.

Enhancing oral bioavailability of andrographolide using solubilizing agents and bioenhancer: comparative pharmacokinetics of Andrographis paniculata formulations in beagle dogs

CONTEXT

The therapeutic potential of andrographolide is hindered by its poor oral bioavailability and unpredictable pharmacokinetics, primarily due to its limited water solubility.

OBJECTIVE

This work aimed to enhance the solubility and pharmacokinetics of andrographolide, a bioactive compound in Andrographis paniculata (Burm. f.) Nees (Acanthaceae), using solubilizing agents and a bioenhancer.

MATERIALS AND METHODS

Four groups of beagles were compared: (1) A. paniculata powder alone (control), (2) A. paniculata powder with 50% weight/weight (w/w) β-cyclodextrin solubilizer, (3) A. paniculata powder with 1% w/w sodium dodecyl sulfate (SDS) solubilizer, and (4) A. paniculata powder co-administered with 1% w/w SDS solubilizer and 10% piperine bioenhancer. All groups received a consistent oral dose of 3 mg/kg of andrographolide, administered both as a single dose and multiple doses over seven consecutive days.

RESULTS

Thirteen chemical compounds were identified in A. paniculata powder, including 7 diterpenoids, 5 flavonoids, and 1 phenolic compound. A. paniculata co-administration with either 50% w/w β-cyclodextrin or 1% w/w SDS, alone or in combination with 10% w/w piperine, significantly increased systemic andrographolide exposure by enhancing bioavailability (131.01% to 196.05%) following single and multiple oral co-administration. Glucuronidation is one possible biotransformation pathway for andrographolide, as evidenced by the excretion of glucuronide conjugates in urine and feces.

CONCLUSION

The combination of solubilizing agents and a bioenhancer improved the oral bioavailability and pharmacokinetics of andrographolide, indicating potential implications for A. paniculata formulations and clinical therapeutic benefits. Further investigation in clinical studies is warranted.

Harmonizing international quality standards for Andrographis paniculata: A comparative analysis of content determination methods across pharmacopeias

The quality standards for Andrographis paniculata, a widely used medicinal herb, exhibited significant variations across different pharmacopeias. In this study, we compared the HPLC content determination methods and total lactone content of A. paniculata samples from different regions, as specified in the Chinese (CP), United States (USP), European (EP), Thai (TP), and Indian pharmacopeias (IP), as well as the Hong Kong Chinese Materia Medica Standards (HK). We aimed to assess the differences and similarities among these pharmacopeias and harmonized international quality standards for A. paniculata. The analysis revealed variations in sample preparation, liquid chromatographic conditions, fingerprint profiles, and total lactone content among the different pharmacopeias. Specifically, the CP and HK methods exhibited superior sample preparation and chromatographic separation. Further comparing the content of 20 A. paniculata samples with the CP, USP, EP and HK methods showed consistent determinations for the same components, indicating similar detection capabilities. The discrepancies in total lactone content primarily stemmed from differences in the number and types of detected compounds. Moreover, the acceptance criteria exhibited a stringency in the order CP > HK > EP > USP. In conclusion, this comparison analysis of content determination in CP, USP, HK, EP, TP and IP provided a scientific foundation for the international standardization and trade regulations of A. paniculata. It also served as a valuable reference for the development of international quality standards for other medicinal herbs, facilitating the harmonization of global pharmaceutical standards.

Synergistic inhibition effects of andrographolide and baicalin on coronavirus mechanisms by downregulation of ACE2 protein level

The SARS-CoV-2 virus, belonging to the Coronavirus genus, which poses a threat to human health worldwide. Current therapies focus on inhibiting viral replication or using anti-inflammatory/immunomodulatory compounds to enhance host immunity. This makes the active ingredients of traditional Chinese medicine compounds ideal therapies due to their proven safety and minimal toxicity. Previous research suggests that andrographolide and baicalin inhibit coronaviruses; however, their synergistic effects remain unclear. Here, we studied the antiviral mechanisms of their synergistic use in vitro and in vivo. We selected the SARS-CoV-2 pseudovirus for viral studies and found that synergistic andrographolide and baicalein significantly reduced angiotensin-converting enzyme 2 protein level and viral entry of SARS-CoV-2 into cells compared to singal compound individually and inhibited the major protease activity of SARS-CoV-2. This mechanism is essential to reduce the pathogenesis of SARS-CoV-2. In addition, their synergistic use in vivo also inhibited the elevation of pro-inflammatory cytokines, including IL-6 and TNF-α-the primary cytokines in the development of acute respiratory distress syndrome (the main cause of COVID-19 deaths). In conclusion, this study shows that synergistic andrographolide and baicalein treatment acts as potent inhibitors of coronavirus mechanisms in vitro and in vivo-and is more effective together than in isolation.

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.

Antidiabetic effects of Andrographis paniculata supplementation on biochemical parameters, inflammatory responses, and oxidative stress in canine diabetes

Introduction: Diabetes mellitus is a common endocrine disorder that causes hyperglycemia in dogs. Persistent hyperglycemia can induce inflammation and oxidative stress. This study aimed to investigate the effects of A. paniculata (Burm.f.) Nees (Acanthaceae) (A. paniculata) on blood glucose, inflammation, and oxidative stress in canine diabetes. A total of 41 client-owned dogs (23 diabetic and 18 clinically healthy) were included in this double-blind, placebo-controlled trial. Methods: The diabetic dogs were further divided into two treatments protocols: group 1 received A. paniculata extract capsules (50 mg/kg/day; n = 6) or received placebo for 90 days (n = 7); and group 2 received A. paniculata extract capsules (100 mg/kg/day; n = 6) or received a placebo for 180 days (n = 4). Blood and urine samples were collected every month. No significant differences in fasting blood glucose, fructosamine, interleukin-6, tumor necrosis factor-alpha, superoxide dismutase, and malondialdehyde levels were observed between the treatment and placebo groups (p > 0.05). Results and Discussion: The levels of alanine aminotransferase, alkaline phosphatase, blood urea nitrogen, and creatinine were stable in the treatment groups. The blood glucose levels and concentrations of inflammatory and oxidative stress markers in the client-owned diabetic dogs were not altered by A. paniculata supplementation. Furthermore, treatment with this extract did not have any adverse effects on the animals. Non-etheless, the effects of A. paniculata on canine diabetes must be appropriately evaluated using a proteomic approach and involving a wider variety of protein markers.