Ethyl palmitate, an anti-chikungunya virus principle from Sauropus androgynus, a medicinal plant used to alleviate fever in ethnomedicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Sauropus androgynus is a medicinal shrub used for the treatment of fever in ethnomedical traditions in various Southeast Asian countries. AIM OF THE STUDY: This study was aimed to identify antiviral principles from S. androgynus against Chikungunya virus (CHIKV), a major mosquito-borne pathogen that re-emerged in the last decade, and to unravel their mechanism of action. MATERIALS AND METHODS: Hydroalcoholic extract of S. androgynus leaves was screened for anti-CHIKV activity using cytopathic effect (CPE) reduction assay. The extract was subjected to activity guided isolation and the resultant pure molecule was characterized by GC-MS, Co-GC and Co-HPTLC. The isolated molecule was further evaluated for its effect by plaque reduction assay, Western blot and immunofluorescence assays. In silico docking with CHIKV envelope proteins and molecular dynamics simulation (MD) analyses were used to elucidate its possible mechanism of action. RESULTS: S. androgynus hydroalcoholic extract showed promising anti-CHIKV activity and its active component, obtained by activity guided isolation, was identified as ethyl palmitate (EP), a fatty acid ester. At 1 µg/mL, EP led to 100% inhibition of CPE and a significant 3 log10 reduction in CHIKV replication in Vero cells at 48 h post-infection. EP was highly potent with an EC50 of 0.0019 µg/mL (0.0068 µM) and a very high selectivity index. EP treatment significantly reduced viral protein expression, and time of addition studies revealed that it acts at the stage of viral entry. A strong binding to the viral envelope protein E1 homotrimer during entry, thus preventing viral fusion, was identified as a possible mechanism by which EP imparts its antiviral effect. CONCLUSIONS: S. androgynus contains EP as a potent antiviral principle against CHIKV. This justifies the use of the plant against febrile infections, possibly caused by viruses, in various ethnomedical systems. Our results also prompt more studies on fatty acids and their derivatives against viral diseases.

Hepatoprotective activity of Oxalis corniculata L. ethanolic extract against paracetamol induced hepatotoxicity in Wistar rats and its in vitro antioxidant effects.

Oxalis corniculata is well known for its medicinal properties like anti-inflammatory, digestive, diuretic, antibacterial, antiseptic etc. The present study focuses on the ability of O. corniculata to alleviate liver damage caused by over dose of paracetamol. Antioxidant activity of O. corniculata was evaluated using the free radical scavenging activity of 1, 1-diphenyl-2- picrylhydrazyl radicals, total anti oxidant capacity by phosphomolybdenum method and total phenolic content was also evaluated. The ethanolic extract of whole plant of O. corniculata (OC, 500 microg/mL, po) significantly reduced 1, 1-diphenyl-2- picrylhydrazyl radicals. This dose also caused significant reduction (62.67%) in malondialdehyde levels of murine hepatic tissues. The antioxidant capacity of OC was comparable to that of standard ascorbic acid and showed 53.5 microg of phenol/mg OC. Rats pre-treated with OC for 4 days showed significant reduction in the serum enzymes such as glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, alkaline phosphatase, serum bilirubin and showed almost normal histological liver architecture of the treated groups compared to paracetamol induced hepatic damage group, indicating its hepatoprotective and antioxidant potential.

Anti-allergic, anti-inflammatory and anti-lipidperoxidant effects of Cassia occidentalis Linn.

Cassia occidentalis Linn. mast cell degranulation at a dose of 250 mg/kg, showed dose dependent stabilizing activity towards human RBC, with is widely used in traditional medicine of India to treat a number of clinical conditions including allergy and inflammatory manifestations. In the present study anti-allergic, anti-inflammatory and anti-oxidant properties of C. occidentalis whole plant ethanolic extract (CO) was investigated. Effects of CO on rat mast cell degranulation inhibition and human red blood cell (HRBC) membrane stabilization were studied in vitro following standard methods. The anti lipidperoxidant effects of CO were also studied in vitro. Effect of CO on carrageenan-induced mouse paw oedema inhibition was also assessed. CO significantly decreased maximum protection of 80.8% at 15 microg/ml. The extract also caused significant reduction in malondialdehyde (MDA) levels of murine hepatic microsomes at 100 microg/ml (56%) and significantly reduced carrageenan induced inflammation in mice at a dose of 250 mg/kg. Results of the present study indicated that CO inhibited mast cell degranulation, stabilized HRBC membrane thereby alleviating immediate hypersensitivity besides showing anti oxidant activity.

Anti-inflammatory and analgesic properties of Drynaria quercifolia (L.) J. Smith.

ETHNOPHARMACOLOGICAL RELEVANCE: Drynaria quercifolia (L.) J. Smith (Polypodiaceae), has been widely used by ethnic groups of India to treat inflammation, rheumatism, headache, bone fracture, jaundice, etc. AIM OF THE STUDY: To evaluate the anti-inflammatory and analgesic properties of the ethanolic extract of rhizome of Drynaria quercifolia (DQ) and its phytochemical profile. MATERIALS AND METHODS: DQ was used to evaluate the anti-inflammatory and analgesic effects using carrageenan-induced paw oedema/cotton pellet-induced granuloma in Wistar rats and acetic acid-induced writhing/formalin-induced paw licking test in Swiss albino mice respectively. RESULTS: Oral administration of DQ produced significant inhibition of carrageenan-induced paw oedema and granuloma formation in rats, almost comparable to that caused by indomethacin. DQ significantly attenuated acute and delayed phases of formalin-induced pain and acetic acid-induced writhing episodes in mice. The analgesia was comparable to that produced by sodium salicylate and aspirin respectively. Phytochemical analysis gave positive tests for catechin, coumarins, flavonoids, phenolics, saponin, steroids, tannins, and triterpenes. The total phenolics in DQ was 244 mg/g and naringin content was 0.048%. CONCLUSION: The results suggest the presence of potent anti-inflammatory and analgesic principles in DQ that justifies its use for alleviating painful inflammatory conditions.

Hepatoprotective effect of three herbal extracts on aflatoxin B1-intoxicated rat liver.

INTRODUCTION: Roots of Ixora coccinea (Rubiaceae), and Rhinacanthus nasuta (Acanthaceae) and whole plants of Spilanthes ciliata (Asteraceae) are extensively used by tribal communities in South India to treat liver diseases. However, the veracity of these tribal claims has not been investigated scientifically using the liver toxin, aflatoxin. This study reports on the protective effects of these three herbal ethanolic extracts on the aflatoxin B1 (AFB1)-intoxicated livers of albino male Wistar rats. METHODS: Biochemical parameters, including serum hepatic enzymes (glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and alkaline phosphatase), were studied. Hepatic tissues were processed for assay of reduced glutathione (GSH) and histological alterations. RESULTS: Pre-treatment of the rats with oral administration of the plant ethanolic extracts, Ixora coccinea (IC), Rhinacanthus nasuta (RN), Spilanthes ciliata (SC), prior to AFB1 was found to provide significant protection against toxin-induced liver damage, determined 72 hours after the AFB1 challenge (1.5 mg/kg, intraperitoneally) as evidenced by a significant lowering of the activity of the serum enzymes and enhanced hepatic reduced GSH status. Pathological examination of the liver tissues supported the biochemical findings. The three plant extracts, IC, RN and SC, showed significant antilipid peroxidant effects in vitro. CONCLUSION: It was concluded that the hepatoprotective effects of the three plant extracts observed in this study might result from their potent antioxidative properties.

Hepatoprotective studies on Sida acuta Burm. f.

ETHNOPHARMACOLOGICAL RELEVANCE: Sida acuta Burm. f. (Malvaceae) is used in Indian traditional medicine to treat liver disorders and is useful in treating nervous and urinary diseases and also disorders of the blood and bile. AIM OF THE STUDY: Evaluation of the hepatoprotective properties of the methanolic extract of the root of Sida acuta (SA) and the phytochemical analysis of SA. MATERIALS AND METHODS: The model of paracetamol-induced hepatotoxicity in Wistar rats, liver histopathological observations, hexobarbitone-induced narcosis and in vitro anti-lipid peroxidation studies were employed to assess the hepatoprotective efficacy of SA. Phytochemical assay of SA was conducted following standard protocols. RESULTS: Significant hepatoprotective effects were obtained against liver damage induced by paracetamol overdose as evident from decreased serum levels of glutamate pyruvate transaminase, glutamate oxaloacetate transaminase, alkaline phosphatase and bilirubin in the SA treated groups (50, 100, 200mg/kg) compared to the intoxicated controls. The hepatoprotective effect was further verified by histopathology of the liver. Pretreatment with Sida acuta extract significantly shortened the duration of hexobarbitone-induced narcosis in mice indicating its hepatoprotective potential. Phytochemical studies confirmed the presence of the phenolic compound, ferulic acid in the root of Sida acuta, which accounts for the significant hepatoprotective effects observed in the present study. CONCLUSION: The present study thus provides a scientific rationale for the traditional use of this plant in the management of liver disorders.

Gastric antisecretory and antiulcer activities of Cyclea peltata (Lam.) Hook. f. & Thoms. in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Cyclea peltata (Lam.) Hook. f. & Thoms. (Menispermaceae), locally called 'Padathaali/Padakizhangu' is used in Ayurvedic medicine to treat peptic ulcer. AIM OF THE STUDY: To evaluate the gastric antisecretory and antiulcer activity of Cyclea peltata. MATERIALS AND METHODS: The ethanolic extract of Cyclea peltata root was used to evaluate its gastric antisecretory and antiulcer effect in the pylorus-ligated rat model and gastric lesions induced by ethanol or ethanol and indomethacin respectively in rats. The levels of gastric wall mucus, non-protein sulfhydryl groups (NP-SH), malondialdehyde, protein and catalase activity in the stomach samples of Cyclea peltata treated and control groups of rats were also quantified. RESULTS: The ethanolic extract of Cyclea peltata roots showed significant antisecretory activity as evidenced by decreased pepsin secretion, gastric juice volume and acid output in pylorus-ligated rats. Pretreatment with Cyclea peltata extract provided significant protection against the peptic ulceration caused by ethanol administered individually, or in combination with indomethacin. Our studies also revealed that pretreatment with Cyclea peltata significantly increased the gastric protein and catalase concentration of ethanol treated rats. Further, it showed significant gastroprotective effects on the stomach wall of ethanol or ethanol and indomethacin treated rats by decreasing malondialdehyde level, increasing the gastric wall mucus and non-protein sulfhydryl groups. CONCLUSION: The present findings demonstrate that Cyclea peltata ethanolic extract has potent antisecretory and antiulcer effects and justify the traditional/ethnic usage of this herb to treat peptic ulcers and consequent stomach ache.

Hepatoprotective effect of Hibiscus hispidissimus Griffith, ethanolic extract in paracetamol and CCl4 induced hepatotoxicity in Wistar rats.

Hibiscus hispidissimus Griff. is used in tribal medicine of Kerala, the southern most state of India, to treat liver diseases. In the present study, the effect of the ethanolic extract of Hibiscus hispidissimus whole plant on paracetamol (PCM)-induced and carbon tetrachloride (CCl4)-induced liver damage in healthy Wistar albino rats was studied. The results showed that significant hepatoprotective effects were obtained against liver damage induced by PCM and CCl4 as evidenced by decreased levels of serum enzymes, glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), serum alkaline phosphatase (SAKP), serum bilirubin (SB) and an almost normal histological architecture of the liver of the treated groups compared to the toxin controls. The extract also showed significant antilipid peroxidant effects in vitro, besides exhibiting significant activity in quenching 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radical, indicating its potent antioxidant effects.

Hepatoprotective effects of Pittosporum neelgherrense Wight&Arn., a popular Indian ethnomedicine.

The stem bark of Pittosporum neelgherrense Wight&Arn. is used by the Kani and Malapandaram tribes of Kerala as an effective antidote to snake bite and for the treatment of various hepatic disorders. In the present study, the effect of the methanolic extract of the stem bark of Pittosporum neelgherrense was studied against carbon tetrachloride (CCl(4))-, d-galactosamine (D-GalN)- and acetaminophen (APAP)-induced acute hepatotoxicity in Wistar rats. Significant hepatoprotective effects were obtained against liver damage induced by all the three liver toxins, as evident from decreased levels of serum enzymes, glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT) and an almost normal architecture of the liver in the treated groups, compared to the toxin controls. Thus the present study provides a scientific rationale for the traditional use of this plant in the management of liver diseases.

Enhancement in the absorption of water and electrolytes from rat intestine by Hemidesmus indicus R. Br. root (water extract).

Hemidesmus indicus root in the form of suspension in water (10 mg/ml) containing 15.5 mM NaCl, 3 mM KCl and 12 mM glucose, when injected into the ligated jejunal sac (1 ml/sac) of rat, increased the absorption of water, Na(+) and K(+) (but not glucose) from the sac. This bioactivity was present in the water extract (5 or 10 mg/sac) of the root and not in the hexane extract. In contrast, the ethanol extract decreased the absorption of water and electrolytes from the jejunal sac. The effect of water extract was not affected by heat at 100 degrees C for 30 min. Intraperitoneal administration of the water extract (50 to 200 mg/kg) was devoid of any significant effect on the jejunal absorption. Neither the root suspension nor the water extract (125-500 mg/kg) showed any significant anti-ulcer and diuretic activities in rats. The intestinal motility was also not influenced by the root (water extract) when tested in mice. The present study indicates that H. indicus root powder or its water extract can be incorporated in oral rehydrating salt solution (ORS) for increasing its anti-diarrhoeal efficacy.