An integrated approach to the structural characterization, long-term toxicological and anti-inflammatory evaluation of Pterospermum rubiginosum bark extract

Chemical profiling, toxicity assessment, anti-diarrhoeal, anti-inflammatory and antinociceptive activities of Canarium schweinfurthii Engl. (Burseraceae) bark in rats

ETHNOPHARMACOLOGICAL RELEVANCE

The bark of Canarium schweinfurthii is used in ethnomedicine for the treatment of diabetes, pain, malaria, fever and diarrhoea.

AIM OF THE STUDY

The chemical phytoconstituents, antidiarrheal, anti-inflammatory and antinociceptive effects and safety profile of the aqueous extract of Canarium schweinfurthii bark (AECSB) were investigated.

MATERIALS AND METHODS

Gas chromatography-mass spectrometry (GC-MS) was used to analyse the phytochemical composition. In the acute toxicity test, AECSB were administered up to 2 g/kg by oral gavage. For the subacute toxicity test (28 days), rats in group 1 (control) received no AECSB, while rats in groups 2-4 were administered different doses of AECSB. Charcoal meal transit and castor oil-induced diarrhoea models were used to study the antidiarrheal effect, while egg albumin/carrageenan and acetic acid/tail immersion models were used for the anti-inflammatory and antinociceptive studies, respectively. With the exception of the acute toxicity experiment, AECSB was administered orally at doses of 200, 400 and 800 mg/kg.

RESULTS

Bioactive phytoconstituents identified include p-cymene, δ-terpinene, linalool and phytol. No adverse effects or mortality were observed in acute and subacute studies. Treatment with AECSB (28 days) had no significant effect on organ weight, biochemical, hematologic and histopathologic parameters compared to the control groups (p > 0.05). Comparable antidiarrheal and antinociceptive effects were observed in both AECSB- and standard drug-treated groups, while the 400 and 800 mg/kg AECSB-treated groups showed remarkable anti-inflammatory effects compared to the standard drug-treated and control groups (p < 0.05).

CONCLUSION

AECSB has antidiarrheal, antinociceptive and anti-inflammatory effects and can be safely used for therapeutic purposes.

Targeting the Role of PRME in Regulating Bone Remodelling During Postmenopausal Osteoporosis

Kariavattom Campus Postmenopausal osteoporosis (PMO) is an old age disorder associated with estrogen deficiency, which reduces bone mass and makes bones more prone to fracture. The present study was proposed to evaluate the invivo osteogenic efficiency of Pterospermum rubiginosum methanolic bark extract (PRME) in the PMO model. Molecular docking studies on transcription factor NFATC1 showed excellent interactions with phytochemical ligands with the lowest binding energies. Female Sprague Dawley (SD) rats (n=24) were divided into four groups, (n=6 each) sham control (Group I) and osteoporotic control (Group II) groups treated with saline, PRME (50 mg/kg/day) and alendronate (10 mg/kg/day) treated with Group III and Group IV (n=6) respectively. The serum tartrate-resistant acid phosphatase 5b and cathepsin-K also exhibited a significant rise after PRME treatment 12.33±2.30 mU/ml and 427.68±46.97 pg/ml, respectively. DEXA results exhibited a remarkable increase in total bone mineral content and density values in PRME-treated animals (0.175±0.002 g/cm2) and (7.95±0.23 g) when compared to osteoporotic control (0.163±0.004 g/cm2) and (6.83±0.34 g). Long-term toxicity study revealed that PRME is non-toxic, up to 100 mg/kg bodyweight for 6 months. Our findings suggest PRME protects osteoporotic SD rats from PMO damage resulting from estrogen deficiency by regulating bone remodelling markers and upregulating BMD indices.

Protective effect of Pterospermum rubiginosum bark extract on bone mineral density and bone remodelling in estrogen deficient ovariectomized Sprague-Dawley (SD) rats

Osteoporosis is a common metabolic old age disorder characterised by low bone mass content (BMC) and mineral density (BMD) with micro-architectural deterioration of the extracellular matrix, further increasing bone fragility risk. Several traditional remedies, including plant extracts and herbal formulations, are used worldwide by local healers to improve the overall bone health and metabolism as an excellent osteoregenerative agent. Pteropsermum rubiginosum is an underexplored medicinal plant used by tribal peoples of Western Ghats, India, to treat bone fractures and associated inflammation. The proposed study evaluates the elemental profiling and phytochemical characterisation of P. rubiginosum methanolic bark extract (PRME), along with detailed In vitro and In vivo biological investigation in MG-63 cells and Sprague-Dawley (SD) rats. AAS and ICP-MS analysis showed the presence of calcium, phosphorus, and magnesium and exceptional levels of strontium, chromium, and zinc in PRME. The NMR characterisation revealed the presence of vanillic acid, Ergost-4-ene-3-one and catechin. The molecular docking studies revealed the target pockets of isolated compounds and various marker proteins in the bone remodelling cycle. In vitro studies showed a significant hike in ALP and calcium content, along with upregulated mRNA expression of the ALP and COL1, which confirmed the osteoinductive activity of PRME in human osteoblast-like MG-63 cells. The in vivo evaluation in ovariectomised (OVX) rats showed remarkable recovery in ALP, collagen and osteocalcin protein after 3 months of PRME treatment. DEXA scanning reports in OVX rats supported the above in vitro and in vivo results, significantly enhancing the BMD and BMC. The results suggest that PRME can induce osteogenic activity and enhance bone formation with an excellent osteoprotective effect against bone loss in OVX animals due to estrogen deficiency.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03942-7.

In silico, anti-inflammatory and acute toxicological evaluation of an indigenous medicinal plant Pterospermum rubiginosum using Sprague-Dawley rats

BACKGROUND

Pterospermum rubiginosum has been traditionally used by the tribal inhabitants of Southern India for treating bone fractures and as a local anti-inflammatory agent; however, experimental evidence to support this traditional usage is lacking. The present study aimed to investigate the phytochemical characterization, in silico and in vitro anti-inflammatory evaluation, followed by in vivo toxicological screening of P. rubiginosum methanolic bark extract (PRME).

RESULTS

The LCMS evaluation revealed the presence of 80 significant peaks; nearly 50 molecules were identified using the LCMS database. In silico analysis showed notable interactions with inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6). In vitro gene expression study supported the docking results with significant down-regulation of iNOS, IL-6, and IL-10. PRME was administered orally to the SD rats and was found to be non-toxic up to 1000 mg/kg body weight for 14 days. The antioxidant enzymes catalase and sodium dismutase exhibited an increased value in PRME-administered groups, possibly due to the diverse phytochemical combinations in bark extract.

CONCLUSIONS

PRME administration significantly downregulated the gene expression of inflammatory markers, such as iNOS, IL-6, and IL-10. The molecular docking analysis of iNOS and IL-6 supports the in vitro study. In vivo toxicological study of PRME in SD rats was found to be non-toxic up to a concentration of 1000 mg/kg body weight for 14 days.