Diaporthe sp. F18; a new source of camptothecin-producing endophytic fungus from Nothapodytes nimmoniana growing in Sri Lanka

An endophytic fungus producing camptothecin (CPT) was isolated from the leaf of Nothapodytes nimmoniana (Sri Lanka), and culture conditions were optimised to enhance the yield of CPT. The TLC, HPLC-PDA, LC-MS/MS and spectroscopic data were used to identify and quantify CPT. Solvent extraction (chloroform: methanol 4:1 v/v) of submerged cultures in Sabouraud Dextrose Broth (SDB) detected CPT in the mycelial extract but not in the culture broth. The fungus was (KX212080) closely related to Diaporthe guangxiensis (MK335772) with 99% sequence similarity, thus tentatively identified as Diaporthe sp. F18. A significantly high CPT content (72.0 ± 0.2 µg/g) was produced in SDB, pH, 5.6 incubated at 30 °C under shake flask condition (150 rpm) for 14 days. Tryptophan significantly (p > 0.05) enhanced CPT production while ethanol increased it by 8-fold. This endophytic source produced higher CPT content than what has been reported hitherto in the literature, with fairly stable production up to sixth subculture generations.

Acute anti-inflammatory and anti-nociceptive activities of crude extracts, alkaloid fraction and evolitrine from Acronychia pedunculata leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Acronychia pedunculata (family: Rutaceae) is one of the commonly used medicinal plants in Sri Lankan traditional medicine. Different parts of this plant are used for the treatment of inflammatory conditions in the form of medicinal oils and herbal porridge.

AIM OF THE STUDY

The present study aimed to evaluate the anti-nociceptive activity and anti-inflammatory activity with their mechanisms and the acute toxicity of crude extracts of the fresh leaves of A. pedunculata for scientific validation of the ethnopharmacological claims for this plant. Further, attention has been focused on the isolation of active compounds from active fractions of the crude extracts.

MATERIALS AND METHODS

The acute anti-inflammatory effect of the aqueous (AELA) and 70% ethanol crude extracts (EELA) and alkaloid fraction of A. pedunculata leaves were evaluated by the determination of inhibition of hind paw oedema induced by carrageenan in Wistar rats. Evolitrine was identified as the major alkaloid with significant bioactivities by column chromatography and NMR. The anti-nociceptive and anti-histamine activities of EELA and evolitrine were evaluated by acetic acid induced writhing and wheal formation tests respectively. In addition, in-vitro (2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay) and in-vivo (lipid peroxidation assay) anti-oxidant activity, nitric oxide (NO) inhibitory activity and acute toxicity of EELA were evaluated.

RESULTS

Acute anti-inflammatory activity of AELA and EELA were dose-dependent. EELA was more active than AELA. The 200 mg/kg body weight (b. w.) dose of EELA was found as the minimum effective dose with maximum inhibition (78%) of oedema at 5th hour compared to the negative control (p < 0.05). Evolitrine was isolated and identified as an active anti-inflammatory and analgesic compound from active alkaloid fraction of EELA. Evolitrine showed activity enhancement when compared with crude EELA. The anti-inflammatory and analgesic activities of evolitrine (50 mg/kg b. w.) were comparable to that of reference drugs indomethacin (5 mg/kg b. w) and acetylsalicylic acid (100 mg/kg b. w.). The significant (p < 0.05) anti-histamine activity, DPPH scavenging in-vitro anti-oxidant activity, in-vivo lipid peroxidation inhibitory activity in-vivo, NO inhibitory activity of EELA as compared with relevant negative controls, were identified as probable mechanisms which mediated its anti-inflammatory action. Further, EELA showed a high safety margin in the limited dose acute toxicity study.

CONCLUSION

The findings of the current study rationalize the usage of leaves of A. pedunculata in Sri Lankan traditional medicine as an analgesic and anti-inflammatory agent. Possible mechanisms mediating this activity included anti-histamine, anti-oxidant and NO inhibitory activities. Evolitrine is the major analgesic and anti-inflammatory compound isolated from the active alkaloid fraction of EELA.

Antioxidant and antibacterial activities on foodborne pathogens of Artocarpus heterophyllus Lam. (Moraceae) leaves extracts

Total water extract, ethyl acetate, and aqueous fractions from the leaves of Artocarpus heterophyllus were evaluated for phenolic content, antioxidant, and antibacterial activities against some foodborne pathogens such as E. coli, Listeria monocytogenes, Salmonella typhimurium, Salmonella enterica, Bacillus cereus, Enterococcus faecalis, and Staphylococcus aureus. The minimum inhibitory concentration (MICs) of extract and fractions determined by the agar dilution method were ranged from 221.9 microg/mL for ethyl acetate fraction to 488.1 microg/mL for total extract. In the agar diffusion method the diameters of inhibition were 12.2 for the total extract, 10.7 and 11.5 for ethyl acetate and aqueous fractions, respectively. A. heterophyllus showed significant antioxidant activity tested in different in vitro systems (DPPH, ABTS, FRAP, and Fe(2+) chelating activity assay). In particular, in DPPH assay A. heterophyllus total extract exhibited a strong antiradical activity with an IC(50) value of 73.5 microg/mL while aqueous fraction exerted the highest activity in FRAP assay (IC(50) value of 72.0 microg/mL). The total phenols content by Folin-Ciocalteau method was determined with the purpose of testing its relationship with the antioxidant and antibacterial activities.

Antiradical and antilipoperoxidative effects of some plant extracts used by Sri Lankan traditional medical practitioners for cardioprotection

Reactive oxygen species (ROS) are implicated in many pathogenic processes including the cardiovascular system. Detoxification of ROS by antioxidants (AO) therefore affords protection against such diseases. There is a growing body of evidence suggesting that antioxidants contribute to cardioprotection. Therefore, nine plants that are components of Ayurvedic formulations used for the therapy of cardiovascular diseases were investigated to determine whether antioxidant activity is one of the mechanisms by which these plants exert cardioprotection. Initially aqueous freeze dried extracts of the plants were prepared and the antioxidant activity was measured (a) in vitro, by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and deoxyribose damage protection assays, and (b) in vivo, by effects on lipid peroxidation. Terminalia arjuna showed significant DPPH radical scavenging activity with EC(50) 8.3 +/- 0.3 microg/mL (similar to L-ascorbic acid). The potency of this activity was much lower in Cassia fistula (EC(50) = 59.0 +/- 2.7 microg/mL). The other seven extracts demonstrated no such activity in the concentration range tested. In the deoxyribose damage protection assay, T. arjuna> demonstrated no significant effect in the concentration range 0-20 microg/mL, but above -20 microg/mL concentration (20-125 microg/mL), a pro-oxidant activity was observed (although markedly less than demonstrated by L-ascorbic acid). A similar trend was observed with Vitex negundo. In contrast, C. fistula afforded a 30% protection against such damage at 125 microg/mL concentration. Other plant extracts did not show any activity in this assay. At a dose of 90 mg/kg (single dose) T. arjuna, cardiac lipid peroxidation in male Wistar rats was reduced by 38.8% +/- 2.6% (p<0.05) whereas the reduction was only 11.6% +/- 3.5% in the case of C. fistula even at a dose of 120 mg/kg. Of all the plants tested, T. arjuna demonstrated the highest antioxidant activity. Overall results show that only some plants used in the therapy of cardiovascular disease exert their beneficial effects via antioxidant activity.

Fermentation in traditional medicine: the impact of Woodfordia fruticosa flowers on the immunomodulatory activity, and the alcohol and sugar contents of Nimba arishta

The impact of Woodfordia fruticosa flowers on the immunomodulatory activity, and alcohol and sugar contents of the ayurvedic drug 'Nimba arishta' was investigated by means of model preparations. The use of Woodfordia flowers in model preparations resulted in a substantial increase of the inhibition of both human complement activity and chemiluminescence generated by zymosan-stimulated human polymorphonuclear leukocytes. It was established that the increased biological activity was not due to microbial interference, but to immuno-active constituents released from the Woodfordia flowers. It was also found that the flowers themselves are not the source of alcohol-producing microorganisms. Experiments performed with yeasts isolated from commercial Nimba arishtas showed, in agreement with empirical findings, significantly raised alcohol content upon addition of Woodfordia. An invertase activity exhibited by Woodfordia flowers may be causative of this effect.