Simultaneous estimation of andrographolide and wedelolactone in herbal formulations

Quantification and Standardization of Andrographolide in Andrographis Paniculata Samples by Validated RP-HPLC and HPTLC Methods

Andrographis paniculata (family Acanthaceae) is known as Kalmegh, one of the traditionally used important medicinal plant contains several biologically active phytochemical including andrographolide. A. paniculata is broadly used by healthcare practitioners in India and also used in different traditional medicinal system. In this study, the leaves of A. paniculata were collected from West Medinipur, East Medinipur, South 24 Parganas, Purulia and Hooghly district of West Bengal, India. This study aiming towards validation and development of a simple, precise and reproducible reverse-phase high-performance liquid chromatography (RP-HPLC) and high-performance thin layer chromatography (HPTLC) methods for quantification of andrographolide in A. paniculata extracts. The validated RP-HPLC and HPTLC study confirmed that different concentrations of andrographolide content present in the plant samples, which are collected from above different districts of West Bengal, India. The amounts of andrographolide were found to be 2.71% (w/w), 3.19% (w/w), 1.83% (w/w), 1.73% (w/w) and 2.94% (w/w) in RP-HPLC study and 2.13% (w/w), 2.51% (w/w), 1.01% (w/w), 1.25% (w/w) and 2.15% (w/w) in HPTLC study. This precise, reproducible, accurate and specific method can be used for the quantification of andrographolide in kalmegh, as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines recommendations.

Andrographis paniculata (Burm.f.) Nees: Traditional uses, phytochemistry, pharmacological properties and quality control/quality assurance

ETHNOPHARMACOLOGICAL RELEVANCE

Andrographis paniculata (Burm.f.) Nees is a medicinal herb of the Asian countries used in many traditional medicinal systems for the treatment of diarrhea, flu, leprosy, leptospirosis, malaria, rabies, upper respiratory infections, sinusitis, syphilis, tuberculosis and HIV/AIDS etc. AIM OF THE STUDY: This review aims to provide the comprehensive, accurate and authentic information on traditional uses, phytochemistry and pharmacological properties of various extracts/fractions as well as phytocostituents of A. paniculata. In addition, this review also aims to provide advance and sensitive analytical methods along with chemical markers used in the standardization of herbal products for quality control (QC)/quality assurance (QA).

MATERIALS AND METHODS

All relevant publications were considered within the years 1983-2020. The publications were searched from Google Scholar, PubChem, Chemspider, PubMed, Elsevier, Wiley, Web of Science, China Knowledge Resource Integrated databases and ResearchGate using a combination of various relevant keywords. Besides, relevant published books and chapters were also considered those providing an overview of extant secondary literature related to traditional knowledge, phytochemistry, pharmacology and toxicity of the plant.

RESULTS AND DISCUSSION

In this review, 344 compounds, including, terpenoid lactones, flavonoids, phenolic acids, triterpenes and volatile compounds were summarized out of which more than half of the compounds have no reported pharmacological activities yet. Terpenoid lactones and flavonoids are the major bioactive classes of compounds of A. paniculata which are responsible for pharmacological activities such as anticancer and antioxidant activities, respectively. Biosynthetic pathways and active sites for target proteins of both terpenoid lactones and flavonoids were considered. Analgesic, anticancer, antidiabetic, antifertility, antiinflammatory, antimalarial, antimicrobial, antioxidant, antipyretic, antiviral, antiretroviral, antivenom, cardioprotective, hepatoprotective, immunomodulatory and neuroprotective activities have been also reported. Andrographolide is a major characteristic active principle and responsible for most of the pharmacological activities. Therefore, andrographolide has been selected as a marker for the standardization of raw and marketed herbal products by TLC, HPTLC, HPLC, GC-MS, HPLC-MS and HPLC-MS/MS methods for QC/QA.

CONCLUSIONS

Conclusive evidence showed that the pharmacological activities reported in crude extracts and chemical markers are supporting and provides confidence in the traditional use of A. paniculata as a herbal medicine. The andrographolide could be used as a chemical marker for the QC/QA of raw and A. paniculata derived herbal products. Lactone ring in terpenoid lactone is an active site for targeted proteins. More efforts should be focused on the identification of the chemical markers from A. paniculata to provide a practical basis for QC/QA. Several aspects such as the mechanism of therapeutic potential, molecular docking technology and multi-target network pharmacology are very important for drug discovery and needed more investigation and should be considered. This compilation may be helpful in further study and QC/QA.

Andrographolide: A Review of Analytical Methods

Bicyclic diterpenoid lactone andrographolide is regarded as a "natural antibiotic" as it is known to exhibit a range of bioactivities including anti-inflammatory, antibacterial, antipyretic, antineoplastic, cardioprotective, hepatoprotective and hypoglycaemic, and is present in Andrographis paniculata. The aim of this article is to review the information on analytical methods for andrographolide in biological samples, pharmaceutical formulations and plant materials. This article includes various techniques such as Spectrophotometry, Chemiluminescence method, Electroanalytical method, Chromatography and various hyphenated techniques.

A one-pot laccase-catalysed synthesis of coumestan derivatives and their anticancer activity

Suberase®, a commercial laccase from Novozymes, was used to catalyse the synthesis of coumestans. The yields, in some cases, were similar to or better than that obtained by other enzymatic, chemical or electrochemical syntheses. The compounds were screened against renal TK10, melanoma UACC62 and breast MCF7 cancer cell-lines and the GI₅₀, TGI and LC₅₀ values determined. Anticancer screening showed that the cytostatic effects of the coumestans were most effective against the melanoma UACC62 and breast MCF7 cancer cell-lines exhibiting potent activities, GI₅₀=5.35 and 7.96μM respectively. Moderate activity was obtained against the renal TK10 cancer cell-line. The total growth inhibition, based on the TGI values, of several of the compounds was better than that of etoposide against the melanoma UACC62 and the breast MCF7 cancer cell lines. Several compounds, based on the LC₅₀ values, were also more lethal than etoposide against the same cancer cell lines. The SAR for the coumestans is similar against the melanoma UACC62 and breast MCF7 cell lines. The compound having potent activity against both breast MCF7 and melanoma UACC62 cell lines has a methyl group on the benzene ring (ring A) as well as on the catechol ring (ring B). Anticancer activity decreases when methoxy and halogen substituents are inserted on rings A and B.

Wedelolactone inhibits breast cancer-induced osteoclastogenesis by decreasing Akt/mTOR signaling

The bone is the most common metastatic site of breast cancer. Bone metastasis causes pain, pathologic fractures, and severely reduces the quality of life. Breast cancer causes osteolytic bone metastasis, which is dependent on osteoclast-mediated bone resorption. While current treatments rely on palliative anti-resorptive agents, there is a need to develop a drug based on potential alternative therapies. This study is the first to determine that wedelolactone (WDL), a natural coumarin isolated from plants, can inhibit breast cancer-mediated osteoclastogenesis. Osteoclasts were generated from human CD14(+) monocytes cultured with M-CSF/RANKL and WDL suppressed human osteoclast differentiation and activity in vitro in a dose-dependent manner. Moreover, WDL inhibited the upregulation of osteoclasts stimulated by MDA‑MB‑231 breast cancer cells. The activity of WDL on osteoclasts and breast cancer-mediated osteoclastogenesis was associated with the inhibition of Akt/mammalian target of the rapamycin signaling pathway (mTOR). Blocking Akt and mTOR by specific inhibitors significantly decreased osteoclast differentiation and bone resorption. Furthermore, WDL regulated breast cancer-enhanced interaction of osteoblasts and osteoclasts by decreasing M-CSF expression in MDA‑MB‑231-stimulated osteoblasts. Thus, this study suggests that WDL may be a potential natural agent for preventing and treating bone destruction in patients with bone metastasis due to breast cancer.

Wedelolactone exhibits anti-fibrotic effects on human hepatic stellate cell line LX-2

Wedelolactone is a major coumarin of Eclipta prostrata, which is used for preventing liver damage. However the effects of wedelolactone on hepatic fibrosis remained unexplored. The purpose of this study was to demonstrate the anti-fibrotic effects of wedelolactone on activated human hepatic stellate cell (HSC) line LX-2 and the possible underlying mechanisms by means of MTT assay, Hoechst staining, as well as real-time quantitative PCR and western blot. The results showed that wedelolactone reduced the cellular viability of LX-2 in a time and dose-dependent manner. After treatment of wedelolactone, the expressions of collagen I and α-smooth muscle actin, two biomarkers of LX-2 activation, were remarkably decreased. The apoptosis of LX-2 cells was induced by wedelolactone accompanied with the decreasing expression of anti-apoptotic Bcl-2 and increasing expression of pro-apoptotic Bax. In addition, phosphorylated status of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was up-regulated, but not in p38. Moreover, wedelolactone significantly repressed the level of phosphorylated inhibitor of nuclear factor κB (IκB) and p65 in nucleus in spite of tumor necrosis factor-α stimulation. In conclusion, wedelolactone could significantly inhibit the activation of LX-2 cells, the underlying mechanisms of which included inducing Bcl-2 family involved apoptosis, up-regulating phosphorylated status of ERK and JNK expressions, and inhibiting nuclear factor-κB (NF-κB) mediated activity. Wedelolactone might present as a useful tool for the prevention and treatment of hepatic fibrosis.

Platelet-activating factor (PAF)-antagonists of natural origin

Presently herbal medicines are being used by about 80% of the world population for primary health care as they stood the test of time for their safety, efficacy, cultural acceptability and lesser side effects. The discovery of platelet activating factor antagonists (PAF antagonists) during these decades are going on with different framework, but the researchers led their efficiency in studying in vitro test models. Since it is assumed that PAF play a central role in etiology of many diseases in humans such as asthma, neuronal damage, migraine, cardiac diseases, inflammatory, headache etc. Present days instinctively occurring PAF antagonist exists as a specific grade of therapeutic agents for the humans against these and different diseases either laid hold of immunological or non-immunological types. Ginkgolide, cedrol and many other natural PAF antagonists such as andrographolide, α-bulnesene, cinchonine, piperine, kadsurenone, different Piper species' natural products and marine origin plants extracts or even crude drugs having PAF antagonist properties are being used currently against different inflammatory pathologies. This review is an attempt to summarize the data on PAF and action of natural PAF antagonists on it, which were evaluated by in vivo and in vitro assays.

Wedelolactone, a medicinal plant-derived coumestan, induces caspase-dependent apoptosis in prostate cancer cells via downregulation of PKCε without inhibiting Akt

Emerging studies indicate that metabolism of arachidonic acid through the 5-lipoxygenase (5-Lox) pathway plays a critical role in the survival of prostate cancer cells raising the possibility that 5-Lox can be targeted for an effective therapy of prostate cancer. Wedelolactone (WDL), a medicinal plant-derived natural compound, is known to inhibit 5-Lox activity in neutrophils. However, its effect on apoptosis in prostate cancer cells has not been addressed. Thus, we tested the effects of WDL on human prostate cancer cells in vitro. We observed that WDL kills both androgen-sensitive as well as androgen-independent prostate cancer cells in a dose-dependent manner by dramatically inducing apoptosis. We also found that WDL-induced apoptosis in prostate cancer cells is dependent on c-Jun N-terminal Kinase (c-JNK) and caspase-3. Interestingly, WDL triggers apoptosis in prostate cancer cells via downregulation of protein kinase Cε (PKCε), but without inhibition of Akt. WDL does not affect the viability of normal prostate epithelial cells (PrEC) at doses that kill prostate cancer cells, and WDL-induced apoptosis is effectively prevented by 5-oxoETE, a metabolite of 5-Lox (but not by 15-oxoETE, a metabolite of 15-Lox), suggesting that the apoptosis-inducing effect of WDL in prostate cancer cells is mediated via inhibition of 5-Lox activity. These findings indicate that WDL selectivity induces caspase-dependent apoptosis in prostate cancer cells via a novel mechanism involving inhibition of PKCε without affecting Akt and suggest that WDL may emerge as a novel therapeutic agent against clinical prostate cancer in human.