Acylated iridoid glycosides with hyaluronidase inhibitory activity from the rhizomes of Picrorhiza kurroa Royle ex Benth

A randomized, placebo controlled, double blinded, parallel group clinical study to evaluate the efficacy and safety of AEV01 along with standard care for elderly patients with mild COVID-19

BACKGROUND

While several drugs are in the pipeline for treatment of various grades of COVID-19 disease, none of them have shown promise until now. Medicinal plants are crucial in developing and developed countries for their primary and basic health needs owing to better tolerability, superior compatibility with human body and having lesser side effects.

OBJECTIVE

To test adjuvant effect of AEV01, a patented herbal extract of kutki (Picrorhiza kurroa), in mild COVID19 in elderly patients at risk of complications and aging immunity.

METHODS

A prospective, phase 3, randomized, multicentric, placebo controlled double blinded parallel group interventional trial was conducted in elderly patients aged above 50 years diagnosed as COVID-19 with mild symptoms. 70 patients were randomized into two groups to receive AEV01 capsule (100 mg) and placebo respectively thrice daily for 30 days along with standard care of treatment as per national (WHO/ICMR) guidelines in both the groups. Clinical improvement timelines and corresponding scores using 8-point ordinal scale and NEWS were assessed for efficacy and safety of AEV01 in COVID-19 patients.

RESULTS

AEV01 group showed a significant improvement (p = 0.0001) in the normalization of the SpO2 rate and relief from cough. There was also significant difference in time to recovery, with patients in the AEV01 drug treated group recovering in 4.5 days as compared to Placebo in 9.1 days. ESR, LDH, serum ferritin, Neutrophil-Lymphocyte ratio (NLR), TNF- alpha, IL-6 and CD4 cell counts, which are considered as prognostic markers in COVID-19 infected patients, showed a significant improvement in patients treated with AEV01. The AEV01 drug treated group showed significant clinical improvement in the 8-point ordinal scale severity rating and National Early Warning Score (NEW) Score from day 3 onwards which continued up to end of study.

CONCLUSION

AEV01 has shown a significant improvement in clinical and laboratory parameters. There was also reduction in the progression of the COVID-19 disease in unvaccinated elderly patients from mild to moderate when treated at an earlier stage.

Simultaneous Determination of Five Iridoids of Picrorhiza scrophulariiflora in Rat Plasma Using UHPLC-ESI-MS/MS

In this study, we developed an ultra-performance liquid chromatography-electrospray tandem quadrupole mass spectrometry (UHPLC-ESI-MS/MS) method to simultaneously determine Picroside-I, Picroside-II, Picroside-III, minecoside, and sweroside in rat plasma. The chromatographic column was an ACQUITY UHPLC® BEH Amide Column (2.1 × 100 mm, 1.7 µm; Waters, MA, USA), column temperature 40 °C. The mobile phase was 0.1% formic acid aqueous solution-0.1% formic acid acetonitrile solution. The flow rate was 0.4 mL/min. Multiple reaction monitoring (MRM) and negative ion modes were adopted. The results showed that the calibration curves of five compounds in plasma showed good linearity (r > 0.9911) over the studied dose range. The lower limits of quantification (LLOQ) for Picroside-I, Picroside-II, Picroside-III, minecoside, and sweroside were 6.876, 5.193, 5.040, 1.260, and 4.527 ng/mL, respectively. The intra-day and inter-day precision were <15%. The matrix effects ranged from 95.77 to 101.9%. The Tmax were 1.1 ± 0.2, 1.1 ± 0.1, 0.8 ± 0.1, 1.0 ± 0.2, and 2.1 ± 0.1 h. This study will be useful in understanding the behavior of drugs in the body and the body's effect on drugs. It also offers theoretical underpinnings and highlights the importance of clinical applications and creating novel drugs.

Network Pharmacology Study of Bioactive Components and Molecular Mechanisms of the Glycoside Fraction from Picrorhiza scrophulariiflora Against Experimental Colitis

Purpose

To explore the potential mechanism of glycosidic fraction of Picrorhiza scrophulariiflora Pennell (GPS) extract for the treatment of colitis using UPLC-QTOF-MS analysis, network pharmacology and experimental research.

Methods

The active components of GPS extract were identified by UPLC-QTOF-MS analysis and extracted their targets from the databases, which was used for network pharmacology analysis. Kyoto Encyclopedia of genes and genomes (KEGG) pathway analysis was performed to discover potential therapeutic mechanisms, and the network pharmacology results were then validated by in vivo and in vitro experiments.

Results

The results showed that GPS extract significantly alleviated the clinical signs of colitis, including body weight, disease activity index, colon shortening, and colon tissue damage, and inhibited the transcription and production of colonic IL-1β and IL-6 in DSS-induced colitis mice. In vitro, GPS extract also significantly suppressed nitric oxide (NO) production, iNOS expression, IL-1β and IL-6 transcription of LPS-activated RAW 264.7 cells. Network pharmacology integrated with experimental validation identified that GPS extract significantly suppressed Akt, p38, ERK, and JNK phosphorylation in vivo and in vitro, and luteolin, apocynin, caffeic acid, caffeic acid methyl ester, luteoloside, picroside II, aucubin, cinnamic acid, vanillic acid, and sweroside were the main components responsible for the anti-inflammatory effect of GPS. These findings demonstrate that the potential anti-inflammatory effect of GPS extract against colitis is achieved through suppressing PI3K/Akt and MAPK pathways, and that the abovementioned active components mainly exerted its anti-inflammatory effect.

Conclusion

The therapeutic effect of GPS extract on colitis is related to PI3K/Akt and MAPK pathways, which is a promising remedy for colitis therapy.

Evaluation potential effects of Picroside II on cytochrome P450 enzymes in vitro and in vivo

ETHNOPHARMACOLOGY RELEVANCE

Picrorhiza scrophulariiflora Pennell, a well-known Chinese herb, has been traditionally utilized as an antioxidant and anti-inflammatory agent. One of its main bioactive components is Picroside II, a glycoside derivative. However, there is limited information on the effects of Picroside II on the activity of cytochrome P450 (CYP) enzymes nor on potential herb-drug interactions are rarely studied.

AIM OF THE STUDY

The purpose of the study was to investigate the effects of Picroside II on the activity of cytochrome P450 enzymes in vitro and in vivo and its potential herb-drug interactions.

MATERIALS AND METHODS

Specific probe substrates were employed to assess the effect of Picroside II on the activity of P450 enzymes. The inhibitory effects of Picroside II on CYP enzymes were assayed both in human (i.e., 1A, 2C9, 2C19, 2D6, 2E1, and 3A) and rat (i.e., 1A, 2C6/11, 2D1, 2E1, and 3A) liver microsomes in vitro. The inductive effects were investigated in rats following oral gavage of 2.5 mg/kg and 10 mg/kg Picroside II. A specific Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) method was developed to determine the formation of specific metabolites.

RESULTS

Enzyme inhibition results showed that Picroside II (0.5-200 μM) had no evident inhibitory effects on rat and human liver microsomes in vitro. Interestingly, the administration of multiple doses of 10 mg/kg Picroside II inhibited the activity of CYP2C6/11 by reducing the rate of formation of 4-hydroxydiclofenac and 4-hydroxymephenytoin, while Picroside II at 2.5 mg/kg increased the activity of CYP3A by promoting the formation of 1-hydroxymidazolam and 6-hydroxychlorzoxazone in rats. In addition, there were negligible effects on CYP1A, CYP2D1, and CYP2E1 in rats.

CONCLUSIONS

The results indicated that Picroside II modulated the activities of CYP enzymes and was involved in CYP2C and CYP3A medicated herb-drug interactions. Therefore, careful monitoring is necessary when Picroside II is used in combination with related conventional drugs.

Iridoid glycosides from Picrorhiza genus endemic to the Himalayan region: phytochemistry, biosynthesis, pharmacological potential and biotechnological intercessions to boost production

Iridoid glycosides are monoterpenoids synthesized in several plant species known to exhibit a diverse range of pharmacological activities. They are used as important bioactive ingredients in many commercially available drug formulations and as lead compounds in pharmaceutical research. The genus Picrorhiza comprises two medicinally important herbs endemic to the Himalayan region viz. Picrorhiza kurrooa Royle and Picrorhiza scrophulariiflora Hong. The medicinal properties of these two species are mainly due to iridoid glycosides present in their root, rhizome, and leaves. Unregulated harvesting from the wild, habitat specificity, narrow distribution range, small population size and lack of organized cultivation led to the enrolling of these species in the endangered category by the International Union for Conservation of Nature and Natural Resources (IUCN). Therefore, there is a need for immediate biotechnological and molecular interventions. Such intercessions will open up new vistas for large-scale propagation, development of genomic/transcriptomic resources for understanding the biosynthetic pathway, the possibility of genetic/metabolic manipulations, and possible commercialization of iridoid glycosides. The current review article elucidates the phytochemistry and pharmacological importance of iridoid glycosides from the genus Picrorhiza. In addition, the role of biotechnological approaches and opportunities offered by next-generation sequencing technologies in overcoming challenges associated with the genetic engineering of these species are also discussed.

Picrorhiza kurroa, Royle ex Benth:Traditional uses, phytopharmacology, and translational potential in therapy of fatty liver disease

Picrorhiza kurroa Royle ex Benth, Kutki (P.kurroa) is an important medicinal plant, traditionally recommended and used in Ayurveda for millennia, with certain cautions. There has been a significant revival of keen interest in its pharmacology, pharmacognosy, and phytochemistry for the last few decades. The evidence of its hepatoprotective activity, in experimental and clinical studies, accelerated the correlation of the specific phytochemical constituents of P.kurroa with precise pharmacological activities. Iridoid glycosides, particularly picrosides, emerged as the active molecules. For effective translation of traditional remedies into modern therapy, value addition by mechanistic understanding of molecular actions, drug targets, the degrees of efficacy and safety as well as convenient dosage forms is needed. Reverse pharmacology approach and phytopharmaceutical drug category facilitate such a translation. The present review illustrates how a potential translation of traditional practices of using P.kurroa into a phytochemically standardized, clinically targeted natural product for global unmet medical needs viz. Fatty liver disease can be attained.

Antiallergic Properties of Biflavonoids Isolated from the Flowers of Mesua ferrea Linn

The methanolic extract from the flowers of Mesua ferrea Linn. (Calophyllaceae) showed significant hyaluronidase inhibitory activity. Following a bioassay-guided separation of the extract, two biflavonoids, viz., mesuaferrone-A (1) and mesuaferrone-B (2), were isolated, along with ten flavonoids (3–12), two xanthones (13 and 14), three triterpenes (15–17), a phenylpropanoid (18), and five aromatics (19–24). Among the isolates, 1 and 2 (IC50 = 51.1 µM and 54.7 µM, respectively) exhibited hyaluronidase inhibitory activity equivalent to that of the commercially available antiallergic agents disodium cromoglycate (64.8 μM) and ketotifen fumarate (76.5 μM). These biflavonoids (1 and 2) are 8-8″ linked dimers that are composed of naringenin (1a) or apigenin (3), with their corresponding monomers lacking inhibitory activity (IC50 > 300 μM). In addition, 1 and 2 (IC50 = 49.4 µM and 49.2 µM, respectively) inhibited the release of β-hexosaminidase, which is a marker of antigen-IgE-mediated degranulation, in rat basophilic leukemia (RBL-2H3) cells. These inhibitory activities were more potent than those of the antiallergic agents tranilast and ketotifen fumarate (IC50 = 282 μM and 158 μM, respectively), as well as one of the corresponding monomers (1a; IC50 > 100 μM). Nonetheless, these effects were weaker than those of the other monomer (3; IC50 = 6.1 μM).

Paving the way towards effective plant-based inhibitors of hyaluronidase and tyrosinase: a critical review on a structure-activity relationship

Human has used plants to treat many civilisation diseases for thousands of years. Examples include reserpine (hypertension therapy), digoxin (myocardial diseases), vinblastine and vincristine (cancers), and opioids (palliative treatment). Plants are a rich source of natural metabolites with multiple biological activities, and the use of modern approaches and tools allowed finally for more effective bioprospecting. The new phytochemicals are hyaluronidase (Hyal) inhibitors, which could serve as anti-cancer drugs, male contraceptives, and an antidote against venoms. In turn, tyrosinase inhibitors can be used in cosmetics/pharmaceuticals as whitening agents and to treat skin pigmentation disorders. However, the activity of these inhibitors is stricte dependent on their structure and the presence of the chemical groups, e.g. carbonyl or hydroxyl. This review aims to provide comprehensive and in-depth evidence related to the anti-tyrosinase and anti-Hyal activity of phytochemicals as well as confirming their efficiency and future perspectives.

Ursane-type triterpene oligoglycosides with anti-hepatosteatosis and anti-hyperlipidemic activity from the leaves of Ilex paraguariensis A. St.-Hil

The methanol extract from the leaves of Ilex paraguariensis A. St.-Hil. (Aquifoliaceae), popularly known as mate, maté, or yerba maté, inhibits the intracellular triglyceride accumulation in HepG2 cells and suppresses the plasma triglyceride elevation in olive oil-treated mice. Three new triterpene saponins, termed mateosides I (1), II (2), and III (3), were isolated from the extract along with 29 known compounds. The structures of 1-3 were elucidated based on chemical and spectroscopic evidence. Among the isolates, principal saponin constituents, 2 and matesaponins 1 (7) and 2 (9), potently inhibited the triglyceride accumulation in HepG2 cells simultaneously treated with oleic acid and high glucose. In vivo assay of the methanol extract of I. paraguariensis revealed that 7 and 9 showed anti-hyperlipidemic activities in olive oil-treated mice. These results suggested that the saponin constituents of I. paraguariensis could be valuable bioactive marker for the anti-obesogenic activity.

Iridoid glycoside isolated from Wendlandia glabrata and the role of its enriched fraction in regulating AMPK/PEPCK/G6Pase signaling pathway of hepatic gluconeogenesis

Phytochemical investigation of W. glabrata and antihyperglycemic potential of isolated novel iridoid glycoside enriched fraction in CC1 hepatocytes and STZ-induced diabetic mice.

The isolation of water-soluble natural products - challenges, strategies and perspectives

Covering period: up to 2019Water-soluble natural products constitute a relevant group of secondary metabolites notably known for presenting potent biological activities. Examples are aminoglycosides, β-lactam antibiotics, saponins of both terrestrial and marine origin, and marine toxins. Although extensively investigated in the past, particularly during the golden age of antibiotics, hydrophilic fractions have been less scrutinized during the last few decades. This review addresses the possible reasons on why water-soluble metabolites are now under investigated and describes approaches and strategies for the isolation of these natural compounds. It presents examples of several classes of hydrosoluble natural products and how they have been isolated. Novel stationary phases and chromatography techniques are also reviewed, providing a perspective towards a renaissance in the investigation of water-soluble natural products.

Indole Glycosides from Calanthe discolor with Proliferative Activity on Human Hair Follicle Dermal Papilla Cells

A methanol extract from the underground part of Calanthe discolor Lindl. (Orchidaceae) demonstrated significant proliferative activity on human hair follicle dermal papilla cells (HFDPC, % of control: 120.8 ± 0.2%) at 100 µg/mL against HFDPC. Through bioassay-guided separation of the extract, a new indole glycoside named 6'-O-β-D-apiofuranosylindican (1) was isolated along with six known compounds (2-7) including three indole glycosides. The stereostructure of 1 was elucidated based on its spectroscopic properties and chemical characteristics. Among the isolates, 1 (110.0 ± 1.0%), glucoindican (3, 123.9 ± 6.8%), and calanthoside (4, 158.6 ± 7.1%) showed significant proliferative activity at 100 µM. Furthermore, the active indole glycosides (1, 3, and 4) upregulated the expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor-7 (FGF-7) mRNA and protein in HFDPC, which could be the mechanism of their proliferative activity.

The beneficial pharmacological effects and potential mechanisms of picroside II: Evidence of its benefits from in vitro and in vivo

Picrorhiza kurroa, the dried rhizome of Picrorhiza kurroa Royle ex Benth, is a famous Chinese herb that has been traditionally used in China. Picroside II (PII), a glycoside derivative, is the main bioactive constituent of Picrorhiza kurroa. In the past several decades, bioactive components from Picrorhiza kurroa have attracted the attention of researchers due to their promising therapeutic effects. A large number of studies have demonstrated the therapeutic potential of PII for the prevention and treatment of some diseases, such as organic ischemia/reperfusion (I/R) injury, liver damage, inflammation, cancer metastasis and angiogenesis. In the present paper, we aimed to provide an overview of the pharmacology of PII, focusing on its anti-oxidant, anti-inflammatory and anti-apoptotic activities. Meanwhile, the plant tissue distribution and pharmacokinetic properties were also described. Due to its beneficial pharmacological effects in I/R injury, PII may serve as a promising therapeutic agent for organic I/R injury prevention.

Collagen synthesis-promoting and collagenase inhibitory activities of constituents isolated from the rhizomes of Picrorhiza kurroa Royle ex Benth

Three new acylated phenylethanoid glycosides, kurroaosides A (14), B (15), and C (16), and a new acylated cucurbitane-type triterpene glycoside, kurroaoside D (17), were isolated from a methanol extract of the rhizomes of Picrorhiza kurroa Royle ex Benth. (Plantaginaceae) along with 29 known isolates including 10 acylated phenylethanoid glycosides (18-27), three cucurbitane-type triterpene glycosides (32-34), and a nortriterpene glycoside (35). The structures of these new compounds (14-17), including their stereochemistry, were determined based on chemical and physicochemical evidence derived from NMR and MS analysis. Among the isolates, acylated iridoid glycosides, picrosides I (8), II (9), III (10), and IV (11) and 6-feruloylcatalpol (12), phenylethanoid glycosides (14-16), triterpene glycosides, cucurbitacin B 2-O-β-D-glucopyranoside (32) and 25-acetoxy-2-β-D-glucopyranosyloxy-3,16,20-trihydroxy-9-methyl-19-norlanosta-5-en-22-one (35), and an acetophenone glycoside, picein (36), significantly promoted collagen synthesis at 10-30 μM, with no cytotoxicity being observed at the effective concentrations. Furthermore, acylated phenylethanoid glycosides, calceolarioside A (19, IC₅₀ = 69.2 μM), plantamajoside (20, 51.8 μM), isoplantamajoside (21, 76.8 μM), and scroside E (23, 65.5 μM), exhibited collagenase inhibitory activity equivalent to that of positive agents caffeic acid (75.6 μM) and epigallocatechin 3-O-gallate (75.4 μM).