Chemical and Biological Investigations on Mangrove Associated Lichens (Manglicolous Lichens) from India: A Review

In 370-285 BC, an itinerant Greek philosopher Theophrastus phrased the term ‘Lichen’, which is a symbiosis between mycobiont (fungus) and a photobiont (algal) or a cyanobiont (cyanobacterium) where the mycobiont provides the shape and structure, while the photobiont or cyanobiont supply food, i.e., carbohydrates. From the folklore, lichen and its substances are used for various biological activities, which include antimicrobial, anticancer, anti-inflammatory, antioxidant and enzyme inhibitory activities. It is interesting to note that lichens are epiphytes as they synthesis their food by photosynthesis by using plants, rocks and dead logs as a substrate. In particular, lichens that betide to mangroves are termed as “Manglicolous Lichens”. Generally, mangroves survive in a unique environment having a high concentration of salt and moisture, low and high tidal water. Hence, lichens growing in such stressful areas may lead to contain variation in their chemical constituents as well as pharmacological actions due to their defensive mechanism from the predators. Keeping the factors mentioned earlier, researchers worked and reported new lichen substances with potent biological properties from manglicolous lichens. The present review, list out all the chemical constituents and biological activities that are reported to date from manglicolous lichens in India. Also, this review remains useful for further research on manglicolous lichens to identify the potential bioactive molecules.