Sphenodesme involucrata var. paniculata (C.B. Clarke) Munir.: Chemical characterization, anti-nociceptive and anti-inflammatory activities of methanol extract of leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Sphenodesme involucrata var. paniculata (C. B. Clarke) Munir is native as well as endemic to South India. Its leaves are used in folklore medicine to treat pain and rheumatism. OBJECTIVE: This study was aimed to investigate the chemical characterization, anti-nociceptive and mode of action underlying the anti-inflammatory effects of methanol extract of S. involucrata leaves (MESi). METHODS: Phytoconstituents of MESi was analyzed using colorimetric and liquid chromatography-mass spectrometry (LC-MS) methods, and the oral acute toxicity was evaluated in mice up to 2000 mg/kg. The anti-nociceptive effect was evaluated in hot plate and writhing tests; whereas the anti-inflammatory effect was investigated using carrageenan, cotton pellet and lipopolysaccharide (LPS)-induced peritonitis models at doses of 100, 200 and 400 mg/kg. Additionally nitric oxide (NO) and inflammatory cytokines levels were also evaluated. RESULTS: MESi exhibited the high content of phenolics and flavonoids as well as compounds like austricine, benzylglucosinolate, gossypin, justicidin B and cirsimarin were detected in LC-MS. In the acute toxicity study, oral administration of MESi did not cause any toxic effect and mortality up to 2000 mg/kg body weight in mice. In the anti-nociceptive tests, MESi augmented the latency period at higher dose (400 mg/kg), on the other hand attenuated writhings at the dose of 400 mg/kg by 87.87% (p < 0.001). In the carrageenan induced paw oedema MESi significantly inhibited the oedema formation at dose 400 mg/kg by 32.1%; besides, anti-inflammatory effect was registered in the cotton pellets-induced inflammation model at doses 200 and 400 mg/kg by 27.09% (p < 0.001) and 35.47% (p < 0.001) respectively. On the other hand, MESi appreciably reduced leukocyte, neutrophils infiltration, nitric oxide, TNF-α and IL-1ß levels and increased the IL-10 level in the (LPS)-induced peritonitis model. CONCLUSION: The results conclude that MESi has no acute toxic effect and it demonstrated potent anti-nociceptive and anti-inflammatory activities. Its anti-nociceptive activities are probably mediated through peripheral and central mechanisms. The anti-inflammatory effect of MESi involved the inhibition of neutrophils migration and the modulation of Th1 and Th2 cytokines, besides the attenuation of production of PGE2 and NO. LC-MS analysis revealed the predominant presence of the austricine, benzylglucosinolate, gossypin, justicidin B and cirsimarin compounds, which are possibly involved in the anti-nociceptive and anti-inflammatory effects of MESi. The current study provided supportive evidence for the folklore use of S. involucrata in the treatment of pain and inflammatory conditions.

Gastroprotective effect and mode of action of methanol extract of Sphenodesme involucrata var. paniculata (C.B. Clarke) Munir (Lamiaceae) leaves on experimental gastric ulcer models.

Sphenodesme involucrata var. paniculata (C. B. Clarke) Munir, endemic to South Asia, is used by tribal for alleviation from abdominal disorders, inflammation and body pain. However, the gastroprotective properties of this species have not yet been studied. The leaves of S. involucrata were extracted by Soxhlet extraction using different solvents successively and the extracts were analyzed for antioxidant and anti-Helicobacter pylori activities using different in vitro assays. The chemical composition of methanol extract of S. involucrata (MESi) was analysed by gas chromatography-mass spectrometry (GC-MS). The gastroprotective action of the MESi at the doses of 100, 200, and 400 mg/kg were evaluated in absolute ethanol, acidified ethanol (EtOH/HCl) and nonsteroidal anti-inflammatory drug (NSAID) induced rat experimental models. To elucidate the mode of antiulcerogenic action, the antisecretory parameters (gastric juice volume, pH, and total acidity) and the catalase (CAT) and superoxide dismutase (SOD) enzymes activity and malondialdehyde (MDA) level were evaluated in gastric ulcer tissue. Also the stomachs of the animals were subjected to histological assessment. MESi presented a high antioxidant activity in several oxidants in vitro systems (DPPH•, ABTS•+ and FRAP) and it demonstrated a good spectrum of inhibitory activity against H. pylori growth (MIC, 100 µg/mL). GC-MS analysis of MESi indicated the presence of twenty one compounds, among them phenol (21.84%), hexadecanoic acid (15.96%), (9E, 12E)-9, 12-octadecadienoyl chloride (11.15%) and palmitic acid-ß-monoglyceride (8.80%) were found higher. MESi (100, 200 and 400 mg/kg, p.o.) produced significant reduction (p < 0.01) of lesion area in the ethanol, acidified ethanol and indomethacin-induced ulcer models. In the pylorus ligation induced ulcer model, the treatment with MESi significantly altered the gastric secretion by decreasing total gastric juice volume and gastric acidity as well as by increasing the gastric pH. MESi pre-treatment significantly (p < 0.05) restored the depleted activity of SOD, CAT enzymes and reduced MDA levels in the gastric tissue as well as the histological analysis of the stomachs of the animals showed that the MESi also prevents local action of offensive factors. Collectively, the present study results suggest that the methanol extract of S. involucrata leaves demonstrates gastroprotective action, supporting the folkloric usage of the plant to treat gastro-intestinal disturbances.