In vitro comparative evaluation of non-leaves and leaves extracts of Andrographis paniculata on modulation of inflammatory mediators

Toxicological safety assessment of AP-Bio®, a standardized extract of Andrographis paniculata in Sprague Dawley rats

Andrographis paniculata, commonly known as green chiretta, is a traditionally used plant in India, China, and Southeast Asian countries for its varied health benefits including immune health. The objective of the present study was to assess the safety of AP-Bio®, a standardized A. paniculata extract in Sprague Dawley rats by following the Organisation for Economic Cooperation and Development (OECD) test guidelines of acute and 90-day repeated dose sub-chronic toxicity studies. AP-Bio® did not show any treatment-related clinical signs of toxicity or mortality during the 14-day observation period in animals tested in the single-dose acute oral toxicity study up to a dose of 5000 mg/kg body weight. In the 90-day repeated dose sub-chronic oral toxicity study, no treatment-related adverse clinical signs were observed in any of the treated groups (300, 600, and 900 mg/kg). All treated animals showed usual weight gain and comparable feed intake. The ophthalmoscope examination did not reveal any abnormalities. Also, no toxicologically significant changes were observed in urinalysis, hematology, and blood chemistry parameters. Absolute organ weights and relative organ weights of vital organs did not differ significantly compared to control. Gross and histopathological findings did not show any remarkable and treatment-related changes. Results of the safety evaluation showed the median lethal dose (LD50 ) of AP-Bio® was found to be more than 5000 mg/kg rat body weight and the no observed adverse effect level (NOAEL) of AP-Bio® was found to be 900 mg/kg rat body weight.

Andrographolide Benefits Rheumatoid Arthritis via Inhibiting MAPK Pathways

Andrographolide (AD) is the main compound distributed in medicinal herb Andrographis paniculata and exhibits anti-inflammatory activity. AD has been used for the treatment of multiple inflammatory diseases. However, the therapeutic value of AD on human rheumatoid arthritis (RA) remains unclear. In this study, we investigated the effects of AD on collagen-induced arthritis (CIA) and human RA synovial fibroblasts (RA-SFs). CIA mice were treated with AD (dissolved in 0.5% CMC-Na, 100 mg/kg per day) or vehicle (0.5% CMC-Na) daily by oral gavage for 2 weeks. The arthritis severity and joint destruction were assessed. Serum anti-collagen II antibody (anti-CII Abs) and cytokines were determined by ELISA. TNFα-stimulated human RA-SFs were treated with varying doses of AD for in vitro investigation. Results showed that AD significantly attenuated the arthritis severity and joint damage. AD treatment significantly reduced the production of serum anti-CII, TNFα, IL-1β, and IL-6. In vitro, AD decreased the secretion of IL-1β and IL-6 from TNFα-stimulated RA-SFs in a dose-dependent manner. AD treatment reduced the TNFα-induced phosphorylation of p38 MAPK and ERK1/2 in a dose-dependent manner. Thus, our findings suggest that AD confers protective effects on autoimmune arthritis through inhibiting MAPK pathways.

Dehydroandrographolide enhances innate immunity of intestinal tract through up-regulation the expression of hBD-2

Background

Dehydroandrographolide (DA) is one of major active components in the well-known oriental herbal medicine Andrographis paniculata (Burm.f) Nees which belongs to the Acanthaceae family. DA is used for the treatment of infections in China. However, DA has not been found to significantly inhibit bacterial and viral growth directly. The current study investigates the effect of DA on the expression of human β –defensin-2 (hBD-2) in human intestinal epithelial cells and the possible signaling pathways.

Methods

Human intestinal epithelial HCT-116 cells were incubated with 1–100 μM DA for 2–24 h. RT–PCR and Western blot were used to assess the expression of hBD-2. The specific inhibitors were used and the levels of phosphorylation of signaling molecules were detected for dissecting the signaling pathways leading to the induction of hBD-2.

Results

MTT assay showed there was no obvious cytotoxicity for HCT-116 cells by 1–100 μM DA treatment. RT-PCR and Western blot assays showed that DA (1–100 μM) could up-regulate the expression of hBD-2, and the effect lasted longer than 24 h. By using SB203580 and SB202190 (inhibitors of p38), the enhancement of hBD-2 expression were significantly attenuated. However, inhibitor of ERK and inhibitor of JNK could not block the effect of DA. Furthermore, Western blot found activation of p38 but not ERK and JNK in DA-treated HCT-116 cells.

Conclusion

The results suggested that DA enhanced innate immunity of intestinal tract by up-regulating the expression of hBD-2 through the p38 MAPK pathways.

An in vitro study of anti-inflammatory activity of standardised Andrographis paniculata extracts and pure andrographolide

BACKGROUND

The anti-inflammatory activity of Andrographis paniculata (Acanthaceae), a traditional medicine widely used in Asia, is commonly attributed to andrographolide, its main secondary metabolite. Commercial A. paniculata extracts are standardised to andrographolide content. We undertook the present study to investigate 1) how selective enrichment of andrographolide in commercial A. paniculata extracts affects the variability of non-standardised phytochemical components and 2) if variability in the non-standardised components of the extract affects the pharmacological activity of andrographolide itself.

METHODS

We characterized 12 commercial, standardised (≥30% andrographolide) batches of A. paniculata extracts from India by HPLC profiling. We determined the antioxidant capacity of the extracts using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, oxygen radical antioxidant capacity (ORAC) and a Folin-Ciocalteu (FC) antioxidant assays. Their anti-inflammatory activity was assessed by assaying their inhibitory effect on the release of tumor necrosis factor alpha (TNF-α) in the human monocytic cell line THP-1.

RESULTS

The andrographolide content in the samples was close to the claimed value (32.2 ± 2.1%, range 27.5 to 35.9%). Twenty-one non-standardised constituents exhibited more than 2-fold variation in HPLC peak intensities in the tested batches. The chlorogenic acid content of the batches varied more than 30-fold. The DPPH free radical scavenging activity varied ~3-fold, the ORAC and FC antioxidant capacity varied ~1.5 fold among batches. In contrast, the TNF-α inhibitory activity of the extracts exhibited little variation and comparison with pure andrographolide indicated that it was mostly due to their andrographolide content.

CONCLUSIONS

Standardised A. paniculata extracts contained the claimed amount of andrographolide but exhibited considerable phytochemical background variation. DPPH radical scavenging activity of the extracts was mostly due to the flavonoid/phenlycarboxylic acid compounds in the extracts. The inhibitory effect of andrographolide on the release of TNF-α was little affected by the quantitative variation of the non-standardised constituents.